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International Symposium on Uranium Raw Material for the Nuclear Fuel Cycle: Exploration, Mining, Production, Supply and Demand, Economics and Environmental Issues (URAM-2018)

Europe/Vienna
Vienna

Vienna

,
Description

Adequate services, expertise and modern technologies are needed to ensure a sustainable supply of uranium raw materials to fuel both operating and future nuclear power reactors. Effective regulation, sound environmental management, training and education are required to minimize the impact of uranium mining and production and to contribute to public acceptance of the global nuclear industry in general. In 2005, 2009 and 2014, the International Atomic Energy Agency (IAEA) hosted International Symposia on Uranium Production and Raw Materials for the Nuclear Fuel Cycle1 at its Headquarters in Vienna, Austria, to discuss all aspects of uranium raw materials for the uranium fuel cycle to ensure the long term sustainability of a nuclear power programme. In response to a challenging economic environment, the industry is currently seeking new and innovative ways to improve efficiencies in producing uranium. Since 2016 the long term median forecast envisages the growth of nuclear power worldwide, thereby leading to an eventual increase in uranium demand and in turn the price of uranium. In the last few years uranium supply has exceeded consumption, leading to historically low spot prices for uranium oxide. This has resulted in decreased exploration activity as well as in some mines being placed in care and maintenance. Looking forward, secondary uranium supplies are expected to dwindle. This, combined with the exhaustion of some active uranium mines, requires that the uranium resource base and global production capacity be further advanced in order to meet current and future demands. The current oversupply could potentially lead to undersupply in the medium to long term. Due to long lead times from discovery to production, the re-evaluation of uranium resources is required now.

The long term sustainability of nuclear power will depend on, among several factors, an adequate supply of uranium resources that can be delivered to the marketplace at competitive prices. New exploration technologies and a better understanding of the recognition criteria and genesis of the uranium ores will be required to discover and delineate increasingly difficult-to-locate uranium deposits, particularly those of low cost. In addition, exploration, mining and milling technologies should be environmentally benign, and site decommissioning plans need to meet the requirements of increasingly stringent environmental regulations and societal expectations. The purpose of the symposium is to analyse uranium supply and demand scenarios and to present and discuss new developments in uranium geology, exploration, mining, milling and processing, as well as the environmental requirements for uranium operations and site decommissioning. The presentations and discussions at URAM-2018 will:

• Lead to a better understanding of the adequacy of uranium supply to meet future demand;
• Provide information on geological models, new exploration concepts, knowledge and technologies that may potentially result in the discovery and development of new uranium resources; 
• Describe new mining and processing technologies that have the potential to support a more efficient and sustainable development of uranium and related resources; and 
• Consider the environmental compatibility of uranium production and the overall effectiveness of progressive waste management, decommissioning and remediation of production facilities.

URAM-2018 is intended to bring together scientists, managers, exploration and mining geologists, mineral economists, engineers, operators, regulators, community representatives, social scientists, nuclear fuel cycle and environmental specialists and young professionals to exchange information and discuss updated research and current issues related to uranium geology and deposits, exploration, mining and processing, production economics and environmental and legal issues.

Support
• Monday, June 25
• OPENING SESSION Boardroom A

Boardroom A

Vienna

Conveners: Dr Michel CUNEY (CNRS - GeoRessources - CREGU - Universite de Lorraine) , Ms Olga Gorbatenko (Kazatomprom)
• 1
• 2
World Nuclear Association 2017 Fuel Report
The World Nuclear Association has published reports on nuclear fuel demand and supply at two-year intervals since 1975. The 2017 report is the 18th edition in the series and looks at scenarios for uranium demand and supply to 2035. *The Nuclear Fuel Report* considers three scenarios (Lower, Reference and Upper); the projections are based on assumptions of electricity demand growth, nuclear economics, public acceptance, government policies and electricity market structure within each country. From 2000 until the Fukushima accident in March 2011, successive editions of *The Nuclear Fuel Report* projected increasing nuclear capacity. But since Fukushima, the reports have reduced nuclear capacity projections year-on-year, with a corresponding reduction in uranium requirements. The extensive range of mining projects that were developed over 2000-2010 have largely fallen away in the light of historically low uranium prices. The World Nuclear Association believes that nuclear energy can make a greater contribution to clean and reliable electricity generation and presents a vision for the future, called ‘Harmony’. In this vision, 25% of global electricity in 2050 would be provided by nuclear energy. We can be confident that sufficient uranium resources exist in the world to allow such a rapid expansion.
Speaker: Ms Olga Skorlyakova (World Nuclear Association)
• 3
Nuclear energy and uranium: looking to the future
In recent years, nuclear power continued to supply significant amounts of low-carbon baseload electricity, despite strong competition from low-cost fossil fuels and subsidised renewable energy sources. However, there is ongoing debate on the role that nuclear energy will play in meeting future energy requirements. Key factors that will influence future nuclear energy capacity include projected electricity demand, public acceptance of nuclear energy and proposed waste management strategies, as well as the economic competitiveness of nuclear power plants. Concerns about the extent to which nuclear energy is seen to be beneficial in meeting greenhouse gas reduction targets could contribute to even greater projected growth in uranium demand. Key issues in terms of nuclear market developments will be discussed in this presentation and how they could impact the broader nuclear and uranium industry.
Speaker: Dr Luminita Grancea (OECD Nuclear Energy Agency (NEA))
• 4
The Impact of Global Nuclear Fuel Inventories on Forward Uranium Production
INTRODUCTION The March 2011 Fukushima accident has not only led to a significant reduction in global uranium demand, but it has resulted in the enormous growth of nuclear fuel inventories. Uranium producers have been unable to compete with the current situation of large and growing nuclear fuel inventories and have recently begun to curtail primary production as these low-cost inventories have pushed uranium prices to levels below the production cost of many uranium projects, making these projects uneconomic in the near- and medium-term. DESCRIPTION Global nuclear fuel inventories are held by numerous entities, including: • End-user nuclear power utilities and their relevant nuclear fuel procurement/management subsidiaries, • Suppliers throughout the supply chain, including uranium producers, converters, enrichers, fabricators, and even reprocessors and mixed-oxide (MOX) fuel fabricators, • Investors, traders, and financial institutions, as well as other non-end users, and • Governments that have historically been involved in the production of nuclear fuel for both civilian and military applications. Among global utility inventories, UxC data shows that the desired level for 2017 was 392 Mlb U3O8e (150,769 tU), with actual inventories amounting to 759 million pounds U3O8e (291,923 tU), or an excess of 367 million pounds U3O8e (141,154 tU) [1]. The U.S. Energy Information Administration (EIA) reported in its 2016 Uranium Marketing Annual Report that U.S. utility inventories held nearly 129 million pounds U3O8e (49,615 tU) at the end of 2016, up 43% from 90 million pounds U3O8e (34,615 tU) in 2011 and 182% higher than the historical low of 46 million pounds U3O8e (17,692 tU) in 2003 [2]. The Euratom Supply Agency (ESA) shows that European Union (EU) utility inventories increased from 123 million pounds U3O8e (47,308 tU) in 2011 to a peak of 142 million pounds U3O8e (54,615 tU) in 2013, but have since decreased slightly to 134 million pounds U3O8e (51,538 tU) [3]. Interestingly, given numerous reactor closures since 2011, EU utilities now hold more inventories per reactor than just a few years ago. Given the highly uncertain situation regarding the future of reactor restarts in Japan, the question of the country’s utility inventories has become even more important to the uranium market. UxC estimates that Japanese utility inventories total 126 million pounds U3O8e (48,462 tU), with very little consumed since 2011, and enough fuel to last most Japanese utilities through most of the next decade and some utilities even beyond 2030. UxC’s Base Case reactor restart/operations forecast for Japan assumes that only 21 of 40 operable units will eventually restart [4]. China’s three main utilities – China National Nuclear Corporation (CNNC), China General Nuclear Power Corp. (CGN), and State Power Investment Corp. (SPI) – are estimated to hold 450 million pounds U3O8e (173,077 tU) at the end of 2017, an increase of 151% compared to an estimated 179 million pounds U3O8e (68,846 tU) in 2011. Starting in 2010, the import of uranium supply tripled, and net uranium imports have surpassed domestic uranium demand by a huge margin in every year since. Supplier inventories have also built up inadvertently to the extent that global uranium demand has dropped off and utilities cancel out of previously contracted commitments. Traders hold inventories as well, although they do not produce or consume uranium. Since traders facilitate the flow of supply in the market, in some cases with offtake agreements, they end up holding inventories. After Fukushima, traders also became heavily involved in mid-term contracting wherein they purchased low-priced spot uranium to hold in inventory for future delivery. Another recent development stemming from the Fukushima accident and subsequent reactor shutdowns has been the use of excess SWU capacity to underfeed enrichment plants and/or re-enrich depleted tails to natural uranium. This underfeeding of enrichment plants has caused the need for newly produced uranium to decline even further. Thus, enrichers have been “creating” or accumulating uranium inventories and have turned around and sold this excess uranium into the market. Additionally, depending on how enrichers elect to use their excess capacity, they can choose to build inventories in the form of enriched uranium product (EUP). UxC estimates that inventories from all the world’s suppliers, traders, and investor-related entities totaled ~231 million pounds U3O8e (88,846 tU) at the end of 2017, with this group holding 53 million pounds U3O8e (20,385 tU) more than it did in 2015. Governments, including the U.S. and Russia, continue to hold uranium inventories for military purposes. Much of the uranium is held in the form of highly-enriched uranium (HEU) contained in nuclear warheads and strategic stockpiles, which can enter the market if it is considered excess to national security interests. U.S. Government inventories, declared as excess or commercial, total ~145 million pounds U3O8e (55,769 tU), but its disposition of natural UF6 and HEU inventories are expected to be largely completed by the end of this decade. The true wildcard going forward is the success of the U.S. Department of Energy’s proposed tails re-enrichment program. The Russian government is the holder of an estimated 368 million pounds U3O8e, (141,538 tU) although most of its material must undergo some type of processing to be utilized. A large portion of the inventory consists of depleted uranium. Furthermore, tails that are deemed to be suitable for re-enrichment have low assays, but with Russia’s large excess enrichment capacity, the volume of re-enriched tails has increased since the Fukushima accident. Two other major components of Russia’s inventory are slightly irradiated uranium and reprocessed uranium. Among the country’s inventory that does not require further processing is primarily natural UF6 stemming from the monitored inventory that became available following the end of the HEU Agreement. DISCUSSION AND CONCLUSION Although current inventory accumulation has taken several years to take shape, it has clearly become a major concern for market participants in the post-Fukushima environment. There is clearly no single opinion about the inventory situation, but most market participants agree that dealing with the growing level of inventories is crucial to rebalancing supply and demand fundamentals and creating a more sustainable future. In early 2017, the world’s largest producer Kazatomprom stated that it would reduce planned 2017 production in Kazakhstan by ~10%, noting that its decision “was based on the current glut of the uranium market [5].” And in late 2017, Kazatomprom announced its intention to further reduce Kazakh planned uranium production by 20% under Subsoil Use Contracts of Company enterprises for the 2018 through 2020 period, “in order to better align its output with demand [6].” More importantly, the cuts come to a country with the majority of its production in the lowest cost tier, with UxC showing a weighted average full cost of ~$15 per pound U3O8 across Kazakh operating uranium projects in 2016 [7]. Other producers have not been immune to the impact of inventories on the market. In November 2017, Cameco Corp. elected to suspend production from its low-cost McArthur River mine for a period of at least 10 months starting in January 2018 [8]. A primary driver in cutting production by ~16 million pounds U3O8 (6,154 tU) in 2018 was the fact that Cameco’s inventory position had ballooned up to ~28 million pounds U3O8 (10,769 tU), which is nearly twice the level of its preferred 6-month inventory position. More than a year earlier, in April 2016, Cameco suspended production at its Rabbit Lake mine in Saskatchewan and began curtailing production at U.S. in-situ recovery (ISR) operations, resulting in the aggregate decline of ~6 million pounds U3O8 (2,308 tU) per year [9]. In Africa, AREVA has reduced production from its two operating projects, SOMAIR and COMINAK, in Niger by 25% since 2015, citing difficult market conditions. Meanwhile, Paladin Energy made an adjustment to its Langer Heinrich mine plan in August 2016, choosing to process stockpiled low and medium grade ores through 2019 and effectively shift higher-grade ore processing into later years when uranium prices may be higher [10]. As a result of the change, Langer Heinrich production was about 1.6 million pounds U3O8 (615 tU) lower over the last year. Going forward, the mostly likely scenario entails additional inventory growth in the near-term, followed by the gradual disposition of utility, supplier, and trader inventories, which cumulatively will be greater than any additional buying on the part of utilities or other market players in the post-2020 period. Inventories will displace primary uranium production on a larger basis, especially after 2020, and as such, they will continue to have a price suppressive effect on the uranium market as existing supply outweighs new demand for inventories. However, this situation should slowly dissipate by the late 2020s, especially with significant uranium resource depletion projected in the mid-2020s. Accordingly, any new production decisions within the next several years will likely be premature unless market fundamentals change significantly in that timeframe. REFERENCES [1] THE URANIUM CONSULTING COMPANY, LLC, Global Nuclear Fuel Inventories, February 2018. [2] U.S. ENERGY INFORMATION ADMINISTRATION, 2016 Uranium Marketing Annual Report, U.S. Department of Energy, June 2017. [3] EURATOM SUPPLY AGENCY, Annual Report 2016, European Commission, June 2017 [4] THE URANIUM CONSULTING COMPANY, LLC, Nuclear Power Outlook, Q1 2018 [5] KAZATOMPROM, Kazakhstan To Reduce Uranium Production by 10%, January 10, 2017, https://www.kazatomprom.kz/en/news/kazakhstan-reduce-uranium-production-10. [6] KAZATOMPROM, Kazatomprom Announces Further Production Cuts, December 4, 2017, https://www.kazatomprom.kz/en/news/kazatomprom-announces-further-production-cuts. [7] THE URANIUM CONSULTING COMPANY, LLC, Uranium Production Cost Study, September 2017 [8] CAMECO CORP., Cameco To Suspend Production from McArthur River and Key Lake operations to reduce its dividend, November 8, 2017, https://www.cameco.com/media/news/cameco-to-suspend-production-from-mcarthur-river- and-key-lake-operations-an. [9] CAMECO CORP., Cameco Announces Operational Changes in Saskatchewan and the United States, April 21, 2016, https://www.cameco.com/media/news/cameco-announces- operational-changes-in-saskatchewan-and-the-united-states. [10] PALADIN ENERGY LTD, 2016 Annual Report and Financial Statements, August 24, 2016, https://www.paladinenergy.com.au/sites/default/files/financial_report_file/160630-paladin- 2016-annual-report.pdf. Speaker: Mr Nicolas Carter (The Ux Consulting Company, LLC) • 5 Foundational fuels of the 21st century: Evolving socio-economics of sustainable energy systems The last few years saw the end of the commodity super-cycle, the gradual fall in oil and gas prices, the carbon crunch and the wide-ranging revolution that is going on in technology, often termed Industry 4.0. Rapid digitization, which is taking over all areas of the industry and the society, including transportation, means that energy in general will be increasingly electric. How the electricity will be produced, stored, distributed and utilized will depend on the acceleration of this change and bare realities of economics. Three fuels assume importance as foundational fuels in this scenario - natural gas, uranium and renewable resources. This paper will discuss the socio-economics of energy transformation, the comparative advantages and disadvantages, especially focusing on the role of nuclear energy in the post Paris Agreement era. Speaker: Mr Harikrishnan Tulsidas (UNECE) • 6 Uranium One development outlook The Russian State Corporation Rosatom has acquired Uranium One in 2010 to secure long term uranium supply for its nuclear fuel cycle chain and consolidated on its basis high quality uranium assets in Kazakhstan and in other countries. Uranium One has increased annual production almost 5 times during the last 7 years and became a fourth global U producer. It has a diversified production base in Kazakhstan, the US and a development project in Tanzania. Known resources and mining capacities secure further sustainable uranium production growth at favorable market conditions. Through its shares in five joint ventures and six mines, Uranium One owns 20% of attributable uranium production and 17% of attributable resources in Kazakhstan, being the second after Kazatomprom and the first among the foreign companies. The designed production capacity of six uranium mines is 12 ktU, half of which is attributable to Uranium One share. The successful innovative technical policy in conjunction with the unique by its geological and technical characteristics deposits, provide significant competitive advantage for Uranium One as the global company with the lowest cost uranium production. Speaker: Mr Vasily Konstantinov (Uranium One Group) • 12:40 PM Lunch Break • Uranium Markets Conveners: Mr Nicolas Carter (The Ux Consulting Company, LLC) , Ms Olga Skorlyakova (World Nuclear Association) • 7 Regulations for the diversification of partners as part of the security of supply policy In the current uranium industry conditions, the stable and sustainable natural uranium and uranium fuel supply is becoming crucial. It can be achieved through the mandatory diversification of uranium suppliers portfolio regulations issued by IAEA for the utilities. Some countries and utilities experience such constraints, when they are not able to procure uranium through different sources, because of some regulations of their arrangements with strategic counterparties. We can take as an example some utilities working in the market, the natural uranium supplier portfolio of which is diversified by means of their own corporate policies, e.g. where they allow not more than 10% of their needs to be fulfilled by the uranium producers with a single mining source, and not more than 20% of their requirements procured from the producers with more than one sustainable mine. Given the prevailing situation on the market, the international political situation, as well as ensuring the stability of fuel supplies for sensitive facilities such as nuclear power plants, it seems advisable to introduce international rules on the mandatory diversification of supplies of natural uranium and uranium fuel for the needs of energy companies. Speaker: Mr Riaz Rizvi (Kazatomprom, Republic of Kazakhstan) • 8 Uranium Resources and Perspectives for Nuclear Supply in Argentina INTRODUCTION In 1992, due to the low prices in the international market, the import of uranium concentrates began from South Africa, a situation that gradually led to the closure of local production in 1997. Since then, there has been no production of uranium in the country, while the uranium needs from operating nuclear power plants have been met with raw materials imports from abroad (i.e. Uzbekistan, Czech Republic, Kazakhstan and Canada). However, despite the fact that international uranium market has been depressed in recent years, the Free On Board (FOB) prices that the country has paid for the purchase of yellowcake in the spot market have not necessarily been trivial, mainly due to the increases in transportation charges, insurance premium and taxes [1]. This paper attempts to present a comprehensive vision of and uranium projects, updated resources, and project statuses and the perspective of local production of uranium oxide concentrate regarding the foreseeable demand for nuclear energy generation in the country. Besides, the eventual row material supply from the Latin American region is briefly discussed. DESCRIPTION Argentina has three heavy water reactors, namely Atucha I with a gross electrical power of 362 MWe that is fuelled with Slightly Enriched Uranium (SEU) (0.85% U-235), and Embalse (CANDU) and Atucha II, both based on natural uranium fuel with generation capacities of 648 MWe and 745 MWe, respectively. At present, Atucha I and Atucha II, located in Buenos Aires province, are in commercial operation, while Embalse, located in the province of Cordoba, has been out of the generation system for two years for refurbishment tasks designed to extend its useful life for a term of 30 years, which includes an increase in its power by an additional 35 MWe [2].With an approximate installed capacity of 1.7 GWe, nuclear power sources have a 10% share in the national electricity matrix, with natural uranium requirements of about 220–250 tU per year. Additionally, at the Atucha site, the Argentine prototype small modular reactor CAREM (27 MWe net/32 MWe gross) is under construction and is planned to come into operation in 2020–2022 and in the future plans are to increase the scale of the unit to a higher capacity of possibly 120 MWe. As part of the nuclear development in Argentina, China and Argentina signed an agreement for the installation of the fourth (CANDU Pressurized Heavy Water Reactor) and fifth (Hualong One Pressurized Water Reactor) nuclear power plants in the country, with construction planned to start in 2019 and 2021, respectively. Based on various nuclear growth scenarios, it is estimated that by 2030 there will be a generation capacity of some 3,470 GWe, for the low case, and about 4,070 GWe, for the high case. Therefore, the raw material needs would consist of 525 tU and 620 tU in the respective scenarios, which is about double the current consumption. In 2017, CNEA reported about 19,000 tonnes of uranium (tU) as identified resources (Reasonably Assured Resources + Inferred Resources) for the production cost category <130 USD/kgU in the OECD-NEA/IAEA classification scheme [3]. Approximately 11,000 tU of Canadian National Instrument 43-101 (NI 43-101) certified resources have been reported in recent years by the public mining company named U3O8 Corporation [4] and the private mining company named UrAmerica Limited [5]. The total uranium resources of Argentina are thus 30,010tU in the aforementioned Identified Resources category. It can be highlighted that if the higher production cost category of <260 USD/kgU is considered there is no substantial variation and identified resources account for 31,060 tU. In the Cerro Solo Deposit (Chubut Province), the tonnage and grade estimated are expected to ensure sustained uranium production in the future. The identified resources are 9,230 tU at approximately 0.1 to 0.2 per cent U, which are included in the < US$260/kg U production cost category. The reported resources correspond to the most studied mineralized bodies, and the available geological knowledge indicates excellent potential to develop new uranium resources in this mining property. In connection with pre-feasibility studies, in 1997 the CNEA retained NAC International to complete the Preliminary Economic Assessment (PEA) of the Cerro Solo uranium deposit [6]. Recently, a programme to complete the technical feasibility study of the deposit has been formulated and started. Also, the social-environmental baseline is being surveyed in cooperation with national universities and research councils. In the Laguna Salada project (Chubut Province) uranium identified resources have been evaluated at 3,880 tU at grades ranging between 55 and 72 ppm U, while vanadium identified resources have been assessed at 21,330 tV at grades ranging from 308 to 330 ppm V. Recently, the NI 43-101 PEA, where U-V comprehensive recovery concept is reinforced. Uranium and vanadium would be extracted from the fine material after screening by alkaline leach, in which the reagents are sodium carbonate (washing soda) and sodium bicarbonate (baking soda) at an optimal temperature of 80°C [7]. Sierra Pintada uranium Deposit (Mendoza Province) [8] has been the focus of the most significant uranium production in the country, with a total of 1,600 tU produced from 1975 to 1997, after which, the mining-milling facility was put in stand-by status for economic reasons. The level of uncertainty in the estimation of remaining resources in is medium to high, which are evaluated to be 10,010 tU recoverable identified resources at a production cost below US $130/kg U. Therefore, feasibility has been partially demonstrated by the fact that this deposit was previously in operation, using an acid heap-leaching mining method. Given the possibility of the reopening of the mining - milling complex, all available data have been processed to redefine the geological model and formulate a more suitable mining design. Meseta Central project (Chubut Province) is located in the vicinity of Cerro Solo and comprises the Graben, Plateau West and Plateau East deposits. The total inferred resources for the project are 7,350 tU at an average grade of 260 ppm U. As reported by UrAmerica Ltd., about 75 per cent of the uranium resources evaluated occur in confined aquifers layers [5]. Therefore, further geological and hydrological studies will be undertaken to determine amenability to in situ leaching mining. The results of these studies could play a relevant role regarding the socio-economic viability of this project. It must be noted that in January 2018, the Ministry of Science, Technology and Productive Innovation of Argentina, Uranium One Group, subsidiary of State Atomic Energy Corporation of the Russian Federation (ROSATOM), and UrAmerica Argentina S.A. signed a memorandum of understanding whose main purpose is to promote cooperation and joint development on uranium exploration and production focused on In Situ Leaching. Planned investment in this project amounts to USD 250 million [9]. The Don Otto (Salta Province) uranium deposit was in operation from 1963 to 1981 and produced 201 tU at 0.1 to 0.2 per cent U grade [10, 11]. The reminding identified resources are 430 tU and current exploration/evaluation studies yielded very encouraging results. Additionally, enlargement of the mining property and resource augmentation are considered key factors to ensure the project feasibility. A comprehensive study that includes updating environmental impact assessment (EIA) reports, block-leaching research and development studies, feasibility of underground extraction, use of a mobile ionic exchange plant, hydrogeological studies to define in situ leaching amenability, vanadium resource evaluation and extraction feasibility, and uranium recovery from the former heaps and remediation of the site, are all factors that would aim to increase project viability [12]. Laguna Colorada is located in the Chubut Province with evaluated resources of 160 t U at 660 ppm U [13]. The limited resources of the project make it difficult to envisage extraction at present unless the characteristics of the ore will allow treatment in a plant that may in the future be located in the area of Cerro Solo. At the exploration level, there are several projects such as Golfo San Jorge, Amarillo Grande, Alipan, Mina Franca and Laguna Sirven within the basins of great interest in the country that are carried out by both the private sector and the government. Initially, it will be necessary to advance the delineation of resources and raise their level of confidence through preliminary economic assessments of these projects, taking into account that, as general rule, the integral exploration at basin level has not been carried out and resources have generally been evaluated with a low level of confidence. In sedimentary environments, particular attention should be given to those sandstone-type deposits that are amenable to in situ leaching to recover uranium. Also, there are some unconventional sources of uranium that could provide sustainable alternatives for nuclear supply in the foreseeable future, such as rare earth projects, phosphates, and lake and sea waters. DISCUSSION AND CONCLUSION Despite the apparent growth prospects of the use of nuclear energy for the generation of electricity in the country, which would lead to double the uranium needs by 2030, there are no immediate prospects for the provision of nuclear raw material for fuel fabrication from the local production of uranium oxide concentrates at Argentine deposits. This has implications for supply and energy security [14]. One main concern is that the identified uranium resources in Argentina are mostly located in the provinces of Chubut and Mendoza. These are areas where no metallic mineral mining projects are in operation, and also, the provincial legislations markedly restrict uranium production. These factors need to be taken into account when studying the socio-economic viability of the projects. However, it could also be assumed that the mining laws could be amended as necessary if a requirement of uranium and other critical materials for clean energy projects becomes very important to Argentina. Also, projects with a higher degree of maturity must complete technical feasibility studies for the recovery of uranium. In the case of possible future production of U, other valuable materials such as V and Mo, can be assumed to be produced as a by- or co-product, contributing to the mineral sector development in Argentina. While U is used for nuclear fuel, V and Mo have critical applications, especially in the renewable energy and steel industry sectors. In the Latin America region both Brazil and Paraguay could be consider as potential uranium suppliers for Argentina. In Brazil, in the short - medium term, domestic needs would be covered and even significant uranium surpluses could be produced that could contribute to nuclear supply for Argentina. On the one hand, with the expansion, the Lagoa Real deposit would produce about 670 tU/ year. On the other hand, some 1700 tU / year would be obtained as a by-product of the extraction of phosphates in the Santa Quitéria deposit, from 2020-2022. As a recent precedent, in 2016 Industrias Nucleares de Brasil (INB) and Combustibles Nucleares Argentinos (CONUAR) signed an agreement for the provision of four tons of low enriched uranium (1.9% - 3.2% U-235) produced at the Rio de Janeiro facility in Brazil to be used for the fuel of the initial load of the CAREM reactor which is under construction at Lima site in Argentina [15]. While in Paraguay there are two projects of interest found in the eastern part of the country, related to sandstones in the western flank of the Parana Basin: Yuty project, with about 4,290 tU of NI 43-101 certified resources, and Coronel Oviedo project, which constitutes a NI 43-101Exploration Target ranging 8,900 to 21,500 tU. In both projects hydrogeological testing indicates that the uranium bearing unit has aquifer characteristics that would support operational rates for ISR mining. These projects are waiting for better market conditions to be developed and as Paraguay has no prospects for the use of nuclear power, these resources could contribute to the supply of nuclear fuel resources for Argentina. To this regards, it must be highlighted that Argentina is constructing a new uranium purification plant located about 200 km far away from Paraguayan uranium projects. Therefore, the transportation of pregnant resins or elluants could be consider as the best economic and technical option, rather than yellowcake to be precipitated in Paraguay ISL facility and to be dissolved at the uranium purification plant in Argentina [16]. REFERENCES [1] MINISTERIO DE ENERGÍA Y MINERÍA, Informe especial, Mercado del Uranio (2016) http://scripts.minem.gob.ar/octopus/archivos.php?file=6939 [2] NUCLEOELÉCTRICA ARGENTINA S.A. , Web pages (2017) http://www.na-sa.com.ar/ [3] BIANCHI, R., GRÜNER, R., LÓPEZ, L., Argentina - Country report, Prepared for Uranium 2018: Resources, Production and Demand, OECD Report, the ‘Red Book’, National Atomic Energy Commission (CNEA) internal report, unpublished (2017). [4] COFFEY MINING PTY LIMITED, NI 43-101 Technical Report Laguna Salada Initial Resource Estimate, Prepared on behalf of U3O8 Corporation, 30 p. (2011) www.sedar.com [5] PEDLEY, A., CONSULTING GEOLOGIST, NI 43-101 Technical Report on the Paso De Indios Block Property Within the Central Plateau Project Located in the Chubut Province of Argentina, Prepared For UrAmerica Ltd., 92 p., unpublished (2013). [6] NAC INTERNATIONAL, Cerro Solo U, Mo Deposit, Chubut Province, Argentina, Pre-feasibility study prepared for the CNEA, 169 p., internal report, unpublished (1997). [7] TENOVA MINING AND MINERALS PTY LTD, Preliminary Economic Assessment of the Laguna Salada Uranium-Vanadium Deposit, Chubut Province, Argentina, Report Prepared for U3O8 Corp. (2014). [8] SALVARREDI, J.,Yacimiento Doctor Baulíes y otros depósitos del distrito uranífero Sierra Pintada, Mendoza,E. Zappettini (Ed.), Recursos Minerales de la República Argentina, Anales No. 35 SEGEMAR, pp. 895-906 (1999). [9] MINISTRY OF FOREIGN AFFAIRS AND WORSHIP OF THE ARGENTINE REPUBLIC, Press Released N°: 014/18. (2018) https://www.mrecic.gov.ar/en/argentina-russia-memorandum-understanding-uranium-exploration-and-mining [10] GORUSTOVICH, S.A., Metalogénesis del uranio en el noroeste de la República Argentina, PhD Thesis, University of Salta, unpublished (1988). [11] ROMANO, H.I., Distrito Uranífero Tonco Amblayo, Salta, E.O. Zappettini (Ed.), Recursos Minerales de la República Argentina, Anales No. 35 SEGEMAR, pp. 959-970 (1999). [12] LÓPEZ, L., SLEZAK, J., Technological transfer on in situ leaching (ISL) mining: A more Sustainable Alternative for Uranium Production in Argentina, Best Practices Dissemination Meeting INT/0/085, IAEA, Vienna(Austria), 3-4 February 2014 (2014). [13] FUENTE, A., GAYONE, M., Distrito uranífero Laguna Colorada, Chubut. (Zappettini, E., Ed.), Recursos Minerales de la República Argentina, Anales Nº 35 SEGEMAR 1253-1254 (1999). [14] UNITED NATIONS ECONOMIC COMMISSION FOR EUROPE, Application of the UNFC for Fossil Energy and Mineral Reserves and Resources 2009 to Nuclear Fuel Resources – Selected Case Studies. ECE ENERGY SERIES No. 46 UN New York and Geneva (2015). [15] INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES, (2016) https://www.ipen.br /portal_por/portal/ interna.php?secao_id=40&campo=7531 [16] YANCEY, C., FERNÁNDEZ, V., TULSIDAS, H., LÓPEZ, L. ,Considerations related to the application of the United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009 to uranium projects and associated resources in Paraguay, Economic and Social Council – United Nations, ECE/ENERGY/GE.3/2016/10 (2016). Speaker: Mr Luis LOPEZ (CNEA (Argentina)) • 9 ESTIMATION OF URANIUM REQUIREMENTS FOR PLANNED NUCLEAR POWER PLANTS AND SUPPLY CAPACITY OF URANIUM RESOURCES IN TURKEY INTRODUCTION The Turkish economy has a projected average annual growth rate of 7-8 % for the near future. Therefore, it has an increasing demand and consumption for electricity. According to the tenth five-year development plan, the primary energy demand of Turkey will increase by 25 %, while the total electricity demand will increase by 34 % during this period [1]. In an effort to achieve energy-supply reliability and diversity; Turkey has undertaken two nuclear power plant (NPP) projects: one with the Russian Federation in Akkuyu in the Mediterranean Region, the other with Japan in Sinop in the Black Sea Region. Additionally, Turkey has plans to initiate a third NPP project and increase the nuclear power capacity gradually. The ongoing NPP projects are based on the external supply of nuclear fuel. However, it is still important to evaluate the identified local resources of Uranium (U) in Turkey, explore U more widely and deeply, and determine the possible domestic contribution to the fuel need for the NPP projects. That is why U exploration and mining activities have been accelerated in recent years. This study aims to assess the fuel-supply capacity of the U resources in Turkey for the Akkuyu and Sinop NPP projects. First, the data related to the identified U resources in Turkey are reviewed. Then, lifetime U requirements for the planned NPPs are estimated and the domestic potential to meet the requirements is put forward. NATIONAL NUCLEAR POWER PROGRAM Turkey signed an agreement with the Russian Federation in 2010 for installation of four VVER-1200 units with a total capacity of 4800 MWe at the Akkuyu site. It is expected that first unit of Akkuyu NPP will be in operation in 2023. A second agreement was signed with Japan in 2013 to build four ATMEA-1 units with a total capacity of 4500 MWe at the Sinop site. Both projects are based on the Built-Own-Operate (BOO) model. In the Akkuyu site, Akkuyu Nuclear Power Plant Electricity Generation Joint-Stock Company (APC), which is a subsidiary of Russia's state-owned nuclear company Rosatom, will build, own and operate the plant. According to the intergovernmental agreement, APC will be responsible for fuel supply, radioactive waste and spent fuel management, and decommissioning of the facility. Provisions of the agreement related to fuel supply states that the nuclear fuel shall be sourced from suppliers based on the long-term agreements between APC and the fuel suppliers [2]. It can be foreseen that APC will deliver fuel from the Russian Fuel Company TVEL, which is the fuel supplier of almost all VVER reactors in operation. APC only recently obtained the Limited Construction Permit from the Turkish Atomic Energy Authority, and is expected to apply for a Construction License pretty soon. The Limited Permit allows some construction activities which do not have a direct bearing on the nuclear safety. The Sinop plant will be built, owned and operated by a consortium established by Mitsubishi Heavy Industries, Itochu Corporation, GDF Suez and the Turkish government-owned Electricity Generation Company (EÜAŞ). The fuel-supply issue is not detailed in the intergovernmental agreement and will be determined after the completion of the feasibility study. Currently, work related to the site and the environmental impact assessment is continuing. Most recently, the Environmental Impact Assessment (EIA) file for the Sinop project has been submitted to the Environment and Urban Planning Ministry. As a result of these developments, Turkey is expected to have at least 9300 MWe installed nuclear-electrical capacity in the next 15-20 years. Besides, the Chinese State Nuclear Power Technology Corporation, the US Westinghouse Electric Company and the Turkish EÜAŞ signed a memorandum of cooperation in 2014 to launch a negotiation in order to construct four NPP units, which apply the advanced-passive PWR CAP1400 and AP1000 technology. For the third project, site selection studies are going on. With respect to this, an agreement between China and Turkey for cooperation in the peaceful uses of nuclear energy was ratified by the Turkish Parliament in 2016 [3]. URANIUM EXPLORATION AND MINING STUDIES AND DOMESTIC RESOURCES In Turkey, radioactive raw material researches and U exploration work were initiated in the 1950s by the General Directorate of Mineral Research and Exploration (MTA). In early stages, the work was concentrated on the vein-type deposits in igneous and metamorphic rocks. Yet, after identification of some uneconomic uraninite mineral occurrences, efforts were directed toward sedimentary-type deposits. Until today, a total of 12614 tons of U resources has been identified in various regions of Turkey, most of them being the sedimentary type [4]. According to the MTA reports, Temrezli deposit in the Yozgat-Sorgun region is the largest and the highest-grade U resource, with 6700 t U at an average grade of 0.1 % U3O8. Other resources are located in Manisa-Köprübaşı, with 3487 t U at an average grade of 0.04-0.07 % U3O8; in Uşak-Eşme-Fakılı, with 3490 t U at an average grade of 0.05 % U3O8; in Aydın-Demirtepe, with 1729 t U at an average grade of 0.08 % U3O8; and in Aydın-Küçükçavdar with 208 t U at an average grade of 0.04 % U3O8 [4]. U exploration and mining activities have gained speed due to the recent developments in the national nuclear power program. In addition to the studies carried out by MTA, Adur, a private Turkish mining company which is a subsidiary of the US-based Uranium Resources Inc. (URI), is conducting drilling activities for resource evaluation in Temrezli and Sefaatli deposits located in the Yozgat-Sorgun region. A preliminary economic assessment of the Temrezli project was completed in 2015. At present, URI is planning to develop an in-situ leaching mine in the Temrezli site. Siting and EIA studies of the Temrezli project are ongoing. URANIUM REQUIREMENTS FOR THE PLANNED NPPs Annual fuel consumption of a nuclear power plant can be calculated by the following equation: M_fuel=(P_e*CF*365)/(η_th*BU)= (P_th*CF*365)/BU where P_e is the installed electrical capacity (MWe), P_th is the thermal power (MWth), CF is the capacity factor, η_th is the thermal efficiency, and BU is the average discharge burnup of the fuel (MWd/tU). The mass balances of the enrichment process yield the following expression for Natural Uranium (NU) requirement per unit of reactor fuel load. M_NU/M_fuel =(x_fuel-x_tails)/(x_NU-x_tails ) where x_fuel is the fuel enrichment, x_NU is the 235U content of NU [taken to be 0.711 weight percent (w/o)], and x_tails is the enrichment of tails (assumed to be 0.25 w/o here). Using the above expressions and the technical data for the Akkuyu and Sinop NPPs, lifetime NU requirements can easily be calculated. Each unit of the Akkuyu NPP (a VVER-1200 design) has a rated electrical power of 1200 MWe and a thermal power output of 3200 MWth. Total lifetime of each unit is 60 years. According to the EIA report, fuel enrichment is 4.79 w/o and the average discharge burnup is 55800 MWd/tU [5]. Using these numbers and an assumed capacity factor of 0.90 in the first equation, annual fuel load for each unit is calculated as 18.8 t U. M_NU/M_fuel is found to be 9.85 from the second equation. Then, lifetime NU requirement for four units is obtained to be 18.8 x 9.85 x 60 = 11110 tons. The Sinop NPP consists of four ATMEA-1 units with a total electrical power of 4500 MWe. The technical features of the plant will be detailed after the completion of the feasibility report. Therefore, the standard design properties of ATMEA-1 reactors are used to calculate NU requirement for the Sinop case. The ATMEA-1 design has a thermal power level of 3150 MWth (for each unit), a capacity factor of 0.90 and a service life of 60 years. The fuel load is 5 w/o enriched and the discharge burnup is 62000 MWd/tU [6]. With these data, annual fuel load for each unit is found to be 16.7 t U and M_NU/M_fuel to be 10.3. Then, lifetime NU requirement for four units is obtained to be 16.7 x 10.3 x 60 = 10320 tons. The total lifetime NU requirements for both Akkuyu and Sinop NPPs are 21430 tons. DOMESTIC SUPPLY CAPACITY For the time being, Turkey’s identified resources add up to 12614 t U. As estimated above, the lifetime NU need for the Akkuyu and Sinop NPPs is (11110+10320=) 21430 t NU. Then, it may be said that the domestic U supply can roughly meet the lifetime NU need for one of the projects (either Akkuyu or Sinop). Nevertheless, there are other issues to be taken into consideration: economy and losses. According to the preliminary economic assessment of the Temrezli project by URI, the deposit (6700 t U) is cost effective. As for the other identified resources in Turkey, the same cannot be said; further investigation is required. As noted above, the in-situ leaching is to be applied in the Temrezli mine. Recovery ratio in the in-situ leaching is less than that in the underground mining and may vary significantly from one site to another (recovery of about 70-90 % uranium ore) [7]. URI has not reported the expected recovery ratio for the Temrezli mine. Additionally, the losses in the other processes leading to the production of nuclear fuel assemblies should be taken into account. Noting that the Temrezli deposit is the only economic resource (that is, reserve under the cost-price conditions) for today in Turkey and presuming that 20 % of the reserve is lost during mining (and milling), refining, enrichment and fabrication; the domestic U supply can more or less meet the lifetime NU requirements for the two units of either Akkuyu or Sinop plants. CONCLUSION AND DISCUSSION At present, the U reserve in Turkey amounts to 6700 t U. Assuming a 20 % loss in all the processes in the front-end of the nuclear fuel cycle, this reserve can nearly feed two units of either Akkuyu or Sinop plants during 60 years. At first glance, this may seem to be insignificant. Yet, the total amount of electricity producible from the two units in 60 years is 1135x109 kWh for Akkuyu and 1064x109 kWh for Sinop. Turkey’s total electricity consumption was 278x109 kWh in 2016 [8]. Then, the possible contribution of nuclear electricity from this reserve is not insignificant. Duly, attempts to explore U resources all over the country and to convert the identified resources into reserves are likely to be fruitful. As well, it is reasonable to focus on research and development in mining (and milling), refining and fuel fabrication in concert with the planned NPP projects. REFERENCES [1] TURKISH REPUBLIC DEPARTMENT OF STATE PLANNING ORGANIZATION, 10th Five-year Development Plan (2014–2018), Ankara, Turkey (2013). [2] Agreement between the Government of the Russian Federation and the Government of the Republic of Turkey on Cooperation in relation to the Construction and Operation of a NPP at the Akkuyu site in the Republic of Turkey (2010). [3] Law on Ratification of Agreement between the Government of China and the Government of the Republic of Turkey for Cooperation in the Peaceful Uses of Nuclear Energy (2016). [4] REPUBLIC OF TURKEY MINERAL RESEARCH & EXPLORATION GENERAL DIRECTORATE, G. Eroğlu, M. Şahiner, Thorium and Uranium in the World and in Turkey, Ankara (2017). [5] EIA Report for Akkuyu NPP, Turkey (2014). [6] INTERNATIONAL ATOMIC ENERGY AGENCY, Interrigional Workshop on Advanced Nuclear Reactor Technology for Near Term Development; Presentation: ATMEA1 Reactor : A mid-sized Generation III+ PWR, Austuria (2011). [7] WORLD NUCLEAR ASSOCIATON, In situ leaching mining of uranium, http://www.world-nuclear.org [8] REPUBLIC OF TURKEY MINISTRY OF ENERGY AND RESOURCES, Electric Consumption data, http://www.enerji.gov.tr Speaker: Dr Banu Bulut Acar (Hacettepe University Nuclear Engineerin Department) • 10 CANADA’S URANIUM MINING INDUSTRY: 75 YEARS OF PRODUCTION AND FUTURE PROSPECTS HISTORICAL BACKGROUND Pitchblende ore was mined at the Port Radium mine in the Northwest Territories from 1932 to 1940 to extract radium for medical use [1]. However, Canadian uranium production did not begin until 1942, when, at the request of the Government of Canada, the Port Radium mine was re-opened to supply uranium for the Manhattan Project [2]. With the onset of the Cold War, military demand for uranium soared, creating a uranium exploration boom in which thousands of uranium occurrences were discovered throughout Canada [1]. Canada’s second uranium mine opened in northern Saskatchewan in 1953, and by the late 1950s, there were 20 uranium production centres in Ontario, Saskatchewan and the Northwest Territories [1,3]. Annual production peaked in 1959 at 12 200 tonnes of uranium (tU), but declined rapidly as U.S. and U.K. military demand had been met and contracts were not extended. Only 8 mines remained in operation in 1961 [1], and by 1966, production had fallen to less than 3 000 tU with only 4 mines remaining in production [4]. In 1965, Canada made a policy decision that all future uranium sales would be for peaceful purposes only, and while the development of nuclear power was expanding, it was not until the 1970s that uranium demand had risen substantially and exploration and development activity increased [5]. By the late 1970s, new uranium mines were being developed in Ontario and Saskatchewan. Annual uranium production grew through the 1980s, with the focus of production shifting to the high-grade uranium deposits of the Athabasca Basin of northern Saskatchewan [6]. Uranium mining in Ontario ceased in 1996, leaving Saskatchewan as the sole producer of uranium in Canada. URANIUM PRODUCTION Canada is currently the world’s second largest producer and exporter of uranium, with 22% of world production in 2016 [7]. More than 85% of uranium production is exported, making it Canada’s largest clean energy export. Canadian uranium exported for use in nuclear power helps combat climate change by avoiding some 600 million tonnes of CO2 equivalent emissions annually. In addition to being a reliable supplier of uranium, Canada has also long been recognized as a responsible producer of uranium due to policies and practices than ensure protection of the environment, corporate social responsibility and nuclear-non-proliferation. The McArthur River Mine and the Cigar Lake Mine are the world’s largest and second largest uranium mines, respectively, in term of annual production [7]. These mines have ore grades of up 20% uranium, one-hundred times higher than the world average. Canada’s annual uranium production has risen substantially since the start-up of the Cigar Lake mine in 2014, increasing by 42% in 2015 and increasing a further 5% in 2016 to reach a record annual production level of 14,039 tU [7]. Low demand and low prices has resulted in a 8% decrease in Canada’s uranium production for 2017. Due to continued depressed market conditions, 2018 production is expected to decrease a further 40% as production at the McArthur River mine and Key Lake mill are suspended for ten months. This action will reduce operating costs, while uranium concentrates will continue to be supplied to customers from the excess inventory that is currently stored at the Key Lake mill [8]. While only the Cigar Lake mine and McClean Lake mill are currently in production, both the Cigar Lake mine the McArthur River mine have extremely high-grade uranium deposits with low production costs. As a result, the Canadian uranium industry is able to remain viable in a low uranium price market and could quickly ramp-up production to meet an increase in demand. In addition, the Rabbit Lake mine and mill, which has been in care in maintenance since mid-2016 due to low uranium prices, could be brought back into production should uranium prices increase substantially. URANIUM RESOURCES Canada has 9% of the world’s low-cost uranium resources (< US$130/KgU) and has the world’s highest-grade uranium deposits, ensuring that Canada will continue to be a major supplier of uranium well into the future [9]. Canada’s low-cost uranium resources have risen by 60% since 2009 due to increased exploration efforts. When uranium demand and prices increase, two advanced uranium projects in Saskatchewan, which have been put on hold due to low prices, could enter production and provide additional feed for the existing mills. Ore from the proposed Millennium mine would be processed at the Key Lake mill, while ore from the proposed Midwest mine would provide additional feed for the McClean Lake mill [9]. There are also additional undeveloped uranium deposits at McClean Lake that could be brought into production. The Athabasca Basin continues to be highly-prospective for discovering new deposits and several large high-grade uranium deposits have been identified that could be developed into mines in the future. Recent large discoveries in the eastern Athabasca Basin include the Roughrider deposit (Rio Tinto), the Phoenix and Griffon deposits (Denison Mines), and the Fox Lake deposit (Cameco) [9]. In the western Athabasca Basin, the Triple-R deposit (Fission Uranium) and the Arrow Deposit (Nex-Gen Energy) are currently the two largest undeveloped uranium deposits in Canada [9]. Through continued exploration, Canada’s uranium resources are expected to increase further. PUBLIC ACCEPTANCE The success of Canada’s uranium industry is not only the result of having a good resource base and the use of modern and sustainable mining methods, but also the result having an appropriate policy and regulatory regime which fosters a high degree of public acceptance. These policies and regulations address public concerns on health, safety and the environment, as well as nuclear non-proliferation and foreign ownership. The industry itself has adopted best practices through which it has earned a high degree of public support, especially among local Indigenous communities with which they have developed partnerships that provide much-needed local employment and business opportunities. SUMMARY This presentation will briefly outline Canada’s 75-year history in uranium mining as well as examine Canada’s current uranium production and the policy and regulatory regime that governs the Canadian uranium industry. Future prospects for uranium mining in Canada will be discussed, as well as the importance of developing community support. REFERENCES [1] J.W. Griffith, The Uranium Industry – Its History, Technology and Prospects, Mineral Report 12, Mineral Resources Division, Department of Energy, Mines and Resources, Ottawa, Ontario Canada, 1967, 335p. [2] R. Bothwell, Eldorado, Canada's National Uranium Company, University of Toronto Press, Toronto, Ontario, Canada, 1984, 515p. [3] O.J.C. Runnalls, Ontario’s Uranium Mining Industry – Past, Present and Future, Mineral Ontario Mineral Policy Background Paper No. 13, Ontario Ministry of Natural Resources, Toronto, Ontario Canada, 1981, 182p. [4] R. Bothwell, Eldorado, Canada's National Uranium Company, University of Toronto Press, Toronto, Ontario, Canada, 1984, 515p. [5] D.A. Cranstone and R.T. Whillans, An analysis of uranium discovery in Canada. 1930-1983, Uranium Resources and Geology of North America, Technical Document 500, International Atomic Energy Agency, Vienna, Austria, 1989, pp. 29-48 [6] Nuclear Energy Agency, Forty Years of Uranium Resources, Production and Demand in Perspective, Organisation for Economic Co-operation and Development, Paris, France, 2006, 276p. [7] World Nuclear Association, World Uranium Production (updated July 2017), http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/mining-of-uranium/world-uranium-mining-production.aspx [8] Cameco Corporation, Cameco to Suspend Production from McArthur River and Key Lake Operations and Reduce its Dividend, November 8, 2017, News Release. [9] Nuclear Energy Agency, Uranium 2016: Resources, Production and Demand. Organisation for Economic Co-operation and Development, Paris. 2016.
Speaker: Dr Tom Calvert (Natural Resources Canada)
• Uranium from Unconventional Resources
Conveners: Dr Brett Moldovan (IAEA) , Mr Harikrishnan Tulsidas (UNECE)
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Unconventional resources in IAEA Uranium DEPOsit Database (UDEPO)
Speaker: Dr patrice bruneton (none)
• 12
Uranium: Waste or Potential Future Resource?
Speaker: Mr Paul Kay (Geoscience Australia)
• 13
Status of Uranium Activities on Unconventional Resources in the Philippines
While the initial search for uranium dates back as early as 1954, it was only in 1977 that the systematic exploration approach for uranium was started under the International Atomic Energy Agency (IAEA) Technical Cooperation (TC) project PHI/3/04 “Uranium Geochemical Prospection” [1]. This was tied up with the decision of the Philippine Government at that time to establish the Philippine Nuclear Power Program and build the first Philippine Nuclear Power Plant (PNPP) in the Country. Unfortunately, due to the Chernobyl accident that happened in April 26, 1986, the first PNPP was not allowed to operate and later on mothballed by the then government dispensation, although it was almost 100% complete. This led to the discontinuance of the quest for indigenous uranium mineral deposits. However, in May 1995, Executive Order No. 243 was issued, which created the Nuclear Power Steering Committee that provided the policies, direction, monitoring, evaluation, and other functions necessary and appropriate to attain the objectives of the overall Nuclear Power Program of the country. It states, in part, that, “the Philippine Nuclear Research Institute (PNRI) shall also conduct research and development programs on the various facets of the nuclear fuel cycle, including the resumption of activities on uranium exploration” [2]. A modest reconnaissance approach using the combined radiometric and geochemical exploration method was launched that resulted in covering, so far almost 70% of the entire Philippine archipelago. Results however were disappointing as no major uranium deposition have been delineated, except for a few minor mineralizations. Hence, the strategy was shifted to sourcing uranium from unconventional resources. This gave rise to the inclusion of PNRI in the IAEA Contract Research Project (CRP 18759) “Geochemical and Radiometric Characterization of the Cu-Mo-U Occurrences in the Larap-Paracale Mineralized District, Camarines Norte, Philippines” in 2015. It is in this mineralized district that the mineral uraninite was discovered by Frost [2] in 1959 and an indicated reserve of about 200 tons U3O8 contained in 500,000 tons of ore with a grade of 0.04% U3O8 at the Bessemer pit being operated by the Philippine Iron Mines was reported by Dr James Cameron, IAEA expert in 1965 [3]. Efforts at that time to locate other uranium mineralized areas were not encouraging, although a few copper (Cu) – molybdenum (Mo) with associated uranium (U) areas were noted. These areas are now the subject of investigation by the present IAEA CRP 18759. Surveys conducted delineated within the Nakalaya locality an area having ﬁeld gamma-ray spectrometric measurements varying from 104 – 138ppm U with the use of RS230 gamma ray spectrometer. Fluorimetric analysis of rock and soil samples gave 39 – 193ppm U while Atomic Absorption Spectrometric analysis gave 209 – 588ppm Cu and 53 – 363ppm Mo. Interestingly, ICP-MS analysis showed 173 – 544ppm rare earth elements (REE). Recently, a more detailed gamma ray spectrometric survey pinpointed an area of about 100 meters south of the Nakalaya area having 76 – 236ppm U. Laboratory analyses of rock and soil samples are still pending. This anomalous area is underlain by the Tumbaga/Universal formation of Eocene age. It is part of a sedimentary rock sequence consisting of limestone, marl and shale that was subjected to thermal metamorphism resulting to skarns, hornfels and marble that acted as hosts to the iron deposits and minor base metal mineralization with associated uranium. It is therefore aimed that uranium will be produced as a by-product or co-product if this area is shown to be economically viable to mine with the combined production of Cu, Mo and REE, including U. Under the IAEA Technical Cooperation project PHI2010 entitled “Enhancing National Capacity for Extraction of Uranium, Rare Earth Elements and Other Useful Commodities from Phosphoric Acid”, a study on uranium recovery from phosphoric acid is being carried-out. This project is being undertaken in collaboration with the Philippine Phosphate Fertilizer Corporation (PHILPHOS) and with financial assistance from the National Research Council of the Philippines – Department of Science and Technology. PHILPHOS imports around 1.97 Mt of raw phosphate ores from different countries per year for the production of fertilizers. Samples of phosphate ores, phosphoric acid and fertilizer products were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) to determine elemental content. Analysis showed that the phosphate ores contain uranium as high as 139 ppm with 20.5 ppm thorium (Th), including REE’s up to 828 ppm. Analysis of phosphoric acid samples using ICP-MS gave values of uranium content varying from 66 – 189 ppm. Phosphatic fertilizer products, particularly Nitrogen-Phosphorus-Potassium (NPK) fertilizers, contain radionuclides and REEs having values reaching up to 223.8 ppm U, 0.8 ppm Th and 36.8 ppm REE and these fertilizers are contaminating the environment upon their application. Uranium in these fertilizers is well beyond the global average of uranium content in soils, which is 0.3 – 11 ppm [5]. A laboratory scale solvent extraction of uranium using a synergistic mixture of diethyl-hexyl phosphoric acid (D2EHPA) and trioctyl phosphine oxide (TOPO) from phosphoric acid was conducted. The static laboratory testing achieved a 92% recovery rate of uranium from phosphoric acid. This experiment thus led to the precipitation of the first yellowcake from phosphates in the Country. This study is projected to produce cleaner fertilizers mitigating the risk from environmental contamination, promote maximization of resources and the opportunity to utilize uranium if the Philippines will decide to go into the nuclear option. REFERENCES [1] Tauchid, M., Uranium Geochemical Prospection, report to the Government of the Philippines, IAEA TA Report No. 1511, International Atomic Energy Agency, Vienna, Austria, (1978). [2] Official Gazette of the Republic of the Philippines. Executive Order No. 243, s. 1995, “Creating a Nuclear Power Steering Committee”. Malacanang Palace, Manila, (1995), http://www.officialgazette.gov.ph/1995/05/12/executive-order-no-243-s-1995/ [3] Frost, J.E., Notes on the genesis of the ore-bearing structures of the Paracale District, Camarines Norte. The Philippine Geologist, 13(2): (1959), 31-43. [4] Cameron, J., Prospection and evaluation of nuclear raw Materials, report to the Government of the Philippines, IAEA TA Report No. 175, International Atomic Energy Agency, Vienna, Austria, (1965). [5] United States Environmental Protection Agency (USEPA). Potential uses of phosphogypsum and associated risks, (1992), https://www.epa.gov/sites/production/files/2015-07/documents/0000055v.pdf.
Speaker: Mr ROLANDO REYES (PHILIPPINE NUCLEAR RESEARCH INSTITUTE)
• 14
Conventional and unconventional uranium resources in the Carajás Mineral Province, Brazil: prospectivity criteria for IOCG and granite-related deposits
INTRODUCTION The Amazonian Craton (South America) hosts several favourable areas for uranium exploration that are still barely acknowledged. The most significant of the recognized resources are in the Carajás Province, the oldest known Archean crustal fragment in the craton. Identified uranium resources are unconventional, hosted by the world-class IOCG deposits from the Carajás Copper-Gold Belt [1, 2]. Nevertheless, the potential for granite-related resources is notable, as Paleoproterozoic A-type granitic plutons cover several thousands of square kilometres of the province’s surface and present very high uranium background values [3-4]. This work aims to present an overview of the uranium potential in the Carajás Mineral Province and regional prospectivity criteria for uranium-rich IOCG and granite-related uranium deposits, based on Airborne geophysics and regional- to deposit-scale structural and geological data. TECTONOSTRATIGRAPHIC FRAMEWORK There are three main rock-generation ages in the Carajás Province tectonostratigraphic evolution, namely in the Mesoarchean (3.02 to 2.83 Ga), Neoarchean (2.76 to 2.55 Ga) and in the Paleoproterozoic (1.88 Ga). The oldest rocks are gneisses, greenstone belts and granitoids developed under an accretionary-collisional system, reported as the Itacaiunas Belt [5-6]. Collisional peak metamorphism was dated at 2.85 Ga, and metamorphic fabrics are of medium to high amphibolite facies [6-7]. This rock association represents the basement of the Carajás Basin (2.76 to 2.70 Ga), a Neoarchean rift-related metavolcanossedimentary sequence [8-9] that hosts supergiant BIF-related iron ore deposits and other exhalative resources, such as Cu-Zn volcanogenic massive sulphides [9]. Coeval bimodal magmatism is represented by several A-type granites and mafic-ultramafic intrusions. Late stage granitic dykes persist to emplace until 2.55 Ga and are spatially and chronologically related to several magnetite-rich IOCG deposits [2, 10]. At about 1.88 Ga, the region experienced an anorogenic magmatic event, which also affected all the central-eastern side of the Amazonian Craton, known as the Uatumã magmatism. This event produced a second generation of A-type granites in the province [3], emplaced at shallower depths and related to widespread hydrothermal activity in a brittle, fluid-dominated extensional environment Neoarchean rocks were only deformed and metamorphosed in the Paleoproterozoic. There are two events of ductile to ductile-brittle deformation and metamorphism that can be recognized. The oldest one is the Transamazonian Orogenic Cycle (2.20 to 2.05 Ga), a collisional system that agglutinated several Archean nuclei and Rhyacian magmatic arcs and greenstone belts [6, 11], related in the province to low green schist (south) to high amphibolite (north) metamorphic fabrics and structures. To the north, the Archean units are limited by a collisional suture from Rhyacian plutonic assemblages that are imbricated over the province [6]. The youngest one is the Sereno Event, an intracontinental orogeny correlated to Orosirian accretionary-collisional belts that surrounded the Amazonian protocraton at 2.00 to 1.98 Ga [6]. Sereno fabrics are of very low grade, from sub-greenschist to greenschist facies. The Mesoarchean main structural trend is ductile in character and of an E-W direction, while the Transamazonian trend varies between ENE-WSW and NE-SW. The Sereno structures are widespread, although less penetrative and of a ductile-brittle style, in an X-shaped pair of oblique structures in WNW-ESE and ENE-WSW directions [6]. URANIUM RESOURCES IN CARAJÁS MINERAL PROVINCE The Carajás Mineral Province hosts some of the largest and oldest IOCG deposits in the world, known for their relatively high uranium contents in comparison to the majority of other deposits from the same class. Main orebodies are Archean (2.70 to 2.55 Ga), but several of them present a Paleoproterozoic (1.88 Ga) granite-related hydrothermal overprint, responsible for local remobilization, endowment in copper sulphides and, as a result, the formation of high grade oreshoots and/or spatially-related secondary orebodies, considered by some authors as a second IOCG-like event [2, 10, 12]. The deposits show a wide range of host rocks but share several characteristics, like an intense Fe metassomatism associated with the occurrence of low sulphidation sulphides, LREE enrichment, high yet variable amounts of Co, Ni, Pb, Zn, As, Bi, W and U, spatial and chronological correlation to A-type granitic plutons / dykes, and breccia-like textures [1-2, 10]. Archean and Paleoproterozoic orebodies differ from each other, however, in their hydrothermal assemblage and ore minerals, reflecting variations in the fluids oxidation stage, pH, fO2 and fS2 [10, 12]. Older deposits are magnetite-rich and thought to be formed in deeper crustal levels, while the secondary younger orebodies are hematite-rich, silica-saturated, and developed in shallower environments [2]. In addition, Archean deposits were deformed and metamorphosed by the Transamazonian and Sereno events, while Paleoproterozoic deposits are post-tectonic, preserving their original textures and mineralogy [13]. The most significant uranium-bearing minerals are uraninite, thorianite and thorite [10]. Allanite and monazite concentrations may also be relevant, although uranium grades are much smaller. All phases occur as inclusions or within massive sulphide and Fe-oxides masses in the ore mineral assemblage. Additionally, uraninite and allanite are common accessory minerals in the potassic alteration assemblage, usually occurring as inclusions in biotite and garnet. Known uranium resources are of 150,000 tU [14], but that value is highly underestimated, as it considers only four out of a dozen known IOCG deposits (Salobo, Sossego-Sequeirinho, Cristalino and Igarapé Bahia-Alemão). Grades are low, ranging from 60 to 130 ppm U [14] Paleoproterozoic granite-related (and metasomatic?) uranium deposits remain undiscovered in the province, but the exploration potential for that mineral system is remarkable, especially where plutons and dykes are affected by late to post-magmatic structures and alteration. Uranium background values are very high in comparison to other A-type granites, varying from 10 to 43 ppm U, while Th/U ratio is between 1.11 and 4.71. The A-type granites are subalkaline to alkaline, developed through fractional crystallization and presenting variable sources derived from Archean crust [3-4]. Hydrothermalism and brittle deformation also affect the granites, along NE-SW and NW-SE structures. Greisen zones are common within the granitic bodies, sometimes related to tin mineralizations [4]. DISCUSSION: PROSPECTIVITY CRITERIA FOR URANIUM RESOURCES Some authors suggest that high uranium grades in IOCG systems are dependent on higher background values of host rocks, as observed in Australian IOCG-U provinces [15-16]. In the Carajás Province, however, uranium (and gold) grades are usually higher at Paleoproterozoic oreshoots and orebodies, especially those that are close or crosscut by coeval granites. This indicate that uranium (and gold?) endowment is at least in part linked to granite-related hydrothermal input. The uranium source, in this case, would be mostly magmatic rather than leached from host rocks. The energy drive for Paleoproterozoic fluid circulation is thought to be related to the granitic magmatism, but the critical control for both magmatic and hydrothermal activities seems to be structural. Granitic plutons and dykes were emplaced in sites where structures are denser and their geometry roughly follows previous structural patterns. Besides this, the structural framework of the host rocks, reactivated under brittle conditions during granitic intrusion, coincides with the main granite-related and IOCG-like alteration zones. Structures that acted as primary fluid pathways usually present breccia textures and silicification, showing a singular prominent topography that is recognizable even in SRTM (Shuttle Radar Topography Mission) images. Regional alteration assemblage that indicates proximity to mineralized sites includes quartz, chlorite, epidote, albite, carbonate, actinolite, scapolite, greenish biotite, sericite, tourmaline and stilplomelane. The main oxide is hematite, but occasionally magnetite is also found, while sulphides include chalcopirite, bornite and chalcocite. This mineral assemblage can pervasively replace the host rocks or occur in zoned sintaxial veins, usually forming stockworks. Airborne radiometric data are a powerful tool to regional targeting for IOCG and granite-related deposits. The uranium concentrations normalized using thorium (Ud) strongly correlate with the extensional structures. Field relations also confirm that Ud anomalies are coincident with regional undeformed Paleoproterozoic alteration zones. Ud maps also highlight several potential sites for uranium research inside the granitic plutons, especially along crosscutting structures of NE-SW and NW-SE directions. CONCLUSIONS The development of prospectivity models for the Carajás Mineral Province is challenging, as three different mineralization ages are recognized. Isolating objective prospectivity criteria for each metallogenic epoch and mineral system is critical to the development of more precise exploration guidelines in the region. The main regional prospectivity criteria to target uraniferous IOCG deposits in the Carajás Province are: • Coincidence between high Ud values and fault zones; • Proximity to deep structures; • Proximity to 1.88 Ga granitic plutons and dykes; • Occurrence of silicified fault zones; • Occurrence of crosscutting structures and higher structural density; • Occurrence of undeformed, post-tectonic, hematite-bearing hydrothermal assemblages. Prospectivity criteria for granite-related deposits are still being investigated, but the most favourable sites seem to be those pointed out by Ud anomalies and that are coincident with post-magmatic alteration sites. REFERENCES [1] TALLARICO, F.H.B., “O Cinturão Cupro-Aurífero de Carajás, Brasil”. Unpublished PhD thesis, Universidade Estadual de Campinas, São Paulo, Brazil (2003), 12 pp. [2] XAVIER, R.P. et al. “The iron oxide copper‒gold deposits of the Carajás Mineral Province, Brazil: an updated and critical review”. In: Porter TM (ed) Hydrothermal Iron Oxide Copper-Gold & Related Deposits: A Global Perspective. Australian Miner. Fund, Adelaide (2010), Vol 3, pp. 285-306. [3] DALL’AGNOL, R. et al. “Petrogenesis of the Paleoproterozoic, rapakivi, A-type granites of the Archean Carajás Metallogenic Province, Brazil”. Lithos 80 (2005) 101-129 [4] TEIXEIRA, N.P. et al. “Geoquímica dos granitos paleoproterozóicos da Suíte Granítica Velho Guilherme, província estanífera do sul do Pará”. Rev Bras Geoc 35 (2005) 217-226. [5] ARAUJO, O.J.B. et al. “A megaestruturação da folha Serra dos Carajás”. Anais do 7º Congresso Latino Americano de Geologia (1988) 324-333. [6] TAVARES, F.M. “EVOLUÇÃO GEOTECTÔNICA DO NORDESTE DA PROVÍNCIA CARAJÁS”. Unpublished PhD thesis, Universidade Federal do Rio de Janeiro, Rio de Janeiro (2015) 115p. [7] MACHADO, N. et al. “U–Pb geochronology of Archean magmatism and basement reactivation in the Carajás Area, Amazon Shield, Brazil”. Precambrian Research 49 (2991) 1-26. [8] GIBBS, A.K. et al. “Age and composition of the Grão Pará Group volcanics, Serra dos Carajás”. Rev Bras Geoc 16 (1986) 201-211. [9] DOCEGEO. “Revisão litoestratigráfica da Província Mineral de Carajás - Litoestratigrafia e principais depósitos minerais”. Anais do 34º Congresso Brasileiro de Geologia, Belém (1988) 11-54. [10] GRAINGER, C.J. et al. “Metallogenesis of the Carajás Mineral Province, Southern Amazon Craton, Brazil: Varying styles of Archean through Paleoproterozoic to Neoproterozoic base- and precious-metal mineralisation” Ore Geology Reviews 33 (2007) 451-489. [11] CORDANI, U.G. et al. “A Serra dos Carajás como região limítrofe entre províncias tectônicas”. Ciências da Terra 9 (1984) 6-11. [12] MORETO, C.P.N. “Neoarchean and Paleoproterozoic iron oxide-copper-gold events at the Sossego deposit, Carajás Province, Brazil, Re-Os and U-Pb geochronological evidence”. Economic Geology 110 (2015) 809-835. [13] TAVARES, F.M. et al. “O Cinturão Norte do Cobre da Província Mineral de Carajás: épocas metalogenéticas e controles críticos das mineralizações”. Anais do 15º Simpósio de Geologia da Amazônia, Belém (2017), CD-ROM. [14] HEIDER, M. “Urânio”. In. Anuário Mineral Brasileiro: principais substâncias metálicas. Departamento Nacional de Produção Mineral, Brasília (2016) 70-92. [15] HITZMAN, M.W., VALENTA, R.K. “Uranium in iron oxide-coppergold (IOCG) systems”. Economic Geology 100 (2005) 1657-1661. [16] SKIRROW, R.G. “Controls on uranium in iron oxide copper-gold systems: insights from Proterozoic and Paleozoic deposits in southern Australia” 11th SGA Biennial Meeting abstracts, Antofagasta, Chile (2011) 482-484.
Speaker: Mr Felipe Tavares (Geological Survey of Brazil - CPRM)
• 15
Uranium Extraction Technology in the Philippines: The Next Step
The phosphate fertilizer industry is one of the key player in sustaining and the continuing development of the vastly agricultural Philippine economy. Since 2002, phosphate-based fertilizers have become one of the most important and consumed fertilizer next to nitrogen-based fertilizers [1]. About 60% of produced and imported fertilizers are consumed by major and staple food crops such as rice (38%) and corn (21%), fruits and vegetables (19%), sugar accounts (7%) and other crops (15%) (Mojica-Sevilla, cited in [1]). Currently, domestic fertilizer production is being sourced from five fertilizer companies. The Philippine Phosphate Fertilizer Corporation (PHILPHOS), located at the Leyte Industrial Development Estate, Isabel, Leyte, is the biggest and the leading fertilizer production company in the country, which has been in operation for the past 28 years. Phosphate rocks are potential sources of uranium (66 – 145 ppm), thorium (1 – 20 ppm), rare earth elements (108 - 1,085 ppm), and almost all elements in the periodic table [2]. Annually, more than 1.97M Mt of imported phosphate rocks are being used as raw materials and are being processed producing 1.17M Mt of diammonium phosphate (DAP) fertilizers at PHILPHOS. During the digestion of phosphate rocks with sulfuric acid, most of the uranium and other trace elements are being transferred into the phosphoric acid and ultimately producing uranium contaminated fertilizers. Around 44.97 Mt of uranium per year are lost into agricultural fields upon fertilizer application putting human and environmental safety at high risk [3]. The Philippine Nuclear Research Institute (PNRI) has pioneered the Uranium Extraction from Wet Phosphoric Acid (UxP) Technology in the country to recover uranium and critical elements from phosphate processing, thus, translating these problems into opportunities. URANIUM RECOVERY BY DEHPA-TOPO METHOD In 1987, the PNRI initiated the uranium recovery from phosphoric acid utilizing the liquid-liquid extraction method using the synergistic mixture of di-2-ethylhexyl phosphoric acid and trioctyl phosphine oxide (D2EHPA - TOPO). Although this method is already established and widely used, it has to be optimized to suit the Philippine phosphoric acid, which is a mixture of different phosphate rocks imported from several countries such as Israel, Egypt, Morocco, Jordan, etc. The team conducted only up to the first cycle solvent extraction and first cycle acid stripping, which had recovery ranging from 64% to 75% [4]. However, this initiative was discontinued due to downtrend of nuclear energy and there was a slump in the global price of uranium. Sometime in 2011, there was renewed interest to continue the UxP Project through the IAEA Technical Cooperation Project PHI/2/010 entitled “Enhancing National Capacity for Extraction of Uranium and other Valuable Elements from Phosphoric Acid”. The project was locally funded by the National Research Council of the Philippines (NRCP) through the project entitled “Comprehensive Extraction Of Uranium, REE and Other Valuable Resources From Wet Phosphoric Acid”. This time around, the PNRI has successfully developed and built its capacity to conduct static laboratory-scale extraction of uranium through trainings, fellowships and expert missions and the upgrade in laboratory infrastructure, which included the procurement of Wavelength Dispersive X-Ray Fluorescence Spectrometer (WDXRF), Fluorometer and portable gamma-ray spectrometer. The process parameters on uranium recovery by D2EHPA-TOPO method from pretreatment of raw phosphoric acid (absorbent materials, optical density, mixing time, and mixing intensity), to extraction (optical density, Organic/Aqueous ratio, P2O5 concentration, and contact time), to stripping (Aqueous/Organic ratio, amount of Fe, temperature) and to precipitation of uranium yellowcake were optimized during the three-year implementation of the project. The project ended on 2017 and demonstrated a feasible UxP technology in a laboratory-scale setup. THE NEXT STEP The UxP research and development undertakings, which started from basic research, will enhance indigenous capabilities and competence to execute the goal of building the first industrial scale UxP facility in the country. As a next step in this endeavor, a newly approved IAEA TC Project PHI/2/013 entitled “Enhancing Bench-scale Simulation for the Development of Continuous Extraction Technology of Uranium and Other Valuable Elements from Phosphates - Phase II” will be implemented for three years, 2018 – 2020, in cooperation with PHILPHOS. The project will develop the comprehensive and environmentally acceptable continuous uranium extraction process, which specifically aims to: (1) perform a scaled-up test, from static laboratory-scale into continuous recovery, for the extraction of uranium; (2) provide engineering design parameters for pilot-plant or commercial scale operations; and (3) determine waste minimization technologies. A bench-scale continuous laboratory-scale extraction system will be installed to validate the results from Phase I project and to obtain a more reliable and realistic process parameters that would better simulate conditions in an industrial/commercial setup. Financial assistance from local funding institution, Philippine Council for Industry Energy and Emerging Technology Research and Development (PCIEERD), through the project “Laboratory/micro-scale Continuous Extraction System for the Recovery of Uranium from Philippine Wet Phosphoric Acid: Phase I” is already in the pipeline. This will sustain other requirements of the project. With the deep dedication of the PNRI Team to develop a comprehensive extraction technology from phosphate resources, a Phosphogypsum Research entitled “Extraction of Radionuclides, Rare Earths and Other Valuable Industrial Elements from Philippine Phosphogypsum Tailings: Phase I” is conceived as a spin off project. The long-term goal of the project is to demonstrate and execute a technology of the recovery of radionuclides, rare earths and other valuable industrial elements in phosphogypsum resources from phosphate fertilizer plants. This project is also in the pipeline and will be financially supported by PCIEERD, as well. The growing capacity in this area in PNRI will have long-term impact in terms of a more sustainable and environmentally friendly methods of mining and extraction in the country. Uranium recovery from phosphates is a prime example of this safe and balanced sustainable management and use of natural resources promoting sustainable socio-economic and environmental development to address the country’s needs in regard to food, energy and water security. This will lead to (1) minimal environmental impacts and protection of human health by producing cleaner fertilizers with greatly reduced uranium content; (2) zero waste and maximized resource utilization; (3) additional revenue in the phosphate processing industry; and (4) an opportunity to utilize uranium in the nuclear fuel cycle if the Philippines decides on the nuclear option. REFERENCES [1] BRIONES, R.M., The Role of Mineral Fertilizers in Transforming Philippine Agriculture, Discussion Paper Series 2014-14, Philippine Institute for Development Studies, (2014), https://dirp4.pids.gov.ph/webportal/CDN/PUBLICATIONS/pidsdps1414.pdf [2] PALATTAO, B.L, RAMIREZ, J.D., TABORA, E.U., MARCELO, E.A., VARGAS, E.P., DIWA, R.R. AND REYES, R.Y. Recovery of Uranium from Philippine Wet Phosphoric Acid Using D2EHPA-TOPO Solvent Extraction, Philippine Journal of Science, 147 (2) (2018) 275-284. [3] HANEKLAUS, N., REYES, R. Y., LIM, W. G., TABORA, E. U., PALATTAO, B. L., PETRACHE, C., VARGAS, E. P., KUNITOMI, K., OHASHI, H., SAKABA, N., SATO, H., GOTO, M., YAN, X., NISHIHARA, T., TULSIDAS, H., REITSMA, F., TARJAN, S., SATHRUGNAN, K., JACIMOVIC, R., AL KHALEDI, N., BIRKY, B. K., AND SCHNUG, E., Energy neutral phosphate fertilizer production using High Temperature Reactors - a Philippine case study. Philippine Journal of Science, 44(1) (2015) 69-79. [4] PETRACHE C.A., MARCELO E.A., SANTOS JR G., Notes on the Extraction of Uranium from Phosphoric Acid. Philippine Technology Journal 12 (4) (1987) 95-99.
Speaker: Ms Jennyvi Ramirez (Philippine Nuclear Research Institute)
• 3:40 PM
Break
• Applied Geology and Geometallurgy of Uranium and Associated Metals
Conveners: Dr Susan Hall (U.S. Geological Survey) , Dr Ziying Li (Beijing Research Institute of Uranium geology)
• 16
The ultimate origin of uranium provinces
Speaker: Dr Michel CUNEY (CNRS - GeoRessources - CREGU - Universite de Lorraine)
• 17
Uranium Provinces of the World
INTRODUCTION Uranium deposits in continental blocks of the Earth are distributed rather randomly and form uranium provinces and districts. Under the uranium ore province we mean crust block characterized by occurrence of uranium deposits of a certain type (or types), main features of which are resulted from specific ore-forming processes and peculiar geotectonic position. When systematizing uranium targets, great importance was attached to the ore-hosting environment and geotectonic conditions of ore formation at early stages of the crust evolution, and for particular areas, their relation to main typomorphic structures (arcogenic, taphrogenic, orogenic, epeirogenic) and derivatives of their activation of different age was considered to be the controlling factor. The analysis of extensive material is aimed at the identification of new patterns and prognostic criteria of commercial uranium mineralization location in various regions of the world. METHODOLOGY AND RESULTS The research is based on the historical-geological approach, which made it possible to systematize data on uranium geology, geochemistry, geophysics and metallogeny in various countries and continents and develop a unified research base. Most of known uranium and complex ore deposits and numerous (95) ore areas in the rank of provinces and regions on five continents were analyzed [1, 2, 3, 4]. Results of original paleotectonic and palinspastic reconstructions were used for analyzing uraniferous areas. It is shown that geological structures of arcogenic (dome) and taphrogenic (rift) origin played a leading role in the uranium metallogeny since the Early Precambrian. Two global generations of gigantic ore-bearing dome structures of different age have been identified: the Archean (3.2 to 2.5 Ma) generation of domes – nuclears and the Paleoproterozoic (2.5 to 1.6 Ma) generation of granite-gneiss domes. The identified generations of dome structures differ in internal structure and metallogeny mainly due to the structure and evolution of the granitized substrate. The metallogenic uranium zoning of the continents made it possible to identify transcontinental marginal and intracontinental ore-bearing megabelts and giant ore clusters in areas of megabelts’ telescoping [1]. Totally, 12 megabelts have been identified on the continents, including marginal continental: 1 – East Pacific with Cordilleran and Andean fragments, II – West Pacific; and inland: III – East African, IV – Damara-Katanga, V – Karpinsky, VI – Baltic-Carpathian, VII – West Siberian-Central Asian, VIII – East Siberian-Gobi, IX – Chara-Aldan, X – Central Australian, XI –Wollaston, XII – Grenvillian. In areas of megabelts’ telescoping (Middle European, Middle Asian, Mongolian-Transbaikalian), uranium resources reach 500,000-1,500,000 tons, but similar amounts are sometimes also typical of some provinces inside the megabelts (Athabasca, Colorado-Wyoming, Arnhemland, Olympic Dam). Two large groups, distinguished based on the degree of lithification of uranium-bearing rock complexes corresponding to main geological structures and genetic classes of uranium deposits are high-order elements in typification of uranium areas. The first group consists of ore provinces and regions with ore deposits in lithified rock complexes in the basement of old and young platforms, median massifs, fold areas, old epicraton depressions and in areas of continental volcanism and granitoid magmatism (endogenic and polygenic classes of deposits). Among them, ore provinces are distinguished in typomorphic proto-structures of nuclears and structures of activation of different age. Commercial uranium concentrations in the nuclears appear at the final orogenic stage of their formation and are often clastogenic formations resulted from the accumulation in placers of accessory uranium-bearing minerals from Late Archean potassium granite and pegmatite. Such metamorphosed placers in quartz-pebble conglomerate are typical of proto-orogenic depressions, occurring as spots along the periphery of the nuclears of mainly antiform (uninverted) type: Superior, East Brazilian, South African and other megaprovinces. With some epochs of activation of nuclears of different age, a number of provinces and regions with deposits of various types are associated: carbonatite (U-TR) in alkaline ring tubes of different ages (Ilimaussaq, Palabora, Khibiny, etc.); black shale type in superimposed foreland basins (South China, Carpathian and other provinces); leucogranite type in fault zones among the Mesozoic highly radioactive rocks in association with rare metal mineralization (Gan-Hang, Kerulen-Argun ore belts) [1, 2, 3]. Uranium mineralization accompanies all stages of the formation and transformation of dome structures of second generation (dome rise stages). The formation of typomorphic structures of domes of this generation started at the stage of compensatory destruction, subsidence, and collapse of the roof. Provinces in the fault-contact metasomatite (alaskite) (Rossing), albitite (Kirovograd) and glimmerite (Padma) types are associated with similar structures. Ore provinces in protostructures of Riphean granite-gneiss domes near zones of structural-stratigraphic unconformities at the base of epicratonic basins belong to polygenic ones (Canadian and Australian subtypes). In the Riphean-Phanerozoic, in some provinces (Franceville, Czech, Katanga), epigenetic regeneration of ore deposits occurred near the unconformity surfaces with a change in their morphology and scale of mineralization [4]. The second group includes ore provinces and areas with deposits in weakly lithified or unlithified rock complexes, in sedimentary basins of covers and young platforms (exogenous class of deposits). This group includes provinces with syngenetic concentrations of uranium of sorption nature (surficial, with carbonized residues, phosphate, black shale types) and provinces with epigenetic sandstone-type hydrogenous deposits represented by stratal, roll and paleovalley types. Ore provinces were formed in sedimentary basins in central (destroyed) parts of dome structures and in the inter-dome space within riftogenic structures. Syngenetic-type provinces are characterized by constant relationship between uranium and phosphorous and carbonaceous matter (Phosphoria, Chattanooga and other provinces) [3, 4]. For most of the epigenetic provinces with hydrogenous deposits in suborogenic depressions and platform covers, overlapping old dome structures, the role of linear, linear-arc faults in sedimentary basin deposits (cis-Tian Shan Province, Colorado Plateau, etc.) is emphasized. Faults play an important role in the localization of hydrogenous uranium mineralization near or in flanks of petroliferous areas, which are sources of gas-liquid reducing agents (South Texas, Central Kyzyl-Kum province) [1, 4]. The identified patterns and spatial position of ore districts and provinces allow drawing several conclusions concerning predicting the ore grade within their limits. The relation of uranium ore districts to similar geological structures does not always means a similar level of possible ore grade. The authors have established that the parameter called the “maturity” of the crust can serve as a regional criterion for predicting rich endogenous ores. The level of “maturity” clearly correlates with the level of medium uranium concentrations in granitoid formations of dome structures. Besides, there are ore formation types of uranium mineralization, which differ significantly in the ore grade. So, there is a group of ore formations characterized by low-grade ores but with huge reserves: Lower Proterozoic quartz-pebble conglomerate (Witwatersrand, South Africa), uranium-bearing black shale (southwestern Sweden), phosphorite (Morocco), pegmatite (Charlebois, Canada), nepheline syenite (Ilimaussaq, Greenland), anatectoid alaskite granite (Rossing, Namibia), carbonatite (Palabora, South Africa), calcrete (Yeelirrie, Western Australia), uranium-coal deposits (Nizhneiliyskoe, Kazakhstan). However, the formation type of mineralization also does not guarantee that the ore grade will be similar. Features of ore-hosting rocks do not always affect significantly the degree of concentration of uranium mineralization. The role of lithological factors as well as structural factors in the localization of rich mineralization cannot be considered separately from the nature of metasomatic transformations. Extensive areas of pre-ore metasomatism testifies to relative openness of hydrodynamic systems and is evidence of the dilution of ore-forming solutions. Closed hydrodynamic systems that ensure the presence of high metal concentrations in the solution and local, contrast zones of wall-rock alterations are more favorable for the formation of rich ores. Probably, the alkaline solution containing H2, H2S, S-2, CH4, hydrocarbons, Fe+2, and other reducing agents is initially most suitable for the formation of a large volume of rich ores. Highly concentrated brine of salt complexes is one of the sources of heated subalkaline waters. The ore grade of hydrogen deposits is also controlled by several ways of ore deposition. If the reduction barrier contains only syngenetic reducing agents (primary grey color), the ores are usually poor and lean. The epigenetic preparation of the barrier to ore deposition can be a result of the action of ascending reducing thermal waters and lateral migration of hydrocarbons from neighboring oil and gas basins. CONCLUSIONS When analyzing the huge factual material, a number of important planetary factors of uranium geology and metallogeny were discovered: linear-geoblock divisibility of the continental crust as the basis of metallogenic zoning on global and regional scales; factor of irreversible geological time in ore genesis; factor of tectonophysical correspondence of global and local geotectonic settings in the forecast of giant deposits; important conditions for the formation of rich ores are shown. Many of the discussed problems are beyond the scope uranium metallogeny and allow the discussion of a number of basic factors of the metallogenic school as a whole from a new viewpoint. REFERENCES [1] Afanasiev G.V., Mironov Yu.B. Uranium in Crust Dome Structures. Experience of paleoreconstructions in metallogeny. – St. Petersburg: VSEGEI Publishing House, 2010. 360 p. [2] Uranium Deposits in Russia/ Edited by G.A. Mashkovtsev. – Moscow, 2010. 850 p. [3] Dahlkamp F.J. Uranium Deposits of the World – Asia. – Berlin-Heidelberg: Springer Verlag, 2009. 508 p. [4] Dahlkamp F.J. Uranium Deposits of the World – USA and Latin America – Berlin-Heidelberg: Springer Verlag, 2010. 518 p.
Speaker: Ms Elena Afanasyeva (Leading Researcher)
• 18
Sr-Nd-Pb isotope systematics of U-bearing albitites of the Central Ukrainian Uranium Province: implication for the source of metasomatizing fluids
INTRODUCTION Sodium metasomatites are relatively widely distributed in the world and often contain uranium mineralization that occasionally may reach industrial scale [4]. Uranium concentrations in deposits of this type are rather low but resources can be quite large especially in the areas where sodium metasomatites achieve wide distribution. As was pointed out by [4], deposits of this type are significantly underexplored and may represent a promising target for further exploration. This is especially true as sodium metasomatites often contain complex mineralization that, besides U, includes Th, Sc, V, Nb, HREE, and Ag. The Central Ukrainian Uranium Province (CUUP) hosts several large deposits and numerous subeconomic deposits and occurrences. The production started in 1951 and since that time two deposits were completely exhausted. The remaining U resources of the CUUP exceed 300 000 t U with grade varying between 0.05 to 0.20 wt. % U [4]. In spite of the long history of exploration and exploitation of Na-metasomatite type of U deposits in Ukraine, many questions regarding their origin still remain unanswered. The main questions that were debated during decades are related to the source of the metasomatic fluids and the source of ore components. A lot of studies were focused on the geological structure of U deposits in the CUUP, on their mineralogical and chemical compositions, and on stable isotope systematics. Results of these studies were summarized in [1, 4, 13]. However, high-quality geochemical data regarding these deposits were absent until recently [4, 5], whereas radiogenic isotope data is still absent that hampers a reasonable discussion about origin and evolution of the Na metasomatites and about the source of ore components. The present ideas regarding the origin of metasomatic fluids and their ore load are controversial. The main problems are: (1) a source of huge volumes of high-temperature hydrothermal solutions (with meteoritic waters, basin waters and magmatic fluids being the main alternatives; complex sources evolving in time were also invoked [4]); (2) a source of U and Na, as large volumes of these elements cannot be derived from low-crustal and mantle lithologies, and middle- to upper-crustal sources were considered. However, simple calculations indicate that hydrothermal leaching of the host upper-crustal rocks cannot produce such enrichment as these rocks are relatively poor in both U and Na, and huge volumes of leached rocks are unknown in the area; (3) the association of elements typical for this type of deposits includes elements that are more typical for mafic alkaline igneous complexes rather than for felsic crustal rocks. In our contribution, we present new Sr-Nd-Pb isotope data obtained for Na-metasomatites of the CUUP and for a large variety of host rocks and discuss possible contribution of different sources to the origin of this type of U deposits. GEOLOGICAL SETTING The CUUP is located in the central part of the Ukrainian Shield, within the predominantly Palaeoproterozoic Inhul mobile belt, and partly within the Mesoarchaean Middle Dnieper domain. Most of the deposits and occurrences are located near the southern contact of the Korsun-Novomyrhorod anorthosite-mangerite-charnockite-granite (AMCG) complex (1757-1744 Ma, [7]) where they are hosted by the Novoukrainka gabbro-monzonite-granite massif (2038-2028 Ma, [3, 10]) and granites and migmatites of the Inhul Complex (2022-2062 Ma, [8, 11, 12]). Several deposits are located within in the Kryvyi Rih synform structure which is filled mainly with siliciclastic sediments and banded iron formation. The age of this structure remains poorly constrained and commonly regarded as Palaeoproterozoic to Neoarchaean. Na-metasomatites being confined to the major fault zones closely associate with numerous mafic dykes widely distributed in the same area. Some of the mafic dykes are older than metasomatites and can be affected by sodium metasomatism whereas other dykes clearly cut metasomatic bodies. Available geochronological data [6] indicate the formation of the mafic dykes at ca. 1800 Ma. Depending on the lithology of the host rocks, Na-metasomatites are represented by two main mineralogical types. The first type develops after felsic igneous rocks and represented by albitite. The second type includes aegerine-riebeckite metasomatites that develop after iron-rich rocks of the banded iron formation. In all cases, metasomatic bodies are confined to the major fault zones and occur as irregular elongated zoned bodies that were traced along strike for several km whereas the widths of metasomatic bodies may reach several hundred meters and over. The largest bodies were traced by drillings down to 1200 meters and over. In the further description, we shall focus on the first type of the Na-metasomatites, i.e. on U-bearing albitites. In a generalized form, zoning in these rocks can be described as a gradual transition from unaltered host rock (granite, migmatites, gneiss etc.) to quartz-free (desilicified) microcline-albite metasomatite (“syenite”) and then to albitite. This rock succession formed during the progressive (albititic) stage of the alkaline sodic metasomatic process. The late mineral assemblage that includes phlogopite (or late chlorite), carbonate and hematite are often superimposed on the internal parts of albitites. Besides this, secondary quartz, epidote, and microcline are often superimposed on intermediate and external parts of the metasomatic bodies. These minerals are regarded as developed during removal of silica, calcium, and potassium from central (albititic) parts of metasomatic bodies [1, 4, 13]. MINERAL COMPOSITION Albite occurs as the main (up to 90 %) rock-forming mineral, whereas the amount of mafic minerals usually does not exceed 10 %. The typical mafic minerals are alkaline amphibole, alkaline pyroxene, epidote, chlorite, diopside, actinolite, and garnet. The proportion of albite and mafic minerals is generally defined by the composition of the initial rock. The amount of pyroxene varies from almost 0 to 10 %. Pyroxenes belong to aegirine (amount of the Ca component varies from 0 to 45 mol. %) and diopside-sahlite (amount of the Na component varies from 0 to 20 mol. %). Pyroxenes that contain over 10 % Sc2O3 occur as well-defined inclusions within the aegirine-pyroxene matrix. Amphibole usually associates with pyroxene and varies in composition from riebeckite to slightly alkaline actinolite. Garnets belong to the andradite-grossular series and occur mainly in deposits located in the Novoukrainka granite massif where the amount of garnet may reach 50 %. Garnets occur in association with diopside, actinolite, and epidote; sometimes it may be found in association with aegirine. Epidote is a rock-forming mineral in so-called “syenites” and certain types of albitites. It often replaces garnet in the garnet-diopside metasomatites. Epidote in albitites of the Partizanske ore field contains a large amount of Sr. Accessory minerals in albitites are apatite, zircon, titanite, monazite, uranothorite, allanite, which present in all types of U-bearing sodic metasomatites. Phenakite, thortveitite, and schorlomite are rare minerals. The origin of accessory minerals is not clear as they may represent relict phases left from the initial (pre-metasomatic) rocks. Albitites contain also various opaque minerals, including hematite, magnetite, titanomagnetite, rutile, ilmenite, galena, pyrite, chalcopyrite, sphalerite etc. Native silver in concentration reaching up to 1 % in Na-metasomatites of the Kryvyi Rih – Kremenchuk zone was known for a long time. In the northern part of the Vatutinske deposit concentration of silver reaches 300 ppm. The accompanying minerals are galena, pyrite, marcasite, chalcopyrite, sphalerite, minerals of U, Ti, and Ba. Main U minerals are uraninite (U4+, U6+ Pb, Ca, RЕЕ, Zr)O2-x and brannerite (U4+, Ca, Th, Y)[(Ti, Fe)2O6]·nH2O. Uraninite is unevenly distributed and absent in some deposits. Electron microprobe analyses have revealed the presence of up to 20.51 % PbO, 6.20 % СаО, 0.78 % Y2O3, 3.90 % Ce2O3, and 1.72 % ZrO2. Brannerite occurs as the main ore mineral in many of the deposits of the CUUP. It often develops after Ti and Ti-bearing minerals; there is a persistent association of brannerite with rutile, anatase, carbonate minerals, quartz, and sericite. GEOCHEMISTRY Our data demonstrate regular variations of the chemical composition in the vertical profile across the albitite bodies. Being compared to the host granite, albitites demonstrate a sharp decrease in the abundances of SiO2 and K2O. Al2O3 slightly increases near contacts against host granites and then decreases in the central part of the metasomatic body. Most other major oxides show significant enrichment in albitites. Fe2O3, CaO, TiO2, and MgO demonstrate pronounced enrichment in the U-rich central (axial) parts of the albitite body. Na2O is sharply increased in metasomatites, but demonstrate a moderate decrease in the axial part of the body. According to [4], distribution of REE in barren albitites is very close to that in the host granite. In general, barren albitites are slightly enriched with respect to LREE, and depleted in HREE, being compared to the host granite, but these differences are not significant. Our new data indicate that albitite samples rich in U are highly enriched in HREE. We suppose that metasomatic fluids responsible for U enrichment were also rich in HREE. This feature is not typical for felsic rocks that may be considered as the main source of U (and Na). SR-ND-PB ISOTOPE SYSTEMATICS A set of whole-rock samples was collected at the Novokostyantynivka and Novooleksiivka deposits. These rocks were analyzed for Sr, Nd, and Pb isotopes. As can be seen from Sr isotope data, metasomatic rocks have isotope signature typical for the crustal rocks. Specifically, rocks of the Novokostyantynivka deposit have 87Sr/86Sr(1800) in the range 0.7087 to 0.7105, whereas in the rocks of the Novooleksiivka deposit 87Sr/86Sr(1800) varies from 0.7172 to 0.7207. There is no strict correlation between 87Rb/86Sr and 87Sr/86Sr ratios that makes impossible the construction of isochrons and production of reasonable Rb-Sr isotope ages. This indicates inhomogeneity of the Sr isotope composition that could result from the variable host rock/metasomatic rock ratio in our samples. In the Novooleksiivka deposits samples were collected systematically across the vertical section of the metasomatic body. As follows from our results, there is a tendency for albitite samples in the axial part of the body to have less evolved initial Sr isotope composition. This tendency may indicate that the metasomatic fluids were derived from a source that had a lower Rb/Sr ratio than the upper crustal granites. However, this question requires further confirmation on other deposits. Neodymium isotope composition, in contrast to Sr, is much more consistent in both studied deposits and allows construction of a rather good isochron. The age yielded by the isochron (1728 ± 110 Ma) corresponds within error to the U-Pb age previously obtained for the U deposits of the CUUP. εNd value according to the isochron is -4.8 and indicates the crustal source of albitites, in accordance with Sr isotope data. There is, however, a small systematic difference between the Novokostyantynivka and the Novooleksiivka deposits: the average εNd(1800) value for the Novokostyantynivka albitites is -3.7, and for the Novooleksiivka albitites is -4.5. These results are consistent with Sr isotope data, according to which the Novooleksiivka deposit reveal more “evolved” crustal source. Lead isotope compositions indicate the great prevalence of radiogenic Pb, whereas “common” Pb is virtually absent. This allows calculation of the Pb-Pb age of the deposits formation. There is no sufficient difference in the age of the Novokostyantynivka and Novooleksiivka deposits, both deposits were formed at 1810 ± 17 Ma. This age is in good agreement with the previously obtained U-Pb ages and with Sm-Nd isochron age (sees above). The obtained isotope results can be compared with data available for the main lithologies present in the area. Albitites of the Novokostyantynivka deposit plot between fields of the Novoukrainka massif and Korsun-Novomyrhorod AMCG Complex, closer to the Novoukrainka field. In contrast, albitites of the Novooleksiivka deposit plot entirely within the field defined by the Inhul granitoid Complex. It has Nd isotope characteristics similar to the Novoukrainka massif but differs by their much higher Sr isotope values. DISCUSSION AND CONCLUSIONS Many features of the U-bearing Na-metasomatites of the Central Ukrainian Uranium Province have received a due attention of the researchers. These features include the geological structure of the deposits, their mineral composition and some aspects of the isotope geochemistry (O, C, and H isotopes, see [4] for an overview). However, some features, very important for the understanding of the origin of Na-metasomatites and related mineralization still remain underexplored. For instance, high-quality geochemical data regarding metasomatic rocks are still very limited in number. This is especially true with respect to U ores geochemistry of which is still poorly studied. The same can be said about isotope geochemistry of Sr, Nd, and Pb. In the author`s opinion, following features are very important for the understanding of the origin of Na-metasomatites and related mineralization: (1) close spatial relation of the Na-metasomatites with the Korsun-Novomyrhorod AMCG plutonic complex. Most of the deposits and occurrences are located within 30 km away from the contact of the complex. In addition, Na-metasomatites closely associate with numerous mafic and ultramafic dykes of tholeiitic affinity; (2) close temporal relationships with mafic dykes which according to the available geochronological and geological data intruded simultaneously with the formation of Na-metasomatites at c. 1815-1800 Ma. The Korsun-Novomyrhorod AMCG Complex is 50-60 M.y. younger, but its formation may have started at c. 1800 Ma, as evident from findings of older xenolith of anorthositic rocks; (3) “Mixed” geochemical characteristics of the Na-metasomatites: these rocks are rich in Na, U, Th, Sc, V, Nb, HREE, and Ag. This combination of elements is not typical for felsic rocks and can be rather related to mafic alkaline sources; (4) newly obtained Sr and Nd isotope data indicate crustal sources of the main volume of Na-metasomatites. Formation of the mafic dykes and Korsun-Novomyrhorod AMCG Complex was linked to a long-lived mantle plume [6, 7], although relation of the mafic magmatism to the rotation-caused crustal extension and mantle melting was also proposed [2, 9]. In any case, emplacement of numerous mafic dykes and formation of the huge Korsun-Novomyrhorod AMCG Complex implies the presence of the large-scale thermal anomaly in the mantle and low crust. Metasomatizing fluids were probably generated in the upper mantle and on the way through the crust they have achieved crustal isotope signature. However, their useful load was probably derived from the mantle as crustal felsic rocks can hardly be considered as a source of such elements as Sc, V, Nb, HREE. We assume that metasomatizing fluids may be related to mafic alkaline melts which were responsible for the formation of various alkaline (syenites, aegerine-riebeckite syenites) and subalkaline (monzonites) rocks that are present in the Korsun-Novomyrhorod plutonic complex. It is interesting that available isotope geochemical data indicate the significant dependence of the isotope composition of the Na-metasomatites on low-crustal (?) rocks. Both studied deposits occur within the Novoukrainka gabbro-monzonite-granite massif and there is no reason to assume that host rocks for these two deposits are very different in terms of their isotope composition. However, one of the deposits (Novokostyantynivka deposit) has Sr-Nd isotope composition more typical for the Novoukrainka rocks, whereas another deposit (Novooleksiivka deposit) reveals Sr-Nd isotope composition more typical for the Inhul granites. Some differences in their mineralogy and geochemistry may also occur, but this question requires further detailed investigation. According to our model, metasomatizing fluids were derived from the hot upper mantle melts from which they have inherited their useful load. On the way through the low crust they achieved their crustal isotope signature which apparently was not significantly modified during the interaction with the upper-crustal rocks. 1. BELEVTSEV, Ya., et al., Genetic types and regularities of the location of uranium deposits in Ukraine, Naukova Dumka, Kyiv (1995) (In Russian). 2. BOGDANOVA, S., et al. Late Palaeoproterozoic mafic dyking in the Ukrainian Shield (Volgo-Sarmatia) caused by rotations during the assembly of supercontinent Columbia, Lithos, 174 (2013), 196–216. 3. CUNEY, M., et al. Petrological and geochronological peculiarities of the Novoukrainka massif rocks and age problem of uranium mineralization of the Kirovograd megablock of the Ukrainian shield, Mineral. J. (Ukraine), 30(2) (2008) 5-16. 4. CUNEY, M., et al., Uranium deposits associated with Na-metasomatism from central Ukraine: a review of some of the major deposits and genetic constraints, Ore Geol. Rev. 44 (2012) 82–106. 5. MYKHALCHENKO, I., et al. A. Rare earth elements in Th-U-bearing albitites of the Novooleksiivka occurrence, the Ukrainian shield, Kryvyi Rih University (2016), pp. 34-39. 6. SHUMLYANSKYY, L., et al. The ca. 1.8 Ga mantle plume related magmatism of the central part of the Ukrainian shield, GFF, 138 (2016), 86-101. 7. SHUMLYANSKYY, L., et al. The origin of the Palaeoproterozoic AMCG complexes in the Ukrainian Shield: new U-Pb ages and Hf isotopes in zircon, Precam. Res. 292 (2017) 216-239. 8. SHUMLYANSKYY, L., et al. The Palaeoproterozoic granitoid magmatism of the Inhul region of the Ukrainian Shield, Geol.-mineral. Proceed. Kryvyi Rih Nation. Uni., 33(1) (2015), 80-87. (In Ukrainian). 9. SHUMLYANSKYY, L., et al. U-Pb age and Hf isotope compositions of zircons from the north-western region of the Ukrainian shield: mantle melting in response to post-collision extension, Terra Nova, 24 (2012), 373-379. 10. STEPANYUK, L., et al. Age of the Novoukrainka massif, Mineral. J. (Ukraine), 27(1) (2005) 44-50. (In Ukrainian). 11. STEPANYUK, L., et al. Geochronology of granitoids of the eastern part of the Inhul region (the Ukrainian Shield), Geochemistry Ore Formation, 38 (2017), 3-13. 12. STEPANYUK, L., et al. U-Pb geochronology of the rocks of the K-U formation of the Inhul region of the Ukrainian Shield, Mineral. J. (Ukraine), 34(3) (2012) 55-63. (In Ukrainian). 13. VERKHOVTSEV, V., et al., Prospects for the development of uranium resource base of nuclear power of Ukraine, Naukova Dumka, Kyiv (2014) (In Russian).
Speaker: Dr Leonid Shumlyanskyy (M.P. Semenenko Institute of geochemistry, mineralogy and ore formation)
• 19
DEVELOPMENT OF HANDHELD X-RAY FLUORESCENCE (hXRF) SPECTROMETRY FOR MAJOR AND MINOR ELEMENTS ANALYSIS IN GEOLOGICAL SAMPLES FROM PHUKET PROVINCE, THAILAND
INTRODUCTION Soils and rocks have a complex matrix composition and their contained-element chemical analysis is interested in geochemical and environmental studies. A well-established and commonly technique to obtain chemical composition in geological sample is X-ray fluorescence (XRF) spectroscopy [1]. The XRF technique has been used to eliminate matrix effects and sample heterogeneity but analytical precision and the ultimate accuracy of the results depend on several factors. These factors includes instrumental setting and stability, the calibration procedure, mineralogical and matrix effects, the reference materials used to calibrate the instrument, sample preparation and the strategy adopted to maintain the results within accepted limits [2]. For providing the higher quality data possible, the measurements can be costly, require intensive sample preparation and analysis time [1]. Field handheld instruments can be a new application for in and out of standard laboratory setting [1]. The hXRF has precisions comparable to benchtop models. Moreover, it allows for direct substrate measurements without the need to collect samples or the use of special containers for the analyses. The hXRF is less expensive than benchtop model [3,4]. In recent years, the hXRF has been used to analyze major and minor elements in different materials (rocks, soil, sediment, wood and archeological [5]. However, the hXRF analysis has some limitations in the efficient application which constrain its reliable uses for optimal element analysis of different types of materials. The hXRF limitations are: (1) calibration of a small number of element analyses; (2) measurement based on the instrument’s internal calibration; (3) a priori measuring-time determination based on the relative deviation as a determinant factor and (4) absence of criteria to establish the minimum amount of sample that can be measured and its container material [3]. In this study, handheld XRF (hXRF) was developed to determine major and minor elements in soil and rock samples at the different horizontal soil profiles. Effect of film type on chemical compositions of samples was investigated. The accuracy of the methods was done by using geological reference materials. MATERIALS AND METHODS **Sample preparation** Ten samples were taken per horizon which varied in thickness according to the profile characteristics, O horizon (0-0.1 m), A horizon (0.1-0.3 m), B1 horizon (0.3-1.0 m), B2 horizon (1.0-2.0 m), C1 (2.0-3.0), C2A (3.0-5.0), C2B (5.0-8.0), C3 (8.0-12.0), D (12.0-20.0) and RK (> 20.0 m).The sample location was Tambon Chalong, Amphoe Meuang, Phuket province, Thailand (Latitude 7°51'24.22"N, longitude 98°19'19.49"E). Each sample was manually homogenized and passed through a 250 µm sieve. The sample was dried to constant weight at 110˚C before the element analyses. **Wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) analysis** The sample was prepared by 2 methods following; Fused bead method: The dried sample and flux were weighed in an exact ratio into the platinum crucible (0.62 g of sample, 1.24 g of lithium metaborate, 4.96 g of lithium tetraborate and 0.08 g of ammonium iodide). The fusion was performed at 1000˚C for 2.30 min in a furnace. Loose powder method: Two types of film were used in this study including (1) 4 µm Prolene® thin film and (2) 6 µm Mylar® polyester film. Each cup was covered with thin film. The fine powder sample was then filled into the cup. **Handheld X-ray fluorescence spectrometry (hXRF) analysis** The sample was prepared by the loose powder method with two film types. A Delta Professional hXRF Analyzer, DPO 2000 (Olympus Scientific Solutions Americas, Inc.) equipped with an instrument’s prolene window of 8 mm2, a 4W miniature X-ray tube (200 μA maximum current), and silicon drift detector (SDD) was used to measure all samples using Geochem mode with two beams. The first beam (40 kV) measured the elements V, Cr, Fe, Co, Ni, Cu, Zn, W, Hg, As, Se, Pb, Bi, Rb, U, Sr, Y, Zr, Th, Nb, Mo, Ag, Cd, Sn and Sb, also Ti and Mn. The second (10 kV) was used to determine the light elements Mg, Al, Si, P, S, Cl, K, Ca, Ti and Mn. The measuring time for an individual beam was set at 120 s. The internal hXRF stability was monitored by measuring Fe K-α count on a 316-stainless steel coin every day of use. Each sample was analyzed three times. The hXRF was calibrated after measuring intensities in the following seven geological reference materials: JA-1, JG-1a, JG-2, JSy-1 (andesite, granodiorite, granite, syenite, GSJ, Japan); BCR-2, COQ-1, GSP-2 (basalt, carbonatite, granodiorite, USGS, rseton). Each reference material was analysed ten times. RESULTS AND DISCUSSION **Calibration curves** The collected data of the reference materials were constructed linear calibration curve for each element. It was found that the calibration curves of Ag, As, Cd, Cr, Hg, Mg, Mo, Ni, S, Sb, Se, Sn, U, V and W measured using hXRF were poor because of their restricted rang in the standard materials for both film types. Whereas those of Al, Ca, Fe, K, Si, Ti, Mn, Nb, Pb, Sr, Th and Zn were acceptable with R2 ≥ 0.95except for Cu, P and Y. The calibration curves of Nb and Rb analyzed using 4 µm Prolene® thin film (R2 ≥ 0.95). The slopes of the regression line for each element was inputted into the hXRF analyser software for automatic correction of sample data, if the difference between the hXRF analysed value and the CRM recommend value was more than 10%. When 4 µm Prolene® thin film was used for the analysis, the recalibration factors for Al, Fe, K, Si, Ti, Rb and Th were 1.0649, 0.8487, 0.9140, 0.9615, 0.9810, 0.9892 and 0.9167, respectively. In the case of 6 µm Mylar® polyester film, these elements including Al, Fe, K, Si, Ti and Th were recalibrated with 1.8805, 0.8969, 1.0251, 1.4803, 1.1013 and 0.8689, respectively. P and Na could not be detected by hXRF spectrometer. For P, it is due to its concentration found in the geological reference materials were very low. In case of Na, it was too light to be detected by the hXRF model [1]. Hunt and Speakman [6] suggested that Na-X rays were extremely low energy, Kα line at 1.041 keV, and re-absorbed into the sample matrix and scattered as Bremsstrahlung radiation. There was a much higher degree of scatter between the hXRF analysis and the results at low concentration [7]. **Measurement of major and minor elements in soil and rock samples by hXRF and WD-XRF techniques** The major elements including Si (20-27 wt%), Al (13-17 wt%), Fe (1-4 wt%) and K (1-3 wt%) could be detected. The minor elements were composed of Mn (135-793 g/kg), Th (128-188 g/kg), Zr (65-89 g/kg) and Sr (25-63 g/kg). It can be also noted that the concentrations of Th found in the studied samples were very high and over the calibrated range (> 105 ppm). There was variation of each element in difference soil and rock horizon. For the hXRF analysis using the 6 µm Mylar® polyester film without recalibration, Al and Si concentrations were lowest values but these values could be improved by the recalibration method. However, the recalibration was not required for the hXRF analysis using the 4 µm Prolene® thin film. Therefore, efficiency of element analysis by the hXRF depended on film type and film thickness. Some elements i.e. Al, Fe, Ti, Pb, Sr, Th and Zr were reliable when compared to WD-XRF results (fused bead and loose powder techniques) but other elements (such as K, Si and Mn) differenced from the laboratory values (> 20%). The concentrations of K, Si and Mn obtained using the hXRF tend to be significantly underestimated. The variance in Pb, Sr, Th and Zr related directly to small concentrations contained in these samples. Though the hXRF was able to dependable measure some geologically important elements (such as Al, Fe, Ti, Pb, Sr, Th and Zr) but the instrument was unable to detect other important elements reliably (i.e. Ca and Mg). This was due to the particle size, mineralogical, the coexisting component effects (matrix effect) when hXRF spectrometer was used for these geological samples even using the recalibration method. These effects were increased when the sample contains abundant sheet silicate minerals, quartz and accessory minerals [8]. CONCLUSION The results demonstrated that the hXRF could provide data consistent with laboratory reported values. The hXRF measurement of geological reference material by both film types were in satisfactory agreement with certified values for all elements except for Cu, Nb, Ni, P, U, V, W, Y, Zn. The recalibration was required for 6 µm Mylar film analysis. The accuracy and precision of the elements in geological reference materials by hXRF after recalibration were acceptable. The elements such as Al, Ca, Fe, K, Mn, Si, Sr, Th, Zn in geological samples were detected by pXRF technique. Good agreement between the result values obtained by pXRF and by WD-XRF was found for some elements including Al, Fe, Ti, Pb, Sr Th and Zn. The study showed that the hXRF had significant potential as a geochemical tool. For the future work, the effect of particle size, sample preparation and moisture content will be investigated for reliable quantitative analysis. REFERENCES [1] YOUN, K.E., et al., A review of the handheld X-ray fluorescence spectrometer asa tool for field geologic investigations on Earth and in planetary surface exploration, Appl Geochem 72 (2016) 77-87. [2] KRISHNA, A.K., et al., Rapid quantitative determination of major and trace elements in silicate rocks and soils employing fused glass discs using wavelength dispersive X-ray fluorescence spectrometry, Spectrochim Acta Part B At Spectrosc 122 (2016) 165-71. [3] MEJIA-PINA, K.G., et al., Calibration of handheld X-ray fluorescence (XRF) equipment for optimum determination of elemental concentrations in sediment samples, Talanta 161 (2016) 359-367. [4] ROUILLON, M., TAYLOR, M.P., Can field portable X-ray fluorescence (pXRF) produce high quality data for application in application in environmental contamination research?, Environ. Pollut. 214 (2016) 255-264. [5] BLOCK, C.N., et al., Use of handheld X-ray fluorescence spectrometry units for identification of arsenic in treated wood, Environ. Pollut. 148 (2007) 627-633. [6] HUNT, A.M.W., SPEAKMAN, R.J., Portable XRF analysis of archaeological sediments and ceramics, J. Archaeol. Sci. 53 (2015) 626-638. [7] FAJBER, R., SIMANDL, G.J., Evaluation of rare earth element-enriched sedimantary phosphate deposits using portable x-ray fluorescence (XRF) instruments, Geological Fieldwork (2012) 199-209. [8] TANAKA, R., ORIHASHI, Y., XRF analysis of major and trace elements for silicate rocks using low dilution ratio fused glass, HUEPS Technical Report 2 (1997) 20.
Speaker: Ms Sasikarn Nuchdang (Thailand Institute of Nuclear Technology)
• 20
Speaker: Mr John Manrique (Universidad Técnica Particular de Loja)
• Nuclear Power and Associated Modern Energy Markets
Conveners: Dr Luminita Grancea (OECD NEA) , Mr Richard Schodde
• 21
The emerging uranium industry landscape: Push or Pull resource recovery?
The simultaneous idling of the world’s richest and one of the largest uranium deposits and cutbacks in production against a background of low prices, has brought to a head the strategic question of what future path the troubled global uranium industry should tread? If there is a positive way forward, the practical consequence is to define in detail how uranium recovery and production pathways should be redesigned for a more predictable and sustainable future. This paper will discuss the inevitable impact of these change drivers as causing the uranium sector to pivot from a “push” to a “pull” business model, one based on uranium as a critical material for climate action not as a traded commodity. This paper will detail the necessary interactions of policy and technology innovation from which this new "push" model can be developed, taking into account the demand for mineral resource recovery of any kind as a low- or zero-waste generating activity. This means rethinking uranium as a new economic resource, placing innovative uranium extraction technologies and flow sheets at the centre of process design and operation, with particular emphasis on uranium as a co- or by-product.
Speaker: Mr Harikrishnan Tulsidas (UNECE)
• 22
Uranium Mining Towards Sustainable Clean Energy: Indian Scenario
Speaker: Dr Akshaya Kumar Sarangi (Uranium Corporation of India Ltd)
• 23
History of nuclear fuel cycle development, facility decommissioning and site restoration at IPEN — CNEN/SP, Brazil
Speaker: Dr Paulo Ernesto Oliveira Lainetti (Nuclear and Energetic Research Institute - IPEN-CNEN/SP Brazilian Nuclear Energy Commission)
• 5:40 PM
Welcome Reception

Untill 20:00

• Tuesday, June 26
Conveners: Dr Igor Pechenkin (All-Russian Scientific-Research Institute of Mineral Resources, Moscow, Russia) , Dr Mark Mihalasky (U.S. Geological Survey)
• 24
INVESTIGATION OF THE GEOLOGICAL PROCESSES WHICH CONTROL THE GENESIS OF UNCONFORMITY-TYPE URANIUM DEPOSITS USING PARALLELIZED NUMERICAL SIMULATION ON A SUPERCOMPUTER
Uranium deposits of the Athabasca Basin, Canada and Alligator Rivers region, Australia are located near subhorizontal unconformities between polydeformed/metamorphosed Archean/Paleoproterozoic rocks and overlying essentially undeformed Proterozoic sedimentary rocks. Most deposits are associated with basement-rooted faults; however the location of uranium mineralization to the unconformity is quite variable. Athabasca Basin deposits occur at/above/below the unconformity. Conversely, all discovered deposits in the Alligator Rivers region occur below the unconformity. Conceptual models for these deposits invoke sandstone-sourced oxidised fluids moving down into the basement (basement mineralisation), or basement-sourced reduced fluids moving up into the sandstone (sandstone mineralisation); driven by topography, deformation or thermal buoyancy. This study focuses on deformation-driven flow, using numerical simulations to explore fluid flow controls. The model is subjected to horizontal shortening, and fluid flow directions are explored by varying fault dip, shortening direction, strain rate, basement rock strength, or permeability. Over 300 finite-element simulations were performed using MOOSE simulation framework. The results indicate that shallow fault dip, high strain, and fault-perpendicular shortening favour downward flow, whereas steep fault dip, low strain, and low-angle-to-fault shortening favour upward flow. These results are used to predict new mineralization targets.
Speaker: Dr Irvine R. ANNESLEY (ENSG, Universite de Lorraine and Department of Geological Sciences, University of Saskatchewan)
• 25
The Midwest Project, East Athabasca Basin, Northern Canada: Reviving old deposits to prepare for the future
Speaker: Mr Trevor Allen (Orano Group Canada)
• 26
POTENTIAL FOR UNCONFORMITY-RELATED URANIUM DEPOSITS IN THE NORTHERN PART OF THE CUDDAPAH BASIN, TELANGANA AND ANDHRA PRADESH, INDIA
Speaker: Mr M. B. VERMA (GOVERNMENT OF INDIA, DEPARTMENT OF ATOMIC ENERGY, ATOMIC MINERALS DIRECTORATE FOR EXPLORATION AND RESEARCH)
• 27
The challenges to explore and discover an unconformity deposit at depth
INTRODUCTION Proterozoic unconformity uranium deposits are considered the highest grade deposits in the world. The most recognized deposits occur in the Athabasca basin in Canada [1]. As indicated in the 2016 “Red Book”, Proterozoic unconformity deposits account for about one-third of the world’s uranium resources based upon reasonably assured resources [2]. In 2017, the only two producing uranium mines in Canada allowed for over 20% of the world supply utilizing underground mining methods [3]. One matrix using current research of active mining operations with publicly disclosed data involving ore reserves, calculated according to an international standard, has outlined Cameco’s Cigar Lake and McArthur River operations as having the most valuable ore [4]. Expenditure spending in the search for deposits has diminished since a peak spot price of uranium in 2007 [5]. There are a number of well documented factors related to a decline in uranium prices that has led to a weak demand for the product. A few of the reasons for the lack of demand, but not limited to, include the events in Fukushima, Japan in 2011, economic challenges from fuel sources with cheaper capital costs for start-up, secondary supplies from government inventories as well as re-enrichment sales has also provided excess inventory. Even with the previous described “headwinds” in the nuclear power industry there are reasons for optimism due to the new builds and forecasted growth in central and eastern Asia. The IAEA’s high case projection has the global nuclear generating capacity increasing from 2016 levels by 42% in 2030, by 83% in 2040 and by 123% in 2050 [6]. Current statistics obtained from the Saskatchewan Mining Association indicate that exploration expenditures in the Athabasca Basin were $CAD 44.8 million in 2016 [7]. Major uranium companies such as Orano Canada (previously AREVA Resources Canada Inc.) and Cameco Corporation have committed the majority of their annual exploration dollars to the Athabasca Basin. Other known uranium companies with publicly announced discoveries such as NexGen Energy Ltd (NexGen), Denison Mines (Denison) and Fission Uranium Corp. (Fission) continue to release promising results in defining new discoveries and provide optimism to investors with their exploration expenditures. CURRENT LAND STATUS IN THE ATHABASCA BASIN An internal review of the current land disposition in the Athabasca Basin (includes the provinces of Alberta and Saskatchewan) involving uranium exploration was conducted in February, 2018. Upon review, it is estimated that 40% of the claims deemed for uranium exploration are located on the edge or outside of the sandstone cover of the Athabasca Basin. In terms of actual surface area within the confines of the basin itself, 53% of the land mass has been staked between the depths of 0 to 500 metres with the majority of the southern, central and eastern edges of the basin being claimed. The rational for the land disposition has to do with current and past mining operations in the eastern Athabasca; the Wollaston-Mudjatik transition zone hosts the Cigar Lake and McArthur River operations and the majority of economical and non-economical deposits. The staking along the southern and central edges of the basin has been driven in part by the discoveries by NexGen and Fission. As the unconformity becomes deeper there is less staked land and at a known unconformity depth between 500 and 1000 metres only 25% of the land mass has been claimed. The acquired land at this depth is associated with the lateral extension of known fertile trends related to conductive corridors or regional fault systems. Within the deepest portions of the basin, greater than 1000 metres depth to the unconformity, less than 4% of the land mass is acquired. There are numerous factors, mainly conjectural, that can be implied to interpret the current land status in the Athabasca Basin including a company’s available funding for exploration, current exploration portfolio, company strategies, availability of favourable geological trends and access to a project area. RATIONAL FOR LOOKING AND DISCOVERING NEW ECONOMIC DEPOSITS AT GREATER DEPTHS Potential for discovering new economic deposits can be evaluated by ranking different projects according to multiple parameters among which the depth of the targets at the unconformity or in the basement can be considered as of most importance. Exploration maturity can be also judged on the basis of potential based on available conductor strike length following the traditional unconformity-type model [8]. Thus, the probability to find a new economic deposit at depth lower than 250m with the minimal footprint such as the Cigar Lake deposit is limited taking into account the existing spacing of drill holes along the main conductive trends. However exploring high grade pods at shallow depth remains a short to medium term objective as these targets may be economic by small open pit means or if the possibilities of surface access borehole extraction methodology becomes cost effective. In a long term vision, the critical depth of exploration within the Athabasca Basin will likely evolve and it is probable that the deepest portions of the basin, will be considered for greenfield exploration. However, several economical and technical challenges will have to be faced. What type of mineral deposit and which size will have to be targeted to become economic? Can we expect some technical and scientific breakthrough that would improve significantly the resolution of the geophysical methods, the drilling technologies and our ability to vector our geological exploration? This new frontier and challenges are discussed in relation to the present state of art and in reference to the Cigar Lake deposit. As a hypothesis, one considers that other world class deposits exist at the unconformity at depths greater than 500 metres. Although the geological conditions under which such a deposit can be formed are not fully understood [8], it is unlikely that these conditions were only met in a single locality over the whole extent of the Athabasca Basin. As a support to this hypothesis, other deposits like Shea Creek [9, 10] or Phoenix [11, 12] are formed under near identical mineral systems: association with long lived deeply penetrating and steeply dipping structures, enhanced permeability fault system within a compressive tectonic context, leaching of huge volume of sedimentary and metamorphic lithologies by oxidized basin and reduced basement fluids, formation of uranium deposits from highly concentrated uranium-bearing acidic brines [13]. An economic scenario for deep unconformity deposits is presently very difficult to define. Kerr and Wallis [14] consider that, if low grade deposits can be economically mined at depth lower than 200m, only purely basement hosted deposits and unconformity hosted giant deposits will possibly be qualified as reserves below 200 metres. A high level study can be completed to determine the economics of a hypothetical mining and milling operation located in the centre portion of the basin. However, such calculation is very sensitive to the uranium price and capital cost and a detailed scenario is out of the scope of this discussion. To follow up the discussion, one considers that the footprint of the targeted deposit should be an unconformity type deposit, comparable if not larger than the Cigar Lake deposit to be effectively economic at an uranium price of$US 40/lbs U3O8 [15]. This deposit style is selected due to the alteration halo that reaches up to 200 metres in width and 250 metres in height and that is associated with mineralizing processes [15, 16]; likely to be identifiable under deep cover. Other styles such as basement mineralization were considered, NexGen’s Arrow deposit and Denison’s Gryphon deposit, but ultimately rejected due to the potential limiting size of an alteration halo in the sandstone for a basement deposit with greater than 500 metres of sandstone cover. THE CHALLENGE TO EXPLORE AND DISCOVER A GIANT UNCONFORMITY DEPOSIT AT DEPTH There is no direct uranium detection for deposits buried at depth. Our present exploration technologies for depth greater than 500 metres are limited by several factors as the cost of drilling, in particular in remote sectors, and the decreasing resolution of geophysical modelling at increasing depth. However, some technical and scientific breakthrough in the coming years may improve our ability to vector our geological exploration. Junior and major companies are investing millions of dollars every year for geophysical surveys, downhole geophysical probing and acquisition of complete petrophysical datasets including density, magnetic susceptibility and resistivity. Numerous case studies of ground and airborne electromagnetics (EM) and magnetics surveys, resistivity ground campaign, downhole geophysics are regularly presented and should enable the definition of best practices according to the different geological context if a complete return of experience could be achieved. Moreover, such analysis should guide the developments for the acquisition, processing and modelling. Thus, the principle of combined acquisition and joined inversion of EM, magnetotellurics (MT) and resistivity surveys is the current inherited way to explore at depth and to improve the resolution of the geophysical 2D and 3D models. The main budget of exploration is oriented to drilling. One of the main problems faced today by the companies is the cost of drilling in purely greenfield terrain, the high risk of lost holes in zones of sandstone dissolution (that induces high cost and then limitation of the meterage to be drilled) and the low recovery of cores in fault zones that hampers the structural reconstruction of the architecture of the explored domains and a careful study of the mineralizations. Innovations should be deployed to use or test equipment in order to limit the risk of hole lost because of difficult geological environment, improve the drilling practices and for example generalize the use of directional drilling to explore large zones at depth from a pilot hole. The monitoring of the drilling parameters should also help to control the progress of the drilling in these zones and enhance the quality of coring. High resolution imagery of the structures of the hole and recording of the physical properties while drilling should also be an objective to be elaborated and tested by the drilling and exploration companies. Exploring Cigar Lake analogs at the base of the unconformity can benefit of the geological knowledge that has been acquired since exploration and exploitation started. The Cigar Lake deposit is located 420-445 metres below the surface within the Athabasca Group’s Manitou Falls Formation. The mineralization has a flat to tubular shaped lens approximately 2000 metres in length, ranges between 20 and 100 metres in width and with an average thickness of about 6 metres [17-19]. The mineralization has a crescent-shaped cross-sectional outline that closely reflects the topography of the unconformity. The alteration halo surrounding the Cigar Lake deposit is extensive and affects both sandstone and basement rocks, characterized by extensive development of Mg-Al rich clay minerals (illite and chlorite). It is presently possible to build a 3D earth model reconciling geological and geophysical data, based on extensive datasets including geological, geochemical and physical properties centered on the deposit but also extending along trend and other underexplored conductive trends. This type of modelling of the Cigar Lake domain could use recent developments performed on the application of Artificial Intelligence and learning machine [20, 21] to update the footprint of the deposit. It will also provide an excellent return of experience for defining appropriate acquisition parameters, processing and modelling of geophysical methods considered above as a first step to be accomplished for exploring at greater depth. An earth model resulting of the updated footprint of Cigar Lake domain could be used to simulate the geological, geochemical and geophysical footprint that could be created by such a deposit in different localities at the base of the basin. Reprocessing and acquisition of complementary geological and geophysical datasets, linked to the measured, estimated or interpolated petrophysical datasets, should then provide a set of unconstrained and constrained inversions that will be compared with the simulated footprint. This modelling, both data and knowledge driven, could lead to a virtual exploration of Cigar lake analogs at the base of the Athabasca Basin. Finally, as the exploration will provide new datasets from drilling, the new information could be used to refine constrained inversion and to evaluate the possibility to vector exploration towards new deposits. In conclusion, this long term vision can be put in perspective with the challenges that were faced by the oil and gas industry when exploration targeted deeper, more structured and remote reservoirs. Although the geology is much more complex than oil and gas reservoir, pre competitive research and development programs could be set up in order to be on time when greenfield exploration will become open for defining a new critical depth for unconformity related uranium deposits. REFERENCES [1] INTERNATIONAL ATOMIC ENERGY AGENCY, World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification, IAEA-TECDOC-1629, Vienna (2009). [2] URANIUM 2016: RESOURCES, PRODUCTION AND DEMAND, Organization For Economic Co-Operation And Development - Nuclear Energy Agency and the International Atomic Energy Agency, NEA No. 7301 (26th edition of the “Red Book”), Paris, France, p. 546. [3] WORLD NUCLEAR ASSOCIATION, World Uranium Mining Production (Updated July 2017), http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/mining-of-uranium/world-uranium-mining-production.aspx. [4] BASOV, V., These 10 mines have the world's most valuable ore (2017), http://www.mining.com/top-10-mines-digging-out-most-expensive-ores. [5] The Ux Consulting Company, LLC, http://www.uxc.com/. [6] INTERNATIONAL ATOMIC ENERGY AGENCY, Board of Governors General Conference - International Status and Prospects for Nuclear Power 2017, GOV/INF/2017/12-GC(61)/INF/8, dated 28 July, 2017. [7] Saskatchewan Mining Association (2016), http://saskmining.ca/ckfinder/userfiles/files/EmergencyResponseCompetitionPhotos/SMA%20-%20Uranium%20Fact%20Sheets%202016ti.pdf [8] Jefferson, C.W., et al., 2007b, Unconformity-associated uranium deposits of the Athabasca Basin, Saskatchewan and Alberta, in Goodfellow, W.D., ed., Mineral deposits of Canada: A synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods, Geological Association of Canada Mineral Deposits Division, Special Publication no. 5, p. 273-305. [9] Carroll, J., Robbins, J., Koning, E., The Shea Creek deposits, west Athabasca Basin, Saskatchewan, in Uranium: Athabasca deposits & analogues, 2006 CIM Field Conference, CIM Geological Society, Saskatoon Section, Saskatoon, Saskatchewan, September 13-14, 2006, Field Trip 3 “Cluff Lake and Shea Creek deposits” guidebook, p. 33-48. [10] Kister, P., Cuney, M., Golubev, V.N., Royer, J.J., Le Carlier De Veslud, C., Rippert, J-C., Radiogenic lead mobility in the Shea Creek unconformity-related uranium deposit (Saskatchewan, Canada): migration pathways and Pb loss quantification. C. R. Geoscience, 2004, 336, p.205–215. [11] Kerr, W.C., The discovery of the Phoenix deposit, a new high-grade, Athabasca Basin unconformity-type uranium deposit, Saskatchewan, Canada. Society Economic Geologist, 2010, Sp. Publi. 15, Chapter 34, p. 703-728. [12] Roscoe, W.E., Technical Report on a mineral resource estimate update for the Phoenix uranium deposit, Wheeler River Project, eastern Athabasca Basin, Northern Saskatchewan, Canada: National Instrument 43-101 Technical Report, 2014, RPA Inc., p.134. [13] Richard, A., Rozsypal, C., Mercadier, J., Banks, D.A., Cuney, M., Boiron, M-C., Cathelineau, C, Giant uranium deposits formed from exceptionally uranium-rich acidic brines. Nature Geoscience, 2012, vol 5, p. 142-146. [14] Kerr, W.C., Wallis, R., “Real-World” economics of the Uranium deposits of the Athabasca Basin, North Saskatchewan: Why grade is not always king! Society Economic Geologists, Newsletter, 2014, 19, p. 10-15. [15] The Ux Consulting Company, LLC, UXC special report, Uranium Production Cost Study, September, 2017, p. 120. [16] Exploration ’17, http://www.exploration17.com/, October 22-25, 2017, Proceedings. [17] Andrade, N., Geology of the Cigar Lake uranium deposit; in The Eastern Athabasca Basin and its Uranium Deposits, Field Trip A-1 Guidebook (ed.) N. Andrade, G. Breton, C. W. Jefferson, D.J. Thomas, G. Tourigny, W. Wilson and G.M. Yeo; Geological Association of Canada-Mineralogical Association of Canada, Saskatoon, Saskatchewan, May24-26, 2002, p.53-72. [18] Bruneton, P., Geological environment of the Cigar Lake uranium deposit; Canadian Journal of Earth Sciences, v. 30 (1993), p. 653-673. [19] Bishop, C., S., et al., Cigar Lake Project Northern Saskatchewan, Canada: National Instrument 43-101 Technical Report. 2010, Cameco Corporation, p. 213. [20]Bishop, C., S., et al., Cigar Lake Project Northern Saskatchewan, Canada: National Instrument 43-101 Technical Report. 2012, Cameco Corporation, p. 196. [21] Bishop, C., S., et al., Cigar Lake Project Northern Saskatchewan, Canada: National Instrument 43-101 Technical Report. 2016, Cameco Corporation, p. 164. [22] Lescher et al., 2017, Disseminated Au, McArthur River-Millennium nconformity U, and Highland Valley Porphyry Cu Deposits: Preliminary Results from the NSERC-CMIC Footprints Research Network. Exploration 17, 23p. [23] Feltrin et al., 2016, HYPERCUBE: mining exploration data, a case study using the Millennium uranium deposit, Athabasca basin. GAC MA
Speaker: Mr Patrick Ledru (AREVA Resources Canada)
• 28
Integration and Cost Saving Utilization of the Seismic Reflection Technique in the Athabasca Basin, Canada
The Seismic Laboratory (UofS) through industrial partnerships has conducted many seismic reflection experiments within the western and eastern Athabasca Basin. Results to date illustrate that the seismic investigations deliver high-quality primary structural images of the subsurface, with resolution not matched by other geophysical techniques. Correlation of similar seismic signatures from section to section has defined the mineralization fault systems and allowed spatial extension of previously unrecognized exploration target zones. Extended analysis of seismic signal attributes and full-wave data offer detailed lithological characterization, including anomalous alteration zones and petrophysical attributes. Although seismically detected anomalies are primary indicators of mineralization, the seismic method is still not a “standard basin” exploration tool because of its negative attribute. Unquestionably, locally, drilling of boreholes provides the most explicit reliable information to a certain depth. Comparing the costs of all geophysical techniques to the cost of a single logged drill-hole illustrates that the results of a properly designed seismic data acquisition program not only leads to more effective drilling programs, but also to much quicker recognition of the major mineralized zones and their fingerprints. This integrated approach to exploration would translate into significant reduction of required exploratory boreholes and the total exploration expenditure.
Speakers: Dr Irvine R. ANNESLEY (ENSG, Universite de Lorraine and Department of Geological Sciences, University of Saskatchewan) , Dr Zoltan HAJNAL (Department of Geological Sciences, University of Saskatchewan)
• Applied Geology and Geometallurgy of Uranium and Associated Metals
Conveners: Mr C.K. ASNANI (HINDU) , Dr Michel CUNEY (CNRS - GeoRessources - CREGU - Universite de Lorraine)
• 29
Structural Characteristics and Its Control on Uranium Mineralization in Xiangshan Uranium Ore-Field
Xiangshan uranium ore-field is the largest volcanic-related hydrothermal uranium deposit in China. Based on high precision deep geophysical survey, 3D geologic modeling and scientific drilling projects, EW-trending faults in basement were rejuvenated by strong shearing of Suichuan-Dexing fault during later Jurassic to Early Cretaceous, the tectonic-stress field changed from compression to extension at the beginning of Early-Cretaceous, and it is advantageous to the ascension of deep-derived materials, with ore-bearing hydrothermal fluid transiting, precipitating and enriching. The favorable position for uranium mineralization include the junctions of faults with different directions, the junctions between main faults and subsidiary fractures, the junctions between branch fractures of main faults and derived fractures of subsidiary faults. EW-trending faults in basement is the main channel-way in which substance can transmit to surface, the linear, ringlike and radial pattern structures which are connect with faults in basement controlled the shape, occurrence, scale and spatial locations of uranium ore bodies, these faults are main ore-hosting structures. Therefore, we hold fault structures are still the emphasis of ore-finding, especially, the belts where deep E-W faults and surface faults intersected are favorable areas to explore uranium resources.
Speakers: Mr Jiangtao Nie (Beijing Research Institute of Uranium Geology) , Dr Ziying Li (Beijing Research Institute of Uranium geology)
• 30
VOLCANIC TYPE URANIUM DEPOSITS IN NORTH CHINA
INTRODUCTION Volcanic type uranium deposit is one of the four largest kind of uranium deposits in China (volcanic type, granite type, sandstone-hosted type and Carbonaceous-Siliceous-Argillaceous Rock Type), and is play an important role in uranium resources. In 90s of last century, before the large-scale application of In-situ Leaching technology (ISL) in sandstone-hosted type uranium deposits, volcanic type uranium deposit was one of the main targets for exploration and exploitation in China. Uranium reserves in volcanic and granite type deposits account for 61% of China's total reserves[1]. As far as 2015, the volcanic type uranium still occupied 35.48% of the annual output[2]. It is different from granite type uranium deposits are mainly developed in southern China and sandstone type uranium deposits are mainly developed in northern China, volcanic type uranium deposits have been found in both southern and northern China. Southern China represented by Gan-hang uranium metallogenic belt, Northern Chinese represented by Guyuan-Hongshanzi uranium metallogenic belt and Qinglong-Xingcheng uranium metallogenic belt. In the two metallogenic belts of northern, there are 17 volcanic type uranium deposits and more than 100 mineralized points have been found, which are the important uranium-mining and production area in China. TYPICAL URANIUM DEPOSITES Guyuan-Hongshanzi uranium metallogenic belt and Qinglong-Xingcheng uranium metallogenic belt are located in northern margin of the North China Craton (NCC) uranium polymetallic metallogenic province of the circum-Pacific metallogenic zone[3]. The former is located in the middle section of northern margin of NCC, and the latter is located in the eastern section of the northern margin of NCC. According to the characteristics of ore-bearing rock and ore-controlling structures, volcanic type uranium deposits can be divided into 5 subtype[4], namely volcanic breccia subtype, sub volcanic subtype, dense fracture zone subtype, interlayer fracture zone subtype and pyroclastic rocks subtype. The volcanic type uranium deposit in north China is mainly composed of sub volcanic subtype and pyroclastic rocks subtype, Zhangmajing deposit, Daguanchang deposit and Hongshanzi deposit in Guyuan - Hongshanzi uranium metallogenic belt as the representative for sub volcanic subtype, and Gangou deposit and Dayingchang deposit in Qinglong- Xingcheng uranium metallogenic belt as the representative for pyroclastic rocks subtype. The geological characteristics of the typical uranium deposits are briefly introduced as follows: Zhangmajing uranium deposit is located in the north edge of Zhangmajing volcanic collapse depression in Guyuan volcanic basin, the southern part of Zhangmajing - Hongshanzi uranium metallogenic belt, and controlled by Sub volcanic type crater. The ore bearing rock is potassium rhyolite, the fifth layer in the third lithology of Zhangjiakou group upper Jurassic and rhyolitic porphyry (main ore host rock). Zhangmajing uranium deposit is a typical sub rhyolite porphyry uranium-molybdenum deposit. It is the product of multi-phases of volcanic magmatic hydrothermal geological events that happened in late Jurassic, early Cretaceous and Paleogene-Neogene, the mineralization age are 122Ma, 89Ma and 23.7Ma. Daguanchang uranium deposit is located in the south edge of Daguangchang volcanic collapse depression in Guyuan volcanic basin, the southern part of Zhangmajing - Hongshanzi uranium metallogenic belt, and controlled by Subvolcanic type crater. The ore bearing rock is potassium rhyolite of volcanic effusive facies (main ore host rock), Zhangjiakou group upper Jurassic and rhyolitic porphyry of volcanic intrusive facies. Daguanchang uranium deposit is a typical cryptoexplosion potassic rhyolite type uranium-molybdenum deposit. It is a product from multi-phase of volcanic magmatic hydrothermal geological events happened in early Cretaceous and Paleogene, and the mineralization age is 67Ma and 30Ma. Hongshanzi uranium deposit is located in the west and east edge of Hongshanzi volcanic collapse depression where rhyolitic porphyry and granite porphyry distribution as ring, the northern part of Zhangmajing - Hongshanzi uranium metallogenic belt, controlled by the contact zone of Subvolcanic type crater. The ore bearing rock is trachyte in middle Manketouebo group upper Jurassic and rhyolite porphyry. Hongshanzi uranium deposit is a typical contact zone of subvolcano controlled - volcanic hydrothermal type uranium deposit. It is the product of multi-phases of Volcanic magmatic hydrothermal geological events that happened in late Jurassic, and early Cretaceous, and the main metallogenic age is 156Ma, 120 ~ 130Ma. Gangou uranium deposit is located in the south edge of Gangou middle Jurassic volcanic fault basin, eastern of Qinglong-Xingcheng uranium metallogenic belt. The ore bearing rock is Sedimentary pyroclastic rock formation of Middle Jurassic Haifanggou group, there were strong mafic and alkaline volcanic magmatic activities in the stage of mineralization. Gangou deposit is a typical volcanic hydrothermal fluid and meteoric water mixed type uranium deposit, it is the product of of multiple geological evolution with syndepositional pre enrichment and multi-stage volcanic hydrothermal fluid superimposed meteoric water mineralization, main metallogenic age is 121Ma and 76Ma. Dayingchang uranium deposit is located in the magmatic active belt of the intersection area of the NE-trending Hongluoshan-Wuzhishan regioanl fault and EW-trending Qinglong-Jinxi regional fault, in the western part of Qinglong-Xingcheng uranium metallogenic belt. The ore bearing rock is medium-coarse grained quartzite in Middle Proterozoic Changzhougou group, Jurassic acid granitic and basic magmatic activities are the main causes of mineralization. Dayingchang uranium deposit is a typical multiple volcanic magmatic hydrothermal superimposed uranium deposit. The uranium mineralization is characterized by contemporaneous sedimentary preconcentration and volcanic magmatic hydrothermal overlap. The main metallogenic epoch is late Jurassic to early Cretaceous (142Ma ~ 123Ma). DISCUSSION AND CONCLUSION Through comprehensive study of geological and mineralized characteristics of several typical uranium deposits, the volcanic type uranium deposits in North China are characterized by the following: (1) Metallogenic geological background: in general, the volcanic uranium deposits occur on the paleo-landmass, especially on the edge of the paleo-landmass. The continental volcanic eruption belt dominated by acidic (or partial alkaline) volcanic rocks is the main production environment. Volcanic type uranium deposits often occur in the composite parts of regional faults and volcanic basins formed by multi-stage volcanic activities. (2) Metallogenic epoch: all uranium deposits have the characteristics of multistage superposition and mineralization. Paleoproterozoic, large-scale potassic migmatization in north margin of NCC caused preliminary enrichment of uranium, formed the mainly uranium source layer in North China. Multi stage volcanic hydrothermal activity in late Jurassic to early Cretaceous is the main heat source and power for activation and migration of uranium mineralization. The intermediate-mafic volcanic magmatic activity in Paleogene Neogene is important to superposition activities for mineralization. The age of main ore mineralization is concentrated in 156~120Ma, 89~67Ma, 30~23.7Ma. (3) Mineralizing characteristics: Coexisting and associated minerals is commonly existed in volcanic uranium deposits in North China. Guyuan - Hongshanzi Uranium metallogenic belt is mainly characterized by uranium - molybdenum mineralization, even the intensity and range of molybdenum mineralization were greater than uranium, such as Zhangmajing deposit, the reserves of molybdenum are more than 100 000 tons, far greater than uranium reserves (8000 tU). From the southern section of Zhangmajing uranium deposit, Daguanchang uranium deposit to the northern section of the Hongshanzi uranium deposit, Guangxingyuan uranium deposits, uranium minerals are mainly pitchblende and coffinite, but molybdenum-bearing mineral changed from jordisite into molybdenite. The temperature from fluid inclusions show that the main metallogenic temperature of Guyuan area concentrated in the 137.7 ~ 217.7℃, and metallogenic temperature of Hongshanzi area concentrated in 218 ~ 275℃, Ore forming temperature increased obviously from south to north. Qinglong - Xingcheng uranium metallogenic belt is mainly single uranium mineralization type, but it is also associated with a small amount of Mo, Pb, Zn, Cu, Ag and other metallic minerals[5]. Uranium is dominated by dispersed as adsorption states, uranium bearing minerals are secondary, are mainly pitchblende, with a small amount of uraninite and secondary uranium minerals. (4) Ore controlling factor: Neoproterozoic - paleoproterozoic potassic migmatitic granite basement; Mesozoic uranium rich volcanoclastic rock, volcanic rock and sub volcanic rock; late Jurassic volcanic-sedimentary basin, volcanic collapse basin and volcanic apparatus, such as caldera structure, volcanic dome structure, volcanic collapse. This entire three are the major controlling factors of volcanic type uranium deposits in North China, and with regional faults together to control the location and scale of uranium deposits. The uranium deposits in Qinglong-Xingcheng uranium metallogenic belt is controlled by layer in general and the uranium ore bodies are stratified and lenticular, the occurrence of ore bodies is in accordance with the formation of the strata. The uranium deposits in Guyuan-Hongshanzi uranium metallogenic belt are controlled by volcanic or sub volcanic rock and tectonic obviously, the ore bodies mainly as disseminated or veins. The host rock in both of two belts, is not given but is diversify, such as volcanoclastic rock, rhyolites, trachyte and rhyolite porphyry. (5) The ore-forming fluid mainly originated from mantle: Isotope research indicate that the ore-forming fluid of Guyuan - Hongshanzi uranium metallogenic belt consists of little change of Pb isotope, 206Pb/204Pb = 16.857 ~ 19.934, 207Pb/204Pb = 15.413 ~ 15.726, 208Pb/204Pb = 37.596 ~ 38.904, it is mainly between the mantle and lower crust or orogenic belt, more closely to mantle. Sr isotopic ratios (87Sr/86Sr)i = 0.707 ~ 0.727, Between the depleted mantle (0.7022 ~ 0.7035) and the upper crust of North China (0.7120 ~ 0.7200), it has a very low Sr content (14.7×10-6 ~ 19.8×10-6), which is close to the content of Sr in depleted mantle, indicating that ore-forming fluid has the characteristics of mantle source. δ34S of pyrite in Gangou deposit varied from 1.2% to 5.7%, close to the sulfur isotopic composition of meteorite. La/Yb - ∑REE diagram shown the lithology belong to continental alkali basalt series, suggesting that the sulfide (also metallogenic material) mainly derived from the upper mantle. (6) Metallogenic regularity: Since Mesozoic, volcanic activity was frequent in North China, and as a regularity of basic ~ intermediate acid ~ basis, intrusion ~ eruption and multi cycle activities in general. Uranium polymetallic deposits are mostly produced in transition zone of gravity high field and low field. The deposits are characterized by structure (include faults and volcanic structures) and sub volcanic rock controlled, reducing ore-forming fluids with high temperature and high pressure derived from mantle, superimposed alteration are development and associated with Mo, Pb, Zn, Ag and other elements. Uranium is enriched in late melts or fluids, and the age of mineralization is later than the intrusive age of the related rock masses[6]. All of above reflect the typical characteristics of hotspot uranium metallogenesis[7], the uranium mineralization may be related to the mantle plume activities in North China. In conclusion, the volcanic type uranium deposits in North China have similar metallogenic epoch, metallogenic regularities, genesis and characteristics, which may be related to the same tectonic settings, indicating that the northern margin of NCC has undergone concerted and relatively large-scale volcanic uranium mineralization activities since Mesozoic era. REFERENCES [1] Shen Feng. Characteristics of Uranium Resources and Prospecting Direction in China. Uranium Geology, 3(1989):129-133 (in Chinese) [2] NUCLEAR ENERGY AGENCY and INTERNATIONAL ATOMIC ENERGY AGENCY, 2016. Uranium 2016: Resources, Production and Demand. [3] Huang ZX, Li ZY and Cai YQ, Metallogenic model of the Uranium deposits in Guyuan area, China. 1146. Abstract 35th International Geological Congress, Cape Town, South Africa (2016). [4] BEIJING RESEARCH INSTITUTE OF URANIUM GEOLOGY. Evaluation of the potential for volcanic uranium deposits in China. 2011. [5] Li Haidong, Zhong Fujun, Zhang Zhiyong, et al. Characteristics and significance of uranium polymetallic combination in volcanic uranium deposits in China. Mineral Resources and Geology 293 (2015):283-289. (in Chinese) [6] Zhixin Huang, Ziying Li and Zhaoqiang Wang. Hotspot uranium metallogenesis in North Heibei province, China. Acta Geologica Sinica, 88 S2 (2014):1360-1361. [7] Li Ziying. Hostspot uranium metallogenesis in South China. Uranium Geology, 222 (2006): 65-69. (in Chinese)
Speaker: Dr Zhixin Huang (Beijing Research Institution of Uranium Geology)
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Geological and geochemical characteristics of the Huayangchuan U-Nb-Pb deposit, Shan'xi China
INTRODUCTION Huayangchuan U-Nb-Pb deposit is located in the west part of Xiao Qinling area at the southern margin of the North China Block. It is proved to be a super-larger U-Nb-Pb polymetallic deposit in China in recent years [1-9]. The Huayangchuan deposit is located at a junction between Huashan Granites (92-142 Ma) [10] on the north and Laoniushan Granites (146 and 228 Ma) [11] on the south. Archeozoic gneissic suite is the wall rock in the area. The NW trending (290°-310°) Huayangchuan fault runs through the area, controlling the distribution of the ore bodies and vein rocks. The fractures are well developed in the deposit with mainly NNW and NW trending. Various vein rocks filled in the fractures includes biotite amphibole, biotite granite porphyry, pegmatite, calcite veins, lamprophyre, fine-grained granite veins and so on. Calcite veins are the main ore-bearing vein rocks. Based on the collection and analysis of regional geological data and the exploration and investigation work in recent years, we made clear about the ore-forming background, the characteristics of ore-bearing pegmatite and carbonate rock and the characteristics of U-Nb-Pb mineralization. The ore-controlling mechanism and genesis of ore deposit are preliminarily discussed under this paper. DESCRIPTION Characteristics of vein rocks Various vein rocks outcroping in the Huayangchuan deposit includes biotite amphibole, biotite granite porphyry, pegmatite, calcite veins, lamprophyre, Fine-grained granite veins and so on. These vein rocks have been divided into three groups (Pre-mineralization group, Mineralization group and Post-mineralization group) based on their rock types, relationship with mineralization and cross-cutting relationship. Biotite granite porphyry veins, located on the south of fault zone, are NNW trending, 4km in length and 10 to 200m in width. They were cut by the ore-bearing quartz-calcite veins. Hui (2014) suggested two episodes of intrusions of biotite granite porphyry veins (225.5±4.2Ma and 207±2.3Ma). Qiu (1993) obtained the K-Ar age of 204-206Ma in the ore-bearing carbonate veins，which is younger than the age of biotite granite porphyry confirmed that they are prior to the mineralization. Lamprophyre amazonite pegmatite and fine-grained granite veins cut the ore-forming quartz and calcite vein rocks, and they are not cut by other veins indicated that they are post to the mineralization. The mineralization epoch is divided into two stages: Pegmatitic stage and Carbonate stage. Veins in the Pegmatitic stage includes Pegmatite veins and migmatic pegmatite veins. The Pegmatite has the porphyritic and graphic texture and lumpy structure. Migmatic pegmatite veins mainly consists of k-metasomatism pegmatite， biotitization- actinolitization pegmatite and the biotite-feldspar -quartz veins. Uneven U-Nb mineralization developed during this stage. Veins in the Carbonate stage include quartz – calcite veins, feldspar- aegirine-augite veins, barite-quartz - calcite veins with aegirinite and sodium amphibolite veins, barite – quartz-calcite veins with biotite and a small number of aetolite and barite-quartz calcite veins with zeolite. (1) Quartz – calcite veins are the most widely distributed ore bearing veins in the region, consisting of quartz (> 50 %), calcite (30-40%,), barite and a small amount of plagioclase. Quartz is mostly “breccia”. The calcite is xenomorphic granular breccia. Pb mineralization was found in this type of veins. There is no obvious uranium mineralization. (2) Feldspar- aegirine-augite veins have strong Pb-U mineralization. The dark minerals in this type of veins are dominated by aegirinite and light-colored minerals are mainly microcline, followed by quartz, calcite and barite. Pb minerals are often disseminated in the aegirine-augite and are irregular clumps and become thin veins between feldspar and calcite granules. (3) Barite-quartz - calcite veins with aegirinite and sodium amphibolite have obvious banding phenomenon. The main mineral is calcite follow by aegiran, microcline, quartz, barite and so on. (4) The barite – quartz-calcite vein with biotite and a small number of aetolite veins are not large and are generally 0.5-1m wide, with the characteristics of collection of biotite. Calcite is mainly gray and white. The gelenite and blomstrandite are disseminated and star point distributed. The mineralization is weak. The mineral distribution in the veins is disorder. (5) Barite-quartz calcite veins with zeolite veins are not large and is generally 1-2mm in width and they are reticular and fine veins filled in the early-formed fractures. It is seen that the galena is granular living with barite, calcite and quartz. The mineralization is weak, we do not find the U mineralization, mainly Pb mineralization. These veins are the last phase of ore-bearing veins, and cut the early mineralized veins. The second and third type of veins are the most important U-Nb-Pb mineralized veins. The ore bearing rocks are mainly pegmatite and carbonate veins. The single vein is not large (tens cm wide), but dense. Veins of different types and scales penetrated in different directions and different types of fractures. The veins of different stages are interlaced and interwoven, so we saw branches and meshes on the wall. The overall trending is NW, especially for those with mineralization. Characteristics of mineralization The Huayanchuan deposit is mainly a U-Nb-Pb deposit, with a combination of precious metals and rare earth elements. The U mineralization minerals are mainly blomstrandite and uraninite, followed by the uranium contained changbaiite and fergusonite. The Nb mineralization minerals are mainly blomstrandite followed by a small amount of fergusonite and niobium rutile. The Pb mineralization minerals are mainly galena and a small amount of oxidized cerussite. Precious metal Ag and scattered elements Bi, Cd, Se and Te are mainly dispersed in galena. Rare earth elements here are mainly about La, Ce and Y, and the minerals mainly include xenotime, allanite , monazite, bastnasite and fergusonite and so on. The biotitization, actinolitization and potassic alteration are typical characteristic of the uranium mineralization during the pegmatite stage. In the pegmatite with biotitization, we found the uranium grade is normally over one-in-one-thousand. Blomstrandite was found in the area where biotitization and actinolitization developed The mineral assemblages of biotite-aegirine-augite-sphene-zoisite-amphibole-apatite is closely related to U mineralization. The more these minerals develop the more obvious uranium mineralization found. Among these assemblages, the biotite-aegirine-augite- sphene is especially closely correlated with the U mineralization. The galena is mainly produced on the boundary, and in general where pyritization developed, where there is strong lead mineralization. Assemblage of aegirine-augite and pyrite is the main metallogenic character of galena. DISCUSSION AND CONCLUSION The wall rock of Huayangchuan deposit is Archeozoic gneissic suite. The boundary between ore-bearing veins and wall rocks is clear. And the wall rock alteration is not obvious. There are no specific wall rocks that are closely related to the mineralization. However, there are differences of the development degree of the fractures among different types of wall rocks. For example, it is easier to form more dense fracture and fissure system among the biotite-plagioclase gneiss than hornblende gneiss and granite gneiss. The development degree of fractures and fissures in the region directly affected the density and mineralization of ore-bearing veins. We divide the metallogenic process into two stages: pegmatite stage and carbonate stage. Qiu (1993) date the feldspar within the carbonate using the K-Ar dating and got 204~206Ma. Yu (1992) date the flogopite in carbonate using the K-Ar dating and got 181Ma. He et al. (2016) obtained the age (39Ar-40Ar）of 133.01±0.74Ma from biotite in the carbonatite, and the age（39Ar-40Ar）of 91.49±1.97Ma biotite in pegmatite. The ages, 204~206Ma and 181Ma can be compared with that of the intrusion of Laoniushan granites (146 and 228 Ma) [11] and the ages, 91.49Ma and 133.01Ma were basically in line with the time of the intrusion of Huashan Granites (92-142Ma) [10]. There is a high degree of consistency and affinity in time and spatial distribution between the formation of pegmatite and carbonate veins and the Huashan and Laoniushan Granites. In different stages, symbols of hydrothermal metasomatism was found. We suggested that the Huayangchuan U-Nb-Pb deposit is the result of the co-action of the carbonate rocks and the Huashan, Laoniushan plutons. And the deposit is magmatic-hydrothermal genetic type. In summary, we found that: (1) The Huayangchuan U-Nb-Pb deposit occurred in the Archean gneiss. The main ore-hosted rocks are pegmatite and various veins of carbonate rocks. (2) U-Nb mineralization occurred during the pegmatite stage within granitic pegmatites and migmatic pegmatite veins. U-Nb-Pb mineralization mainly developed in the carbonate rock stage within quartz- carbonatite veins. (3) Ore bodies extended NW and are mainly controlled by the NW-trending Huayangchuan fault followed by NNW-trending secondary fractures. (4) The characteristic symbols for the uranium mineralization within the pegmatite stage are the biotite-actinolite assemblages, and that in the carbonate rock stage are the biotite-aegirine-kaolinite-kaolinite-amphibole-apatite assemblages. In contrast, characteristics of Pb mineralization are marked by breccia aegirineaugite -metal sulfide combinations. (5) We proposed that the Huayangchuan deposit is the magmatic-hydrothermal superposition type. REFERENCES [1] WANG, L.，XU, C.，WU, M., SONG, W., A Study of Fluid Inclusion from Huayangchuan Carbonatite, ACTA MINERALOGICA SINICA 31 (2011) 372-379 [2] GAO, C., KANG, Q., ZHANG, X., CHEN, X., and HU, J., Uranium occurrences and carbonatite petrology in Huayangchuan, Geology of Shanxi 33 (2015) 10-13 [3] HUI, X., HE, S., Mineralization Characteristic of Carbonatite Veins in Huanyangchuan U-polymetal Deposit, Shanxi Province, Uranium Geology32 (2016) 93-98 [4] HE, S., LI, Z., HUI, X., GUO, J., 40Ar/ 39Ar Geochrononlogy of biotite in Huayangchuan uranium-polymetallic deposit in Shanxi Province and its Geiological significance, Uranium Geology 32 (2016) 159-164 [5] HUI, X., LI, Z., FENG, Z., CHENG, D., Research on the Occurrence State of U in the Huayangchuan U-Polymetallic Deposit, Shanxi Province, ACTA MIERALOGICA SINICA 34 (2014) 573-580. [6] HE, S., LI, Z., HUI, X., GUO, J., Characteristics of mineralization alteration from Huayangchuan U-Nb deposit in Shanxi province, World Nuclear Geoscience 33 (2016) 8-32. [7] WU, C., LIU, Z., MA, J., TANG, B., Occurrence state of uranium in Huayang Chuan polymetallic deposit. Uranium Mining and Metallurgy 34 (2015) 30-34. [8] XU, C.，CAMPBELL, I .H.，ALLEN, C. M.，HUANG, Z. L，Qi, L.，ZHANG, H，ZHANG, G. S., Flat rare-earth element patterns as an indicator of cumulateprocesses in the Lesser Qinling carbonatites，China, Lithos 95(2007) 267-278. [9] XU, C.，WANG, L.，SONG, W., Carbonatites in China: A review for genesis and mineralization, Geoscience Frontiers 1 (2010) 1-10. [10] GUO, B., ZHU, L., LI, B., GONG, H., WANG, J., Zircon U-Pb age and Hf isotope composition of the Huashan and Heyu granite plutons at the southern margin of North China Carton: Implication for geodynamic setting. Acta Petrologica Sinica 25 (2009) 265-281. [11] QI, Q., WANG, X.，KE, C. and LI, J., Geochronology and origin of the Laoniushan complex in the southern margin of North China Block and their implications: New evidences from zircon dating, Hf isotopes and geochemistry, Acta Petrologica Sinica 28 (2012) 279 -301 [12] YU, X., Geological，petrol-mineralogical characteristics and origin 0f the carbonatites from Huayangchuan, Shaanxi province, Earth Science-Journal of China University of Geosciences 17(1992) 151-158. [13] QIU, J., ZHEN, G., LI, C., Qinba alkaline rock, BEIJING:GEOLOGY PRESS, 1993.
Speaker: Dr Jie Yan (East China University of Technology)
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Alteration fingerprint of the early Yanshanian granite-related high-temperature hydrothermal uranium mineralization in the Nanling Metallogenic Belt, Southeast China
ABSTRACT In the Xiazhuang and Zhuguang uranium ore fields of the Nanling Metallogenic Belt, southeast China, granite-related hydrothermal uranium deposits formed in two major mineralisation stages: (i) an early Yanshanian high-temperature stage (175–145 Ma) concomitant with the early Yanshanian magmatic event; and (ii) a late Yanshanian low-temperature stage (110–50 Ma) that occurred during the Cretaceous-early Cenozoic crustal extension in eastern Asia. To date, the Baishuizhai occurrence (175±16 Ma) and the Shituling and Zhushanxia deposits (162±27 and 165–146 Ma, respectively) represent the early Yanshanian uranium mineralisation in the belt. The Zr-Th-Ta-bearing disseminated-to vein-type uranium mineralisation is cogenetic with a hydrothermal alteration assemblage of epidote, chlorite, muscovite, adularia, illite, calcite, apatite, APS and titanite. The ore trace element signature and the propylitic and potassic alteration are both in agreement with relatively high temperatures (>250°C), corroborated by temperatures of 316–455 °C estimated from chlorite. This early mineralisation stage appears to be related to the intrusion of the early Yanshanian granites where the mineralising fluids could partly to totally derive from the granites in a high-temperature hydrothermal system. This would be to date, the first description and known occurrences for a new type of hydrothermal uranium deposit associated with granites worldwide. INTRODUCTION AND GEOLOGICAL SETTING The South China Uranium Province accounts for the largest amount of explored uranium deposits and resources in China (∼50% of identified uranium resources; [1-4]). It includes three major types of uranium deposits, from the most to the least economic: (i) granite-related vein-type deposits, (ii) volcanic-related vein-type deposits and (iii) black shale-related deposits (i.e., C-Si-pelite type; [1, 5, 6]). Some small sandstone-type uranium deposits are also hosted in several Mesozoic-Cenozoic basins of the province. In addition to uranium, the province is also renowned for W, Sn, Bi, Sb, Mo, Au, Ag, Cu, Pb and Zn deposits [2, 3, 6], some of which belonging to the world-class category in terms of grade and tonnage. Granite-related hydrothermal uranium deposits from the Xiazhuang (eastern part of the Guidong batholith) and Zhuguang ore fields (OF) within the Nanling Metallogenic Belt (NMB) formed in two major mineralisation stages [5]: (i) an early Yanshanian high-temperature stage (175–145 Ma) concomitant with the early Yanshanian magmatic event that occurred in South China during the Jurassic; and (ii) a late Yanshanian low-temperature stage (110–50 Ma) that occurred during the Cretaceous-early Cenozoic crustal extension in eastern Asia. To date, the early Yanshanian stage is only represented by the Baishuizhai occurrence (175±16 Ma) and the Shituling (162±27 Ma) and Zhushanxia (165–146 Ma; [7]) deposits located in the Xiazhuang OF [5]. These early Yanshanian deposits are mainly hosted in Triassic granites (e.g., Baishuizhai and Maofeng plutons) emplaced during the Indosinian orogeny, among which peraluminous S-and L-type leucogranites and highly fractionated high-K calc-alkaline A2-type granite constitute the most favourable U sources [5]. The primary uranium mineralisation mainly occurs as Zr-Th-Ta-bearing uraninite and pitchblende disseminated in the host-granite or as vein filling fractures. Large amounts of secondary uranium mineralisation are also characteristics of these deposits. Preliminary description of the alteration mineral assemblage including hydrothermal epidote, chlorite, muscovite, K-feldspar, apatite etc. presented in [5] and ore-forming fluid temperatures ranging from 290 to 338 °C at the Shituling deposit [8] were strong evidence for a high-temperature hydrothermal system. Now, this work aims to better characterise the genetic conditions of the early Yanshanian uranium stage through detailed petrographic and mineralogical studies carried on the alteration minerals associated with the uranium mineralisation. **MATERIAL AND METHODS** Six mineralised samples were collected from the Baishuizhai occurrence (XB1) and the Shituling (XS1, XS2) and Zhushanxia (ZSX1, ZSX2, ZSX3) deposits in the Xiazhuang OF. The textural and paragenetic relationships of the alteration minerals associated with the early Yanshanian uranium mineralisation were determined through detailed petrographic studies by optical reflected light microscope and scanning electron microscope (SEM). The chemical composition of the alteration minerals was analysed by electron microprobe (EMP) and their trace element concentrations were measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). RESULTS 1. PETROGRAPHY AND MINERAL ASSEMBLAGE OF THE ALTERATION The hydrothermal alteration of the host granites associated with the early Yanshanian uranium mineralisation can be pervasive (e.g., Baishuizhai) or confined in the vicinity of fractures (e.g., Shituling and Zhushanxia). The alteration mineral assemblage identified in the studied deposits includes epidote, chlorite, calcite, adularia, muscovite, illite, quartz, apatite, titanite, aluminium phosphate-sulphate (APS) minerals, albite and Fe-oxide. Sulphide minerals such as pyrite, chalcopyrite, galena, molybdenite, sphalerite, bismuthinite and greenockite are also frequently observed. These alteration minerals either occur disseminated in the altered host-granite (e.g., Baishuizhai) or along the mineralised veins (e.g., Shituling). This typical mineralogy characterise extensive propylitic (epidote-chlorite-calcite±albite) and potassic (adularia-muscovite-illite) alterations and silicification (quartz). In the Baishuizhai occurrence, the magmatic feldspars are completely replaced by muscovite, illite and quartz, which is characteristic of greisenisation. 2. CHEMICAL SIGNATURES OF THE ALTERATION MINERALS Among the alteration minerals that were identified, epidote, chlorite and muscovite occur in the three studied deposits and show specific major, minor and trace element compositions, although chlorite is rare in samples from the Shituling deposit. Epidote from Baishuizhai is characterised by its Mn content (16.3–17.5 wt%) whereas epidote from Shituling and Zhushanxia presents similar compositions ranging from 22.9–36.4 wt% CaO, 11.4–25.9 wt% Al2O3 and 5.7–13.4 wt% FeO. All epidotes are characterised by variable concentrations of Ti (27–1215 ppm), V (10–819 ppm), Zn (6–309 ppm), Y (0.1–99 ppm), Sn (5–89 ppm) and Zr (limit of determination (LOD)–8 ppm). It can be noted that only epidote from Baishuizhai returned heavy REE concentrations up to 7 ppm Lu, 11 ppm Er and 33 ppm Yb. Epidote from Shituling and Zhushanxia also has additional concentrations of Sr (5–287 ppm), W (3–56 ppm) and Nb (9–42 ppm). Chlorite from Baishuizhai and Zhushanxia is Fe-dominant (18.9–31.4 wt% FeO; 9.0–16.9 wt% MgO) giving a chamosite composition. Trace elements of petrogenetic interest are Ti (70–1559 ppm), Zn (473–1450 ppm), Li (441–1024 ppm), V (25–425 ppm), Rb (4–170 ppm), Sn (2–58 ppm), Cs (9–51 ppm), Nb (LOD–31 ppm) and Zr (LOD–12 ppm). The calculated temperatures from the chlorite compositions (Al IV thermometer, after [9]) range from 316 to 455 °C (n= 19). Muscovite from the three studied deposits shows relatively homogeneous composition with 46.2–53.2 wt% SiO2, 27.4–33.8 wt% Al2O3 and 3.1–11.5 wt% K2O contents. It has variable Rb (120–2856 ppm), Ti (37–2319 ppm), Cs (29–1667 ppm), Li (43–1084 ppm), Sn (LOD–628 ppm), Sr (LOD–252 ppm), Nb (LOD–451 ppm), W (LOD–111 ppm), Zr (LOD–57 ppm) and Ta (LOD–31 ppm) concentrations. Titanite from the Zhushanxia deposit (average of 34.4 wt% TiO2, 30.9 wt% SiO2 and 29.4 wt% CaO) shows minor Al2O3 (0.9–1.4 wt%) and FeO (0.1–0.8 wt%) contents and has variable W (160–2010 ppm), Zr (42–878 ppm), Y (81–352 ppm), Sn (47–248 ppm), Nb (100–190 ppm) and Ta (4–12 ppm) concentrations. Finally, apatite from the Shituling and Zhushanxia deposits presents a fluorapatite composition with 52.2–58.5 CaO wt%, 38.0–43.3 wt% P2O5 wt% and 1.6–2.2 F wt% contents. Trace elements with significant concentrations are Sr (615–3640 ppm), Y (69–777 ppm), Rb (2–151 ppm), Th (1–130 ppm), W (3–70 ppm) and Sn (2-19 ppm). DISCUSSION AND CONCLUSIONS The alteration mineral assemblage from Baishuizhai, Shituling and Zhushanxia including epidote, chlorite, K-bearing silicate, titanite and apatite associated with Zr-Th-Ta-bearing uranium oxides characterise an extensive propylitic and potassic alteration strongly suggesting high temperature conditions. The high temperature of the hydrothermal system was thus confirmed by temperature estimates ranging from 316 to 455 °C calculated with the Al IV thermometer in chlorite [9], which is also corroborated by temperatures of 290–338 °C determined from fluid inclusions for the ore-forming fluid of the Shituling deposit [8]. The chemical signatures of the alteration minerals showing characteristic concentrations of incompatible elements (K, Cs, Li, Rb, Sr, Y, Zr), rare metals (Sn, W, Nb, Ta) and occasionally heavy REE indicate highly differentiated crustal source-rocks [10, 11] such as peraluminous leucogranite or highly fractionated high-K calc-alkaline granite [5], widely represented in the NMB, and also suggest the contribution of magmatic-derived fluids. For instance, hydrothermal titanite largely occurs in alteration zones associated with the intrusion of igneous rocks. It is a common alteration product highlighting late magmatic to post-crystallisation hydrothermal alteration in porphyry Cu and Fe-Cu-Au-W-Mo skarn mineralising systems [12, 13]. Moreover, the Zr content in titanite, up to 878 ppm in titanite from Zhushanxia, also reflects the magmatic contribution as a source of fluid for the hydrothermal system [13]. The greisenisation characterised in Baishuizhai constitutes another strong evidence for the contribution of magmatic-derived fluids to the hydrothermal system. It is indicative of late magmatic alteration of the host-granite that most likely occurred during the cooling stage of emplacement of the early Yanshanian granite in the district. As they are generated during the final stage of granite crystallisation, the late magmatic fluids responsible for the greisenisation tend to be enriched in incompatible elements [10, 11], and also known to be at the origin of W-Sn-Mo-(U) etc. mineralisation in the province [2, 3, 6, 14]. Then the significant and systematic record of this suite of elements in the studied alteration minerals would be the marker of the contribution of such fluids. In the Xiazhuang OF, the early Yanshanian uranium mineralisation is also associated with minor tungsten occurrences such as wolframite in the Shituling deposit [15] and sheelite in the Zhushanxia deposit (up to 0.3% W; [7]), indicating possible genetic relations between uranium and tungsten mineralisation. Finally, the occurrence of fluorapatite (up to 2.2 wt% F) in the Shituling and Zhushanxia deposits together with calcite in the three studied deposits suggest that the hydrothermal solutions were enriched in fluoride and carbonate ions that can form complexes able to transport metals including uranium [5]. Therefore, the early Yanshanian uranium stage appears to be strongly related to the intrusion of the early Yanshanian granites providing: (i) the heat source for the high temperature hydrothermal system, (ii) magmatic-derived fluids that can mix with hydrothermal fluids already present in the basement and (iii) major sources for incompatible elements and rare metals that are concentrated in the alteration minerals and the uranium mineralisation. This model is new for hydrothermal uranium deposits related to granites and seems to represent the only occurrence of this type in the world. At the scale of the NMB, the alteration fingerprint that was characterised in this study for the early Yanshanian uranium event presents numerous similarities with the genetic model proposed for the giant W-Sn event in South China [5, 6, 14], also related to the intrusion of the early Yanshanian granites (peak at 160–150 Ma). Further studies will be conducted in order to characterise the spatial-temporal relations between the U and W-Sn mineralising systems in the NMB. ACKNOWLEDGMENTS The study was supported by the East China University of Technology in Nanchang, Jiangxi Province, and the Research Institute No. 290 from the Bureau of Geology of the Chinese Nuclear National Corporation (CNNC) in Shaoguan, Guangdong Province. REFERENCES [1] DAHLKAMP, F.J., Uranium Deposits of the World. Springer Ed., Asia (2009) pp. 493. [2] MAO, J.W., et al., “Mesozoic metallogeny in East China and corresponding geodynamic settings – an introduction to the special issue”, Ore Geology Reviews 43 (2011) pp. 1–7. [3] MAO, J.W., et al., “Major types and time-space distribution of Mesozoic ore deposits in South China and their geodynamic settings”, Mineralium Deposita 48 (2013) pp. 267–294. [4] OECD-NEA/IAEA, Uranium 2016: Resources, Production and Demand (2016). [5] BONNETTI, C., et al., “The genesis of granite-related hydrothermal uranium deposits in the Xiazhuang and Zhuguang ore fields, North Guangdong Province, SE China: Insights from mineralogical, trace elements and U-Pb isotopes signatures of the U mineralisation”, Ore Geology Reviews 92 (2018) pp. 588–612. [6] PIRAJNO, F., Yangtze craton, Cathaysia and the South China block, In: Pirajno, F. (Ed.), The Geology and Tectonic Settings of China's Mineral Deposits, Springer Ed, (2013) pp. 127–247. [7] HU, B.Q., et al., “The early high-temperature uranium mineralization in Zhushanxia deposit”, Journal of East China Geological Institute (2003), in Chinese with English abstract. [8] WU, L.Q., et al., “Discussion on uranium ore-formation age in Xiazhuang ore-field, northern Guangdong”, Uranium Geology 19-1 (2003) pp. 28–33. [9] CATHELINEAU, M., “Cation site occupancy in chlorites and illites as a function of temperature”, Clay Minerals 23 (1988) pp. 471–485. [10] LEHMANN, B., “Metallogeny of granite-related rare-metal mineralization: a general geochemical framework”, Resource Geology Special Issue 15 (1993) pp. 385–392. [11] CERNY, P., et al., “Granite-related ore deposits”, Economic Geology 100 (2005) pp. 337–370. [12] CAO, M.J., et al., “In situ LA-(MC)-ICP-MS trace element and Nd isotopic compositions and genesis of polygenetic titanite from the Baogutu reduced porphyry Cu deposit, Western Junggar, NW China”, Ore Geology Reviews 65 (2015) pp. 940–954. [13] CHE, X.D., et al., “Distribution of trace and rare earth elements in titanite from tungsten and molybdenum deposits in Yukon and British Columbia, Canada”, The Canadian Mineralogist 51 (2013) pp. 415–438. [14] LEGROS, H., et al., “Detailed paragenesis and Li-mica compositions as recorders of the magmatic-hydrothermal evolution of the Maoping W-Sn deposit (Jiangxi, China)”, Lithos 264 (2016) pp. 108-124. [15] ZHU, B.Q., et al., “Isotopic geochemistry of Shituling uranium deposit, northern Guangdong Province, China”, Mineral Deposits 25–1 (2006) pp. 71–82, in Chinese with English abstract.
Speaker: Dr Christophe Bonnetti (State key laboratory breeding base of nuclear resources and environment, East China University of Technology)
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RARE EARTH ELEMENTS IN URANINITE: BRECCIA PIPE URANIUM DISTRICT, NORTHERN ARIZONA, USA
INRODUCTION Interest in rare earth minerals (REE) originated in 1883 with the development of incandescent gas mantles containing rare earth and zirconium oxides. The knowledge that the supply of REE will not be able to keep up with new and ever-growing demands has been no secret in the geological community for years. However, it was not until it was presented to congress as a “potential shortage that could impact US renewable energy sources, communications and defense industries” that politicians and the public tumbled to how critical these metals are and just how vulnerable the US currently is to supply disruption. In 2008, China produced 97% of the worlds REE (primarily from Bayan Obo), India 2.2%, Brazil 0.5%, and Malaysia 0.3%. Up until 2002, the Mountain Pass REE Mine in California produced about 5% of the world’s REE supply. China’s lock on the world’s supply will be difficult to break. Starting in 2005, China put export taxes on REE of 15-20% and put on export restrictions. Forecasts predicted a critical shortage for the rest of the world outside of China by as early as 2012. So, REE prices went up. Just as the Mountain Pass Mine was getting ready to go into production in 2012, China eased their export restrictions and the price of most of the REE plummeted downward. Three years later in 2015, Mountain Pass mine went into bankruptcy. REE were extracted as a by-product of uranium mining in Canada during 1966-1970 and 1973-1977 at the Blind River and Elliott Lake deposits. The ore mineral uraninite contained sufficient REE to make extraction of REE profitable from the raffinate fluids. From 1966 to 1970, uranium mines in the Elliot Lake district were the world’s major source of yttrium concentrate. All rare earths except promethium have been detected in these ores. The Elliot Lake ores also contain about 0.11% uranium oxide (U3O8), and 0.028% rare-earth oxides [1]. The economic appeal of this occurrence is that the REE are concentrated in the uraninite, which was already being concentrated from the ore, so the REE are a bonus. “For a short period of time, HREE were extracted from the raffinate fluids that emanated from the chemical processing of uraninite at Blind River, Ontario.” [2]. Since REE are significantly concentrated within the uraninite from breccia pipes in northern Arizona, they likewise could be extracted from northern Arizona uraninite. POLYMETALLIC NORTHERN ARIZONA BRECCIA PIPE DISTRICT A unique polymetallic-rich uranium, solution-collapse breccia-pipe district lies beneath the plateaus and in the canyons of northwestern Arizona. It is known for its large reserves of high-grade uranium (average grade of 0.65% U3O8 [3]) that were estimated by the US Geological Survey to comprise over 40% of the US’s domestic uranium resources [4]. The breccia-pipe uraninite contains REE enrichment similar to that of the Canadian Athabasca Basin’s uranium deposits. From late1980’s until about 2004, the price of most metals had been sufficiently depressed such that little was done to explore or study these polymetallic ores, particularly the REE, that are rich in the district’s uranium deposits. Since 2008, the price of most REE has increased over 10-fold. This is true of all energy critical elements, including Co and Cu, also heavily enriched in the breccia pipe ore. These important elements commonly comprise over 1% of the breccia pipe ore. The northern Arizona metallic district can be thought of as a paleo-karst terrain pock-marked with sink holes, where in this case most “holes” represent a collapse feature that has bottomed out over 3000 ft below the surface in the underlying Mississippian Redwall Limestone. These breccia pipes are vertical pipes of breccia formed when the Paleozoic layers of sandstone, shale, and limestone collapsed downward into underlying caverns. A typical pipe is only approximately 300 ft (91 m) in diameter and extends upward as high in the section as the Triassic Chinle Formation. Although each breccia pipe in itself is not a huge ore deposit – up to 10 million pounds (lbs) (4500 tU) of uranium per pipe – in total the resources in the district are enormous. Many of the various small, mineralized pipes are clustered together providing somewhat contiguous mineralization, which reduces the mining costs. The water table is deep below the orebodies, which lie 500-1600 ft below the surface, sufficiently above the water table to minimize potential contamination of the aquifer. Mining activity in the Grand Canyon breccia pipes began during the nineteenth century, although at that time mining was primarily for copper, with minor production of silver, lead, and zinc. It was not until 1951 that uranium was first recognized in the breccia pipes. The intrinsic geology of these pipes, together with growing understanding of the nature of telethermal ores, (a classification category to which the base-metal deposits of the pipes belong), are important components of the model of their genesis. The metallized pipes are base-metal bearing and, regionally, bear a slightly later metal overprint of uraninite. A model was proposed for genesis of these ores as members of the class of Mississippi Valley Type (MVT) deposits, but with late-stage uranium mineralization [3]. U-Pb ages on uraninite of 200 and 260 Ma [5] link the mineralization with Pangean time, events, and mid-continent MVT ores; chemistry and fluid-inclusion temperatures on sphalerite and dolomite of 80°-173° also link them with MVT deposits [3]. Mixing of oxidizing groundwaters from overlying sandstones with reducing brines that had entered the pipes due to dewatering of the Mississippian limestone created the uranium deposits. Proximity to the west of the Cordilleran miogeocline and various uplifts to the east allow consideration of a basin-dewatering mechanism as the genetic mechanism [3]. RARE-EARTH ELEMENTS IN BRECCIA PIPE URANINITE REE are significantly enriched in much of the breccia pipe ore. Whole-rock analyses of uranium ore-bearing rock from across the district show REE enrichment that is not uncommonly 20 times average crustal abundance. A study of REE within uraninite was undertaken at the facilities of CREGU-GeoRessources, Nancy, France, using Laser Ablation ICP-MS in conjunction with electron microprobe analyses of the uraninite [6]. This research has confirmed that a significant percentage of the bulk rock REE content is tied up in the uraninite crystal structure. Although the breccia-pipe bulk-rock REE content is not as enriched as in the carbonatites at Mountain Pass, California (CA), the breccia-pipe uraninite contains concentrations of Nd, for example, that are between 15-20% of the Nd concentrations in the bastnaesite of Mountain Pass. Considering that at Mountain Pass the bastnaesite (REE ore mineral) has to be mined strictly for REE, the uraninite in the breccia pipes is already processed for the uranium. Hence, the Nd and other REE collected from the raffinate fluids are an added value to the profit. Additionally, the more valuable heavy REE (HREE) are enriched in the uraninite, whereas the Mountain Pass, CA and Bayan Obo, China ore deposits contain essentially little significant HREE. REE PRIMARY & REMOBILIZED ORE-DEPOSIT SIGNATURES Distinctive REE signature in uranium oxides is directly related to the variability of the mineralizing processes and geological setting between uranium deposit types [9]. All the uranium oxides from unconformity related deposits, such as from the Eastern Alligator district in Australia and Athabasca Basin district in Canada, are characterized by a bell-shaped REE pattern centered on dysprosium. This type of pattern seems to be characteristic of uranium oxide primary ore deposited from high-salinity basinal brines. The Sage and Pinenut breccia pipes of northern Arizona have bell-shaped chondrite-normalized distributions that are remarkably similar to the Athabasca Basin’s McArthur River (currently produces 25% of the world’s uranium) and Shea Creek uraninites [8], with a normalized maximum centered on Sm-Eu-Gd. Interestingly, the Pinenut breccia pipe, with its bell-shaped REE pattern, has the oldest age, 260 Ma [5] of those that were part of this study, suggesting it is primary ore (no age determination was completed on the Sage orebody by Ludwig & Simmons). The REE element patterns of uraninite samples from three of the breccia-pipe uranium mines (Pigeon, Kanab N, and Hack 2) have chondrite-normalized distributions that show some fractionation and a negative Eu anomaly. They distinctly resemble chondrite-normalized plots of uraninite samples [7] from the Athabasca Basin Eagle Point deposit, but with overall lower REE content. The rocks from both the three breccia pipe orebodies and Eagle Point show striking oxidation-reduction fronts within some of the ore. Such samples correspond to uranium oxides that are remobilized by oxidized meteoric fluids. These fluids mobilized the LREE preferentially over the HREE. Therefore, the uranium oxides from the redox front are characterized by LREE enrichment, which differs from the primary ores, and clearly demonstrate their distinct conditions of formation from the primary ore [9]. The HREE part of the chondrite-normalized distribution is preserved. The negative Eu anomaly of these samples could possibly be a result of oxidizing meteoric fluids albitizing the detrital feldspars in the clastic host rocks, permitting preferential incorporation of Eu over the other REE into the albite structure (similar to magmatic plagioclase creating a negative Eu anomaly). The three more-fractionated uraninite orebodies (Pigeon, Kanab N, and Hack 2) have younger ages of 200 Ma [5] as contrasted with the Pinenut 260Ma ore with a bell-shaped REE pattern. All of the breccia-pipe orebodies are believed to have formed due to a mixing of high-salinity basinal brines (based on fluid inclusion results) and oxidizing groundwaters [3]. Hence, the primary ore, breccia pipe uraninite samples fit the same REE chondrite-normalized pattern as do uraninites from the primary uranium deposits of McArthur River and Shea Creek. Interestingly, the Pigeon, Kanab N, and Hack 2 mines all lie along a N45°E trend that is parallel to one of the two major fracture directions in northern Arizona. So, they may have been more open to oxidizing groundwaters than the Pinenut and Sage orebodies. More samples from each mine and from other uraninite deposits within the district will provide insight into the fluids containing the REE. However, the pipe in pipe structure in many breccia pipes proves secondary dissolution. It is quite possible that all of the breccia-pipe orebodies have an older primary ore preserved and a later secondary oxidation/reduction front ore. The primary ore would be a higher U and REE grade. BRECCIA PIPE URANIUM & REE RESOURCE ESTIMATES The northern Arizona breccia-pipe district contains the highest-grade uranium in the U.S., with the potential for reserves that greatly exceed any other province in the U.S. With an average grade of 0.65% U3O8, and an environment conducive to relatively low cost conventional mining, these deposits are still economic in the $45/lb price range [10]. Unfortunately, in 2011, President Obama chose to issue an executive order withdrawing the million acres of northern Arizona land that encompassed most of the mineralized breccia pipes in the district. With the current emphasis by President Trump enabling exploration for strategic metals, these lands may soon be reopened to mineral exploration. Multiple approaches to uranium-resource calculations on these lands by separate researchers have shown remarkably similar results: 1. A uranium-resource estimate (referred to as resource endowment [11]) based on industry drilling for the 1050 mi2 (2719 km2) “mineralized corridor” of the breccia-pipe district have been made by [11]. Spiering and Hillard defined a “mineralized corridor” within the Breccia Pipe uranium district where they believe most of the mineralized pipes lie. It provides a smaller focused area to work with where more data are available. However, these authors still believe that considerable mineralized rock abounds beyond this corridor on private and public lands (the NE quadrant of the Hualapai Reservation is an example). Spiering & Hillard calculated the uranium resources [11] by (a) using VTEM Airborne Geophysics results and concluded that the mineralized corridor had 270 million lbs (122,500 tU) of U3O8 and (b) using known pipe density they concluded the corridor has 269 million lbs (122,000 tU) U3O8. 2. In 1987, the USGS [4] calculated the uranium endowment of the entire breccia pipe district. Spiering and Hillard [11] show that these calculations when applied to the “mineralized corridor” result in 375 million lbs (170,000 tU) of U3O8. 3. Using a control area of detailed surface mapping of solution-collapse features and mineralized rock [12] on the NE portion of the Hualapai Reservation, the current authors calculated that the “mineralized corridor” contains 260 million lbs (118,000 tU) of U3O8 (table 2) and the entire withdrawal area contains 385 million lbs (175,000 tU) U3O8.(table 2) These 3 independent resource estimates average to 302 million lbs (137,000 tU) of U3O8. The estimate by Spiering and Hillard and that by Wenrich et al. using completely different types of data within different geographic parts of the district (industry drilling vs. detailed surface mapping) have come to remarkably similar resource endowment estimates—270 vs. 260 million lbs (122,000 vs. 122,500 tU) of U3O8. Yetin 2011, the USGS, within the Final Environmental Impact Statement (EIS) for the breccia-pipe land withdrawal, arrived at a paltry 79 million lbs (36,000 tU) for their resource estimate. To arrive at this number, they did not use industry drilling [11], or previous USGS maps [12] or extensive resource calculations [4], but rather a non-peer reviewed elementary article written for the general public by Wenrich in 1988 where a simple statement was made that about 8% of collapse features and breccia pipes were mineralized. There were no data provided for this statement. To formulate such a low resource estimate based on such unsubstantiated data may have been an effort to support an administration political agenda. The three resource calculations above are in amazing agreement, so for the USGS in 2011 to arrive at such low numbers, ignoring industry drilling and other resource calculations indicates an incomplete and biased analysis. 4. A 4th approach is also applicable, which results in an estimate closer to the IAEA reasonably assured resources (RAR) 4 rather than a resource endowment. Prior to 1989 over 110 breccia pipes were drilled; 71 of these were identified to have ore-grade mineralization [13]. At an average of 2.9 million lbs (1300 tU) of uranium/pipe, the RAR (IAEA) or “indicated reserves” (USGS definition) total 206 million lbs (93,400 tU) of resources in the part of the district covered by Sutphin and Wenrich’s map [13]. Of these 71 mineralized pipes, 9 became uranium mines, 27 are known to contain an orebody, and 46 were mineralized, but with insufficient drilling to identify an orebody. Because the district is known to have very little low grade mineralization, if a pipe is mineralized with ore-grade mineralization, the odds are great that it contains an orebody. Since 1989, there has been significant exploration for uranium in the northern Arizona breccia-pipe district and more pipes have been located that are known to be mineralized. Hence, this Reasonably Assured Resource number of 206 million lbs (93,400 tU) is probably not an unreasonable estimate based on the historic drilling in the district. U.S. Energy Information Administration (EIA, U.S. Uranium Reserves Estimates, 2008) estimates that at$50/lb uranium, the US reserves are 539 million lbs (244,000 tU) of U3O8. They state that the definition of “’reserves’ for these estimates “…corresponds, in general, to the category of ‘Reasonably Assured Resources’ often used in international summaries of uranium reserves and resources…” Comparing the US RAR of 539 million lbs (244,000 tU) of U3O8 .and the RAR calculated above in item 4 to be 206 million lbs (93,400 tU), the breccia-pipe district contains 38% of the US uranium reserves. Using the minimum reserve calculation of 206 million lbs (93,400 tU) of U3O8 and the maximum endowment of 375 million lbs (170,000 tU), the “mineralized corridor” contains between 10 and 18 billion dollars at $50/lb uranium price and 21 and 38 billion dollars at$100/lb uranium price. REE analyses of breccia-pipe uraninite ore (this study) in France showed the total REE content of the uraninite to be around 0.43%. Hence, between 471,000 and 860,000 lbs (214 and 390 tU) of LREE and 405,000 and 737,000 lbs (184 and 334 tU) of HREE could be produced from the breccia-pipe district. The more valuable HREE have a greater presence in uraninite ores than in bastnaesite ores from the Bayan Obo and Mountain Pass Districts. The value added by REE to the uranium ore at $3.10/lb of U3O8 would be between 639 million dollars and 1.2 billion dollars (based on 2011 REE prices). The REE, badly needed for energy and industrial technology, coupled with the 10 to 38 billion dollars of uranium is a significant amount of money and energy reserves to lose from the US economy due to a land withdrawal that has essentially no significant scientific or environmental basis, as shown in the final EIS analysis. These estimates do not include value for other metals that are significantly enriched (many reaching and exceeding 1%) in the breccia-pipe polymetallic ore. These metals include Ag, Co, Cu, Mo, Ni, Pb, V, and Zn [3]4 CONCLUSIONS Rare earth elements are significantly enriched in much of the breccia-pipe ores. A study of REE within uraninite has confirmed that a significant percentage of the whole rock REE content is tied up in the uraninite crystal structure. All the uranium oxides from unconformity related primary ore deposits from the Eastern Alligator district in Australia and the Athabasca Basin district in Canada are characterized by a bell-shaped pattern centered on dysprosium. The Sage and Pinenut breccia pipes have bell-shaped chondrite-normalized plots that are remarkably similar to the Athabasca Basin’s McArthur River and Shea Creek uraninites). The Pinenut breccia pipe, with its bell-shaped REE pattern, has the oldest age, 260 Ma [5] in the district, suggesting it is primary ore. The REE patterns of uraninite from Pigeon, Kanab N, and Hack 2 breccia pipes (age of 200 Ma) have chondrite-normalized distributions that show some fractionation and a negative Eu anomaly, similar to the Athabasca Basin’s Eagle Point uranium deposit. The rocks from both these 3 breccia pipe orebodies and Eagle Point show oxidation-reduction fronts within some of the ore suggesting remobilization by oxidized meteoric fluids. Multiple approaches to uranium resource calculations have been made by separate scientists: (1) Uranium resource estimates based on industry drilling for the 1050 mi2 (2720 km2) “mineralized corridor” have been made by Spiering and Hillard [11], to be 270 million lbs (122,000 tU) of U3O8. (2) In 1987, the USGS [4] calculated the uranium endowment of the entire breccia pipe district. Spiering and Hillard [11], show that these calculations, when applied to the “mineralized corridor,” result in 375 million lbs (170,000 tU) of U3O8. (3) A resource estimate (part of this study) using detailed surface mapping of breccia pipes and mineralized rock [12], on the NE portion of the Hualapai Indian Reservation, showed that the “mineralized corridor” contains 260 million lbs (118,000 tU) of U3O8 and the entire withdrawal area contains 385 million lbs (175,000 tU). Uraninite analyses (this study) show the total REE content of the uraninite to be 0.43%. Hence, using the average 302 million lbs (137,000 tU) of the above three estimates, 1.3 million lbs (590 tU) of REE could be produced from the breccia pipe district “mineralized corridor”, adding REE value to the uraninite of$936 million. Between 28 and 48% of the REE production would be the more valuable HREE. REFERENCES CITED [1] CRANSTONE, D.A. 1981, Rare earths. Can. Miner. Yearb., 1979, pp. 365–371. [2] MARIANO, A.N., Hedrick, J., and Cox, C., 2010, REE deposits on a world level – real and potential: Part I: SME Technical Program Abstracts, March 2010, p. 87. [3] WENRICH, K.J. and Titley, S.R., 2008, Uranium exploration in Northern Arizona breccia pipes in the 21st century and consideration of genetic models, in: Titley, S.R. and Spencer, J., Ores & Orogenesis: Circum-Pacific Tectonics, Geologic Evolution, and Ore Deposits: Arizona Geological Society Digest 22, pp. 295-309. [4] FINCH, W.I., Sutphin, H.B., Pierson, C.T., McCammon, R.B., and Wenrich, K.J., 1990, The 1987 estimate of undiscovered uranium endowment in solution-collapse breccia pipes in the Grand Canyon region of northern Arizona and adjacent Utah: U.S. Geological Survey Circular 1051, 19 pp. [5] LUDWIG, K.R., and Simmons, K.R., 1992, U-Pb dating of uranium deposits in collapse breccia pipes of the Grand Canyon region: Economic Geology, v. 87, pp. 1747-1765. [6] LACH, P., Mercadier, J., Dubessy, J., Cuney, M., Boiron, M.C. 2013. Improved in-situ quantitative measurements of rare earth elements in uranium oxides by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry. Geostandards and Geoanalytical Research, accessed on line. [7] MERCADIER, J., Cuney, M., Lach, P., Boiron, M.C., Bonhoure, J., Richard, A., Leisen, L., Kister, P. 2011. Origin of uranium deposits revealed by their rare earth element signature. Terra Nova, v. 23, p. 264–269. [8] BONHOURE, J., Kister, P., Cuney, M., and Deloule, E., 2007, Methodology for Rare Earth Element Determinations of Uranium Oxides by Ion Microprobe: International Association of Geoanalysts, Geostandards, and Geoanalytical Research, v. 31, n. 3, pp. 209-225. [9] MERCADIER, J., Cuney, M., Cathelineu, L. Mathieu, 2011, U redox fronts and kaolinisation in basement-hosted unconformity-related U ores of the Athabasca Basin (Canada): Late U Remobilization by Meteoric Fluids: Mineral Deposita, v. 46, pp.105-135. [10] PILLMORE, Donn, 2013, oral communication. [11] SPIERING, E.D. and Hillard, P.D., 2013, Estimates of the withdrawn uranium endowment of the Arizona Strip District, Northern Arizona: Society of Mining Engineers, 2013 Annual Meeting, Feb 25, 2013. [12] WENRICH, K.J., Billingsley, G.H., and Huntoon, P.W., 1997, Breccia-pipe and geologic map of the northeastern part of the Hualapai Indian Reservation and vicinity northwestern Arizona: U.S. Geological Survey Miscellaneous Investigations Map I-2440, 19 p., 2 plates (includes fifteen 7-1/2 minute quadrangles), scale 1:48,000. [13] SUTPHIN, H.B., and Wenrich, K.J., 1989, Map of locations of collapse-breccia pipes in the Grand Canyon region of Arizona: U.S. Geological Survey Open-File Report 89-550, 1 plate with text, 1:250,000. [14] EIA US Uranium Reserves Estimates 2008.
Speaker: Dr Karen Wenrich (Wenrich Consulting 4 U)
• 10:40 AM
Break
• Applied Geology and Geometallurgy of Uranium and Associated Metals
Conveners: Dr Alexander Boytsov (Uranium One Group) , Mr Christian Polak (AREVA MINES)
• 34
GENETIC DEPOSIT MODEL FOR CALCRETE URANIUM IN THE SOUTHERN HIGH PLAINS REGION, UNITED STATES OF AMERICA
The semiarid Southern High Plains (SHP) physiographic region hosts calcrete uranium deposits in Pliocene and Pleistocene sediments. This region was identified by the U.S. Geological Survey (USGS) as prospective for calcrete uranium deposits, although no deposits of this type had been identified in the US. The existence of deposits in the area was confirmed through historic exploration reports that identified two drilled deposits and additional prospects in the region. Outcropping mineralization adjacent to a known deposit was sampled and analyzed and combined with analysis of regional geology to develop a genetic deposit model. USGS dating of uranyl vanadates, and volcanic ash found in the host rock indicates periodic mineralization occurred between about 631,000 and 4,000 years before present. The entire SHP is characterized by elevated dissolved uranium in groundwater, likely derived from the Triassic Dockum Group or volcanic ash in host sediments. Elevated dissolved vanadium in groundwater, coupled with areas of higher hydraulic conductivity define areas most highly prospective for the formation of carnotite, the major ore mineral for this deposit type. Mineral-solution equilibrium modeling indicates that evaporative concentration of local groundwater could produce saturation with carnotite, which suggests that the mineralizing systems may remain active.
Speaker: Dr Susan Hall (U.S. Geological Survey)
• 35
UDEPO: THE IAEA URANIUM DEPOSITS DATABASE
Speaker: Dr Patrice Bruneton (Private Consultant)
• 36
URANIUM DEPOSITS OF THE KARELIAN-KOLA PROVINCE (RUSSIAN FEDERATION)
Speaker: Ms Elena Afanasyeva (Russian Geological Research Institute)
• 37
Free thermal convection model for formation of the largest uranium field in the Streltsovka caldera (Transbaikalia, Russia)
• 38
EXPLORATION AND RESOURCE DEVELOPMENT OF URANIUM MINERALIZATION IN CENTRAL JORDAN
INTRODUCTION Uranium mineralisation has been known within the central areas of the Hashemite Kingdom of Jordan for a long time [1], however uranium resources were only estimated in 2014 [2]. The exploration success has become possible because of detailed geological studies that has allowed to better understand the geological control of uranium mineralisation in central Jordan. Based on these studies the exploration model was revised and implemented by Jordanian Uranium Mining Company (JUMCO) for delineating mineralisation and estimated resources. REGIONAL GEOLOGICAL CONTROL Most of Jordan’s territory is covered by platform sedimentary rocks of Cretaceous and Paleogene age. Uranium mineralisation was discovered within the platform cover where it is confined mainly to the Upper Cretaceous rocks, in particular the MCM (Muwaqqar Chalk Marl) formation. Uranium minerals, found in the weakly lithified friable sediments of the MCM formation are represented mainly by uranium vanadates colloquially termed carnotite [2]. Uranium mineralisation is distributed as fine-grained disseminations forming areas of variable size and shape that have impregnated the host sedimentary rocks and also coating the surfaces of the joints and fractures. The faults possibly also played a role in distribution of the uranium mineralisation in central Jordan where higher grade mineralisation and associated gamma anomalies are broadly coincident with the location of regional faults, mainly the East-West and North West–South East striking splays of the Dead Sea Transform fault. PYROMETAMORPHISM Unique feature of the surficial uranium mineralisation in central Jordan is its close spatial relationship with pyrometamorphic marbles that are hosted by unmetamorphosed marls, chalks and limestones. The marbles are varicoloured, commonly brown, greenish, reddish, white and locally black. They are cut by hydrothermal veins and have experienced different degrees of low temperature alterations. A unique feature of these rocks is the widespread distribution of high- and ultra-high temperature (up to 1500°C) low-pressure metamorphic mineral assemblages including spurrite, wollastonite, ellastadite, diopside and garnet [3-5]. The contacts of marble with the unmetamorphosed host sequence are sharp, although contact outlines are often irregular. The formation of marbles in central Jordan is commonly explained by pyrometamorphism, either caused by the burning of bituminous marls [5] or alternatively by the combustion of deep reservoirs of hydrocarbon gases relating to mud volcanoes [3-4]. Another unique geological feature of the uranium deposits in Jordan is occurrences of the exotic paramagmatic dykes that cut pyrometamorphic marbles. These dykes were identified in exploration trenches and marble quarries in central Jordan. These are similar to the dykes found in the in Israel and Palestine, where they also associate with high-temperature metamorphic rocks [3]. The dykes are interpreted as paralavas that have been formed as a result of the host rocks melting during high-temperature combustion metamorphism [2-4]. Dating of these pyrometamorphic rocks has identified several episodes of combustion metamorphism that have occurred in Miocene (~16 Ma), Pliocene (~ 3 Ma) and Pleistocene (1.7 – 1.0 Ma) [6]. These ages broadly coincide with the age of mafic magmatism that occurred in Jordan during the Miocene (23.8 - 21.1 and 12.05 - 8.08 Ma) and Pleistocene (3.2 - 1.5 Ma) [7-8], suggesting that this basaltic magmatism could have triggered the rapid combustion of hydrocarbons, or at least that these processes are part of the same tectono-magmatic event. SUPERGENE PROCESSES Within the MCM formation the uranium mineralisation is hosted by near-surface weathered chalks and marls and concentrated in a narrow layer, approximately 4.5m thick, distributed close to the topographic surface. Vertical profile of uranium distribution in central Jordan was studied in high details using 2188 trenches and 5691 drill holes [2]. It was noted [2] that the degree of weathering varies from complete alteration, when rocks have been converted to saprolite, to mildly weathered sedimentary rocks and the highest uranium concentrations were found located along the contact between saprolite and mildly weathered/fresh rocks. Near surface distribution of uranium mineralisation which was characterized by highly variable degree of isotopic disequilibrium has required using of exploration trenches for obtaining representative samples and estimating uranium resources [9]. Mapping of the trench walls have shown that uranium mineralisation is not controlled by phosphorite layers. SUMMARY AND CONCLUSIONS In general, the uranium mineralisation that is hosted by the weathered chalk and marl of the MCM formation in central Jordan has many common characteristics with the conventional surficial-type uranium mineralisation [10]. However, a close spatial relationship of uranium in central Jordan with the pyrometamorphic rocks suggests that this is a special type of surficial uranium mineralisation which has resulted from the interplay of the different processes, where combustion metamorphism has played a very important role in facilitating leaching of uranium from the host rocks. The liberated uranium was eventually redistributed by supergene processes towards the surface, where uranium minerals were precipitated along the contact between saprolite and fresh to weakly weathered rocks. This mineralization should not be confused with synsedimentary accumulations of uranium in the phosphorite beds which also present in Jordan [2]. REFERENCES [1] BENDER, F. (1975) Geology of the Arabian Peninsula, Jordan: US Geological Survey, Professional Paper 560-1, p.1-36. [2] ABZALOV, M.Z., et al. (2015) Geology and metallogeny of Jordanian uranium deposits: Applied Earth Science, 124, p.63-77. [3] VAPNIK, Ye. et al. (2007) Paralavas in a combustion metamorphic complex, Hatrurim basin, Israel, in Geology of coal fires: Case studies from around the world (ed. G.B.Stracher): Geological Society of America, GSA Reviews in Engineering Geology, XVIII, p.133–153. [4] SOKOL, E., et al. (2010) Combustion metamorphism in the Nabi Musa dome: new implications for a mud volcanic origin of the Mottled Zone, Dead Sea area: Basin Research, 22, p.414–438. [5] KHOURY et al. (2014) Mineralogy and origin of surﬁcial uranium deposits hosted in travertine and calcrete from central Jordan: Applied Geochemistry, 43, p.49–65 [6] GUR, D., et al. (1995) Ar40/Ar39 dating of combustion metamorphism: Chem. Geol., 122, p.171–184. [7] STEINZ, G., and BARTOV, Y. (1991) The Miocene – Pleistocene history of Dead Sea segment of the rift in light of K-Ar ages basalts: Isr. Journal of Earth Sciences, 40, p.199-208. [8] IBRAHIM, K.M., et al (2003) Phases of activity and geochemistry of basaltic dike systems in northeast Jordan parallel to the Red Sea: Journal of Asian Sciences, 21, p. 467-472. [9] ABZALOV, M. (2016) Applied Mining Geology. Modern Approaches in Solid Earth Sciences, 12, Springer, Berlin, 448p. [10] DAHLKAMP, F.J. (1993) Geology of the uranium deposits, Springer, Berlin, 460p.
Speaker: Dr Marat Abzalov (MASSA geoservices)
• Health, Safety, Environment and Social Responsibility
Conveners: Mr Harikrishnan Tulsidas (UNECE) , Prof. Jim Hendry (University of Saskatchewan)
• 39
AN INTERNATIONALLY STANDARDIZED REPORTING TOOL TO UNDERSTAND THE SUSTAINABLE DEVELOPMENT PERFORMANCE OF URANIUM MINING AND PROCESSING SITES
The World Nuclear Association has developed an internationally standardized reporting tool to understand the sustainable development performance of uranium mining and processing sites (referred to as the ‘Checklist’). The goal is to achieve widespread agreement on a list of topics and indicators (for example, environment, health and safety, corporate social responsibility) for common use in demonstrating producers’ adherence to sustainable development performance. Accompanying guidelines have also been prepared to support its use and completion. The Checklist is designed to draw on producers’ existing reporting, supplemented by additional information required to achieve comprehensive supply chain risk management. The Checklist has been developed to align with the Association’s policy document ‘Sustaining Global Best Practices in Uranium Mining and Processing: Principles for Managing Radiation, Health and Safety, and Waste and the Environment’. It has been prepared in cooperation with experts from some of the Association’s member organizations. It is anticipated that the Checklist will be reviewed over the next year to ensure that it accounts for any recent developments and feedback from user testing.
Speaker: Mr Frank Harris (Rio Tinto Uranium)
• 40
URANIUM, THE ENVIRONMENT AND SUSTAINABLE DEVELOPMENT: LESSONS FROM NAMIBIA
Speaker: Dr Gabi Schneider (Namibian Uranium Institute)
• 41
PERSPECTIVES ON SOCIAL COMMUNICATION IN THE BRAZILIAN NUCLEAR LICENSING PROCESS AND CHALLENGES ON STAKEHOLDER ENGAGEMENT: CAETITÉ URANIUM MINING CASE
Speaker: Mr Alexandro Rocha Scislewski (Brazilian Nuclear Energy Commission (CNEN) / District of Caetité (DICAE/BA))
• 42
Uranium deposit types, exploration methods and Corporate Social Responsibility (CSR) Programs: Case of LERE (Chad)
INTRODUCTION The Lere Uranium deposit was one of numerous uranium showings in Chad. It was highlighted in the Mayo-Kebbi West, close to the border with Cameroon. This deposit is best known because it has been the subject of previous studies by UNDP (United Nations Development Program) and the IAEA (International Atomic Energy Agency) between 1970 and 1980. Recently, these studies were supplemented by exploration Signet Mining Services Ltd (SMS), a European-based mining company called in Chad by Chad Mining Service (CMS). Furthermore, SRK was requested by Signet to generate a mineral resource estimate of the lere deposit as part of the initial exploration program. DESCRIPTION: METHODS AND RESULTS Located in southwestern of Chad, the Lere deposit has uranium hosted near vertical shear zones and secondary foliation in albitised and silicified granite in a mixed terrain of Precambrian units. It occurs within the Zabili granitoids, proximal to the contact with the schist and amphibolites of the Mayo kebbi series. The ore-body is a weathered, iron-stained (hematised), fractured and sheared, feldspar-rich (albite), low-quartz granite. Within the orebody; de-silicified as well as silica impregnated zones, are recognized. Signet Mining Services Ltd had (6) concessions comprising (841 kilometer-square km2) that include the Lere Project in south-western Chad near the towns of Lere and Pala. Exploration activities have included an airborne geophysical survey, a geological survey and a surface radiometric survey. Uranium anomalies and potentially significant structures have been identified. Anomaly A and B have been drilled by percussion drilling (18 541 meter) and core drilling (2 676 meter), enabling the development of a geological model and providing sufficient data for resource estimation. Chad Mining Services Company has completed over 170 vertical wells, 22 trenches and a dozen drilling inclined concentrations vary from one well to another the greatest value is in the order of (4000 ppm) in wells and is (50 to 100 ppm) in surface during the mapping. The deposit is estimated at (8,000,000 t) [2]. Resources compliant with the South African code for the reporting of exploration results, mineral resources and minerals reserves (The South African Mineral Resource Committee [SAMREC] Code) have been evaluated to amount to (3 190 tU), at an average grade of (200 ppm U) or (0.020% U). At a uranium price of less than USD 50/lb U3O8, the identified deposit is considered uneconomic. Further structures will need to be identified to increase the resources in order to move the project to a development stage [1]. CSR initiatives of CMS included various aspects namely: Employment, Infrastructure, Supplies, Compensation, Transfer of competences, Safety, Environmental protection, Information and communication, other community programs. DISCUSSION AND CONCLUSION In general, the subsoil of Chad has an abundance of important mining resource particularly an important potential in uranium’s ore that it exploitation will contribute to the national economy. It is important to note that Chad is still very under explored compared with other African countries. For that reason, as prospecting or mining research is the first step in the development of the mining sector, Chad Mining Services (CMS) made uranium exploration in the Mayo Kebbi Province (LERE). Studies conducted by CMS have outlined several areas that are highly prospective for uranium. However, exploration, mining and/or processing operations can have both positive and negative environmental, economic and social impacts on communities. They can provide employment and business opportunities to local communities such as exploration activities of CMS. In addition, a rational exploitation coupled with the modernization of techniques for extracting and processing minerals will increase employment nationally and regionally. REFERENCES [1] CHAD MINING SERVICE, report (2011). [2] NAYGOTIMTI BAMBE, Exploration of Uranium in Chad, State of places, (2010).
Speaker: Mr Abdallah Hassan Abakar (Ministry of Petroleum and Energy)
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SOCIETAL BARRIERS TO URANIUM MINING: A CASE STUDY FROM BRAZIL
Speaker: Dr Mariza Franklin (Brazilian Nuclear Energy Commission (CNEN) - Institute of Radiation Protection and Dosimetry (IRD))
• 12:40 PM
Lunch Break
Conveners: Dr Igor Pechenkin (All-Russian Scientific-Research Institute of Mineral Resources, Moscow, Russia) , Dr Susan Hall (U.S. Geological Survey)
• 44
DASA: AFRICA’S NEWEST WORLD CLASS URANIUM DEPOSIT IN NIGER, WEST AFRICA — A GLOBAL ATOMIC CORPORATION PROJECT
Speaker: Dr Peter Wollenberg (Global Atomic Fuels)
• 45
ADVANCES IN HYPERSPECTRAL REMOTE SENSING TECHNOLOGY FOR THE EXPLORATION OF HYDROTHERMAL TYPE URANIUM DEPOSITS IN CHINA: A CASE STUDY IN THE XUEMISITAN AND LONGSHOUSHAN AREAS
Speaker: Dr Fawang Ye (Beijing Research Institute of Uranium Geology)
• 46
Uranium Potential of Singhbhum Shear Zone, India: Future Prospects
Speaker: Dr D. K. SINHA (GOVERNMENT OF INDIA DEPARTMENT OF ATOMIC ENERGY ATOMIC MINERALS DIRECTORATE FOR EXPLORATION AND RESEARCH)
• 47
URANIUM EXPLORATION BY REMOTE SENSING METHODS IN THE KALEYBAR AREA, NORTH-WESTERN REGION, ISLAMIC REPUBLIC OF IRAN
Kaleybar area is located in Alborz-Azerbaijan zone northwest Iran, there is Cu-Fe-Au indices in this area; according to the earlier studies, this area can be considered for radioactive elements mineralization; also according mentioned study, radioactive anomalies are related to clay and silica Alterations, so these alterations can be used as a key to investigate other parts of Kaleybar area. In other side, remote sensing methods have made a good progress in detection and separation of alterations in recent years. Shortwave infrared (SWIR) bands from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with the wavelength between 1.65 and 2.43 µm has a good potential for mapping hydrothermal alteration minerals. In this study False Color Composite (FCC), Band Ratio (BR), Principle Component Analysis (PCA), Spectral Angel Mapper (SAM) methods where used to detect and separate Alterations. As result, 4 new areas where detected with clay alteration. After radiometry of these areas, 2 areas where identified as anomaly areas. Recent methods where used in this study and had good results for alterations detection and separation in Kaleybar area. These methods can be used as a key to research in similar areas.
Speaker: Dr Jalil Iranmanesh (Atomic Energy Organization of Iran)
• Health, Safety, Environment and Social Responsibility M3

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Conveners: Mr Dennis Amos MWALONGO (Tanzania Atomic Energy Commission) , Dr Gabi Schneider (Namibian Uranium Institute)
• 48
SUSTAINABLE WATER RESOURCE MANAGEMENT AT A URANIUM PRODUCTION SITE
Speaker: Dr Mariza Franklin (Brazilian Nuclear Energy Commission (CNEN) - Institute of Radiation Protection and Dosimetry (IRD))
• 49
URANIUM MINING WASTE, RISK PERCEPTION BY POPULATIONS AND ENVIRONMENTAL REMEDIATION IN PORTUGAL
Mining of radioactive ores for radium and uranium production took place in Portugal from 1908 up to 2001. Over the years, several companies produced salts of radioactive elements according to mining laws at the time. Following closure of the last uranium mine and milling facilities at Urgeiriça, local populations and the municipalities claimed for surveillance and responsibility on the legacy of uranium waste. An environmental radioactivity assessment and a public health assessment were carried out in the years 2003-2005. Based on the results and recommendations, the Government approved an environmental remediation plan. Local communities have been listened, intervened in the process, and contributed to solve radiation protection and environmental contamination issues. Up to the present, more than half of the former uranium sites were remediated, milling waste confined, mine water treatment stations installed or upgraded. At the same time a radiation monitoring programme of uranium areas is carried out by the LPSR/IST and the results annually delivered to Government and rendered public. Results has shown effective reduction of ambient radiation doses, treatment of acid and radioactive mine drainage before discharge, and abatement of radiation exposure in several areas.
Speaker: Prof. Fernando P. Carvalho (Instituto Superior Técnico/Laboratório de Protecção e Segurança Radiológica,)
• 50
ADVANCED QUANTITATIVE GAMMA SPECTROMETRY SOFTWARE FOR OPTIMIZED ENVIRONMENTAL ASSESSMENT DURING ‘CRADLE-TO-GRAVE’ URANIUM EXPLOITATION MANAGEMENT
INTRODUCTION Reliable, fast and cost effective assessment of various environmental parameters related to exploration, mining, production and decommissioning/remediation is an essential input parameter for the “cradle-to-grave” (“exploration-to-remediation”) uranium management. In the present paper ANGLE software for advanced quantitative gamma-spectrometry is briefly outlined and its applicability to that aim discussed. In any gamma-spectrometric measurement with semiconductor or scintillation detectors, the question of converting the number of counts (collected in a full energy peak) into the activity of the sample/source cannot be avoided. There are, in principle, three approaches to this problem [1]: o Relative, where one tries to imitate as good as possible the source by a standard (or vice versa), while keeping the same counting conditions for the two. Paid enough care, the result is, in general, so accurate that cannot be surpassed by other methods. However, we all know what "enough care" means in practice. Combined with the inflexibility in respect with varying source/container parameters (shape, dimensions, material composition), this represents raison d'être of the other approaches, as follows. o Absolute, like “Monte Carlo” calculations (MC), yielding full energy peak efficiency for a given counting arrangement. It is essentially statistical treatment of the events which photons undergo – from being emitted by a source atom until the interaction with the detector active body – including the treatment of the so produced electrons, positrons and other subsequent energy carriers. This approach is beautifully exact, on condition that we consider sufficiently large amount of incident photons, and that we know the details about a huge number of physical parameters characterizing the process. After many years of practice, still these are limiting factors for its applicability. o Semi-empirical, trying to conciliate the previous two. Semi-empirical models commonly consist of two parts: (i) experimental (producing one kind or another of reference efficiency characteristic of the detector) and (ii) relative-to-this calculation of peak efficiency. Inflexibility of the relative method is avoided in this way, as well as the demand for some of the physical parameters needed in MC calculations. Numerous variations exist within this approach, with emphases either to experimental or to computational part. Most of them (over)simplify the physical model behind, i.e. the treatment of gamma-attenuation, geometry and detector response. Stemming from the above, ANGLE purpose is to allow for simple, but accurate determination of the activities of gamma spectroscopic samples for which no “replicate” standard exists, in terms of geometry and matrix. It employs a semi empirical “efficiency transfer” (ET) approach, which combines advantages of both absolute and relative methods to determine sample activity by gamma spectrometry. In doing so, practical limitations of the latter methods are reduced, while the potential for systematic errors in the former is minimized [1, 2]. The physical model behind is the concept of the effective solid angle – a parameter calculated upon the input data on geometrical, physical and chemical (composition) characteristics of the source, the detector and counting arrangement (“geometry”). These three parameters are accounted for through a simultaneous differential elaboration, which leads to complex mathematical expressions – however easily managed by means of numerical integration with ordinary computers (PCs). A sound theoretical foundation in the above sense is hence laid in the beginnings of ANGLE development [1-4]. ANGLE is conceived and developed at the University of Montenegro, while commercially distributed by AMETEK-ORTEC, U.S.A. [5]. International cooperation has been an essential part during its evolution. Numerous scientific and technical papers, as well as Ph. D. theses, have emerged from ANGLE progression and utilization. OUTLINE OF ANGLE SOFTWARE All relevant information about ANGLE – including theoretical background, features, downloads, references, papers, questions, etc. – is found in much detail at its web site [6]. During its development, care was taken to reflect and take into account numerous users (gamma-spectrometrists’) needs, perspectives and feedback. User communication/support was thus an important part of the software development. Four main versions emerged since 1994 (current one being ANGLE 4), with nearly 300 updates. ANGLE 4 main features can be summarized as: o high accuracy – typical uncertainties at results obtained (quantitative gamma-spectrometry report) are of the order of a few percent – even introduced by input data, not the software itself; o broad range of applicability (e.g. in environmental monitoring, fuel cycle and nuclear industry, waste management, regulatory control, nuclear security and safeguards, medicine, research and education, etc.); o ease of use; there is a highly user oriented and intuitive interface, supported by graphical scaled visualization; o all parameters characterizing efficiency calculations are shown at one screen, thus easy to control and comprehend; o short computation times, which are an order of magnitude shorter than those of MC methods – even the most complex calculations are executed within minutes on ordinary PC machines; o flexibility in respect with input parameters and output data; o easy communication with another software – thus, can be regarded as a modular software; o suitability for teaching/training purposes; o calculates detection efficiencies for most common counting arrangements; o software supports:  semiconductor and scintillation detectors  closed end, open end, planar, well-type detectors  cylindrical, Marinelli, disc, point sources  various source containers  any source dimension  any matrix composition o detector calibration is done by the user; o there is no need for detector factory characterization and.or re-characterization o it is compatible with most common (ORTEC’s and Canberra’s) spectrum emulation software (GammaVision, Genie2000); o one copy of the software can serve all detectors in the lab, regardless of detector type, age and manufacturer; o transparent, hands-on software (no “black box” for the user) – all parameters of the detector, sample, counting geometry etc. are under control and subject to modification; o practical educational and training tool for gamma-spectrometry courses at all levels; o highly convenient for scientific research; o software design is aimed at bringing user to a higher level of gamma-spectrometry practice; o preview possibility for input data; visualizes counting arrangement (detector, source, geometry) and indicates potential systematic errors (blunders) o enables easy programming of huge batch jobs for efficiency calculations; suitable for monitoring, research (e.g. error propagation studies), optimization, etc. o has a modular nature – made to easily fit into more complex programs, which supply data to it and/or make use of its output results o highly informative web site o software architecture offers potential for accommodating other efficiency calculation methods of semi empirical or absolute (MC) type o its current scope of applicability can readily be extended to further/particular user's needs and/or fields of interest – it can be thus regarded as an “open ended” computer code; o multi language interface; currently exists in English, French, Spanish, Russian, Chinese and Japanese, but new languages can readily be added by translating (through a dedicated subroutine) an Excel file of cca 700 short strings A key aspect and difference from other approaches, which greatly enhances practicality, is that no “factory characterization” of the detector response is required. In fact any HPGe detector may be used so long as some basic knowledge concerning its construction is available. These technical data are normally supplied to the customers by detector manufactures, in form of accompanying data sheets, or can be obtained upon request. Care should be taken for the data to be as accurate as possible, since the accompanying uncertainties are propagated into final analytical results as systematic errors. As to reliability, let us mention here an IAEA organized intercomparison exercise, which was conducted in 2010 by European Commission JRC IRMM (Geel, Belgium) [7]. Ten laboratories took part, applying nine prominent efficiency transfer calculation codes: semiempirical (source derived) and absolute (Monte Carlo). The exercise revealed that systematic errors (differences occurring between experimental and calculated efficiency results) are, for the most part, not due to the calculation methods/procedures themselves (including attenuation coefficients, cross sections and other physical parameters used), but more to uncertainties in input data (detector, source, materials, geometry). ANGLE was one of participating codes, scoring 0.65% average discrepancy from the exercise mean values, with no evidence of systematic bias. APPLICABILITY TO URANIUM EXPLOITATION MANAGEMENT ANGLE applicability in uranium exploitation management is evident and straightforward – its simplicity, flexibility and fast performance allows for quantitative analyses of large numbers of samples in short periods of time, regardless of type, origin, size, shape, matrix composition etc. In practice, this translates into ability of quantitatively analyzing thousands gamma-spectroscopic probes within the counting capacity limits of the equipment – including samples of geological, environmental, industrial, biological, medical… or whatsoever origin, as these may occur during uranium exploitation management – from exploration to remediation phase (“cradle-to-grave”). This constitutes a considerable source of reliable first-hand information, which is essential in the decision makings. Applying ANGLE in uranium related matters is not a new story. Namely, in its various forms, ANGLE has been in use for 25 years now in hundreds of gamma spectrometry oriented laboratories worldwide, including many dealing with different aspects of uranium exploitation – either directly (in exploration, mining, processing, environmental and workplace monitoring, QC/QA, etc. facilities) or indirectly (e.g. within regulatory, health, research, educational or other institutions) [8]. However, a sort of topical (uranium) standardization – for instance in form of a dedicated “U” module – would be a welcome future development in this respect. ACKNOWLEDGEMENTS Kind and valuable assistance from the colleagues of the University Centre for Nuclear Competence and Knowledge Management (UCNC) in preparing this manuscript is highly appreciated. REFERENCES [1] Jovanovic, S., Dlabac, A., Mihaljevic, N., Vukotic, P., ANGLE: A PC code for semi-conductor detector efficiency calculations, J. Radioanal. Nucl. Chem., 218 (1997), pp. 13 20. [2] Jovanovic, S., Dlabac, A., Mihaljevic, N., ANGLE v2.1 – New version of the computer code for semiconductor detector gamma efficiency calculations, Nucl. Instr. Meth. A 622 (2010), pp. 385 391. [3] Vukotic, P., Mihaljevic, N., Jovanovic, S., Dapcevic, S., Boreli, F., On the applicability of the effective solid angle concept in activity determination of large cylindrical sources, J. Radioanal. Nucl. Chem., 218 (1997), 1, pp. 21 26 [4] Moens, L., De Donder, J., Xilei, Lin, De Corte, F., De Wispelaere, A., Simonits, A., Hoste, H., Calculation of the absolute peak efficiency of gamma ray detectors for different counting geometries, Nucl. Instrum. Methods Phys. Res., 187 (1981), 2 3, pp. 451 472 [5] AMETEK-ORTEC, U.S.A., http://www.ortec-online.com [6] ANGLE software for quantitative gamma-spectrometry, http://angle4.com [7] Vidmar, T., Celik, N., Cornejo Diaz, N., Dlabac, A., Ewa, I.O.B., Carrazana Gonzalez, J.A., Hult, M., Jovanovic, S., Lepy, M.C., Mihaljevic, N., Sima, O., Tzika, F., Jurado Vargas, M., Vasilopoulou, T., Vidmar, G., Testing efficiency transfer codes for equivalence, Appl. Radiat. Isot. 68 (2010), pp. 355 359. [8] ANGLE software – Prominent Users, http://angle4.com/references.html
Speaker: Prof. Slobodan Jovanovic (University of Montenegro, Centre for Nuclear Competence and Knowledge Management (UCNC))
• 51
DEVELOPMENT, EVOLUTION AND IMPLEMENTATION OF ENVIRONMENT PROTECTION STANDARDS FOR URANIUM MINING IN THE AUSTRALIAN TROPICS
The Ranger uranium mine is surround by dual World Heritage Listed Kakadu National Park. Kakadu is recognised for its significant cultural and environmental attributes. Because of this, the Ranger mine is subject to very stringent environmental protection standards. These standards are developed and overseen by the Australian Government through its Supervising Scientist Branch, which is part of the Department of the Environment and Energy. For 40 years the Supervising Scientist Branch has undertaken site-specific monitoring and research into the impacts of uranium mining on the sensitive environment surrounding the Range mine site. The collected data was used to derive site-specific water quality compliance objectives that have helped to ensure the protection of the environment from effects of mining operations. The data is now being used to develop closure criteria for the rehabilitation of the Ranger site, which is scheduled to be complete by 2026. This presentation will provide an overview of the Supervising Scientist Branch’s monitoring and research programs and demonstrate how the collected data has been used to ensure protection of the environment throughout the operation and after the rehabilitation of Ranger uranium mine.
Speaker: Ms Kate Turner (BSc)
• 52
A RISK BASED APPROACH TO URANIUM MINING REHABILITATION
The Supervising Scientist is established to protect the environment from the effects of uranium mining in Northern Australia, including overseeing the operation and closure of the Ranger uranium mine. Ranger has operated since 1980 and is surrounded by the dual World Heritage listed Kakadu National Park. Uranium milling operations at Ranger must cease by 2021, with rehabilitation work to be completed by 2026. A risk-based program of assessment and research has been developed by the Supervising Scientist Branch to ensure the protection of the environment throughout the decommissioning and rehabilitation process, between now and 2026. This presentation will provide details of the risk assessment and planning work undertaken by the Supervising Scientist Branch to systematically identify the knowledge needed to ensure environmental protection, the project work required to address these needs, align these with the mine rehabilitation schedule and inform the regulatory assessment process.
Speaker: Mr Keith Tayler (Australian Government)
• 3:40 PM
Break
• Health, Safety, Environment and Social Responsibility M3

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Conveners: Dr Gabi Schneider (Namibian Uranium Institute) , Prof. Jim Hendry (University of Saskatchewan)
• 53
IAEA Coordination Group for Uranium Legacy Sites (CGULS): Strategic Master Plan for the Environmental Remediation of Uranium Legacy Sites in Central Asia
Uranium mining and processing activities have been carried out in Central Asia since the mid-1940s, particularly in the mountainous areas above the Syr Darya River and the Ferghana valley, where the borders of the Kyrgyz Republic, Kazakhstan, Tajikistan and Uzbekistan intersect. Many of these activities ceased in the 1990s, leaving numerous sites containing uranium and other hazardous and radioactive wastes in populated areas. Left un-remediated, these uranium legacy sites (ULS) pose a hazard to future generations. To move forward CGULS developed and is implementing a Strategic Master Plan (SMP) for environmental remediation of ULS in Central Asia. The SMP sets out a strategy for adoption and a master plan for implementation for the remediation these ULS. The SMP addresses three main activities: 1. Systematic and comprehensive studies to assess the current status of each ULS and to propose appropriate and effective remediation solutions. 2. Remediation solutions implemented according to international standards and good practice. 3. Countries develop the capacity to implement remediation projects and assume long term stewardship of the remediated sites. The first step of site evaluation and remediation solutions design is underway; the next step, the actual implementation of the remediation work, requires additional funding.
Speaker: Ms Michelle Roberts (IAEA)
• 54
Five Years After The UPSAT Mission: Progress and challenges
Regulating Uranium extraction industry is complex process which involves multi-regulators with different requirements. Tanzania had several regulators with less experience in uranium mining domain. Different government departments’ legislation and regulations lacked clarity and consistency. Overlapping mandates between different government departments complicated to the operator to which laws should follow. International Atomic Energy Agency (IAEA) Uranium Production Site Appraisal Team (UPSAT) was an assistance requested to address this challenge. UPSAT was first assistance mission of its kind in African soil. The mission assessed the following five primary parameters, the regulatory system, Sustainable uranium production life cycle, Health, Safety and Environment (HSE), social licensing and Capacity building. This paper presents the progress and development made since 2013 mission execution.
Speaker: Mr Dennis Amos Mwalongo (Tanzania Atomic Energy Commission)
• 55
URANIUM MINING REMEDIATION IN AUSTRALIA’S NORTHERN TERRITORY
INTRODUCTION AND HISTORY Uranium was first identified in the Northern Territory (NT) in the late part of the nineteenth century [1]. However, it was only in the years immediately after World war Two that the mineral took strategic importance and exploration efforts really took off. The discovery of the Rum Jungle deposit by Jack White in 1949 is generally accepted as the start of the modern era of uranium mining in the NT [2]. Located about 75km south of Darwin the Rum Jungle mine operated from 1954 to 1971 and produced 3,530 t of uranium oxide and 22,000 t copper. A number of smaller mines in the vicinity also contributed to the development of the industry. However, when contracts were fulfilled or deposits worked out, little effort was put into remediation of the sites and many were simply abandoned. In some cases these legacy sites were relatively benign but others became sources of contamination; usually due to the development of acid and metalliferous drainage (AMD) arising from the sulphides in the remaining waste rock piles. Only in later years did legislation and public concern lead to action being taken. Some of those actions are described later in this paper. THE SECOND MINING ROUND After the “rush” of the 1950s the taste for uranium seemed to quieten down until the prospect of uranium as a fuel for nuclear power became firmly set in people’s minds. In the later 1960s exploration returned to locations which had been successful previously. The NT was one of those areas, especially around the Pine Creek geosyncline. The results of the exploration effort in the Alligator Rivers Region (ARR) were the deposits at Ranger, Jabiluka, Nabarlek and Koongarra. But by the time the development proposals were being formulated a new paradigm had been established with respect to mining, environmental management and remediation. Society was no longer prepared to accept that mining, especially uranium mining, would be a one-time user of land in the NT. The result was Australia’s first environmental inquiry, the Ranger Uranium Environmental Inquiry (RUEI). This is perhaps better known as the Fox Inquiry after the Chairperson, Mr Justice Fox. The Inquiry produced two reports [3, 4] which decided that (a) Australia could become involved in nuclear fuel cycle activity by mining uranium, but that would be the limit of the involvement; and (b) that the four identified deposits in the ARR would be able to proceed to development, subject to the process of environmental impact assessment required under recently promulgated laws. Only two of the four identified uranium resources have been developed to date, Nabarlek and Ranger [5];both sites are subject to strict environmental regulation set down in the Environmental requirements from the Commonwealth Government (ER). Koongarra has been returned, unworked, at the request of the Aboriginal Traditional Owners of the land to become a part of the surrounding world heritage listed Kakadu National Park. Jabiluka was investigated and an EIS submitted but the site been put back into long term care and maintenance with the disturbed areas now in an advanced state of remediation following the removal of all infrastructure and the backfilling of the underground development trial workings [6]. MODERN REMEDIATION Small scale operations from the 1960s in the South Alligator Valley had been simply abandoned when production quotas were filled. About 13 mines and three processing sites produced approximately 850 tonnes of uranium oxide in this programme [7]. The sites were left un-remediated until the area was designated to be included in Stage 3 of the Kakadu National Park, at which time a series of hazard reduction works (HRW) were undertaken to improve public safety both physically and radiologically [8]. As part of a longer term lease agreement with the Aboriginal Traditional Owners in 1999 a programme was begun to undertake the planning and implementation of the various mining and processing sites in the valley [9]. This programme was begun eventually in 2007 and completed in 2008 with the various small containments built under the earlier HRW programme being opened up and the contents relocated to a central customised central containment built to modern standards. The containment was instrumented and monitoring is ongoing. Various reports have been made regarding the success of this project and presented at international meetings [10, 11]. The Nabarlek mine operated between 1979 and 1988; mining of the relatively high grade ore was undertaken in one dry season and the stockpile was processed over the following ten years at a production rate of about 1000t of U3O8 annually [12]. From the outset the mine had a plan of remediation and a fund to cover the cost of the works was guaranteed. After about a year or so the mine employed a decommissioning engineer whose main task was to ensure the plan was kept up to date and every opportunity for progressive remediation was taken up. One of the environmental requirements (ER) for uranium mines in the ARR was that all mill tailings had to be returned to the mined out pits at the end of the mine life. In the case of Nabarlek the ore body was excavated entirely in 1979 and then processed over the following ten years with tailings being returned directly to the pit. In 1989 the mine was mothballed in case another ore body could be found. However, this was not the case and the mine was decommissioned and remediated in 1995 with the final work of seeding the site being completed before the onset of the wet season in December 1995. Since then the site has continued to revegetate with varying degrees of intervention from successive lease holders. Some exploration activity has been based at the site and in the surrounding areas since that time although the minesite has been allowed to continue to remediate. Revegetation has been moderately successful despite severe damage from a tropical cyclone in 2006 [12]. The Rum Jungle uranium and copper mine operated from 1954 to 1971 [2] and produced 3,530t U3O8 and 20,222t Copper. The site was abandoned with little remediation apart from a token effort in 1976. Ongoing AMD production resulted in significant impacts in the Finniss River. As a result $18.6M was spent on remediation between 1983 and 1986 and the program was hailed as best practice at the time. Sadly the works did not completely solve all the issues and by 2000 the situation was deteriorating. A series of investigations began in 2004 which eventually resulted in the NT and Commonwealth Governments entering into a National Partnership Agreement (NPA) in 2009 which was the beginning of a long term comprehensive program to characterise the site and develop new designs for its remediation. Under the NPA and successive project agreements a wide variety of studies have been under taken to obtain data which has facilitated a comprehensive characterisation of the site, assisted in improving the day-to-day management of the site and enabled development of an improved remediation plan for the site. A major feature of the programme has been the extensive consultation with the Aboriginal Traditional Owners of the land and their inclusion in the process of determining final land form and land use objectives. The project has also provided business development opportunities for the land owners which has resulted in small business ventures being created and developed at the project, which have then gone on to compete successfully in the local market. The final design data are currently being collected and contracts let to develop the final remediation plan; this includes preparation of an Environmental Impact Statement for assessment under NT and Commonwealth legislation. This work is due to be completed in 2019, with the production of costed designs for the final remediation program. CURRENT ACTIVITY The Ranger Uranium Mine, operated by Energy Resources of Australia Ltd (ERA), is, after 36 years, the longest producing uranium mine in Australia. Located about 250km east of Darwin, the mine is surrounded by, but not part of, Kakadu National Park. Operating since 1980 the mine has produced more than 125,000 tonnes of uranium oxide to date. ERA finished open pit mining in 2013 with the end of work in Pit 3. The previous pit, Pit 1, was backfilled with tailings between 1996 and 2004, in accordance with the ERs. In 2017 work started on completing the back filling Pit 1 using waste rock to commence construction of the final land form. Details of the final land form design are yet to be finally agreed with Aboriginal Traditional Owners but the requirement is that the area could be incorporated into Kakadu National Park if desired, without the need for any special management [11]. ERA is continuing to process ore from existing stockpiles on site. The present administrative arrangements require ERA to cease production and processing in January 2021 and to have completed remediation of the site by January 2026. Since 2013 ERA has continued to implement progressive remediation works as and where it has been possible to do so, compatible with the last of the processing operations. When mining ended in Pit 3 work began immediately on preparing the void to be used as a disposal site for mill tailings. The main part of this programme was the placing of 33 M t of waste rock in the base of the pit to provide a level floor for deposition of tailings. Since 2015 mill tailings have been deposited directly to this pit. As well as the tailings in Pit 1 ERA also has a tailings dam approximately one kilometre square containing nearly 23 M t of tailings. Since 2016 work has been underway transferring these tailings into Pit 3 using a custom built dredge. This operation is scheduled to last until 2021. At that time the excess process water will be disposed of through treatment and the tailings allowed to dry out and stabilised using prefabricated vertical drains. The final land form construction will then begin using waste rock with the final surfaces being made of material containing less than 0.02% uranium oxide, i.e. non-mineralised material. All this work is due to be completed in 2025 to allow planting to be completed by 2026, as required by the present administrative arrangements. The Ranger site currently has a considerable inventory of process water which cannot be released from site. A brine concentrator, built in 2013, treats process water to produce 1.8GL of clean distillate per year, which is suitable for controlled release. The residual brines are to be injected into the void space in the back fill at the base of Pit 3. Other, less contaminated, waters on site are passed through conventional water treatment plants (reverse osmosis) and the permeate is released in accordance with the appropriate approvals. As the climate has marked wet and dry seasons, discharge of clean water is only permitted when creeks and rivers are running. During the dry season, when ephemeral rivers have ceased to flow, water may only be released through evaporation. ERA are introducing turbomisters during the dry season as a way of enhancing natural evaporation losses for treated water. The progress of the remediation work is overseen by a Minesite Technical Committee (MTC) which comprises ERA, the NT DPIR, the Supervising Scientist and, to represent the Aboriginal traditional Owners, The Northern Land Council and the Gunhdjeimi Aboriginal Corporation. The Commonwealth Government Department of Industry, Innovation and Science attends meetings as an observer. ERA is producing a Mine Closure Plan as a document for publication to the community; standards and criteria for the remediation programme are developed in consultation with the MTC members and other interested parties as appropriate. CONCLUSION Uranium mine remediation in Australia’s Northern Territory has come a long way from the days of simple abandonment that were the normal procedure only 50 years ago. Recent and current sites are being remediated in accordance with current leading practice and considerable attention is paid to consultation with stakeholders to ensure all concerns are understood and have the opportunity to be addressed. The efforts have not stopped there with a number of legacy uranium sites being cleaned up as well. There have been valuable lessons learned at every stage of this story and they are in turn being applied to the future work programmes for remediation of these and other mines in the region. REFERENCES [1] Department of Primary Industry and Resources (DPIR) (2018) Rum Jungle Mine History-Discovery and Exploration. https://dpir.nt.gov.au/__data/assets/pdf_file/0017/261512/Discovery_and_Exploration.pdf. Accessed February 2018. [2] https://dpir.nt.gov.au/mining-and-energy/mine-rehabilitation-projects/rum-jungle-mine (accessed February 2018) [3] Ranger Uranium Environmental Inquiry. First Report. Australian Government Publishing Service, Canberra, 1977 [4] Ranger Uranium Environmental Inquiry. Second Report. Australian Government Publishing Service, Canberra, 1977 [5] Waggitt, P. (2017). Update on uranium mining in the Northern Territory, Australia 2017. Presentation at the IAEA-UMREG meeting of the Uranium Mining and Remediation Exchange Group (UMREG), Bessines , France 16-18 October 2017(Powerpoint and abstract only). [6] Waggitt, Peter (2012). The Northern Territory’s Uranium Industry: Past, Present and Future. In proceedings SWEMP 2013. 13th International Symposium on Environmental Issues and Waste Management in Energy and Mineral Production, New Delhi, India. 28-30 November 2012. [7] Waggitt PW (2000) The South Alligator Valley, Northern Australia, Then and Now: Rehabilitating 60’s uranium mines to 2000 standards. in proceedings of the SWEMP 2000 Conference, Calgary, Canada. May30 – June 2, 2000. pub: Balkema. [8] Waggitt PW (1996) Hazard reduction works in the upper South Alligator Valley. Proceedings of the SPERA Specialist Workshop - Radiological aspects of the rehabilitation of contaminated sites (RARCS), Jabiru NT 20-22 June 1996. Pub. South Pacific Environmental Radiation Association. [9] Needham S & Waggitt P (1998) Planning Mine Closure and Stewardship in a World Heritage Area-Alligator Rivers Region, Northern Territory, Australia. in Proceedings of the Long Term Stewardship Workshop, Denver, CO, 2-3 June 1998. US Department of Energy, Grand Junction Office (CONF-980652). [10] Waggitt, Peter & Fawcett, Michael. (2008). Implementation of Uranium Mine Remediation in Northern Australia. Australia’s International Uranium Conference, Adelaide 18-19 June, 2008. Australasian Institute of Mining and Metallurgy (AusIMM), Melbourne (CD-ROM). (Powerpoint and abstract only [11] Waggitt PW (2000) Nabarlek uranium mine: From EIS to decommissioning. in Proceedings, URANIUM 2000 - International Symposium on the Process Metallurgy of Uranium. Saskatoon, Canada 9-15 September 2000. Pub. Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, Canada. Speaker: Mr Peter Waggitt (Department of Primary Industry and Resources of the Northern Territory) • 56 ASSESSMENT OF THE IMPACT OF URANIUM PRODUCTION WASTE STORAGE FACILITIES ON THE ENVIRONMENT BASED ON THE RESULTS OF HYDROGEOLOGICAL MONITORING AND NUMERICAL MODELING INTRODUCTION The largest uranium mining enterprise in Russia, Public Joint-Stock Company Priargunsky Industrial Mining and Chemical Union (PJSC PIMCU) was established in 1968. Uranium mining is carried out by underground mining on the basis of operating mines, and ore processing is carried out at a hydrometallurgical plant[1] ], which began operating since 1976. Simultaneously with the commissioning of the GMZ, a sulfuric acid plant was started. The sulfuric acid was produced from pyrite cinders. Since 2009, the sulfuric acid plant has been switched to block sulfur. The wastes with a residual radioactivity caused by processing uranium ore are deposited in a ravine in two tailing dumps, neutralized with calcareous water. A cinder storage facility for the wastes produced by pyrite roasting process at the sulfuric acid plant is located in the same ravine. These wastes are characterized by high sulfate ion concentration and a lack of radioactivity. All these storages are a wet type, in the landscape its represents as cascade of three lakes. Leaks through earthen dams within the limits of normative losses are intercepted by a system of drainage wells in the lower tail of the storage facility dam and are returned into the technological process. Monitoring of leakages from them is carried out by 196 observation wells. To inform the public about the state of the environment in the area where the enterprise is located, summarized results are published in annual environmental reports [2]. Wells field situated near a river is located within the study area provide water for a city with a population of 45 thousand people. Water is obtained from first aquifer of the intermountain artesian basin. The exploration wells are located in 12 kilometers from storages. For over 40 years of the storages existence a contamination plume in the aquifer has formed by the filtration through earth dams. The plume does not exceed area of the sanitary protection zone of these three storages. As practice shows, the leaks through earth dams are very common for the wet type of tailings in old mines of hydrometallurgical plants (in Germany, USA, Canada, Niger, Australia, etc.) [3]. The main objective of this study was a conservative forecast of the spread of contamination plume towards the water intake. The forecast was carried out with two assumptions that from now on (from 2015), the collection of waste into the storage facilities is stopped and the interception of contaminated water by drainage wells in the lower tail of the cinder storage dam is stopped. Conservative approach means maintaining the concentration of pollutants in the sources at a constant level for the entire forecast period. DESCRIPTION The geological structure of the territory involves two structural floors. The lower floor is represented by Proterozoic and Early Paleozoic metamorphic rocks, Riphean, Vendian and Paleozoic granitoids. The upper floor contains Mesozoic (J-K) terrigenous strata of sedimentary and sedimentary-volcanic rocks that fill up depressions and calderas, Upper Jurassic small intrusions of the Kukulbei complex and subvolcanic rocks genetically related to the Late Jurassic and Cretaceous volcanism. The research area is located within an intermountain depression. The intermountain artesian basin is associated with this depression. This basin consists of a few aquifers which are hydraulically connected and formed an aquifer system. The upper part of a cross-section consists of conglomerates, sandstones, siltstones (Lower Cretaceous rocks) that overlap with Quaternary sediments of alluvial, limnetic and proluvial genesis, which are the main collector of fresh groundwater used for the city's water supply. For generalize purpose once considered all types of groundwater in this basin as parts of unite aquifer system, but conditionally divided by the types of water-bearing rocks and their filtration properties. Systematic observations of the state of the environment on the territory of PJSC PIMCU began in 1973. Hydrogeological monitoring is currently carried out in 196 observation wells. Data analysis of groundwater level dynamic shows, that the longest observed steady period was the last 14 years. The groundwater average depth for this period is no deeper than 5 m on the most of the research area, which leads to a high rate of the evapotranspiration. The well field situated nearby the river doesn’t make a significant impact on groundwater level, because pumping wells obtain water what before was discharging by evapotranspiration and the river. Also, it is important to mention that near the location of tailings dumps are stand out a mine drainage, that cause a local groundwater depression and prevents the spread of contaminated water. METHODS Based on the created GIS project, digital elevation model, digitized geological maps, engineering geological well logs and hydrogeological monitoring data, a three-dimensional geological model (GM) was created in the GMS software package. The GM was used as the basis for filtration and solute transport models. In the transport solute model, sulfate ion is selected as an indicator of groundwater contamination, since it has the greatest migration capacity compared to other contaminants in storages. Based on the analysis of the data of the geological site structure model was performed with a 4-layer. The area of the model is 4283 sq. km; the boundaries of the model are determined by the boundaries of the catchment basins. To verify hydrodynamic and transport solute model, ground water levels and concentration of sulfate ion from observation wells located in the ravine were used. Once obtained a good convergence of field and model data. The deviations of the model and measured concentrations of the sulfate ion are within the limits of the determination errors. RESULTS AND DISCUSSION The simulation results indicate that the contamination plume from the first tailing dump is stable and partially discharged in the mine drainage. The contamination plume from the second tailings dump is less influenced by the mine drainage and its slowly spreading along the ravine toward the river. The cinder storage facility, which closes the cascade of simulated lakes, has the main role in the groundwater contamination process. As it was mentioned above the cinder storage facility is a main source of sulfate ion contamination that is the reason why sulfate ion is a very suitable indicator for this particular model. The prediction modeling of remediation actions showed that in the case of complete elimination of the cascade of man-made lakes the currently existing plume of pollution will migrate at a significantly lower rate and gradually degrade due to hydrodynamic dispersion. Reduction of the sulfate ions concentration to the values of MPC for drinking water (500 mg / l) will take about 300 years CONCLUSION Conducting facility-focused monitoring allows implementing the concept of controlled pollution. This concept includes an information analysis system for facilities of the nuclear power industry based on facility-focused monitoring system of subsurface state, hydrodynamic and solute transport modeling and as a result an informational geo-ecological report. Conclusions: 1. The current state of groundwater in the area of waste storages shows that the groundwater contamination does not exceed the boundaries of the sanitary protection zone for all kind of manmade pollutants; 2. The primary manmade contamination of groundwater is the sulfate ion coming from the cinder storage facility; uranium pollution mainly is intercepted by the mine drainage. Therefore sulfate ion was used in the solute transport model as an indicator of contamination spread; 3. Conservative forecast shows the spread of contamination in the groundwater from the tailing dumps does not reach the water supply wells even at the horizon of the forecast of 300 years. REFERENCES [1] www.priargunsky.amz.ru [2] Environmental Safety Report PJSC PIMCU 2015 (www.rosatom.ru) [3] INTERNATIONAL ATOMIC ENERGY AGENCY, Technologies for the treatment of effluents from uranium mines, mills and tailings. IAEA-TECDOC-1296, IAEA, Vienna (1996). Speaker: Ms Natalia Kurinova (Federal State Budgetary Institution "Gidrospetsgeologiya") • 57 Development of mine water quality, subsequent sediments contamination and passive 226Ra treatment in Zadní Chodov, Czech Republic – case study INTRODUCTION The uranium deposit Zadní Chodov was discovered using a car-borne gamma survey in the year 1952. In 1958, the uranium mining area Zadní Chodov was established, covering 7.16 km2. During operation, 5 mining shafts were constructed on the deposit [2]. Shaft No. 1 with a total depth of 401.6 m was closed in 1963, the shaft No. 2, reaching depth 761.8 m was closed in 1989. Shaft No. 3 was excavated to 28th floor level in depth of 1263.2 m. Furthermore, there were shafts No. 12 (780.4 m depth) and No. 13 (1083.8 m depth). As with many other ore deposits in the Czech Massif, local uranium ores were exploited by using method of cut-and-fill stopping and gradual top-slicing stoping under a man-made ceiling. MINING HISTORY Uranium ore was mined at the site for 40 years and the total production exceeded 4,000 t U (the 6th largest deposit in the Czech Republic). The exploration activities were completed in 1988, and mining operation ceased in 1992, concurrently with many other mines during the first wave of ordered mining activities reduction. The mine was closed, the surface area mitigated, while waste dumps material was processed into crushed aggregates. In February 1993, the underground water pumping was discontinued and spontaneous flooding of mine was allowed. MINE WATER TREATMENT Due to the mine flooding, in March 1995 the water streamed to the surface, yielding 15 L/s. To resolve these circumstances, a Hydrogeological Study of the Region was performed aimed to asses a final management system for the water outflow and subsequent treatment [5]. A drainage system was built in the area of concern, connected to an accumulation pond followed by a decontamination station (water treatment plant). The captured mining waters were continuously sampled prior to entry, while the dissolved contaminants, especially Uranium and Radium, were monitored. The initial high Uranium and Radium concentrations associated with the first flush effect had in first five years (1995 – 2000) a declining trend. In November 2001, a borehole HVM-1 was drilled from the surface to the second mine level, from the area with the lowest surface elevation (from the "melioration ditch") and thus was created a new pathway, allowing efficient, spontaneous runoff of the mine water to the surface, while reducing the water level inside the mine. This was done to eliminate any previous outflows and enable the deposit to be gravitationally drained. In 2010, the mine water reached quality which allowed its release into the watershed, without pumping and cleaning. Since then, the mine water has been experimentally discharged without cleaning into the melioration ditch that leads to the Hamer Creek, however the mine water treatment plant (decontamination station) is still on standby and ready to be activated if necessary. MINE WATER, SEDIMENTS AND LEGISLATION FRAME The initial high Uranium and Radium concentrations associated with the first flush effect had in first five years (1995 – 2000) declining trend. Nowadays mining water has a low content of dissolved solids (ca 300-350 mg/L) and hydrochemistry has greatly stabilized. Unat. (less than 0.1 mg/L on average) and 226Ra (1,600 mBq/L on average) concentrations do not show significant anomalous variations since 2010. In accordance with valid Czech legislation in the field of radiation protection, the quality of the discharged mine water is continuously monitored and concentration of 226Ra is also monitored in the sediments along the melioration ditch up to the Hamer Creek estuary. Currently along approximately 900 m of the stream there are 11 monitoring locations. Measured concentration values are compared with reference levels. Particular attention is paid to the accumulation of 226Ra in the sediments along the upper segment of the melioration ditch. If the values of the Radium concentrations in the sediments would consistently exceed the reference levels, and the contamination would spread towards the Hamer Creek, the situation would have to be addressed. One possible solution would be reactivation of the decontamination station. Therefore, a preliminary exploration of the area was launched in 2017 to test other potentially useful methods of "cleaning" mine water on the site. ENVIRONMENTAL IMPACT ASSESSMENT Through the year 2017, an in-situ gamma spectrometric survey of the area, surrounding the mine water outflow, was conducted to determine the background values of natural radionuclides and localized possible anomalies of 226Ra or Unat mass activities. This was carried out mainly in locations of the previous water exhausts and in the area of the melioration ditch. The monitored locality is minimally populated and presently used as a grazing pasture for cattle. The gamma spectrometry method did not show exemption levels of radionuclides in the soil, the only possible source of cattle contamination could be the pasture watering system. Based on known concentrations of radionuclides in water, a commitment effective dose was estimated for a representative person, resulting from the meat consumption of cattle, grazing on the site under observation, in the usual pasture regime. At the recommended consumption of 20 kg of beef from Zadní Chodov area, the estimated commitment effective dose was calculated at less than 1 μSv. WATER VOLUME-LIMITED TREATMENT EXPERIMENTS Experimental treatment of the outflowing mine water using adsorbents was started in May 2017, based on studies documented in [1, 3, 4, 6, 7]. Two different adsorbents – peat and zeolites (grain size 1-1.25 mm, 2.5-5 mm and 4-8 mm), was placed at the bottom of the 200 L volume barrels. A part of the borehole whole volume of water entered the barrels bottom and passed through the adsorbent layers and finally overflown the barrels. The water flow rate was measured continuously. The peat had low effectiveness from beginning of the experiment and was washed out due to its low specific weight. The treatment using zeolites grain size 4 – 8 mm resulted in very low efficiency and thus both experiments were terminated. Next step was the use of smaller adsorbent pellets (grain size 1-2.5 mm and 2.5-5 mm) starting in June 2017. The testing continued for 4 months and the water samples for radionuclides concentration measurement (before and after treatment) were taken 5 times per week and later 3 times per week. The relative effectiveness of 226Ra treatment was calculated. DISCUSSION The water flow rate in barrels was approximately 0.25 L/s, effective height of barrels was 80 cm and the thickness of the zeolite layer was 20 cm. Taking into account that zeolite layer decrease effective flow volume by about 50 percent, the time interval for contact between water and zeolite is estimated to be 1 minute 40 seconds. In case of zeolite with grain size 1.0-2.5 mm the average initial adsorption ability reached 70%, which after 3 month of experiment duration decreased to level of 40%. In comparison the zeolite of grain size 2.5-5 mm had average initial adsorption ability approx. 80%. The linear trend describing radionuclides concentration decrease indicates adsorption ability about 50% after 4.5 months of operation. The average water flow rate from the drilling well HVM-1 was from October 2016 to September 2017 14.92 L/s. It could be expected that with increasing of the adsorbed radioactive contaminants (and minerals) the adsorption ability of the zeolites will decrease. In case of desired higher water flow rate the amount of required adsorbent must increase proportionally, to maintain the same treatment effectiveness. So far performed introductory experiments do not enable correct estimation of direct dependence between amounts of zeolite used, water throughput and treatment efficiency. Given the above mentioned parameters interdependence, for cleaning mine water using throughput of 15 L/s would require 60 times higher volume of adsorbent to achieve 50% capture effectiveness for 226Ra. That corresponds to 3 tons of zeolite utilization during each 4 month period. COST BENEFIT ANALYSIS In the years 2008 - 2010, the average annual cost of running the mine water treatment plant (using the conventional barium chloride active treatment process) was on the order of millions CZK. Searching for less expensive alternative, a zeolite-based cleaning technology could be passive, greatly reducing the operating costs. If we will consider the use of common “pool mixes” and the adequate amount of approximately 10 ton, the cost of adsorbents consumption can be at the level of hundred thousand CZK per year. In that case it is necessary to add the cost of maintenance, control, monitoring, removal of contaminated materials and landfill. All these operations are expected to be one order less expensive than water treatment plant in operation. CONCLUSIONS On the basis of the available data, the passive method of mine water treatment at the site of Zadní Chodov, using zeolite adsorbents, appears to be potentially applicable. Mining water at the site has low mineralization with a low proportion of suspended matter, which has a positive effect on the life of the sorbent [4]. For the first experiments, commonly available “pool mixes” of adsorbent based on clinoptilolite were utilized. However, it would be desirable to utilize adsorbents based on synthetic zeolites which could have much higher efficiency for adsorption of 226Ra. Higher efficiency and capacity of the adsorbent would, of course, mean overall cost saving, lower consumption, simplification of the loading, unloading and transport process, while reducing the amount of "waste" to be deposited at the tailings pond. Assembling a technological unit utilizing the zeolite technology will be the subject of further deliberation. The main issues will be: - Choice between settling tank and closed piping system - Ensuring a uniform flow through the adsorbent - avoiding preferential path formation - Testing the effectiveness of different types of adsorbents - Adsorbent recycling options - Use of a wetland system - the natural way of the mine water cleaning These and other tasks are planned for the next stages of testing the mine water treatment process in Zadní Chodov and assumes that the findings will also be used at other localities, where the deposition of mine water can cause ecological load. REFERENCES [1] BARESCUT, J., CHAŁUPNIK, S., WYSOCKA, M. Radium balance in discharge waters from coal mines in Poland the ecological impact of underground water treatment. Radioprotection, 44-5 (2009), 813-820. [2] DIAMO, s. p.. Závěrečná zpráva o ložisku Zadní Chodov. DIAMO, státní podnik – správa uranových ložisek, o. z. Příbram (1996). [3] CHAŁUPNIK, S. Impact of radium-bearing mine waters on the natural environment. In Radioactivity in the environment (Vol. 7, pp. 985-995). Elsevier (2005). [4] CHAŁUPNIK, S., FRANUS, W., WYSOCKA, M., GZYL, G. Application of zeolites for radium removal from mine water. Environmental Science and Pollution Research, 20-11 (2013), 7900-7906. [5] ŠTROUF, R. Hydrogeologická studie podchycení plošného výronu důlních vod na lokalitě Zadní Chodov. MS, AQUATEST – Stavební geologie a.s., (1999). [6] WANG, S., PENG, Y. Natural zeolites as effective adsorbents in water and wastewater treatment. Chemical Engineering Journal, 156-1 (2010),11-24. [7] WENDLE, G. Radioactivity in mines and mine water-sources and mechanisms. Journal of the Southern African Institute of Mining and Metallurgy, 98-2 (1998), 87-92. Speaker: Mr Jirí Wlosok (DIAMO, state enterprise) • Underground and Open Pit Uranium Mining and Milling Conveners: Mr Christian Polak (AREVA MINES) , Dr Mark Mihalasky (U.S. Geological Survey) • 58 COMPREHENSIVE EXTRACTION SCHEME FOR MULTIMETAL RECOVERY FROM METASOMATITE–ALBITITE HOSTED LOW GRADE INDIAN URANIUM ORE COMPREHENSIVE EXTRACTION SCHEME FOR MULTI-METAL RECOVERY FROM METASOMATITE-ALBITITE HOSTED LOW-GRADE INDIAN U ORE INTRODUCTION India is making focused efforts to reach human development index (HDI) of 0.9+, a number considered to indicate decent state of living, from its present index value of 0.6 by 2040 [1]. Meeting the projected HDI necessitates amongst others, the strategies for utilization of various energy resources in a sustainable way. The contribution of nuclear energy in the overall mix is very critical in achieving the target HDI primarily due to its low carbon foot-print and local availability of fertile thorium resources [1]. The installed capacity of nuclear power plants of India at the end of 2017 was 6780 MWe [2]. It is planned to increase this to about 35000 MWe by the year 2022, comprising mainly of PHWRs and LWRs with minor contribution from Fast Breeder Reactor (500 MWe) and Advanced Heavy Water Reactor (300 MWe) [3]. It is reported that the identified Conventional uranium resources in India so far are sufficient to support 10-15 GWe installed capacity of PHWRs operating at a lifetime capacity factor of 80% for 40 years [3]. Continuous efforts are being made by different agencies in India to increase the indigenous uranium production for realizing the fuel demand which include exploration for new deposits, establishing of new mills and augmentation of existing mills. Majority of the Indian uranium occurrences discovered so far fall in low-grade category [4,5]. Maximum utilization of mined ore or comprehensive extraction is an ideal approach for exploitation of lean tenor ores as it addresses the sustainability principles as well as commercial viability terms. Successful cases in this respect which are familiar for uranium ore processing fraternity are the Palabora copper mines (South Africa) [6] and Olympic Dam poly-metallic copper mines (South Australia) [7] and the Jaduguda uranium mines (India) where a Byproduct Recovery Plant (BRP) was in operation for recovering useful metals like Cu, Ni, Mo and magnetite values [8]. With growing interest in rare earth elements for green energy applications many phosphate mine operators are looking into recovery of rare earths in addition to the already established schemes for phosphate and uranium values [9, 10, 11]. Amongst the most promising new uranium findings explored by the Atomic Minerals Directorate for Exploration and Research (AMD), the uranium exploration Agency in India, the Rohil-Ghateswar uranium ore deposit, Sikar district, Rajasthan is prominent one [12]. The Rohil - Ghateswar uranium ore is a metasomatite type deposit hosted by albitised metasediments of Delhi Supergroup in north-west India. The metasomatite uranium occurrences in India are reported to contribute about 3.3% of the total uranium resources and the most important amongst them is the Rohil multi-metal uranium ore which is reported to contain Cu, Mo, Ni and Co values. This paper gives details of the process development studies carried out for multi-metal recovery from the Rohil – Ghateswar low-grade uranium ore. ORE SAMPLE AND CHARACTERISATION A composite feed for the experimental studies is prepared by judicious mixing of split core bore-hole ore samples of different locations of Rohil – Ghateswar ore deposit. The XRD and optical microscopic study of the feed indicated uraninite as the chief uranium bearing phase with traces of brannerite and davidite. The other minerals identified are: chalcopyrite, molybdenite, pyrite, pyrrhotite, riebeckite, quartz, traces of albite, biotite, boulangerite, chlorite, covellite and goethite. Chemically the ore sample showed U3O8 0.04%, Cu 0.14%, Mo 0.024%, total S 4.3%, FeO 13%, SiO2 58.9%, CaO + MgO 6.7%, Na2O 4.3%, K2O 1.04% and Loss of Ignition 4.3%. Amongst the sulfides pyrrhotite content is about10% and pyrite 1.1%. Uraninite is mostly liberated however occasionally uraninite of very-fine size is associated with non-pyrrhotite sulphides. The Bond’s Work Index of the sample is 21.4 kilo Watt h/metric ton. PROCESS DEVELOPMENT The predominant presence of siliceous minerals in the Rohil ore led to the option of choosing sulfuric acid based hydrometallurgical processing scheme for the recovery of uranium values. However, the presence of excessive content of sulfide minerals, particularly the pyrrhotite and pyrite in the ore necessitated a step of physical beneficiation to be integrated with chemical extraction process. Similarly a scheme suitable for recovering copper and molybdenum values in the ore inspite of their low concentration needs to be evaluated due to their vital utility in different futuristic materials. The occurrence of the Rohil-Ghateswar ore body in water-arid region makes design of process scheme for multi-metal recovery a challenging task. Different options have been formulated for achieving the objective of maximum recovery of multi-metals with minimum fresh water requirement. The options include: Option I: Comminution – physical separation of all the sulfide minerals (magnetic + froth flotation) – hydrometallurgical recovery of uranium values – tailings disposal. Option II: Comminution – separation of ferro-magnetic pyrrhotite by physical separation (magnetic) – hydrometallurgical recovery of uranium values – tailings disposal. Option III: Comminution – hydrometallurgical recovery of uranium values – separation of sulfide minerals from leach residue by physical separation (magnetic + flotation) - tailings disposal. Option IV: Comminution – separation of ferro-magnetic pyrrhotite by physical separation (magnetic) – hydrometallurgical recovery of uranium values – gravity separation of leach residue for non-magnetic heavy sulfide minerals recovery – tailings disposal. Option I helps in prior removal of sulfides which are detrimental during leaching of uranium values and simultaneously offer exclusive Cu-Mo sulfide minerals pre-concentrate besides yellow cake. Further the negative effects of acid mine drainage (AMD) are also minimized. However, the two disadvantages here are (i) loss of some uranium values in the sulfide float due to their composite nature and (ii) need for larger volume of water during froth flotation and difficulty in effective recycling of flotation reagent water consisting of residual collector reagent and frother. Though treatment of the reagent water post-flotation on biologically activated carbon (BAC) column is reported to remove organics, the process is nevertheless expensive. Option II yields higher uranium recovery, requires relatively less water due to absence of froth flotation but the problem of AMD persists due to left-over sulfides (Cu-Mo and pyrite) in leach residue or solid tailings. Option III too needs higher volume of water but gives sulfide-free tailings and slightly higher or similar uranium recovery like Option II. Though the surface of sulfide minerals may undergo partial chemical modification due to previous chemical leaching (Option II), the availability of specific collector reagents for mixed oxide-sulfide minerals (unlike alkyl xanthates) would minimize Cu-Mo losses. The major advantage of Option IV is maximum uranium and by-products recovery with minimum water inventory due to easy recyclability of water used in both magnetic and gravity separation stages. The experimental studies were carried out by optimizing various parameters of each unit operation both in physical separation and hydrometallurgical processes. Pyrrhotite values were separated using wet low-intensity magnetic separator (applied magnetic field 4 kilo Gauss), while pyrite, chalcopyrite and molybdenite were pre-concentrated using froth flotation with ‘alkly xanthate – pine oil’ reagent combination. Gravity separation was conducted on wet shaking table using slimes deck. Uranium values were recovered in the form of uranium peroxide by adopting the following unit operations in sequence namely, conventional agitation leaching with sulfuric acid-pyrolusite reagents – filtration – ion exchange purification – multi-stage precipitation viz. initially the iron-gypsum cake at pH 3 followed by precipitation of uranium peroxide. Separation and purification of uranium from the leach liquor was carried out on a strong base anion exchange resin in sulfate form but eluted with chloride reagent. The overall recovery of uranium for different options was 80 – 83%. The U3O8 assay of uranium peroxide product was 73.8%. The mass and water balance computations showed fresh water necessity of about four times more when flotation of sulfides is incorporated in the process flowsheet over the scheme which relies on specific-gravity difference for pre-concentration of Cu-Mo values. A recovery of about 75% was obtained with respect to Cu & Mo by-products at the pre-concentration stage of the Rohil ore. The sulfide mineral concentrate consists of Cu, Mo, and Fe with traces of Ni and Co. Anand Rao et al have demonstrated sulfation roasting - leaching process for quantitative separation of Cu, Mo, Ni and Co values keeping the Fe oxide phases as insolubles. [13]. Roasting converts sulfides of Cu, Ni and Co to their respective sulfates, and transforms the sulfides of Mo and Fe to their respective oxides by carefully controlling the roasting temperature. The sulfates of Cu, Ni and Co are soluble in mild acidic aqueous medium and MoO in alkaline medium, whereas FeO is insoluble. A forward integration approach helped in treating low-grade concentrates itself for maximizing overall recovery of Cu & Mo. REFERENCES [1] KAKODKAR, A. Low Carbon Pathways for India and the World. Springer Nature Singapore Pte Ltd. 2017. K.V. Raghavan and P. Ghosh (eds.), Energy Engineering, DOI10.1007/978-981-10-3102-1_1.(http://www.anilkakodkar.in/presentations/ lectures/Plenary_lecture_at_INAE-CAETS_Convocation_at_New_Delhi.pdf) [2] http://www.npcil.nic.in/content/302_1_AllPlants.aspx [3] URANIUM 2016: RESOURCES, PRODUCTION AND DEMAND, NEA No. 7301, © OECD (2016) 254 – 268. [4] PARIHAR P S. Uranium and thorium resources in India: UNFC system. (2013) http:// www.unece.org/fileadmin/DAM/energy/se/pp/unfc/UNFC_ws_India_Oct2013/5b.2_Parihar.pdf. [5] SARANGI,A.K.(2014).https://www.unece.org/fileadmin/DAM/energy/ se/pp/unfc_egrc/egrc5_apr2014 /1May/13_Sarangi_IndiaUraniumUNFC.pdf [6] https://en.wikipedia.org/wiki/Palabora [7] https://en.wikipedia.org/wiki/Olympic_Dam_mine [8] BHASIN, J.L. “Mining and milling of uranium ore: Indian scenario”. Technical committee meeting on impact of new environmental and safety regulations on uranium exploration, mining, milling and management of its waste; Vienna (Austria); 14-17 Sep 1998. IAEA-TECDOC-1244, Vienna (2001) 307 – 331. [9] DUTTA,T. et al. “Global demand for rare earth resources and strategies for green mining”. Environmental Research 150 (2016) 182–190 [10] ANDROPOV, M.O. et al. “Extraction of rare earth elements from hydrate-phosphate precipitates of apatite processing”. IOP Conf. Series: Materials Science and Engineering 112 (2016) 012001 doi:10.1088/1757-899X/112/1/012001 [11] ZHANG, P. “Comprehensive recovery and sustainable development of phosphate resources”. Procedia Eng. 83 (2014) 37-51. [12] YADAV, O.P. et al, “Metasomatite-albitite hosted uranium mineralization in Rajasthan”, Exploration and Research for Atomic Minerals, 14 (2002) 109-130. [13] ANAND RAO et al. “Studies on recovery of copper, nickel, cobalt and molybdenum values from a bulk sulphide concentrate of an Indian uranium ore”. Hydrometallurgy 62 (2001) 115–124 Speaker: Dr SREENIVAS T. (Bhabha Atomic Research Centre) • 59 Modern uranium open pit grade control The Langer Heinrich mine resource definition work was based around radiometric logging of drill holes and this has been carried through to mining grade control. The resource model is an MIK estimation with a variance adjustment based on expected mining parameters. Due to the large block size of 50mx50m, infill to 12.5mx12.5m to allow for detailed mine planning is undertaken. This intermediate stage is designed to provide accurate information for mine planning and scheduling for a forward 12 month period and significantly reduces the risks associated with mining a highly variable and nuggety deposit. The blast hole logging process is a one man operation using logging equipment installed on a small four wheel drive vehicle. This allows easy access to close spaced blast holes without the risk of damaging hole collars. The data is downloaded at the end of each shift and is processed to an equivalent uranium grade value using software developed on site. The resulting uranium values are then used to define grade control blocks via conditional simulation software. All material of ore grade is hauled to the ROM pad via a radiometric discriminator system to add a final level of selectivity to the mining process. Speaker: Mr David Princep (Paladin Energy Ltd) • 60 PRELIMINARY STUDY ON URANIUM ORE GRADE CONTROL TECHNIQUES FOR THE HUSAB MINE, NAMIBIA The Husab mine is situated within the Namib Desert in the Erongo region of western-central Namibia, only 6km south of the Rossing mine owned by Rio Tinto, approximately 60km east of the coast town of Swakopmund and less than 100km northeast from the Walvis Bay Port, the largest deep water port in the southwestern Africa and thus it has convenient traffic conditions and extremely favorable infrastructure conditions for development. As the most important uranium discovery in the world since 2000, the Husab mine has total uranium resource of nearly 300,000 tons of U3O8 with ore reserves of 300 million tons containing 156,000 tons of U3O8 at average grade of 518ppmU3O8. The Husab mine is the first ultra large uranium mine under the construction and operation by China General Nuclear Power Corporation (thereinafter “CGN” for short). Since its mine construction and pre-stripping commenced in 2013, its ore mining commenced in May 2015 and the first barrel of uranium oxide was produced on 31th Dec., 2016, indicating that the Husab mine had been constructed and put into production successfully since CGN acquired it in 2012. The Husab mine has a designed annual mining capacity of over 100 million tons, an annual ore processing capacity of 15million tons and an annual output of 6500tons of U3O8 and it will be the largest open-pit uranium mine with the largest mining capacity and ore processing capacity in the world. Over more than one year’s mining production and operation, the production management, equipment maintenance and technical management system have been fully established at the Husab mine and its operation activities such as the operation of process plant and mining production and so on has gradually gone to the right way. However, due to the larger variations in the shapes of ore bodies than expected, the inaccuracy of measurement of uranium grade, large-scale mining fleets and the precision loading errors etc., lots of outstanding issues have been identified in the fields of the consistency between the grade of resource model and that of mined ore and the control on dilution and loss in the course of mining such as high dilution and loss ratios, large variation in the grade in the mining process. These issues will have important bad effect and even impede the stable production of the Husab mine and thus it is urgent to carry out the study on key techniques of uranium ore grade control for the Husab mine to solve these issues from its mining production. This study focuses on the whole process of mining production and has conducted the following research work including the establishment of geological resource – grade control model system, the optimization on the mining production procedures, the application of controlled blasting technology with a higher precision and its optimization, the application of rapid and accurate grade measurement by down-hole gamma logging. This research work will effectively improve the ore dilution and loss in the course of mining production and further improve the production capacity and its economics of the Husab mine. ADVANCEMENT ON THE STUDY OF ORE GRADE CONTROL TECHNIQUES FOR THE HUSAB MINE 1) Establishment and improvement of “three stage” resource – grade control model system At the moment, the “two stage” resource – grade model system has been adopted at the Husab mine, that is, geological resource model (MIK model) based on exploration database and grade control model (GC model) based on down-hole gamma logging data from blasting holes. The annual plan for mining production, blasting block design, mining and stripping production plan and blasting hole design are proposed based on the MIK model and the mining block definition (composite model) and loading plan are proposed based on the GC model. But due to the fact that the drilling exploration grid is mostly 25m×25m to 50m×50m or larger and the fact that the MIK model is not updated using the mining production data, the MIK model has a low accuracy and reliability with respects to the mining production and thus it cannot be used to effectively guide the annual mining production plan, blasting block design, blasting hole design and its optimization. At the same time, however, the unreasonable model parameters reduce the accuracy of GC model and thus it cannot well define the ore-waste boundary so as to meet requirements of loading and ore blending. On the basis of extensive discussions and sites to other large scale open-pit mines and combined with the actual mining production of the Husab mine, this study proposes the hierarchical, segmental and stable “three stage” resource – grade control model system consisting of resource/reserve model – interim model – grade control model that can be updated dynamically. The grade control model is created based on down-hole gamma logging data from blasting holes by interpolating the ore grade for the block model of a specific blasting block and is used to guide the definition of mining blocks, wire connection for blasting, ore loading and blending. The geological resource model is created by using the geological database incorporating drill-hole data from resource drilling and blasting hole from mining production, it interpolates the ore grade distribution for all the ore bodies within the mining district with an updated within each year or once two years and it is used for the optimization on the ultimate open pit boundary, mid- and long-term mining and stripping plan and annual mining production plan. The interim model proposed in this study is a transitional model between the geological model and grade control model that establish the interconnection of the geological model and grade control model to form an inherent geological model system. This interim model is created by using down-hole gamma logging data from blasting holes drilled for 2~3 benches above the current bench and resources drill-hole data below the current bench, it interpolates the grade distribution for the downward one or two benches from the current bench; it is used for the monthly and weekly mining and stripping plan, blasting block design and blasting hole design and thus improves the blasting and mining efficiency. 2) Optimization and improvement of mining production procedures Since the pre-stripping commenced in 2013 and the ore mining commenced in 2015, a set of intact mining production procedures have been established and the whole mining capacity also increases gradually. But there is still much uncertainty in the whole mining production without the more accurate resource – grade control models in different scales for guidelines and thus it is difficult to meet requirements on the tonnage and grade of ore to be mined so as to ensure the smoothness of mining production at the Husab mine. Hereby, the geological resource models are re-created and updated for the first stage of mining areas in Pit #1 and #2 based on understanding of the mine geology and combined with the geological information and grade data, further define the spatial distribution of ore bodies and exhibit the grade distribution, which will provide guidelines for preparing the mid- and long-term mining plan and annual mining plan. The interim model proposed in this study provides more accurate ore-waste boundaries within the benches to be mined and thus it lays a better foundation for preparing the monthly and weekly mining plans, blasting block design and blasting hole design. The more scientific and reasonable grade control models and accurate ore-waste boundaries will greatly enhance the blasting efficiency and the output of mined ore and reduce the ore dilution and loss and at the same time, it is also very favorable to ore blending directly within the pit to reduce the ore re-transport. 3) Application of advanced controlled blasting technology and its optimization Up to present, the mining production still focus on increasing the stripping capacity at the Husab mine and is not completely transited to focus on mining capacity to provide the ore in tonnage and expected grade required by the process plant. Therefore, the relatively simple blasting technology and blasting scheme are adopted currently at the Husab mine. Neither different blast schemes are adopted according to the differences in mechanical properties of rocks within different blasting blocks and nor the advanced blasting technology is adopted to effectively separate the ore and waste. Thus it is required to improve the blasting efficiency. In this study, the quality of rock masses has been assessed on the basis of studying the physical and mechanical properties of main ore and rocks within the mining district and the rock masses are divided into two categories according to their blastability: one is rock masses of easy to blast consisting of near-surface loose and poorly cemented sandstone and calcrete; the other is rock masses of difficult to blast consisting of underground hard and intact granite, marble, gneiss, schist and quartzite. The ore and rocks are classified as the rock types of difficult to blast at the Husab mine. On the basis of analyzing the blasting parameters currently used at the Husab mine and considering the requirements of ore loading, hauling and primary crushing of ore, it is believed that the current blasting parameters are effective for blasting within the areas of ore and thus relatively reasonable . But it is not reasonable that these parameters are used for blasting within the areas of waste without any modification and they could be improved greatly. Consequently, lots of research work has been conducted to improve blasting parameters used for blasting within the areas of waste, the desktop analyses and digital stimulation are also proceeded and the next step to carry on the field trial on site and then they are applied at the Husab mine. In addition, it is difficult to control the ore dilution and loss due to the fact that there is no interim model and accurate grade control model to guide the mining production and the special technologies, such as pure blasting, separating blasting and slag-remaining blasting, are not applied at the Husab mine and at the same time, the field trial of blast-induced movement monitoring does not provide a good result. It is proposed in this study to adopt different blasting technology and schemes to control the blasting and successfully separate the ore and waste according to the distribution of ore and waste and their scale within the mining area based on the more accurate interim – grade control models. For the blocks with a large scale and area of ore and waste, it is proposed to individually design blasting holes on the block of ore or waste and then blast to successfully separate the ore and waste when the ore area or waste area meets the requirements of an individual block; when the area or waste area is not large enough to be designed an individual block, it is proposed to modify the blasting parameters such as the blasting hole design, charge structure, blasting delay time and initiation mode to generate physical zones of easy to identify in visibly such as zones with visible difference in sizes within the ore or waste areas and flutes at the boundaries of ore and waste and thus, the ore and waste are finally separated to guide the ore loading and reduce the ore dilution and loss. 4) Application of uranium grade measurement technology by down-hole gamma logging At the moment, the uranium content of ore is determined dominantly by the chemical method of analysis and assisted by the radiometric measurement at the majority of uranium mines in the world except those in China and in the Commonwealth of Independent States. It not only takes a long time but also expensive to determine uranium by the chemical method of analysis and thus it is difficult to ensure the smooth operation at the Husab mine. A set of intact radiometric measurement technology and method system has been established including the technology, equipment, operation manuals and technical standards etc., through over tens of years’ efforts especially the practices in the exploration and production of uranium mines in China. Since early the Husab mine was put into production, the radiometric measurement system and related operation manuals and standards has been established gradually, including key equipment facilities such as down-hole gamma logging system, truck scanner system, belt scanner system at the primary crushing station and corresponding calibration of technical parameters and the construction of standard calibration models on the site. Consequently, it ensures the grade of ore will be determined accurately on time to fully meet the production requirements at the Husab mine. CONCLUSIONS A set of intact mining production procedures and technical standards have been established preliminarily since the Husab mine was put into production. The continuous research achievements in this study shows that the effective results have been achieved in the fields of the resource – grade control models, optimization on the mining production procedures, controlled blasting technology and radiometric measurement technology and thus the mining capacity and efficiency has been improved effectively and the ore dilution and loss has been reduced obviously, laying a strong foundation for the ramp-up production of the Husab mine. Speaker: Mr Wenming DONG (CGN Uranium Resources Co Ltd) • 61 Cost Effective Heap Leaching, the case study of Mutanga, Zambia GoviEx Uranium Inc (“GoviEx”) holds several contiguous mining and prospecting licences in Southern Zambia that are grouped as the Mutanga Project. The deposit comprises of shallow sandstone hosted uranium ore. The Mutanga Project contains a mineral resource of 96.2 million tonnes (“Mt”) of ore at an average grade of 283 ppm U3O8 containing 60.0 million pounds (“Mlb”) of U3O8 in six deposits (Mutanga, Dibwe East, Dibwe, Gwabe, Njame, and Njame South), located over 65 km strike. Processing of the ore has been demonstrated to be effective using sulfuric acid leaching with ion exchange recovery of uranium. Test work has confirmed heap leaching is viable and permeability of the ore is good with low acid consumption at 3-18 kg/t. The process is robust, simple and has a low environmental profile. Overall uranium recovery varies with recoveries from each of the deposits averaging 74 to 94%. An important aspect of improving project economics is to rely on a central process recovery close to the main deposits of Mutanga and Dibwe East and using satellite heaps and adsorption circuits to obtain uranium and transport to the main recovery plant. This allows a large cost saving in transport of ore and allows for optimization of heap conditions in each of the heaps focused on the locally mined ore. For Mutanga-Dibwe East leach pad, pregnant leach solution will be pumped to the adjacent central process plant for stripping and concentrating uranium. For the other deposits pregnant leach solution will be pumped to an adsorption plant where uranium will be stripped of uranium and loaded onto resin. Approximately 24,000 litres per day of resin will be transported by truck to the central process plant for concentrating, barren resin will be trucked back to satellite operations. Uranium production recovery is expected to be on average of 2.4 Mlbs U3O8 per annum of uranium contained in uranium oxide. Life of mine capital cost for the project is low at USD167M and operating costs of approximately USD20/t of ore processed (equivalent to USD31/lb). The return on the project has reasonable post tax Net Present Value of USD114M (at 8% discount) and internal rate of return of 25% based on a uranium price of USD58/lb U3O8. In order to achieve this with a low grade deposit required lateral thinking about exploiting efficiencies of the different ores and removing redundant processes in order to deliver a realistic project. Such an approach can improve project economics (even at low uranium prices) and provide sustainable mining operations. Speaker: Mr Robert Bowell (SRK Consulting (UK)) • Wednesday, June 27 • Advances in Exploration Conveners: Mr Luis LOPEZ (CNEA (Argentina)) , Martin Fairclough (International Atomic Energy Agency) • 62 Quantitative Mineral Resource Assessments of Roll-Front and Calcrete Uranium in Southern Texas and the Southern High Plains Province of the United States: Results and Simple Economic Filter Analysis INTRODUCTION The U.S. Geological Survey (USGS) recently completed two uranium mineral resource assessments in the south-central United States (U.S.) as part of a re-evaluation of domestic resources previously considered by the 1980 National Uranium Resource Evaluation program [1]. These new assessments include: (1) in 2015, an assessment of undiscovered roll-front uranium resources in Tertiary coastal plain sediments of southern Texas [2]; and (2) in 2017, an assessment of undiscovered calcrete uranium resources in Pliocene and Pleistocene carbonate-rich sediments of the Southern High Plains region of Texas, New Mexico, and Oklahoma [3]. Roll-front uranium in southern Texas has been recognized since the mid-1950s. Calcrete uranium, however, a deposit style known elsewhere around the world but previously unreported in the U.S., was only brought to the attention of the USGS in 2015 after two small deposits (Buzzard Draw and Sulphur Springs Draw) and several prospects were recognized in northern Texas in the mid-1970s [4]. METHODS AND RESULTS The roll-front assessment was conducted using a combination 3-Part quantitative [5] and Weights-of-Evidence qualitative mineral potential modelling [6] methods, and identified 54,000 tU, with 85,000 tU estimated mean undiscovered. The calcrete assessment was conducted using the 3-Part quantitative method, and identified 1,000 tU, with 15,000 tU estimated mean undiscovered. Collectively they total about 155,000 tU. DISCUSSION AND CONCLUSIONS If these identified and estimated undiscovered uranium resources are economic, and if the identified resources are mined and undiscovered resources found and produced, this represents over 8 years of U.S. civilian nuclear power reactor fuel requirements. The application of a simple economic filter based on the Pareto principle, and using uranium resource data from the IAEA global UDEPO database [7] and a USGS-compiled database for southern Texas [8], was used to investigate whether the undiscovered uranium resources could be economic in relation to known and(or) produced regional and global uranium resources. Given the uranium resource endowment (size) of deposits regionally and globally, and the current market prices for uranium (October, 2017; approximately$20 USD per pound U3O8 or $52 USD per kg U), the results suggest that: (1) the undiscovered calcrete uranium resources are not likely to be economic at the present time; and (2) the undiscovered roll-front resources are economic in context of regional (southern Texas) uranium production considerations and setting, but marginally- to sub-economic when regarded in a larger, global context. REFERENCES [1] U.S. DEPARTMENT OF ENERGY, An assessment report on uranium in the United States of America, U.S. Department of Energy Grand Junction Office, Grand Junction, Colorado, USA, Report Number GJO-111(80), 160p. (1980). [2] Mihalasky, M.J., Hall, S.M., Hammarstrom, J.M., Tureck, K.R., Hannon, M.T., Breit, G.N., Zielinski, R.A., and Elliot, Brent, Assessment of undiscovered sandstone-hosted uranium resources in the Texas Coastal Plain, 2015, U.S. Geological Survey Fact Sheet 2015–3069, 4 p. (2015), http://dx.doi.org/10.3133/fs20153069. [3] Hall, S.M., Mihalasky, M.J., and Van Gosen, B.S., Assessment of undiscovered resources in calcrete uranium deposits, Southern High Plains region of Texas, New Mexico, and Oklahoma, 2017, U.S. Geological Survey Fact Sheet 2017–3078, 2 p. (2017), https://doi.org/10.3133/fs20173078. [4] Van Gosen, B.S., and Hall, S.M., The discovery and character of Pleistocene calcrete uranium deposits in the Southern High Plains of west Texas, United States, U.S. Geological Survey Scientific Investigations Report 2017–5134, 27 p. (2017), https://doi.org/10.3133/sir20175134. [5] Singer, D.A., and Menzie, W.D., Quantitative mineral resource assessments: An integrated approach, Oxford University Press, New York, New York, USA, 219 p. (2010). [6] Bonham-Carter, G.F., Geographic information systems for geoscientists: Modelling with GIS, Pergamon Press / Elsevier Science Publications, Tarrytown, New York, USA, 398 p. (1994). [7] INTERNATIONAL ATOMIC ENERGY AGENCY, World Distribution of Uranium Deposits (UDEPO), IAEA-TECDOC-1629 (2009; 2012 online edition), https://infcis.iaea.org/. [8] Hall, S.M., Mihalasky, M.J., Tureck, K.R., Hammarstrom, J.M., and Hannon, M.T., Genetic and grade and tonnage models for sandstone hosted roll-type uranium deposits, Texas Coastal Plain, USA, Ore Geology Reviews, v. 80, p. 716–753 (2016), https://doi.org/10.1016/j.oregeorev.2016.06.013. Speaker: Dr Mark Mihalasky (U.S. Geological Survey) • 64 PROSPECTIVITY ANALYSIS OF THE MOUNT ISA REGION (QUEENSLAND, AUSTRALIA) FOR METASOMATITE-TYPE URANIUM Results of quantitative mineral resource assessment (QMRA) and mineral prospectivity analysis (MPA) for metasomatite-type (albitite-type) uranium deposits in the Mount Isa region of Queensland, Australia, are discussed. The study illustrates the process of using a geological model and various input data to define areas prospective for undiscovered uranium resources. The approach was fundamentally knowledge-driven and required use of geological judgment in choosing appropriate input layers, in assigning fuzzy membership values and in deciding the most appropriate methods of combining the input layers. The prospectivity mapping was successful in that known deposits, particularly larger examples, fall within pixels categorized as highly prospective. Ultimately, however, the success of the approach will need to be judged by the success of ongoing mineral exploration in areas deemed to have prospectivity. A comparison of regional and detailed studies illustrates the scale dependency of the input parameters, with some input layers being appropriate for the regional analysis but not for the more detailed one. Prospectivity maps generated by the fuzzy gamma and vectorial fuzzy logic techniques are similar. The latter technique may, however, provide better discrimination of areas prospective for large (rather than medium or small) deposits. A further benefit of this technique is that there is no need to produce intermediate combinations of input layers and no necessity for a gamma parameter. This results in a simplified process and makes subsequent applications of the technique more repeatable and comparable. This work also used MPA as the basis for defining a prospective tract which was the input for QMRA. A global regression model of total ore tonnage estimated undiscovered ore tonnage for the entire Mt Isa North tract at 83 Mt. Speaker: Dr Andy Wilde (Deep Yellow Ltd) • 65 Using continent-scale spatial targeting to delineate permissive areas for sandstone-hosted uranium INTRODUCTION An ambitious sandstone-hosted uranium mineral prospectivity model covering the entire Australian continent hints at undiscovered mineral potential. Australia was chosen to demonstrate the usefulness of huge-scale multi-criteria analyses due to the relatively large volume of publicly available data covering the entire continent and because it is host to a considerable number of spatially distributed and economically significant deposits (e.g., Beverley, Manyingee, Bigrlyi). It is important to note that although all of the deposits under consideration are similarly classed as ‘sandstone-hosted’, significant differences exist in their host rock and mineralisation ages, mineralogy and in their underlying mineralising processes. Can a single predictive model really be expected to account for the distribution of all these genetically diverse systems? Traditional approaches to mineral potential mapping involve interpretation of individual maps, or manual overlay of groups of ‘predictor maps’ to delineate favourable exploration areas. In the (not so distant) past, simple overlays were commonly performed using light tables and analogue interpretation methods (i.e., a pencil). An inevitable consequence of the rapid advancement in both the availability of vast, high-resolution digital data sets and the inexorable growth in computing power has been that geographical information systems (GIS) and spatial analysis have rapidly become ubiquitous in mineral exploration. Traditional approaches have been supplanted by the use of GIS and digital overlays, allowing for the rapid interpretation of a huge variety of spatial data with an ever increasing assortment of analytical techniques. Multi-criteria spatial targeting is now being deployed routinely in the search for, and assessment of areas that have potential to contain economic concentrations of desirable minerals [1-9]. The ultimate goal of this study is to reduce a wide range of complex conceptual models of ore genesis to their most fundamental mappable components. These basic elements are then reconstructed in a targeting model which aims to imitate the thought processes of the exploration geologist. The underlying challenge is to construct a single mathematical model which adequately describes the distribution of known sandstone-hosted uranium deposits across a wide variety of terrains, ages and mineralisation (sub-)styles for an entire continent. The success criteria are that the model must be capable of effectively ‘re-discovering’ all areas of known mineralisation, yet it must be discerning enough that it doesn’t highlight vast areas which are confidently regarded as having limited upside potential. Areas highlighted by such a model which lie outside of known mineralised zones logically possess all of the critical components of sandstone-hosted uranium mineralising systems. These areas are potentially under-explored and may be worthy of further investigation. METHODS AND RESULTS The basic premise of this GIS-based mineral prospectivity analysis (MPA) is the recognition of the essential criteria of sandstone-hosted uranium deposits [10] and translation of those criteria into quantifiable spatial parameters which can then be handled mathematically. The first step is to acquire and assess any spatial data that may be turned into useful proxies for components of the mineralisation genetic model. This generally requires a thorough audit of all publically available data. Data sets that were selected as being of potential use for the construction of the Australia-wide MPA include: • surface geology (1:1m, 1:5m & 1:2.5m scale) • crustal elements • Australian geological provinces • metamorphic grade and ages • structural data • radiometrics • digital elevation models (SRTM and derivatives) • drainage pathways • sedimentary basin extents and thicknesses • paleo-channel distribution Australian explorers have access to an extraordinary amount of publicly available, multi-disciplinary data sets of very high quality. However, not all these data are useful for their straightforward inclusion in a continent-scale MPA. Some lack sufficient resolution, while others are too data-rich to be practical at the continent scale without significant modification. A holistic mineral systems approach [11 - 13] is used to classify and combine the data so that a meaningful output can be generated. This approach considers all geological factors which control the generation and preservation of mineral deposits (including sources of metals, ligands and energy, fluid migration pathways and focusing mechanisms, and chemical and/or physical causes for precipitation at the trap site). A range of ‘predictor maps’, which represent mappable components of the mineralisation system under consideration, are derived from the spatial data. For this study, predictor maps are designed to represent individual components of the ‘Source’ (e.g., basement, uranium-enriched felsic igneous rocks), ‘Transport’ (e.g., faults, drainage pathways) or ‘Trap’ (e.g., reduced sediments, morphological barriers) parts of the mineral system. The creation of predictor maps and the subsequent analysis was performed in ESRI ArcGIS (Version 10.4.1). Data preparation and the creation of predictor maps commonly involve some simplification and interpretation. For example, complex geology data can be re-classified into simpler stratigraphy and lithology predictor maps, each comprising a manageable number of classes. Multi-ring buffers can be constructed around features (e.g., granite bodies) to test proximity effects, with each concentric buffer being treated separately in the model. Thresholding can be used to simplify geophysical and other raster data into classes that can be handled more readily in the mathematical model. The construction of some of the 26 predictor maps used in this study is briefly outlined in this presentation. A knowledge-driven approach (Fuzzy Logic) relies entirely on expert input to assign weights to individual predictor maps and their components to account for the relative importance of each feature in the mineralising system. A relatively simple method is used to calculate ‘Fuzzy Membership’ values in this study. ‘Class weights’ (0-10) are assigned to each feature within a predictor map based on the relative prospectivity of the feature. Additionally, ‘Map weights’ (0-10) are assigned to each predictor map based on the relative importance of the component it represents in the genetic model, and confidence in the underlying data. Multiplying the class by the map weights for each feature in a predictor map gives a ‘class score’ for that particular feature; dividing the class score by 100 results in a ‘Fuzzy Membership’ value between 0 and 1 for the feature. This is done for every feature in every predictor map. This is the value that is used in the final analysis. The (vector) predictor maps are converted to numerical raster grids based on the Fuzzy Membership value, allowing mathematical operations to be carried out on the newly created ‘stack’ of rasters on a cell-by-cell basis. A logic network combining the input predictor rasters is carefully constructed such that it follows sound geological reasoning appropriate to the targeting model. The judicious use of Fuzzy ‘AND’, ‘OR’, ‘SUM’, ‘PRODUCT’ and ‘GAMMA’ logic operators allows quite complex relationships between components to be expressed in the model, reflecting the way in which a geologist might think but extrapolated up to the scale of the analysis (continent-scale in this example) and over a multitude of simultaneous input criteria. In our model, the three major mineral system components (Source, Transport and Trap) are treated separately before being combined in the final stage of the logic network. Solving the logical arguments for each corresponding cell in the stack of weighted predictor map rasters, results in a numerical grid that is interpreted to represent spatial variations in prospectivity. This can then be reclassified and displayed as a colour-coded, multi-class favourability map. DISCUSSION AND CONCLUSION We consider the fuzzy logic mineral prospectivity model presented herein to be a successful first-pass GIS-based analysis for sandstone-hosted uranium deposits on the Australian continent. Crucially, the majority of known sandstone-hosted uranium deposits and provinces occur within areas of elevated to very high favourability in the resulting favourability map, demonstrating the geological validity of the model. Additionally the model identifies several regions that should contain all the ingredients for sandstone-hosted uranium but may have been overlooked or underexplored by previous explorers. However, the model has substantial limitations that must be kept in mind when interpreting the resulting favourability map. At the continental scale and due to the necessary use of highly simplified and modified versions of the spatial data, substantial uncertainties in the properties of the inputs remain. This is particularly true of the heavily modified geology (simplified lithology and stratigraphy) predictor maps but affects all data sets to some extent. Due to these uncertainties, the continental-scale model presented herein is not considered useful for delineating specific exploration targets but is particularly effective at identifying broader permissive areas, as well as regions of elevated favourability within these zones. It is also important to note that the output generated from this model represents just one of an infinite number of possible solutions. Every step in the process, including initial data selection, predictor map design, assigning weights to features and maps and construction of the logic network was driven by a very small group of ‘experts’. While we maintain a high level of confidence in our analysis, the opinions of alternative ‘experts’ are likely to differ (at least somewhat). A significant advantage of this type of analysis over more traditional approaches is that it allows for rapid iterative modification. New data, weights or modified logic network designs that target specific deposit types, or that consider alternate genetic models (for example) can be readily accommodated and tested. The MPA methodology has the ability to quickly reduce the search space, highlighting specific zones of elevated mineral potential. These targets can then be ranked and prioritised for more detailed follow-up, ground-truthing or higher resolution MPA. At a continental scale, such target zones effectively highlight so-called ‘permissive tracts’ [14], representing geological regions that have potential to host undiscovered mineral deposits. The delineation of a permissive tract can contribute to estimating the potential number and size of undiscovered mineral deposits in an area, which has a variety of important economic, land, resource and environmental planning applications [15 – 16]. The continent-scale Fuzzy Logic MPA for sandstone-hosted uranium in Australia demonstrates that GIS-based targeting concepts can be used to objectively delineate and visualise permissive areas for uranium, thereby dramatically reducing the search space and assisting with area selection and decision making processes. This study demonstrates how multiple specifically designed and weighted input predictor maps can be combined using a carefully constructed logic network to create a spatial representation of relative favourability for a specific mineral deposit type at the continental scale. This study clearly benefits from the relatively large volume of high quality, relevant and publicly available spatial data for the Australian continent. However, this type of study is possible in areas where less (or different) data are available because the analysis is built up around to the type of mineralising system under consideration and according to the available data. The veracity of any MPA depends heavily on the quality of suitable input data (“rubbish in – rubbish out”) so questionable data should be rejected as part of the preliminary data assessment. A simpler model is always preferable to one containing erroneous data. If performed carefully and meticulously, GIS-based Fuzzy Logic mineral prospectivity modelling can provide an extremely powerful visualisation and decision-making tool. A comprehensive account of the methods used in this study, including the rationale for using particular data sets, the construction of predictor maps, assigning fuzzy membership values and construction of the logic network is presented as a chapter in an upcoming IAEA TecDoc on “Spatial and quantitative modelling of undiscovered uranium resources” [17]. REFERENCES [1] TURNER, D.D., Predictive GIS model for sediment-hosted gold deposits, North-Central Nevada, USA, Proceedings of Exploration 97: Fourth Decennial International Conference on Mineral Exploration (1997) 115–126. [2] HARRIS, J.R., WILKINSON, L., HEATHER, K., FUMERTON, S., BERNIER, M.A., AYER, J., DAHN, R., Application of GIS Processing Techniques for Producing Mineral Prospectivity Maps – A Case Study: Mesothermal Au in the Swayze Greenstone Belt, Ontario, Canada. Natural Resources Research 10, No. 2 (2001) 91–124. [3] PORWAL, A., CARRANZA, E.J.M., HALE, M., Extended weights-of-evidence modelling for predictive mapping of base metal deposit potential in Aravalli Province, Western India, Exploration and Mineral Geology 10 (2001) 273–287. [4] LUO, X., DIMITRAKOPOULOS, R., Data-driven fuzzy analysis in quantitative mineral resource assessment. Computers and Geosciences 29 (2003) 3–13. [5] NYKÄNEN, V., SALMIRINNE, H., Prospectivity analysis of gold using regional geophysical and geochemical data from the Central Lapland Greenstone Belt, Finland Geological Survey of Finland, Special Paper 44 (2007) 251–269. [6] JOLY, A., PORWAL, A., MCCUAIG, T.C., Exploration targeting for orogenic gold deposits in the Granites-Tanami Orogen: mineral system analysis, targeting model and prospectivity analysis, Ore Geology Reviews 48 (2012) 349–383. [7] LISITSIN, V.A., GONZÁLEZ-ÁLVAREZ, I., PORWAL, A., Regional prospectivity analysis for hydrothermal-remobilised nickel mineral systems in western Victoria, Australia, Ore Geology Reviews 52 (2013) 100–112. [8] LINDSAY, M., BETTS, P.G., AILLERES, L., Data fusion and porphyry copper prospectivity models, southeastern Arizona, Ore Geology Reviews 61 (2014) 120-140. [9] CHUDASAMA, B., PORWAL, A., KREUZER, O.P., BUTERA, K., Geology, geodynamics and orogenic gold prospectivity modelling of the Paleoproterozoic Kumasi Basin, Ghana, West Africa. Ore Geology Reviews 78 (2016) 692-711. [10] INTERNATIONAL ATOMIC ENERGY AGENCY, World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification, Vienna, IAEA-Tecdoc-1629 (2009) 126pp. [11] WYBORN, L.A.I., HEINRICH, C. A., JAQUES, A.L., Australian Proterozoic mineral systems: essential ingredients and mappable criteria, Australasian Institute of Mining and Metallurgy Annual Conference Proceedings (1994) 109–115. [12] KNOX-ROBINSON, C.M., WYBORN, L.A.I., Towards a holistic exploration strategy: Using geographic information systems as tool to enhance exploration, Australian Journal of Earth Sciences 44 (1997) 453-463. [13] JOLY, A., PORWAL, A., MCCUAIG, T.C., CHUDASAMA, B., DENTITH, M.C., AITKEN, A.R., Mineral systems approach applied to GIS-based 2D-prospectivity modelling of geological regions: Insights from Western Australia. Ore Geology Reviews, 71 (2015) 673-702. [14] SINGER, D.A., Basic concepts in three-part quantitative assessments of undiscovered mineral resources, Nonrenewable Resources 2, vol 2 (1993) 69–81. [15] CUNNINGHAM, C.G., ZAPPETTINI, E.O., VIVALLO S., WALDO, CELADA, C.M., QUISPE, JORGE, SINGER, D.A., BRISKEY, J.A, SUTPHIN, D.M., GAJARDO M., MARIANO, DIAZ, ALEJANDRO, PORTIGLIATI, CARLOS, BERGER, V.I., CARRASCO, RODRIGO, SCHULZ, K.J., Quantitative mineral resource assessment of copper, molybdenum, gold, and silver in undiscovered porphyry copper deposits in the Andes Mountains of South America, U.S. Geological Survey Open-File Report 2008-1253 (2008) 282 p. [16] SINGER, D.A., JAIRETH, S., ROACH, I., A three-part quantitative assessment of undiscovered unconformity-related uranium deposits in the Pine Creek region of Australia. IAEA TecDoc, Spatial and Quantitative Modelling of Undiscovered Uranium Resources (in preparation). [17] BIERLEIN, F.P., BRUCE, M.D., A continent-scale GIS-based assessment of the distribution and potential for sandstone-hosted uranium deposits. IAEA TecDoc, Spatial and Quantitative Modelling of Undiscovered Uranium Resources (in preparation). Speaker: Mr Matthew Bruce (Thunderbird Metals) • 66 Spatial analysis of prospectivity for surficial uranium deposits: a case study in British Columbia, Canada INTRODUCTION Surficial uranium (U) resources exist in the southernmost part British Columbia (Canada). The known U resources in the region (hereafter denoted as SBC) are comprised by four surficial U deposits and 32 small prospects/showings. The prospectivity of the SBC for surficial mineralization has, however, not been entirely evaluated yet. Here, results of spatial analysis of prospectivity for surficial U in the SBC, using a geographic information system (GIS) and following the mineral systems approach [1], are presented. SURFICIAL U MINERAL SYSTEM IN THE SBC In the SBC, surficial U mineralisation consists of fluviatile and/or lacustrine/playa U occurrences within loose, pervious fluvial sediments of Late Miocene age along paleodepressions or paleochannels [3]. The mineralisation is composed largely by uranyl carbonates [2] and/or uranous phosphates such as autunite, ningoyite and saleeite [3]. The rocks that are probable sources of U in the SBC include small units of uraniferous pegmatites in the Shuswap Metamorphic Complex of Palaeozoic age, granitoids of Jurassic–Cretaceous and Eocene–Oligocene age, and volcanic rocks of Eocene age [2], [3]. Data on reactive U content of rocks [3] suggest that Okanagan granites/pegmatites of Jurassic–Cretaceous age are major sources of U in the SBC. The release of U from the potential sources has probably been favoured by repeated tectonism and multiphase intrusions that have taken place in the SBC during the ancient geologic past [3]. Tectonically deformed intrusive rocks cut by interconnected faults/fractures also favoured deep-seated flow and wide-distribution of U-bearing groundwater, which ultimately permeated pervious sediments along paleodepressions or paleochannels [2]. The U, in these surficial environments, exists as soluble uranyl carbonate complexes carried by oxygenated alkaline groundwater [4]. Flow of groundwater is focused through pervious paleodepressions or paleochannels filled with permeable fluviatile sediments. Energy for flow of groundwater is chiefly due to gradient along paleodepressions or paleochannels. In playa/lacustrine environments, organic-rich sediments act both as physical and chemical traps for surficial U formation [2]; whereas in pervious zones of channel fluviatile environments, organic-rich soils or sediments act both as physical and chemical traps In either environment, surficial U forms mainly by either evaporation or reduction. The latter is due to bacteria or to sediments that are rich in organic matter. However, because no common U minerals are known in the SBC, the role of evaporation in the SBC is less likely, as groundwater is not saturated with respect to typical U phosphates [5]. Thus, in the surficial U mineral system in the SBC, adsorption onto organic-rich sediments is the most probable factor of surficial U mineralisation, followed by reduction owing to bacteria or organic-rich sediments [2], [5]. SURFICIAL U MINERALISATION: CRITERIA FOR TARGETING, SPATIAL PROXIES The deposits/occurrences of surficial U in the SBC are alike but dissimilar to the most significant surficial U deposits worldwide, namely calcrete-hosted carnotite [6], [7], [8], [9]. Therefore, mapping of surficial U prospectivity in the SBC will make use of criteria for targeting and respective spatial proxies that somewhat differ from those used exactly for the same purpose in the Yeelirrie area (Australia) [1]. The criteria for targeting that were used here include: (a) source rocks for U; (b) pathways; and (c) traps. A single U source targeting criterion, namely felsic volcanic or intrusive rocks with reactive U, was used. The corresponding spatial proxy used was presence of and/or proximity to felsic volcanic or intrusive rocks with reactive U. Instead of using Euclidean distance to model proximity, fuzzy proximity (representing probability-like values) was used because the fuzzy set theory [10] was used here for mapping surficial U prospectivity. To model fuzzy proximity, Euclidean distances were transformed through a logistic function [11] to non-linearly decreasing values ranging from 1 for the nearest distance to 0 for the farthest distance. Three maps of fuzzy proximity to probable U-source rocks (i.e., Jurassic–Cretaceous Okanagan Batholith, Eocene–Oligocene Coryell Plutonic suite, Eocene Volcanics) were combined into a single map of fuzzy proximity to U-source rocks, by applying a weighted fuzzy algebraic sum operator whereby the weights are defined from the reactive U content of each of the three rock units. A single pathways criterion, namely Tertiary to Recent paleochannels, was also used. The corresponding spatial proxy used was fuzzy proximity to paleochannels. The paleochannels were remotely-sensed using a digital elevation model and night-time ASTER thermal infrared data [12], [13]. For chemical traps, two criteria were used: (1) bicarbonate contents of fluvial waters; and (2) U-rich groundwater. The respective spatial proxies used were: (1) fuzzy alkalinity of fluvial waters, modelled by applying a non-linear logistic function to data on stream water pH [14]; and (2) fuzzy U-abundance of fluvial waters, modelled by applying a non-linear logistic function to data on U content of fluvial waters [14]. Bicarbonate contents of strongly alkaline fluvial waters in the SBC range from 50 to 600 ppm. This considerably boosts the ability of soils/sediments in paleodepressions of paleochannels to concentrate U [2]. Dispersion of U from source rocks and its enrichment in surface water and groundwater permits huge quantities of this element to reach trap areas wherein surficial U mineralisation ensues. For physical traps, two criteria were used: (1) nearly-stationary fluvial water in paleodepressions or paleochannels [1]; and (2) size of source area [1]. The corresponding spatial proxies used were: (1) presence of and fuzzy proximity to nearly-level topographic depressions, modelled by applying a non-linear logistic function to topographic slopes derived from a digital elevation model; and (2) fuzzy flow accumulation, modelled by applying a non-linear logistic function to sizes of catchments derived from a digital elevation model. Because surficial U precipitates from nearly-stationary fluvial water in paleodepressions or paleochannels [1], depressions in the topography with level or nearly-level slopes were used as spatial proxies because it can be expected that substantial fluid modification occurs in such locations but not in locations having dissimilar topographic characteristics. Because locations where fluvial water flow accumulates from huge U-source rock areas are prone to amass, enrich, and precipitate more U, a map of flow accumulation was used as spatial proxy because it represents areas that may contain significant potential U-source rocks for surficial U mineralisation. MODELLING OF REGIONAL-SCALE SURFICIAL U PROSPECTIVITY The spatial proxies generated were combined in systematic way that mimics the interaction of processes involving sources, pathways and traps, which result in surficial U mineralisation. This was achieved by adapting an inference engine that symbolise hypotheses or knowledge regarding the interactions of a variety of processes that are relevant to a surficial U mineral system [1], [15]; thus, a mineral systems approach. Therefore, a fuzzy inference engine was used to model regional-scale surficial U prospectivity in the SBC according to the above-discussed surficial U mineral system and regional-scale criteria for targeting (and respective spatial proxies) for surficial U mineralisation in the SBC. Considering its simplicity and flexibility, the fuzzy set theory [10] is regarded by [16] to be the most appropriate for integrating spatial data to model the interaction of certain geologic processes. For every step in the fuzzy inference engine used, a suitable fuzzy operator was used to combine at least two spatial proxies to mimic the interaction of at least two processes pertinent to surficial U deposit formation. The fuzzy inference engine and the fuzzy operators that were used formed a sequence of logical rules that successively combined the fuzzy spatial proxies, and they also served to negate the influence of spatial proxies with significant uncertainty. As mentioned earlier, a map of integrated U sources spatial proxy was derived by using a weighted fuzzy algebraic sum operator to combine the potential U-source rocks spatial proxies. A map of integrated chemical traps spatial proxy was derived by using fuzzy AND operator to combine the U-abundance and alkalinity of fluvial waters spatial proxies. That is because both U-abundance and alkalinity of fluvial waters are needed for surficial U deposits to form. A map of integrated physical traps spatial proxy was derived using fuzzy OR operator to combine the flow accumulation and nearly-level depressions spatial proxies. That is because adequate physical constrain on surficial U deposit formation may be provided by either catchments with voluminous flow accumulation or nearly-level depressions. Finally, a map of surficial U prospectivity was derived by using fuzzy AND operator to combine the pathways spatial proxy with the integrated U sources, chemical traps, and physical traps spatial proxies. That is because formation of surficial U deposit requires all the processes symbolised by these spatial proxies. Experiments on different map combinations were then performed to determine (a) sensitivity of the prospectivity to input spatial proxies, (b) which spatial proxies are best predictors, and (c) which prospectivity map can be best used to guide further exploration for surficial U deposits in the SBC. The predictive performance of each out prospectivity map [17] was determined by using the four known deposits and 32 prospects/showings of surficial U in the SBC. RESULTS AND DISCUSSION The two best maps of surficial U prospectivity that were generated here are inclusive of the proximity to potential U-source rocks spatial proxy, indicating the significance of data on reactive U content of rocks in modelling of surficial U prospectivity and the efficacy of the weighted fuzzy algebraic sum operator to integrate such kind of data in spatial analysis of surficial U prospectivity. The two best prospectivity maps are exclusive of the nearly-level depressions spatial proxy, indicating the inadequacy and thus inaptness of this spatial proxy in modelling of surficial U prospectivity in the region, or the better efficacy of the flow accumulation spatial proxy. However, if, among the traps spatial proxies, only the U-abundance of fluvial waters spatial proxy was combined with the pathways and potential U-source rocks spatial proxies, the output surficial U prospectivity map is just very slightly inferior to the two best prospectivity maps. This demonstrates that either the flow accumulation spatial proxy or alkalinity of fluvial waters spatial proxy just has very little influence on the predictive capacity of prospectivity mapping even though they are important criteria for targeting of surficial U in the region. Nevertheless, the results show that alkalinity of fluvial waters is more efficient than U-abundance in fluvial waters as spatial proxy of U-transporting ability of surface waters. These limitations demonstrate that the prospectivity model requires updating when more appropriate data become available. The two best-performing prospectivity maps derived here suggest presence of undiscovered surficial U resources in the SBC. However, the identified prospective areas mostly identified are those where the known deposits/occurrences of surficial U are mostly present in the SBC. This indicates that two best-performing prospectivity maps carry type II (or false-negative) error with respect to possible undiscovered resources of surficial U in other parts of the SBC, whereas the two worst-performing prospectivity maps carry type I (or false-positive) error with respect to the known deposits/occurrences of surficial U in the SBC. The type I and type II errors are equivalent to over- and under-estimation of prospectivity, respectively. Avoiding type I error is crucial as this will render failure to discover new deposits, whereas type II error will render missed chance for discovery of new deposits. CONCLUSIONS The above-discussed methodology for spatial analysis of regional-scale prospectivity for surficial U in southern British Columbia (Canada) is quite straightforwardly implementable by using a geographic information system. A more intricate fuzzy inference system consisting of more elaborate logical rules representing expert reasoning for delineating zones prospective for surficial U [1] is likely to be as instructive for researchers with more profound insight to the surficial U system in the region. REFERENCES [1] PORWAL, A., DAS, R.D., CHAUDHARY, B., GONZÁLEZ-ÁLVAREZ, I., KREUZER, O., "Fuzzy inference systems for prospectivity modeling of mineral systems and a case-study for prospectivity mapping of surficial uranium in Yeelirrie area, Western Australia", Ore Geology Reviews 71, 839-852 (2015). [2] CULBERT, R.R., BOYLE, D.R., LEVINSON, A.A., "Surficial Uranium Deposits in Canada", In: "Surficial Uranium Deposits", IAEA-TECDOC-322, IAEA, Vienna, pp. 179-191 (1984). [3] BOYLE, D.R., "The Formation of Basal-type Uranium Deposits in South Central British Columbia", Economic Geology 77, 1176-1209 (1982). [4] CULBERT, R.R., LEIGHTON, D.G., "Uranium in alkaline waters – Okanagan area, British Columbia", CIM (Canadian Institute of Mining & Metallurgy) Bulletin 71, 103-110 (1978). [5] TIXIER, K., BECKIE, R., "Uranium depositional controls at the Prairie Flats surficial uranium deposit, Summerland, British Columbia", Environmental Geology 40, 1242-1251 (2001). [6] CARLISLE, D., "Surficial uranium occurrences in relation to climate and physical setting", IAEA-TECDOC-322, IAEA, Vienna, pp. 25-35 (1984). [7] CAMERON, E., "The Yeelirrie calcrete uranium deposit, Western Australia", IAEA-TECDOC-322, IAEA, Vienna, pp. 157-164 (1984). [8] MISRA, A., PANDE, D., KUMAR, K.R., NANDA, L.K., MAITHANI, P.B., CHAKI, A., "Calcrete-hosted surficial uranium occurrence in playa-lake environment at Lachari, Nagaur District, Rajasthan, India", Current Science 101, 84-88 (2011). [9] KHOURY, H.N., "Geochemistry of surficial uranium deposits from Central Jordan", Jordan Journal of Earth and Environmental Sciences 6, 11-22 (2014). [10] ZADEH, L.A., "Fuzzy sets", IEEE Information and Control 8, 338-353 (1965). [11] YOUSEFI, M., CARRANZA, E.J.M., "Fuzzification of continuous-value spatial evidence for mineral prospectivity mapping", Computers & Geosciences 74, 97-109 (2015). [12] STAMOULIS, V., "ASTER night-time thermal infrared data: interpreting subsurface features from high resolution data", MESA Journal 43, 36-39 (2006). [13] THAKUR, S., CHUDASAMA, B., PORWAL, A., GONZÁLEZ-ÁLVAREZ, I., "Sub-surface paleochannel detection in DeGrussa area, Western Australia, using thermal infrared remote sensing", Proceedings SPIE 9877, Land Surface and Cryosphere Remote Sensing III, 98772C (May 5, 2016), doi:10.1117/12.2223626. [14] LETT, R., "Regional Geochemical Survey Database", GeoFile 2011-07, British Columbia Geological Survey (http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/GeoFiles/Pages/GF2011-7.aspx) (2011). [15] CARRANZA, E.J.M., HALE, M., "Geologically constrained fuzzy mapping of gold mineralization potential, Baguio district, Philippines", Natural Resources Research 10, 125-136 (2001). [16] BARDOSSY, G., FODOR, J., "Geological reasoning and the problem of uncertainty". In: Cubitt, J., Whalley, J., Henley, S. (Eds.), Modeling Geohazards: IAMG2003 Proceedings, Portsmouth UK. Portsmouth University, UK (2003). [17] AGTERBERG, F.P., BONHAM-CARTER, G.F., "Measuring performance of mineral-potential maps", Natural Resources Research 14, 1–17 (2005). Speaker: Prof. John CARRANZA (UNIVERSITY OF KWAZULU-NATAL) • Uranium Newcomers Conveners: Dr Brett Moldovan (IAEA) , Mr Dennis Amos MWALONGO (Tanzania Atomic Energy Commission) • 67 Deploying Technology and Management of Sustainable Uranium Extraction Projects Through its Technical Cooperation programme, the IAEA is supporting a major, four-year interregional project on deploying technology and management of sustainable uranium extraction projects. Fifty-two of the IAEA’s Member States are involved, from 2016-2019 inclusive. This project is in continuation of the interregional project on supporting uranium exploration and production that was active during 2012 – 2013. The main activities are Workshops and Training Courses held in the Member States, with both general and specialized topics in the themes of the project, and to provide inputs that can help leverage the value-addition of the uranium value chain and build business models that adaptive to a wide range of local conditions. At the half-way point, the activities of the project are summarized and the activities for the last two years are set out, which have been refined based on feedback from the participants and the specialized experts who have assisted the IAEA. Speaker: Dr Jing Zhang (IAEA) • 68 Supporting Sustainable Development of Uranium Resources in Africa The IAEA contributes to the balanced development of uranium resources in Africa by facilitating the application of good practices in uranium production cycle, from exploration to closure and remediation, which in turn contribute to the socioeconomic development of the region. From 2014 it enacted a major, four-year regional Africa project through its Technical Cooperation (TC) programme on supporting the sustainable development of uranium resources. This project, RAF2011, was in continuation of a regional Africa uranium-themed project that was commenced in 2009, and the work will be continued with a follow-on regional project from 2018. The main activities were general and specialized workshops and training courses held in African Member States, supporting the sustainable development of uranium resources there. A Uranium Production Site Appraisal Team (UPSAT) review mission was undertaken for the first time in Africa (in Tanzania) under the framework of this project. This paper summarizes the activities of the project and looks forward to planned activities for the follow-on project, which have been refined based on feedback from the participants and the specialized experts who have assisted the IAEA with this project. Speaker: Dr Peter H. Woods (IAEA) • 69 Uranium from domestic resources in Poland INTRODUCTION Uranium mining activities in Poland took place in Sudetes since the end of the 1940s until 1968. Industrial plants R-1 in Kowary carried out the processing of uranium ores till 1973. Outside Sudetes region, uranium was also found and mined from the Staszic pyrite deposit in Rudki, the Holy Cross Mountains. Total production of uranium in these times in Poland is estimated at about 650 t [1]. The mining activities resulted in remains of some 100 dumps, mostly abandoned, of waste rock and ore totalling approximately 1.4 x 106 m3 as well as one tailing pond, which has been the object of a remediation project partly funded by the European Commission aid in 2001 [2]. In the Polish Lowland, in the area of Podlasie Depression (NE Poland), concentrations of uranium were discovered in the Lower Ordovician Dictyonema shale. In the 70s of last century, there was found about 1400 tons of uranium at an average content of 250 ppm and 3800 tonnes of uranium of the ore content of 75 ppm ("Rajsk" deposit). Even then, this occurrence was considered as non-economic. The most interesting uranium mineralization on Polish territory occurs is in the Lower and Middle Triassic rocks of the central parts of Peribaltic Syneclise (N Poland). The highest concentrations were found in the sandstone-conglomerate continental series of Upper Bundsandstein, where for the layer of thickness of about 3.4 m, the average uranium content is 0.34%, with a maximum content exceeding 1.5%. Uranium is accompanied by other metals, like V, Mo, Pb and Se. In January 2014 Polish Government adopted the Program of Polish Nuclear Energy [3]. One of the objectives of this Program is the assessment of domestic uranium deposits as a potential source of uranium for Polish nuclear reactors. The studies on the prospects of recovery of uranium from domestic resources are in progress keeping in mind the inevitable growing uranium demand and perspectives of the global uranium market. CONVENTIONAL RESOURCES OF URANIUM IN POLAND Poland, like most countries in the world, has only the resources of low-grade uranium ores. In the period of 1948-1972, there were 5 mines extracting uranium ores. Four of them were located in the Sudetes, and only one outside of this region - in Rudki near Nowa Slupia, in the Holy Cross Mountains [1]. The uranium content in these deposits was typically about 2,000 ppm. Currently, no uranium mine is working in the country. In the second half of the 20th century, the Polish Geological Institute (PGI) made numerous assessments of prospects for exploration of uranium ore deposits in Poland [4]. According to the PGI estimates, the Ordovician Dictyonema shales of the Podlasie Depression (NE Poland) seem to be the most prospective, with uranium concentration in the 75-250 ppm range and the sandstones of Peribaltic Syneclise (Paslek-Krynica Morska), where uranium concentration reaches even 1, 5%. These deposits, as a potential source of uranium for Polish nuclear power plants, were investigated by the PGI and the Institute of Nuclear Chemistry and Technology (INCT) as part of the Operational Programme – Innovative Economy (POIG) project implemented in 2010-2013. Within the framework of the POIG project, Polish uranium deposits and their exploitation options were reassessed. Based on the archival ore samples from previously tested boreholes, various technological schemes and methods of obtaining uranium from Polish ores were examined with an initial economic assessment of the studied processes. Optimal leaching conditions for uranium from both Dictyonema shales and sandstones as well as uranium separation from other metals, like rare earth elements (REE) that have undergone leaching into the aqueous phase, have been found [5-8]. It has been shown that it is possible to sequentially separate these metals from the solution by means of ion exchange [9]. Uranium can also be separated using solvent extraction [10]. An alternative to solvent extraction carried out in traditional reactors or columns is extraction using membrane contactors, which constitute modern separation systems, allowing for two processes to be carried out: extraction and reextraction in one installation [11, 12]. An effective and selective extractant plays an important role in the extraction process. In recent years, great interest in new extracting agents of uranium like calixarene derivatives is shown [13]. The project developed a synthesis path for these compounds. They may also find other applications in the nuclear fuel cycle, e.g. for the separation of fission products and minor actinides from spent nuclear fuel. By using a membrane module with a helical flow in the uranium ore leaching process, high U leaching rates were obtained. In this system it is possible to simultaneously separate the leachate from the remaining solid phase (parent rock) [14]. Such a method of conducting the leaching process, with the simultaneous filtration of the sludge in the membrane contactor with the helical flow, became the basis for the patent application in the Patent Office of the Republic of Poland and the European Patent Office [15]. In 2014, Poland completed geological and technological analysis and modelling of the process of uranium extraction from low-grade Ordovician Dictyonema shale (black shale-type). Analysis has shown that the costs of obtaining raw material for production of 1 kg of uranium would be several times higher than the current market price of that metal [16]. URANIUM FROM UNCONVENTIONAL SOURCES Although uranium concentrations in unconventional sources are low, all together they are inexhaustible sources of uranium for future use. One of these sources are phosphates, which constitute the raw material for the production of chemical fertilizers. These rocks contain the largest concentrations of uranium from all unconventional uranium deposits occurring in the world. In Poland, phosphorites are found in vicinity of Annopol, the Holy Cross Mountains. The exploitation of phosphate rock in the country began in the interwar period and was discontinued in the 1970s. The mine in Chalupki was closed in 1961, and in Annopol in 1971. At present, domestic demand for phosphate rock is entirely covered by import from countries such as Algeria, Senegal, Morocco, Egypt, Tunisia and Syria. In the technology of phosphate fertilizers, the first stage is the production of phosphoric acid. In this process, ground phosphorites are treated with sulfuric acid, as a result of which phosphoric acid and insoluble calcium sulphate (gypsum) precipitate contaminated with the remaining raw material are obtained. Phosphogypsum after washing with water is directed to heaps as waste. Most of uranium contained in phosphorites goes to phosphoric acid. In Poland, in the 1980s at the Institute of Nuclear Chemistry and Technology and at the Wroclaw University of Technology, a technology for recovering uranium from phosphoric acid was developed for expected use in Chemical Works in Police. According to this technology, uranium can be extracted from phosphoric acid in a coupled extraction-re-extraction process. The mixtures of mono- and dinonyl-phenylphosphoric acids (NPPA) and D2EHPA and TOPO were used as extracting agents in this process. In 2015, the Institute of Chemistry and Nuclear Technology together with PwC Sp. z o.o, as part of the Bridge Mentor project (NCBiR), prepared a preliminary analysis of the possibilities of obtaining uranium from industrial phosphoric acid by the hybrid method, which was a combination of solvent extraction with membrane processes. The project was presented at Chemical Works in Police (at present AZOTY Group). Phosphogypsum usually contains many different components like heavy metals, among them also some amounts of uranium. During the production of phosphate fertilizers, part of the uranium contained in phosphate rock passes to solid waste and is collected in heaps. In Poland, phosphogypsum dumps are located in Police, Wizow and Wislinka near Gdansk. These landfills are heterogeneous in chemical terms, because over the years, various raw materials have been used for the production of phosphate fertilizers. In phosphogypsum samples from the landfill in Wislinka collected in 1997, uranium concentration was 4.03 ± 0.08 mg / kg, while in the samples from 2007 – only 0.65 ± 0.05 mg / kg [17,18]. The heap in Wizow, which is a residue from the production of fertilizers from apatites from the Kola Peninsula (magmatic rocks), does not contain uranium, but has a significant concentrations of REE. Uranium from phosphogypsum can be recovered by washing with sulfuric acid [19,20]. In some parts of the world there are carbon deposits with elevated uranium content. The average uranium concentration in Polish coal from mines located in the Upper Silesia, Lower Silesia and Lublin regions is approx. 2 ppm. Research conducted at the Polish Geological Institute did not show differences in content depending on the origin of coal [21]. Uranium can also be obtained from coal ash; its content in coal ash from Polish coal-fired power plants amounts to several ppm [22]. Another source of uranium can be the copper industry. Similarly, as in the Olympic Dam mine in Australia, uranium can be obtained as a by-product during the production of copper by KGHM. The studies of copper industry waste as an alternative source of uranium was conducted by INCT as part of the POIG project. The content of U in the tested waste samples was not high, while the occurrence of other valuable metals was observed [23]. The recovery of uranium and other metals from industrial waste, by-products and phosphates is currently being investigated by the INCT as part of a project coordinated by the International Atomic Energy Agency. Determination of uranium content in the fluids from hydraulic fracturing of shales in the process of searching for natural gas deposits, carried out in Poland, was performed at INCT. The highest U concentration found in the fluid samples was 3.5 ppm. The possibility of recovering uranium from these wastewater has been demonstrated [24]. The other possible secondary source of uranium can be uranium tailings and old dumps which were abandoned after exploitation of uranium mines in Sudetes. Reserves of uranium in waste heaps from prospecting and extractive operations in this region in the years 1948-1967 are estimated at 10 to 30 tU. CONCLUSION Research projects conducted in Poland in recent years have confirmed the presence of low-grade uranium deposits in Poland. Methods for its extraction from black shale and sandstones in the framework of the POIG project were developed. The results collected as part of the project confirmed that currently there is no economic justification for the exploitation of Polish ores with low uranium content, but the situation may change with the continuing development trend of nuclear energy in the world and gradual depletion of uranium resources in rich ores. The secondary sources of uranium in the country were also assessed. The most promising ones are waste from the copper industry and phosphoric acid obtained in the production technology of phosphate fertilizers. In May 2012, September 2013 and October 2013, three concessions for prospecting for polymetallic uranium deposit for a private company were granted (“Radoniow”, “Wambierzyce” and “Dziecmorowice” areas in southern region of Lower Silesia). At present, geological exploration of uranium ore is not conducted in Poland. REFERENCES [1] MIECZNIK, J. B., STRZELECKI, R., WOLKOWICZ, S., Uranium in Poland – history of prospecting and chances for finding new deposits), Przeglad Geologiczny, vol. 59, nr 10, (2011), 688-697 (in Polish). [2] G.E.O.S. Freiberg Ingenieurgesellschaft mbH, Remediation of the low-level radioactive waste tailing pond at Kowary, Poland. Final Report, European Commission, (2002). [3] RESOLUTION No. 15/2014 of COUNCIL OF MINISTERS, Program of Polish Nuclear Energy, Warsaw (2014). [4] NIEC, M., Polityka Energetyczna, Wystepowanie rud uranu i perspektywy ich poszukiwan w Polsce, Tom 12, Zeszyt 2/2 (2009) 435-451. [5] KIEGIEL, K., ZAKRZEWSKA-KOLTUNIEWICZ, G., GAJDA, D., MISKIEWICZ, A., ABRAMOWSKA, A., BIELUSZKA, P., DANKO, B., CHAJDUK, E., WOLKOWICZ, S., Dictyonema black shale and Triassic sandstones as potential sources of uranium. Nukleonika; 60 (2015) 515-522. [6] FRACKIEWICZ, K., KIEGIEL, K., HERDZIK-KONECKO I., CHAJDUK, E., ZAKRZEWSKA-TRZNADEL, G., WOLKOWICZ, S., CHWASTOWSKA, J., BARTOSIEWICZ, I., Extraction of Uranium from Low-grade Polish Ores: Dictyonemic shales and Sandstones, Nukleonika, 58 (2012) 451-459. [7] GAJDA, D., KIEGIEL, K., ZAKRZEWSKA-KOLTUNIEWICZ, G., CHAJDUK, E., BARTOSIEWICZ, I., WOLKOWICZ, S., Mineralogy and uranium leaching of ores from Triassic Peribaltic Sandstones, Journal of Radioanalytical and Nuclear Chemistry, 303 (2015) 521-529. [8] ZAKRZEWSKA-KOLTUNIEWICZ, G., HERDZIK-KONECKO, I., COJOCARU C., CHAJDUK, E., Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo and Yb and Th) from low-grade uranium ore, Journal of Hazardous Materials, 275 (2014) 136-145. [9] DANKO, B., DYBCZYNSKI, R. S., SAMCZYNSKI, Z., GAJDA, D., HERDZIK-KONECKO, I., ZAKRZEWSKA-KOLTUNIEWICZ, G., CHAJDUK, E., KULISA, K., Ion exchange investigation for recovery of uranium from acidic pregnant leach solutions, Nukleonika, 62 (2017) 213-221. [10] KIEGIEL, K., ABRAMOWSKA, A., BIELUSZKA, P., ZAKRZEWSKA-KOLTUNIEWICZ, G., WOLKOWICZ, S., Solvent extraction of uranium from leach solutions obtained in processing of Polish low grade ores, Journal of Radioanalytical and Nuclear Chemistry, 311 (2017)589-598. [11] ZAKRZEWSKA, G., BIELUSZKA, P., CHAJDUK, E., WOLKOWICZ, S., Recovery of uranium(VI) from water solutions by membrane extraction, Advanced Materials Research Vol. 704 (2013) 66-71. doi:10.4028/www.wcientific.net/AMR.704.66 [12] BIELUSZKA, P., ZAKRZEWSKA-TRZNADEL, G., CHAJDUK, E., DUDEK, J., Liquid-liquid extraction of uranium(VI) in the system with a membrane contactor. Journal of Radioanalitical and Nuclear Chemistry, 299 (2014) 611–619. [13] KIEGIEL, K., STECZEK, L., ZAKRZEWSKA-TRZNADEL, G., Application of calix[6]arenes as macrocyclic ligands for Uranium(VI) – a review Journal of Chemistry Volume 2013, Article ID 762819, 16 pages, http://dx.doi.org/10.1155/2013/762819. [14] MISKIEWICZ, A., ZAKRZEWSKA-KOLTUNIEWICZ, G., DLUSKA, E., WALO, P.F., Application of membrane contactor with helical flow for processing uranium ores. Hydrometallurgy, 163 (2016)108–114. [15] ZAKRZEWSKA-TRZNADEL, G., JAWORSKA-SOBCZUK, A., MISKIEWICZ, A., LADA, W., DLUSKA, E., WRONSKI, S., Method of obtaining and separating valuable metallic elements, specifically from low-grade uranium ores and radioactive liquid wastes, EP2604713, (2015). [16] GALICA D., DUNST N., WOŁKOWICZ S.: Wykorzystanie cyfrowego modelu zloza i harmonogramu produkcji do stworzenia koncepcji zagospodarowania zloza uranu „Rajsk”. Wiadomosci Gornicze nr 2 (2016) s. 94–99. [17] SKWARZEC, B., BORYLO, A., KOSINSKA, A., RADZIEJEWSKA, S., Polonium (210Po) and uranium (234U, 238U) in water, phosphogypsum and their bioaccumulation in plants around phosphogypsum waste heap at Wislinka (northern Poland), Nukleonika, 55(2) (2010) 187−193. [18] OLSZEWSKI, G., BORYLO, A., SKWARZEC, B., The radiological impact of phosphogypsum stockpile in Wislinka (northern Poland) on the Martwa Wisla river water, J. Radioanal. Nucl. Chem., (2015) DOI 10.1007/s10967-015-4191-5. [19] SCHROEDER, J., LEWANDOWSKI, M., KUZKO, A., GORECKI, H., ZIELINSKI, K., POZNIAK, T., ZIEBA, S., GORECKA, H., PAWELCZYK, A., WYSOCKI, A., Sposób przemywania fosfogipsu, Patent nr PL 116006 B1 (1983). [20] GORECKI, H., KUZKO, A., GORECKA, H., PIETRAS, L., Sposob oczyszczania fosfogipsu, Patent nr PL 119692 B1 (1984). [21] BOJKOWSKA, I., LECH, D., WOŁKOWICZ, S., Uran i tor w weglach kamiennych i brunatnych ze zloz polskich. Gospodarka Surowcami Mineralnymi, T. 24, Z. 2/2 (2008) 53‐65. [22] CHWISTEK, M., CHMIELOWSKI, J., KALUS, J., ŁACZNY, J., Biochemiczne lugowanie uranu z weglowych popiolow lotnych, Fizykochem. Probl. Mineralurgii, Vol.13(1981) 173-183. [23] SMOLINSKI, T., WAWSZCZAK, D., DEPTULA, A., LADA, W., OLCZAK, T., ROGOWSKI, M., PYSZYNSKA, M., CHMIELEWSKI, A.G., Solvent extraction of Cu, Mo, V, and U from leach solutions of copper ore and flotation tailings, Journal of Radioanalytical and Nuclear Chemistry, 314(1) (2017) 69–75. [24] ABRAMOWSKA, A., GAJDA, D. K., KIEGIEL, K., MISKIEWICZ, A., DRZEWICZ, P., ZAKRZEWSKA-KOLTUNIEWICZ, G., Purification of flowback fluids after hydraulic fracturing of Polish gas shales by hybrid methods, Separation Science and Technology, (2017) DOI: 10.1080/01496395.2017.1344710 Speaker: Prof. Grazyna Zakrzewska-Koltuniewicz (Institute of Nuclear Chemistry and Technology) • 70 Uranium exploration and mining activities of Turkey as a newcomer Countries embarking on a nuclear power programme that called “a newcomer” need to make sure that the development of their legal, regulatory and support infrastructure keeps pace with the construction of the power plant itself. This is the only way to ensure that the programme proceeds in a safe, secure and sustainable way, concluded participants of a workshop on nuclear power infrastructure development. Through several initiatives, the transfer of information and knowledge from states with extensive experience in uranium mining and production to "newcomers" to the sector. Growing demand from a much anticipated nuclear power renaissance and consequent soaring prices for nuclear fuel have recently spurred greater investment in uranium exploration in an increasing number of countries. Nuclear power is an inevitable option for Turkey to meet energy security. Turkey has distinctly progressing its nuclear energy program in nuclear milestones. As being aware of that uranium mining and activities would be a significant role in the nuclear power plant projects. This paper wholly investigated the recent uranium exploration activities, drilling efforts, identified conventional resources, environmental activities and regulatory regime of Turkey with the details. INTRODUCTION Background: uranium for nuclear power Uranium resources are an integral part of the nuclear fuel cycle. To increase the capability of interested Member States for planning and policy making on uranium production, the IAEA works together with the OECD Nuclear Energy Agency (NEA) to collect and provide information on uranium resources, production and demand. With uranium production ready to expand to new countries, efforts are being made to develop transparent and well-regulated operations similar to those used elsewhere to minimise potential environmental and local health impacts [1]. The general energy policy of Turkey focuses on the supply of secure, sustainable and affordable energy by diversifying energy supply routes and source countries, promoting usage of domestic resources and increasing the energy efficiency and renewable energy usage to decrease the energy intensity of production. Nuclear energy is considered for diversification of electricity generation and also for mitigation of GHG emissions from energy sector. The Akkuyu NPP project started with the IGA between Turkey and Russia for construction and operation of 4 VVER-1200 reactors in Akkuyu site situated on the Mediterranean coast of Turkey. A comprehensive EIA report had been prepared by the PC taking into consideration the requests from a wide range of stakeholders which was approved in December 2014. EMRA had granted electricity generation licence in June 2016 which will form the basis of the PPA. The revised site parameters report was approved by TAEK on February 2017 and granted limited work permit for construction of non-nuclear safety related facilities in October 2017. The full construction of the first unit is planned to start in the first quarter of 2018 with the grant of construction licence by TAEK. The other nuclear power plant project IGA which includes construction and operation of 4 ATMEA1 reactors in Sinop site and development of nuclear industry in Turkey was signed between Turkey and Japan in 2013 and ratified in 2015. EÜAŞ ICC established in November 2015 will participate to the project as shareholder of the project company which will be established based on the results of the feasibility study. The feasibility study started in July 2015 and the further support from Japanese government was provided with the MoU signed between MENR and METI in September 2016. The feasibility study is expected to be completed in the first quarter of 2018. The strategic goal of nuclear energy usage is mentioned in the strategic plan of MENR under the goal for optimum energy resource diversity. Turkey has a high energy import and fossil fuel dependency which makes it vulnerables to external shocks in global markets. Nuclear energy is considered as one of the options together with local resources and renewable energy to sthrengthen the energy sector in Turkey. Radioactive minerals have been historically explored in Turkey which requires further studies for their feasibilities to start production [2]. As a result the strategic plan includes the target for reserve determination of radioactive minerals together with their respective feasibility studies for usage in the nuclear energy sector [3]. DESCRIPTION General Directorate of Mineral Research and Exploration (MTA) Uranium exploration in Turkey began in 1956-1957 and was directed towards the discovery of vein-type deposits in crystalline terrain, such as acidic igneous and metamorphic rocks. As a result of these activities, some pitchblende mineralisation was found but these occurrences was not accepted as economic deposits. Since 1960, studies have been conducted in sedimentary rocks which surround the crystalline rock and some small orebodies containing autunite and torbernite mineralisation have been found in different parts of the country. In the mid-1970s, the first hidden uranium deposit with black ore, below the water table, was found in the Koprubaşı area of Manisa. As a result of these exploration activities, a total of 9 129 tonnes U3O8 (7 740 tU) in situ resources were identified in the Manisa-Köprübaşı (2 852 tonnes U3O8; 2 419 tU), Uşak-Eşme (490 tonnes U3O8; 415 tU), Aydın-Koçarlı (208 tonnes U3O8; 176 tU), Aydın-Söke (1 729 tonnes U3O8; 1 466 tU) and Yozgat-Sorgun (3 850 tonnes U3O8; 3 265 tU) regions. Eti Mine Works General Management (Eti Maden) State-owned organization Eti Maden is responsible for a total of six uranium mine sites with uranium resources. Geological exploration has been performed by MTA at these sites in the past. Between 1960-1980 uranium exploration was performed by aerial prospecting, general and detailed prospecting on-site, geologic mapping studies and drilling activities. These uranium sites were transferred to Eti Maden as possible mines which can be operated by the state under law number 2840 on the “Operation of Boron Salts, Trona and Asphaltite Mines and Nuclear Energy Raw Materials” (10 June 1983). Recent and ongoing uranium exploration and mine development activities General Directorate of Mineral Research and Exploration (MTA) In 2012, granite, acidic igneous and sedimentary rocks around Manisa, Denizli and Aydın (an area of approximately 5 000 km2) were explored for radioactive raw materials. Exploration for radioactive raw materials was also performed in sites licenced by MTA inside Manisa, Uşak and Nevşehir. In 2013, granite, acidic igneous and sedimentary rocks around Aydın and Denizli (an area of approximately 5 000 km2) will be explored for radioactive raw materials. Exploration for radioactive raw materials was also performed in sites licenced by MTA inside Manisa, Uşak and Nevşehir. In 2014, Exploration for radioactive raw materials was conducted in sites licenced by MTA inside Manisa, Uşak and Nevşehir. In 2015, Exploration for radioactive raw materials will be conducted in sites licenced by MTA inside Manisa and Nevşehir [4]. Private sector exploration Adur, a wholly owned subsidiary of Anatolia Energy, a Turkish uranium exploration company with current and active drill programmes at the Temrezli and Sefaatli uranium sites, has carried out exploration and resource evaluation drilling with a total of 206 drill holes completed for a total drill advance of over 26 000 m since 2011 in both Şefaatli and Temrezli projects. Over 16 000 m of drilling was in Temrezli region. Until now, 112 holes have been completed in Temrezli project. The drilling in Temrezli, mostly twinning the earlier MTA drill holes but also in-fill and step-out holes, confirmed work conducted in the 1980s and extended the uranium mineralisation to the north-east over a strike length of more than 3 000 m. In 2011, CSA Global Pty Ltd prepared a JORC compliant mineral resource estimate for the Temrezli deposit of 13.282 Mlb U3O8 (6 025 tU) (measured, indicated and inferred) in situ uranium at an average grade of 1 157 ppm (0.117% U3O8). Preliminary metallurgical bottle-roll leach test work confirmed MTA’s earlier work and returned 93% and 90% uranium recovery was obtained by using an acid or alkali leach method, respectively. Several hydrological test wells were constructed at Temrezli since 2012 in order to assess the regional groundwater conditions and to conduct hydraulic testing of the mineralised horizons at a scale typically seen at in-situ recovery (ISR) operations. Test work was performed by HydroSolutions, a US-based hydrogeologist with considerable experience in ground water conditions relating to uranium ISR operations throughout western United States. The test confirmed the aquifer has sufficient flow rate for ISR mining. Regional exploration identified new areas of mineralisation, at West Sorgun and Akoluk. The rotary and diamond drill programme tested a number of regional sites that are considered prospective for Eocene-aged sediment-hosted uranium mineralisation, similar to what is seen at the Temrezli uranium deposit. Since early stage studies indicate that the Temrezli uranium deposit will be amenable to ISL mining, a preliminary economic assessment (PEA) contract was awarded to US based WWC Engineering of Sheridan, Wyoming. The PEA is completed and followed by PFS study which was awarded to Tetra Tech, US origin company PFS was completed and issued in early 2015 which indicated that the project is economically feasible to proceed, with a total expected recovery of 9.7m lbs. over 12 years, with operating costs of less than USD17 per lb U3O8 (USD44.2 per kg U). Adur initiated the Environmental Impact Assessment (EIA) process by preparing and submitting a Project Description to the Ministry of Environment and Urban Planning in 2015. Adur will also initiate the permitting process with Turkish Atomic Energy Commission regarding licensing Temrezli site as a nuclear facility since ISR operations are considered as nuclear facilities. In 2015, the permits and licenses will be obtained prior to initiating the construction in early 2016. DISCUSSION AND CONCLUSION  Identified conventional resources (reasonably assured and inferred resources) Identified conventional uranium resources in Turkey determined from exploration activities performed by MTA in the past are listed below, with the addition of JORC compliant resources identified through recent work by Adur exploration, described in more detail: • Manisa-Köprübaşı: 2 419 tU in ten orebodies and at grades of 0.04-0.05% U3O8 (0.034 0.042% U) in fluvial Neogene sediments. • Uşak-Eşme: 415 tU at 0.05% U3O8 (0.042% U) in Neogene lacustrine sediments. • Aydın-Koçarlı: 176 tU at 0.05% U3O8 (0.042% U) in Neogene sediments. • Aydın-Söke: 1 466 tU at 0.08% U3O8 (0.068% U) in gneiss fracture zones. • Yozgat-Sorgun: 4 633 tU at 0.117% U3O8 in Eocene deltaic lagoon sediments. Temrezli (Yozgat / Sorgun) uranium deposit is one of Turkey’s largest and highest grade uranium deposits, with a JORC compliant Mineral Resource estimate of 13,282 Mlb of contained uranium at an average grade of 1,157 ppm (0.117%) U3O8 with an average depth of 120 m.  Undiscovered conventional resources (prognosticated and speculative resources) Temrezli Project: The ongoing exploration and development drillings is to be continued and is expected to increase the resource by a potential of 1-3 Mlb U3O8. Şefaatli Prospect: exploration and development drillings is being conducted in 2015 and is expected to increase the known uranium resource values by approximately 5-6Mlb U3O8. The recent drill results include 1,10m at grade 2,150ppm e U3O8 from 39m [4].  Unconventional resources and other materials None reported, but grassroots exploration is in place. REFERENCES [1] The Red Book 2014: Resources, Production and Demand A Joint Report by the OECD Nuclear Energy Agency and the International Atomic Energy Agency/Turkey Updated Chapter 2016 [2] T.R. Ministry of Development 2013: “The tenth Development Plan” T.R. Ministry of Development [3] T.R. Ministry of Energy and Natural Resources Strategic Plan 2015 - 2019 [4] ALKAN M. GÜLMEZ A. ULUSOY M. A Review of Uranium and Thorium Studies in Turkey, IMMC 2016: 18. International Metallurgy and Materials Congress Speaker: Mrs Sibel GEZER • 71 A milestones approach to uranium mining and development: an IAEA initiative OVERVIEW Many IAEA Member States without current uranium production activity have expressed interest in uranium mining, in order to meet their or other countries’ energy needs. To introduce or reintroduce uranium mining and processing, a wide range of issues needs to be considered. With the assistance of experts from around the world, the IAEA is preparing a guide setting out a milestones approach to the uranium production cycle. This will assist Member States to take a systematic and measured approach to responsible uranium mining and milling. The information in the guide will be provided within the context of other IAEA guidance and materials relevant to development of the Uranium Production Cycle, including the IAEA Safety Standards and Safety Guides Series. Although not the emphasis of the guide, the vital importance of appropriate radiation protection, security and non-proliferation safeguards is acknowledged. In the development of the guide, four generalized stages with associated milestones of preparedness are being considered (subject to amendment): • Those considering exploration or mining of uranium for the first time, or after many years, but without an identified project. • Those seeking to initiate/ reinvigorate uranium mining with one or more identified projects. • Established producers of uranium wishing to enhance existing capacity/capability. • Historic producers with closed sites in the stage of closure and rehabilitation/remediation or aftercare. The situation of Member States will be unique, at least in detail. It is also acknowledged that a given Member State may simultaneously be in more than one of these generalized stages. Nevertheless, the report will comment on common threads and good practices, and assist a Member State to identify areas within a stage where they are less prepared, and give advice for a way forward towards a later stage. However, an important consideration with uranium mining and milling is that uranium ore may or may not be present in a particular Member State. Hence, even with excellent work in uranium exploration, with good policies, legislation, regulation and well-trained experts, a Member State may remain in the earliest stage. This is in contrast to the milestones approach for some other purposes, where the opportunity to progress through the various milestones to their successful implementation is more generally applicable, should a Member State choose. ACKNOWLEDGEMENTS The uranium production milestones guide will be designed for use around the world, but the specific involvement of African Member States and IAEA’s Technical Cooperation Regional Africa Projects to launch the work is acknowledged. To date, the following experts from around the world have been directly assisting the IAEA in the preparation of the milestones guide. Abbes, N., Groupe Chimique Tunisien, Tunesia Blaise, J.R. , Consultant, France Brown, G., Boswell Capital Corporation, Canada Dunn, G., Hydromet Pty Ltd, South Africa Hama Siddo Abdou, Ministère des Mines, Niger Hilton, J., Aleff Group, United Kingdom Itamba, H., Ministry of Mines and Energy, Namibia Lopez, L., CNEA, Argentina Mwalongo, D., Tanzania Atomic Energy Commission, United Republic of Tanzania Consultancy Meetings were held in Vienna, Austria on 12–14 December 2016 and 4–7 September 2017. It is intended that a full draft document will be made available for comment to the IAEA’s member states during 2018. BIBLIOGRAPHY EUROPEAN COMMISSION, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANIZATION, OECD NUCLEAR ENERGY AGENCY, PAN AMERICAN HEALTH ORGANIZATION, UNITED NATIONS ENVIRONMENT PROGRAMME, WORLD HEALTH ORGANIZATION, Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, General Safety Requirements Part 3, IAEA Safety Series No. GSR Part 3, IAEA, Vienna (2014). INTERNATIONAL ATOMIC ENERGY AGENCY, Steps for preparing uranium production feasibility studies: A guidebook, IAEA-TECDOC-885, IAEA, Vienna (1996). INTERNATIONAL ATOMIC ENERGY AGENCY, Environmental Impact Assessment for Uranium Mine, Mill and In Situ Leach Projects, IAEA-TECDOC-979, IAEA, Vienna (1997). INTERNATIONAL ATOMIC ENERGY AGENCY, Occupational radiation protection in the mining and processing of raw materials, Safety Guide RS-G-1.6, IAEA, Vienna (2004). INTERNATIONAL ATOMIC ENERGY AGENCY, Guidebook on Environmental Impact Assessment for In Situ Leach Mining Projects, IAEA-TECDOC-1428, IAEA, Vienna (2005). INTERNATIONAL ATOMIC ENERGY AGENCY, Assessing the Need for Radiation Protection Measures in Work Involving Minerals and Raw Materials, Safety Reports Series 49, IAEA, Vienna (2007) INTERNATIONAL ATOMIC ENERGY AGENCY, Establishment of Uranium Mining and Processing Operations in the Context of Sustainable Development, IAEA Nuclear Energy Series No. NF-T-1.1, IAEA, Vienna (2009). INTERNATIONAL ATOMIC ENERGY AGENCY, Best Practice in Environmental Management of Uranium Mining, IAEA Nuclear Energy Series No. NF-T-1.2, IAEA, Vienna (2010). INTERNATIONAL ATOMIC ENERGY AGENCY, Specific Considerations and Milestones for a Research Reactor Project, IAEA NP-T-5.1, IAEA, Vienna (2012). INTERNATIONAL ATOMIC ENERGY AGENCY, Milestones in the Development of a National Infrastructure for Nuclear Power, IAEA NG-G-3.1 (Rev. 1), IAEA, Vienna (2015). INTERNATIONAL ATOMIC ENERGY AGENCY, Nuclear Security in the Uranium Extraction Industry, IAEA- TDL-003, IAEA, Vienna (2016). Speaker: Dr Peter H. Woods (IAEA) • 10:40 AM Break • Underground and Open Pit Uranium Mining and Milling Conveners: Dr Luminita Grancea (OECD NEA) , Dr Ziying Li (Beijing Research Institute of Uranium geology) • 72 Overview of Uranium Heap Leaching Technology in China With the merits of low power, reagent and water consumptions and low operational cost, heap leaching of uranium ores has become the most widely used technological process for natural uanium production in China. Of the proved uranium reserves in China, hard-rock minerals of low uanium grade take a large proportion and these reserves are mainly located in southern China and suitable for heap leaching. Study on heap leaching of uranium ores has been emphasized in the past decades in the country and some technical achievements have been made and already applied in commercial production. The present status of uranium heap leaching application in China, including the ore characteristics and technological processes for typical processing mills and some new technological developed and applied is introduced in this paper. Some existing problems in practical operation are also discussed. Speaker: Mr Pingru Zhong (Beijing Research Institute of Chemical Engineering and Metallurgy) • 73 Development of Alkali leaching technology: Key to Self Sufficiency in Uranium Production in India INTRODUCTION Geological investigations for uranium deposits initiated in India during 1949-50 have led to the discovery of a number of favourable geological basins in the country. First uranium deposit located at Jaduguda in Singhbhum Shear Zone in the eastern state of Jharkhand continued to attract investments in exploration and mining of uranium for over five decades. However, extensive exploration in other parts of the country has brought to light more uranium deposits / occurrences in South Cuddapah basin (Andhra Pradesh), North Cuddapah Basin (Telangana), Mahadek basin (Meghalaya), Bhima basin (Karnataka) and Delhi Supergroup of rocks (Rajasthan) in addition to Singhbhum Shear Zone (Jharkhand). Uranium mining in India, the front end activity of the Indian nuclear power programme, has always been challenging considering the uranium deposit characteristics in the country. Indian uranium deposits in general are of medium-tonnage and low-grade. Detailed studies of geological characteristics of these deposits are undertaken for selection of proper mining method and technology. Ore processing technology is subjective to mineralogical and metallurgical characteristics of the ore and hence determination of suitable technology and process parameters is crucial for successful operations of these deposits. Of all the above areas, South Cuddapah basin in Andhra Pradesh accounts for about 49% of Indian uranium resources, occurring in carbonate hosted rock which calls for development of alkali leaching process route. Part of this resource extending over a strike length of 6.6 km is under development at Tummalapalle. An underground mine with a capacity to produce 3000 tonnes of ore per day with a plant of matching capacity based on alkali leaching has been set-up. ALKALI LEACHING TECHNOLOGY AT TUMMALAPALLE The ore zones at Tummalapalle are confined two thin distinct bands within a thick pile of carbonate rocks - massive limestone, intra-formational conglomerate, dolostone, shale and cherty limestone. The mined out ore, after conventional crushing and grinding (80% passing 74 micron) are thickened, re-pulped and subsequently subjected to alkali leaching by sodium carbonate and sodium bicarbonate solution. Leaching is carried out under high pressure and temperature conditions in autoclaves in series with a nominal residence time of 6.5 hrs. The leached slurry is then filtered in Horizontal Belt Filter (HBF) and the desired concentration leached liquor is achieved through repeated recirculation and washing. The washed cake in the form of slurry is disposed in tailings impoundment facility. The leached filtrate, after clarification and pre-coat filtration is subjected to precipitation with the addition of sodium hydroxide. The final product, at a pH of 12 or above is precipitated as sodium di-uranate (SDU). Extensive laboratory and pilot plant studies have been undertaken to develop this process parameters and flow sheet. The process has undergone several up-gradations in different areas for better leaching and precipitation efficiency. A major breakthrough has been recently achieved for settling and complete recovery of precipitated product by commissioning the Re-dissolution System facility wherein part of the product is sent to precipitation tanks. Regeneration of sodium carbonate and sodium hydroxide treating barren liquor before recycling has been taken up. The plant will also produce sodium sulphate as by-product. Uranium tailings management is an integral part of the uranium mining industry. In view of effective utilization of available and acquired land and ease of handling and monitoring of tailings, UCIL has recently proposed the concept of Near Surface Trench disposal of uranium tailings which consists of an earthen Construction with the use of impervious & geo-synthetic liners along with arrangements for withdrawal of excess water and temporary coverage of top surface during heavy rain. This method will lower the transportation cost as well as increase the stability and life of the structure. Successful implementation of this concept will benefit new uranium mining projects in the country in terms of time and cost. A further detailed study on the concept and its implementation is currently being undertaken. CONCLUSION India has had a long commitment to nuclear energy since the establishment of the Atomic Energy Commission in 1948 and the Department of Atomic Energy in 1954. Nuclear energy plays a critical role in addressing energy challenges, meeting massive energy demand potentials, mitigating carbon emissions and enhancing energy security. The three-stage nuclear power programme being pursued to develop nuclear power in India is consistent with India’s unique resource position of limited uranium and large thorium reserves and hence, uranium production plays a vital role in this growing indigenous nuclear power program of the country. The alkali leaching technology adopted for processing of low grade ore at Tummalapalle is the result of extensive research work of the Department of Atomic Energy. Carbonate hosted uranium mineralization accounts for lion’s share of the Indian uranium inventory, therefore, successful operations and extraction of uranium at Tummalapalle shall enable to develop more uranium deposits in this area (South Cuddapah basin in Andhra Pradesh). Newer areas in other geological basins amenable to acid leaching have also been taken for development to meet the requirement of uranium in coming decades. BIBLIOGRAPHY GUPTA, R. and SARANGI, A. K., “Overview of Indian uranium production scenario in coming decades”, International Seminar on Asian Nuclear Prospects (ANUP-2010), Energy Procedia, Volume 7, pp. 146-152 (2011) GUPTA, R. and SARANGI, A. K., “A new approach to mining and processing of a low grade uranium deposit at Tummalapalle, Andhra Pradesh, India”, IAEA Technical Meeting on “Uranium Small-Scale and Special Mining and Processing Technologies” Vienna during 19th – 22nd June 2007. SARANGI, A.K. and KRISHNAMURTHY, P., “Uranium metallogeny with special reference to Indian deposits”, Trans. Min. Geol. and Met. Inst. India, Vol. 104. (2008) SURI, A.K., “Innovative process flowsheet for the recovery of uranium from Tummalapalle ore”, Bhabha Atomic Research Centre (BARC), Newsletter Issue no. 317, Nov. - Dec. 2010. SURI, A.K., PADMANABHAN, N.P.H., SREENIVAS, T., et al., “Process development studies for low grade uranium deposit in alkaline host rocks of Tummalapalle”, IAEA Technical Meeting on Low Grade Uranium Deposits, Vienna, March 29-31, 2010. Speaker: Mr C. K. Asnani (Uranium Corporation of India) • 74 Coagulation of Colloidal Silica from Uranium Leach Solutions for Improved Solvent Extraction Colloidal silica generated in the leaching process by contacting clays and concrete with sulphuric acid has caused operational problems in solvent extraction (SX) at Cameco’s Key Lake uranium mill throughout its history. This colloidal silica stabilizes aqueous continuous emulsions in SX, resulting in increased solvent losses and operational downtime. Silica coagulation was investigated in 2014 with POLYSIL RM1250, a polyethylene glycol coagulant. Lab results showed excellent clarification of the process solution, but subsequent mill trials were unsuccessful. In 2015 the problem shifted from optimizing solution clarity to measuring the changes in phase separation performance under both organic and aqueous continuous mixing with varying POLYSIL doses. This analysis showed aqueous continuous separation performance was equivalent to organic continuous separation performance at doses approaching 300 ppm, significantly higher than anything previously tested. A follow-up pilot study confirmed the lab results, but also discovered an inverse relationship between acid concentration and separation time, suggesting less acid would be required in the mill process. A mill trial with POLYSIL RM1250 was performed in 2017 with doses ranging from 170-300 ppm. The mill trial was successful in reducing SX solvent consumption by 85% and overall acid and lime consumption by 7%. Speaker: Dr Brett Moldovan (IAEA) • 75 Investigation of Key Parameters for Effective SDU Precipitation INTRODUCTION While precipitation of sodium diuranate (SDU) has been practiced commercially from leach liquors since the 1950’s, there is very limited information on the impact of operating conditions on the efficiency of uranium precipitation from the “low-tenor’ liquors that are produced from the carbonate leaching of carnotite in calcrete ores. ANSTO Minerals recently carried out a program of work investigating direct SDU precipitation from carbonate/bicarbonate leach liquors. A number of variables were examined to assess their impact on the precipitation efficiency, including carbonate feed concentrations, terminal caustic concentration and seeding. In addition to a batch test work program, a continuous mini-plant was also operated. WORK PROGRAM Test work was completed on pregnant leach solution (PLS) produced from bulk leaching of a carnotite in calcrete ore. Two different leach regimes were used to generate PLS with differing concentrations of Na2CO3 and NaHCO3 (high bicarbonate - 12 g/L NaHCO3, 33 g/L Na2CO3 and; low bicarbonate – 7 g/L NaHCO3, 31 g/L Na2CO3). The uranium concentration was ~ 1 g/L U3O8 in both cases. The same solutions were used in both batch laboratory-scale tests and in a continuous mini-plant. Laboratory batch tests were conducted by heating the PLS to the target temperature (70 or 80 °C) and adding a pre-determined quantity of SDU seed or uranium stock solution, to achieve a target total U3O8 concentration (1-6 g/L U3O8). Typically, a 2 h seeding time was allowed at temperature to promote dissolution of the seed. After the seeding time, NaOH (50 wt% solution) was added to consume the NaHCO3 and obtain the target caustic concentration (6 or 8 g/L) in solution. Samples were withdrawn regularly for analysis by ICP for U and V concentrations. RESULTS AND DISCUSSION Impact of Bicarbonate and Total Carbonate Concentrations A series of tests were completed examining the impact of total carbonate concentration in the PLS on SDU precipitation. The total Na2CO3 ranged from 38 – 78 g/L, after reaction of all of the NaHCO3 with NaOH. Lower uranium in barrens was achieved from solutions containing lower carbonate concentrations. When considered in the context of an entire flowsheet and the preceding leach conditions, this is an important observation. Bicarbonate is required for uranium extraction but it is also generated during the leaching of carnotite in calcrete ores. The chosen Na2CO3/NaHCO3 reagent concentrations at the start of the leach will therefore define the composition of the PLS being fed downstream to SDU precipitation. The higher the terminal bicarbonate concentration in leach, the more caustic required to neutralise it (Equation 1), resulting in a greater total Na2CO3 concentration. NaHCO3 + NaOH -> H2O + Na2CO3 Equation 1 A higher concentration of bicarbonate in the PLS was shown to increase the dissolution of seed, resulting in a higher dissolved uranium concentration prior to precipitation. However, the improved dissolved uranium concentration prior to precipitation was offset by the increased total carbonate concentration obtained, resulting in higher concentrations of uranium in barrens. Impact of Seeding Seeding is recognised as an important component of SDU precipitation in a continuous operation and our results support the need for seeding. The best uranium in barrens achieved in tests completed in the absence of seeding was 163 mg/L U3O8 (138 mg/L U) whereas the presence of seeding under the same operating conditions reduced the uranium in barrens to 57 mg/L U3O8 (48 mg/L U). Comparison of target seed concentrations (4 and 6 g/L U3O8), however, showed that while there was a reasonable improvement in the amount of dissolved U after seeding at 6 g/L U3O8, the final difference in U in barrens was minimal. It should be noted that with greater seed dissolution, more caustic is subsequently required to re precipitate the uranium (Equation 2). 6 NaOH + 2 Na4UO2(CO3)3 -> Na2U2O7 + 6 Na2CO3 + 3 H2O Equation 2 Further testing looked at the impact of “total dissolved” uranium concentration on precipitation (over the range of 1-6 g/L U3O8), by spiking the PLS with a uranyl carbonate solution rather than seeding with solid SDU product. A dissolved U3O8 concentration of 3 g/L was shown to be optimum for producing the lowest uranium in barrens, with the lowest consumption of caustic. There was a small kinetic impact on precipitation at higher concentrations (4, 5 or 6 g/L U3O8), which may permit a reduced reaction residence time, although at the cost of higher caustic consumption. Impact of Caustic Concentration A higher terminal caustic concentration has a positive impact on the kinetics of precipitation. Considerably lower uranium in barrens were observed at 8 g/L NaOH, compared to 6 g/L, particularly after the first 30 minutes of precipitation. With increasing residence time, the gap narrows, although the final uranium in barrens after 8 hours precipitation was still lower at 8 g/L NaOH (by 9 – 16 mg/L U). This result suggests that operating at a lower NaOH target may be offset by increasing the precipitation residence time and has the added benefit of reducing costs due to a lower caustic requirement. Impact of Temperature Comparable tests completed at 70 and 80 C showed a significant increase in seed dissolution at the higher temperature, therefore increasing the concentration of dissolved uranium in solution. The subsequent impact on SDU precipitation, however, was not significant. CONCLUSIONS The carbonate and bicarbonate concentrations in the feed liquor were determined to have a significant impact on the success of SDU precipitation. Our investigations have shown that a higher total carbonate concentration in the feed solution is a key factor impeding SDU precipitation, resulting in an increased concentration of uranium in the barren solution. The concentrations of the preceding leach reagents (Na2CO3 and NaHCO3) are therefore important as this will define the total carbonate concentration in the SDU precipitation circuit. The caustic concentration was demonstrated to have a kinetic effect on the precipitation reaction and consequently residence time may also be critical, depending on the terminal caustic concentration selected for a given flowsheet. Higher temperature was shown to improve the dissolution of seed but did not show a significant impact on the final precipitation result. Greater seed dissolution was also achieved in the PLS which contained a higher concentration of bicarbonate but the resulting total sodium carbonate concentration was higher from this PLS and this had a negative impact on the precipitation and final U in barrens. Seeding was demonstrated to be necessary for effective precipitation. The complex relationship between dissolved uranium concentration and the presence of seed on SDU precipitation has been investigated to fully define the nature and amount of solid seed required. Speaker: Mr Mark Maley (ANSTO Minerals) • Uranium Newcomers Conveners: Dr Alexander Boytsov (Uranium One Group) , Prof. Richard Schodde • 76 An integrated Capacity Building Approach to Uranium Production Cycle Milestones for regional Asia Pacific Technical Co-operation Asia-Pacific region is the major consumer of mineral raw materials including uranium and other its associated mineral resources materials. However, production of the required raw materials which are required for many sectors including energy production and agro-industries are not sufficient to meet the demand. This is many due to predominantly low grade, unconventional and relatively technologically difficult to process mineral ore available in the region. Radioactive and associated mineral resources that could be extracted as co or by product far outweighs the conventional mining projects in the region. But the regional capacity to address challenges in economic, environmental and social returns and formulate a well-defined project through the life-cycle is found lacking. Creating a base line capacity and knowledge management platform to address the deficiency in those areas will greatly assist MSs in the region. The IAEA through the technical cooperation (TC) regional project RAS2019 – “Conducting the Comprehensive Management and Recovery of Radioactive and Associated Mineral Resources” provides capacity building in core technology in uranium production, feasibility and macro-economic aspect of uranium production, facilitate exchange of information and good practices, and also provide opportunities for dissemination of R&D results through publication and participation in international conferences. Speaker: Mr Syahril Syahril (IAEA) • 77 Uranium potential in Nigeria INTRODUCTION The Nigeria Atomic Energy Commission (NAEC) was established by Degree 46 (Now Act 46) in August, 1976 and became operational in July, 2006 as a specialized National Focal Agency with the mandate for the promotion and development of atomic energy and for all matters relating to the peaceful uses of atomic energy. The Commission was further mandated to: Prospect for and mine radioactive minerals; manufacture or otherwise produce, buy or otherwise acquire, treat, store, transport and dispose of any radioactive substances. The uranium potential in Nigeria is considered to be in commercial quantity with several known uranium occurrences [1-2]. Given the limited uranium exploration carried out in Nigeria to date, a greater potential is presumed to exist based on spot observations and the knowledge of favorable geological environment for uranium deposits (sandstone and unconformity-related deposit types) [1,3}. GEOLOGICAL SETTING OF NIGERIA The geology of Nigeria is composed of 4 main groups [3-4], namely: 1. The Basement Complex, 2. Younger Granites, 3. Sedimentary series and 4. Tertiary-Recent volcanic rocks. The Basement Complex is made up of the migmatitegnesis complex, pegmatites, the schist belts composed of metasedimentary and metavolcanic rocks and the pan- African granitoids comprising the Older Granites and the associated charnockitic rocks. The Younger Granites are of Jurassic age and they are found as ring-complex outcrops within the Basement Complex areas [3-4]. NIGERIAN URANIUM OCCURRENCES Uranium potential in Nigeria occurs in sandstone-hosted and vein-type mineralization. Sandstone-hosted deposits occurs in sedimentary/volcano sedimentary sequences in structurally controlled Bima sandstone at Zona and Dali, while the vein-type mineralization occurs in the deformed migmatites and granitoids at Gubrunde, Kanawa, Ghumchi, Mika and Monkin-Maza deposits [5-7]. Substantial Uranium mineralization occurs in the Ririwai area of southern Kano. According to Obaje et al [8], uranium occurred in peraluminous and peralkaline granites and the content of uranium in peraluminous granite lies between 16 and 32 ppm. Mika, Gumchi, Zona and Mayo Lope areas of Adamawa State have good uranium exploration prospect localized in the mylonitized, sheared and brecciated fine-grained to porphyritic granites. Analysis of cores from 40 drilled holes gave values of 2,000 ppm uranium content [2]. HISTORY OF URANIUM EXPLORATION IN NIGERIA In Nigeria Uranium exploration started in 1973. Uranium has been found in six states of the country. The six states are Cross River, Adamawa, Taraba, Plateau, Bauchi and Kano. The mineralizations are Guburende, Kanawa, Zona, Dali, Mika, and Monkin-Manza and were all discovered by three government agencies [9]: 1. GEOLOGICAL SURVEY DEPARTMENT (GSD) In 1974, GSD discovered the uraniferous pyrochlore in Ririwai hills in Kano State and Kigo hills in Plateau State. The Grade is 0.012% uranium oxides. 2. THE DEFUNCT NIGERIAN MINING CORPORATION The Defunct Nigerian Mining Corporation Exploration campaigns in Kogi State (North Central Nigeria) collaborated with NUMCO in the exploration of some areas in North Eastern Nigeria in 1980. 3. NIGERIAN URANIUM MINING COMPANY (NUMCO) Established in 1979 with the mandate to explore and exploit all available uranium ore deposits in Nigeria. It was in public/private partnership with Total Compagnie Miniere of France, which owned 40% of the company as a technical partner. In 1989, Total pulled out of the partnership as a result of lack of funding. The company carried out exploration programmes at both the reconnaissance and semi detailed levels. Areas of activities covered about 112,346 Km² in the North Eastern Nigeria bordering the Cameroun [2]. Areas of interest include Gubrunde, Mika and Ghumchi all underlain by the rocks of the basement complex; and Mayo Lope area which is underlain by the Cretaceous continental sedimentary rocks [9]. FINDINGS AND CURRENT PROGRESS At the end of the various exploration campaigns; Uranium reserve at Mika was put at about 52T U. Grade was 0.63% U. At a vertical depth of 130m. Uranium reserve at Ghumchi was estimated at 100T U Grade was 0.9 % U. At a vertical depth of 200m Cut-off was 0.03% U [2]. Presently, the mandate for the exploration of Nigeria Uranium is vested in the Nigeria Atomic Energy Commission. Currently the Nigeria geological Survey Agency (NGSA) and three university research centres are carrying out limited exploration of uranium in the potential areas due to limited funds. CONCLUSION Uranium exploration in Nigeria is still in progress. They are being carried out by NGSA and three universities research centers under the coordination of NAEC with limited funds. At present the investigated deposit size and potentials are still insufficient to motivate the resource drilling and feasibility studies. A classical geophysical method applicable to faults detection is also needed. Economic viability of extraction has not been determined due to insufficient information. NAEC is therefore, calling on all serious investors in this area to come to Nigeria and invest in this uranium potential that exist in commercial quantity. REFERENCES [1] MINISTRY OF SOLID MINERALS DEVELOPMENT, “An Inventory of Solid Minerals Potentials of Nigeria; Prospectus for Investors” (1996), pp.1 – 15. [2] NUMCO,” Nigerian Uranium Mining Company Annual Reports” (1983, 1986). [3] OGEZI, A. E., Nature, Exploration and Exploitation of Metallic Mineral (ore) Deposits in Nigeria and Prospects in the Chad Basin. workshop proceedings, Univ. of Maiduguri (2006), pp.19-33 [4] MALLO, S. J., The Nigerian Mining Sector: An Overview. Continental Journal of Applied Science, Vol. 7 (2012), pp.34-45 [5] ADEKANMI. A. A, OGUNLEYE. P.O, DAMAGUM, A.H. and OLASEHEINDE, O., Geochemical Map of Uranium Distribution in the Residual Soil of GRN Cell Number N08 E05. Unpublished Report, Nigerian Geological Survey Agency (2007). [6] IGE, T. A., OKUJENI, C. D. and ELEGBA, S. B., Distribution Pattern of REE and other Elements in the Host Rocks of the Gubrunde Uranium Occurrence, Northeastern Nigeria. Journal of Radio-analytical and Nuclear Chemistry, Vol. 178 (1994), pp.365-373. [7] FUNTUA, I.I. and OKUJENI, C.D., Element Distribution Patterns in the Uranium Occurrence at Mika, Northeastern Nigeria. Chemie der Erde, Gustav Fischer Verlag Jena (1996), 245 – 260. [8] OBAJE S.O., OJUTALAYO A., OGEDENGBE O. and OKOSUN E.A., Nigeria’s Phosphate and Uranium Mineral Occurrences: Implication for Mineral Investment, Journal of Environment and Earth Science Vol.4, No.1, 1-10 (2014). [9] DADA, S. S., and SUH, C. E., Finding Economic Uranium Deposits and the Nigerian Energy Mix. Workshop proceedings, Univ. of Maiduguri (2006), pp.34-43 Speaker: Mr Justine Karniliyus (Nigeria Atomic Energy Commission) • 78 Uranium/Thorium Resource Assessment in Saudi Arabia ABSTRACT As part of the ambitious Saudi’s vision 2030, the minerals sector has been considered as one of the key industries in the Kingdom. Uranium, among all minerals, has received an intensive attention due to its strategic value in securing the nuclear fuel for future reactors. Uranium occurrence was indicated by prospecting surveys made in 1979-1984. These surveys have identified 9 nominated exploration areas, with 35 inner sites. Studies also revealed five important geological environments of uranium resources. The project “Uranium/Thorium Resource Assessment in the Kingdom” was launched in April 2017 as a collaboration between K.A.CARE and the Saudi Geological Survey. It is two phase’s project; general exploration and detailed exploration. Beside the self-sufficiency in fuel production, the project aims to encourage investment in uranium mining and enhance the human and technical local content in this area. The work includes the following activities: radiometric and magnetic airborne survey, geological survey, image processing of remote sensing interpretation, anomaly verification and evaluation, gamma-ray spectrometer and radon surveys, geophysical survey, trenching, borehole drilling, sampling, chemical analysis mapping, radiometric analysis mapping and Geo-database construction. Also, a systematic exploration drilling and core sampling will be developed in the prospecting targets. INTRODUCTION The project aimed to evaluate uranium and Thorium resources in the kingdom of Saudi Arabia according to JORC standards through two exploration Phases, the first phase is planned to be accomplished in two years to evaluate Uranium and Thorium resources (Inferred definitions) started in April 2017. The second phase will utilizes the results and recommendations from the previous exploration phase to reach resources estimation according to indicated and measured definitions, in three years. In the first phase, the project activities will concentrate on the nominated exploration areas and 35 inner sites defined from previous prospection exploration 1965-1987. The Project Partners are King Abdullah City for Atomic and Renewable Energy (KACARE) as project owner, Saudi Geological Survey (SGS) as exploration program manager, China National Nuclear Corporation (CNNC) as exploration contractor. The project scope of work and JORC compliance will be supervised for quality assurance and control by Geological Survey of Finland (GTK). DESCRIPTION Saudi Arabia Geology is consisting of two major units: Arabian Shield and sediment cover rocks that contributed to the existence of different geological environments and led to the presence of variety uranium and thorium Ores deposits. Uranium and Thorium ores deposits are found in different geological environments, and divided into several types based on their geological setting, therefore uranium and thorium may presences as major minerals in ores deposits and/or in other as secondary minerals with some precious metals ores such as copper, silver and rare earth metal elements. There are several studies and reports related to radioactive ores deposits and contamination phenomena have been done by many government institutes such as (Mineral Resources Ministry (DGMR), Saudi Geological Survey (SGS), King Abdulaziz City for Science and Technology (KACST)) and universities and consultants (Minatome, BRGM, USGS) more than 50 years ago. These studies show that the presences of uranium/Thorium ore deposits in the kingdom can by classified as follow: • Sandstone deposit • Veins deposit (Granite related deposit) • Intrusive deposit • Volcanic and caldera related deposit • Surficial deposit • Phosphorite deposit Airborne spectrometric survey was incorporated into Phase 4 of the prospection for uranium mineralization by MINATOME on behalf of the Ministry of Petroleum and Mineral Resources of the Kingdom of Saudi Arabia. The survey covered a surface area of approximately 26000 km2 divided into 9 areas. The airborne field operations were carried out by the Arabian Geophysical and Surveying Company (ARGAS) between December, 1981 (first flight) and March 26th, 1982 (last flight). During these field operations 28519 kilometers were flown: 26083 km along the 1 km line spacing grid initially scheduled, and 2436 km with a 0.5 km line spacing over areas where more detail was considered necessary on the basis of spectrometric results obtained during the survey or after geological reconnaissance. Measurements were made with a 256 energy channel spectrometer GR8O0D from GEOMETRICS with a detector of 2048 cubic inches. The spectrometric survey used in the prospecting stage records radioactivity in the uranium, potassium and thorium channels, to ascertain the uranium potential of these 9 areas and to contribute geological and radiometric information for their further study, and for another, to discover possible uranium anomalies or anomalous areas. In the first Phase of the project, CNNC the exploration contractor, plans to verify prospecting anomalies and uranium resources exploration in these 9 areas (35 inner sites) over three stages. In Stage (1), CNNC has been conducted the following technical work: (1) Geological route survey (1:50,000), cross section and mapping (Scales 1:10,000~1:5,000); (2) Gamma ray spectrometric measurements at different scales (1:10,000~1:5,000), on plane or along geological section; (3) Soil radon survey at different scales (1:10,000~1:5,000), on plane or along geological section; (4) The uranium/thorium or radioactive anomalies’ verification and evaluation; (5) In some places, the geological route survey, XRF and gamma ray spectrometric measurement and/or soil radon survey are integrated in profiles; (6) Remote sensing image processing, interpretation and field evaluation； (7) Geo-database construction； (8) Major and trace elements analysis, Microscopic analysis, SEM, EPMA and data processing of rock/ore samples； (9) Map compilation. Based on the geological conditions and previous work, CNNC plans detail investigations for stage (2); this include carrying out remote sensing interpretation, geological survey and anomaly verification, to find out the regional metallogenic conditions and preliminarily assess the U/Th mineralization potential. Next, is to perform the 1:10,000 or 1:5,000 geological mapping, ground gamma-ray spectrometric survey and radon survey in soil in key sectors, in order to evaluate the scale and U/Th contents of the mineralization and provide the basis for further geophysical, geochemical, drilling and borehole logging work arrangements. After the field work, the indoor laboratory analyses, map compilation and comprehensive research work need to be conducted. DISCUSSION AND CONCLUSION The current reconnaissance exploration reveal on discover of many uranium anomalies inside the nominated exploration sites and a discovery of a number of new uranium anomalies nearby the boarder of the exploration areas. In addition to the above success discoveries, the exploration program fails to verify some of uranium anomalies nominated in the previous prospection exploration and radiometric airborne survey. This failure may refer to the poor accuracy of GPS used in the previous prospecting program which leads to error in coordinates, beside the contribution of the combined effect of the relatively lower survey instrumentation sensitivities and their efficiency of the surveying parameters like airborne survey line spacing. The difficulties of the mountains topographies and wide speared of the exploration areas will add some limitations to verification of the uranium anomalies discovery, beside the complexities of the geological structures. In attempts to resolve these exploration difficulties and for more accurate uranium resources estimation, the following recommendations is to be implemented: • A new planned airborne survey radiometric (four channels radiometry spectrometry) combined with magnetic survey may be implemented. • Maintain/support the role of QA/QC supervisor to fulfill JORC code compliance. • Exploration contractor CNNC must plan the drilling program with higher precision, because diamond drilling are expensive and time consuming, so it should start only after comprehensive studies have been completed, that cover all prospective areas to allow targets to be ranked in terms of economic potential, and to ensure that no viable target is overlooked. • The project timeline may expand, if necessary. REFERENCES • Prospection for uranium mineralization in favorable areas of the kingdom phase4 airborne gamma ray spectrometer survey, interpretation report 1982. • Exploration and Evaluation of Uranium and Thorium Resources in the Kingdom of Saudi Arabia, Technical Progress Report No.1, BY Contractor Beijing Research Institute of Uranium geology, August 20, 2017. • Australian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves: The JORC Code 2012 Edition. • QA/QC Quarterly report , GEOLOGICAL SURVEY OF FINLAND & WGM, Q4 2017. Speaker: Mrs Suzan Katamoura (King Abdullah City for Atomic and Renewable Energy) • 79 Uraniferous potential and occurrences of Madagascar: an overview I- INTRODUCTION Geologically, Madagascar is divided in two parts: (i) the 2/3 eastern part formed the crystalline bedrock which composed by six Domains, from North to South: Bemarivo, Antongil – Masora, Antananarivo, Ikalamavony, Androyen –Anosyen, and Vohibory. These are the Precambrian shield [1]. (ii) And the 1/3 left in the western part formed the sedimentary cover: from North to South, there are three important basins: Diego basin, Mahajanga Basin and Morondava basin. A small basin in the Eastern coast is also signalized. In additional of these basins: there is a lake basin in the center part. Uranium occurrences and uraniferous potential are hosted in two domains in crystalline bedrock: Antananarivo and Anosyen Domain. And in sedimentary cover: there are two deposits: in Morondava Basin and in lake basin. Two types of Uranium deposits appeared in crystalline bedrock and two another types in sedimentary cover. The present work develops these uraniferous potential and occurrences of Madagascar and proposed a new potential uranium deposit. II- DESCRIPTION OF OCCURRENCES AND URANIFEROUS POTENTIAL 1- URANIUM IN SEDIMENTARY COVER In sedimentary cover, there are two types of deposits: (i) sandstone Uranium deposit and (ii) surficial lacustrine deposit. 1.1 Sandstone Uranium deposit Makay and Folakara Uranium deposit are classified in Sandstone Uranium deposit. Geographically, Makay and Folakara deposit are located in North Western part of Madagascar, in Morondava basin. Makay in the Southern part and Folakara in the Northern part. From bottom to top, there are: Sakoa, Sakamena, Isalo I and Isalo II in Morondava basin. Uranium occurrences formed by carnotite found in Isalo II. Isalo II is composed by sandstone and fine clays. After geological prospecting, geophysical airborne survey and geochemical studies realized by CEA (Commissariat Français à l’Energie Atomiques); OMNIS (Office Militaire National pour les Industries Strategiques) in partnership with PNUD (Programme des Nations Unies pour le developpement) – IAEA (International Atomic Energy Agency) continued to undertake geological, geochemical and drilling work on 1979 – 1982, and evaluated its economic potential and estimated 272.000 tons of reserves [2]. 1.2 Surficial lacustrine deposit Vinaninkarena deposit can put in Surficial deposit type. Uranium occurrences formed by uranociricite is hosted in Lake Basin. Geographically, this deposit is situated in central part of Madagascar, south of Antsirabe. The uraniferous zone is located in the contact of crystalline bedrock and Southern part of the lake. This deposit is considered like secondary deposit after alteration – erosion – transport phenomena from crystalline bedrock (primary deposit). Since 1910, during thirty years, CEA evaluated 140.000 tons of Uranium in Vinaninkarena deposit [2]. 2- URANIUM IN CRYSTALLINE BEDROCK In the crystalline bedrock there are: (i) Metasomatitite deposits and (ii) Intrusive deposits 2.1 Metasomatite deposit Tranomaro uranium deposit is classified in metasomatite deposit [1]. Geographically, this deposit is located in southern part of Madagascar. And geologically, in Androyen - Anosyen domain, at Anosyen sub – domain. This Anosyan sub – domain is formed by metagabbros, granitic orthogneiss and their age were interpreted as paleoproterozoic. This deposit is placed in Tranomaro group, which is composed by calcomagnesian paragneiss, Werneritites, cipolin, leptynite with Uranium – Thorium and quartzite. This formation is crossed by three suits: (i) Dabolava suit (1000 MY), (ii) Imorona – Itsindro suit (820 – 760 MY) and (iii) Ambalavao suit (570 – 550 MY) [1]. Uranothorianite mineralization is associated with pyroxenites in granulite facies. The CEA and OMNIS have also taken an exploration work (cartography in small scale, mining work: trenches, pits, and geophysical airborne in this area) on 1947 – 1969. Since 1953 – 1967, OMNIS in partnership with IAEA estimated 50.000 tons of Uranium in Tranomaro deposit [2]. 2.2 Intrusive deposit Two areas are classified in this type: Ankazobe – Vohimbohitra and Antsirabe Uranium deposits which are located in Antananarivo Domain. This Domain is formed by Neoarchean orthogneiss and paragneiss with greenschist to granulite facies. This domain includes also three greenstones belts from West to East: Bekodoka – Maevatanana belt, Andriamena belt, and Beforona belt [1]. These three greenstones belt constitute Tsaratanana complex. These formations are crossed by Imorona – Itsindro suit (860 – 720MY) with ultrabasique to acid facies [1]. - Antsirabe uranium deposit Geographically, Antsirabe Uranium deposit is situated in East part of Antsirabe, central part of Madagascar (in Betafo town). Noted that Betafite, is a mineral ore of uranium and its name is from Betafo town. Three types of potassic – pegmatites are present in this area according to their enclosing formation. There are: o Pegmatite crossed the granites. Except the quartz, and mineral of pegmatite, this pegmatite is composed also by betafite, euxenite, columbite, pyrite, and garnet. o Pegmatite crossed the gabbros This pegmatite is appeared as veins filling the fracture; this is a pegmatite with magnetite, euxenite, betafite, and beryl. o Pegmatite crossed the crystalline bedrock This pegmatite filled also the fractures but in migmatite gneissic complex. Some exploration work has already carried out in this area: the first one is an airborne overflight on 1947 – 1969 by CEA. Government agency of Malagasy states (OMNIS) in partnership with UNDP (United Nations Development Programme and System) continue this work on 1976 – 2000 [2]. Thirty pegmatites were exploited in this area and have collected 50 tons of ore at an average ore grade 12 à 15 % U3O8 [1]. Pegmatite crossed the granite (Vavato granite 860 – 720MY) was the important Uranium occurrences [1]. - Ankazobe – Vohimbohitra Uranium deposits Geographically this deposit is located in the central part of Madagascar (X: 502 500 (m) – 519 800 (m) et Y:1 048 800 (m) – 1 082 300 (m)). This deposit is located in Andriamena belt with uraninite bearing pegmatite which composed by heterogenous formations, with various metamorphism degrees. But the gneissic complex in this area is in high degree [1]. This is very similar in Zimbabwe greenstone belt. “The 2014 Red Book notes 1400 tU as RAR in the$130-260/kg bracket, and also speculative resources of 25,000 tU.” [3]. Recently, Zimbabwe is believed to have uranium reserves of around 45.000 tonnes [4]. Robert F. Bacher and Hans J Morgenthau discovered that “The pegmatites in Madagascar are the only one that have furnished appreciable tonnage of Uranium minerals. Records indicate the sale of over 100tons of autunite and uranociricite ores” [5]. III- DISCUSSION AND CONCLUSION After geological study, exploration work by different entity (National and international), compared with Zimbabwe greenstone belt which is very similar in Andriamena belt and known that pegmatite in Madagascar are very rich in tonnage of Uranium minerals. Ankazobe –Vohimbohitra uranium deposit in pegmatite could present an important uranium pegmatite deposit. A deep exploration work in this area is needed. IV- REFERENCES [1]- Cartes géologique et metallogeniques de la République de Madagascar à 1/1 000 000, Projet de Gouvernance des Ressources Minérales de Madagascar, Juin 2012. [2]- http://www.omnis.mg. [3]- Resources, Production and Demand Paladin Energy Denison Mines Mantra Resources OECD NEA & IAEA, 2016. [4]- Daily Mail Reporter “mail online” http://www.dailymail.co.uk/news/article-2388685/Zimbabwe-signs-secret-deal-supply-Iran-uranium-build-nuclear- bomb.html#ixzz5834ueESi,10 août 2013. [5]- Robert F. Bacher, Hans J.Morgenthau, Bulletin of the Atomic Scientists, May 1950.
Speaker: Dr Vololonirina RASOAMALALA (Responsible of bachelor's degree - UNIVERSITY OF ANTANANARIVO - MADAGASCAR)
• 12:40 PM
Lunch Break
• Health, Safety, Environment and Social Responsibility
Conveners: Mr Dennis Amos MWALONGO (Tanzania Atomic Energy Commission) , Mr Luis LOPEZ (CNEA (Argentina))
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Effective Radiation Monitoring: Back to Basics
Speaker: Ms Alice Jagger (Yarex)
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Speaker: Mr Jim Hondros (JRHC Enterprises Pty Ltd)
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Action Levels for Airborne Natural Uranium in the Workplace: Chemical and Radiological Assessments
Speaker: Dr Robert Meck (Science and Technology Systems)
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Radiological Aspects of Alkaline Leach Uranium In Situ Recovery (ISR) Facilities in the United States
Speaker: Mr Steven H Brown (SHB Inc)
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A New IAEA Safety Report on Occupational Radiation Protection in the Uranium Mining and Processing Industry
Speaker: Mr H. Burcin Okyar (International Atomic Energy Agency)
• Uranium Production by the In Situ Leaching (ISL) Process
Conveners: Mr Christian Polak (AREVA MINES) , Ms Olga Gorbatenko (Kazatomprom)
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MAJOR INNOVATIONS IN ISL MINING AT URANIUM ONE MINES IN KAZAKHSTAN
The successful innovative technical policy in conjunction with the unique by its geological and technical characteristics deposits, provide significant competitive advantage for Uranium One as the global company with the lowest cost uranium production. Uranium One gain broad expertise in the various aspects of ISL exploration and mining, including: uranium prospecting and exploration for sandstone hosted deposits from greenfield to mining phase; geological geo modelling and resources estimation; pilot ISL testing; feasibility and engineering studies at all stages of deposit development. The main areas of ISL innovative developments and efficiency improvements at Uranium One mines in Kazakhstan include: geological 3D modelling for resources estimation; ISL process modelling and simulation for projects design and its implementation in ISL process management; implication of modern methods for wells construction and restoration; estimation of additional technogenic and residual resources; rare earth elements and other valuable components recovery from leaching solutions. Uranium One attributable CIM compliant resources in Kazakhstan have tripled over 10 years through acquisitions, extensive exploration and by applying 3D modelling in resource estimation. Previous technical reports on NI 43-101 codex were based on geological information compiled from Kazakhstan national technical reports on resources (GKZ codex), which assumed polygonal geostatistical method for resources calculation. Uranium One has hired CSA Global to develop a robust methodology for 3D geological modelling and Mineral Resource and Ore Reserve estimation for roll-front deposits in Kazakhstan. This methodology was applied from 2012 through 2017 to Budenovskoye and South Inkai deposits modelling in Chu-Sarysu province, and Zarechnoye and Kharasan-1 deposits modelling in Syrdarya province. The ISL modelling complex includes the set of integrated systems: geological data room and geological model, technological data room and ISL process simulation model, technical-economical system, ISL development and wellfield design system, mining planning complex. The modelling complex may be applied for ISL process design and management at all stages of deposit development. The complex was developed by Russian Seversk Technological Institute and originally implemented at Russian ISL mine Dalur. In 2017 Uranium One has started pilot project on ISL process modelling and simulation at one of the areas of the Akbastau mine. The developed ISL model for main technical parameters has identified main issues for ISL process optimization in a short, mid and long-term period. The obtained results confirmed the high potential for simulating systems implementation at ISL mines in Kazakhstan. Wellfields design and installation is one of the most important component of ISL mine development. Drilling and wells installation costs comprise about 70% of mining CAPEX or 25-30% in the total uranium production cost. Major ISL mines in Kazakhstan use unified technique and design for technological wells drilling and installation. The stable performance of wellfield units largely depend on efficiency of wells work over procedures focused on wells flow rates restoration and on plugging impact elimination. Plugging is the process when a well-known screen loose its capacities and the ore bearing horizon loose its permeability. A new method for wells flow rates restoration is based on wells screen treatment by a mixture of reagents with the additive of ammonium bifluoride. The method has no alternatives for the restoration of problematic wells, when traditional methods of chemical treatments for flow rates recovery do not give significant results. Application of the method restore flow rates to original parameters and increase the workover cycle by 2.5 to 3 times. Estimation and development of additional technogenic (or newly formed) and residual resources within existing wellfields is a particularly vital issue for a life of mine extension. By technogenic resources we mean uranium concentrations formed due to leaching solutions exposure on primary mineralization and redeposition of dissolved uranium, including the remaining lenses of productive solutions. By residual resources we mean part of remained in situ and not affected by leaching processes uranium mineralisation. In 2016 Akdala mine completed research work focused on the forecast of areas with residual and technogenic resources [4]. Prospective areas for 419 tons of potentially residual resources were allocated within existing wellfield units. Further verification drilling confirmed the presence of residual and newly formed ores. 15 of 25 wells drilled in 2017 identified commercial uranium concentrations in leaching solutions and in hosting sediments. Off-balance resources of valuable by-product components (rhenium, scandium and rare earth metals) are identified in the contours of uranium resources at ISL mines in Kazakhstan. All valuable components are partially dissolved in sulfuric acid during ISL process. Six mines with Uranium One ownership pump out more than 120 million. cubes of productive solutions annually, which contain up to 1 mg/l of scandium and rhenium and 5-20 mg/l of rare earth elements [5]. Lanthanum, cerium and neodymium give the major input to rare earth elements. About 40t rhenium, 30t scandium, more than 2000t of rare-earth metals is pumped out annually with leaching solutions and returned back to aquifer. Major technologies of by-products extraction from sorption mother liquors has been developed. They assume by products sorption by cationic exchange resins or REE chemical precipitation. Rhenium is partially absorbed together with uranium by anionic ion exchange resins and its concentration in saturated resins may reach 950g/t [5]. The key technological challenge is a selection of sorbents, which provide selective extraction of valuable components free of radioactive metals impurities. REFERENCES [1] Boytsov A.V., Thys H., Seredkin M.V. Geological 3-D modelling and resources estimation of the Budenovskoye uranium deposit (Kazakhstan). Uranium Raw Material for the Nuclear Fuel Cycle: Exploration, Mining, Production, Supply and Demand, Economics and Environmental Issues. IAEA-CN-216 Abstract 038. Vienna, 2014 [2] Noskov M.D. et all. Application of geotechnical simulation for ISL uranium mining higher operational efficiency. Book of papers VIII-th International Conference “The topical Issues of the Uranium Industry”, pp.108-113. 03-05 August 2017, Astana, Kazatomprom. In Russian. [3] Noskov M.D. et.al. Intellectual technology of ISL uranium mining management. Book of papers VIII-th International Conference “The topical Issues of the Uranium Industry”, pp. 102-108. 03-05 August 2017, Astana, Kazatomprom. In Russian. [4] Nietbaev M.A. et al. Experience and prospects of newly formed and residual uranium resources development. Book of papers VIII-th International Conference “The topical issues of the uranium industry”, pp. 72-78. 03-05 August 2017, Astana, Kazatomprom. In Russian. [5] Kozhakhmetov S.K. et.al. The possibility of rare and rare earth metals by products recovery from pregnant ISL solutions at South Kazakhstan uranium deposits. The VI-th International Conference “The topical issues of the uranium industry”, pp. 452-456. 14-16 September 2010, Almaty, Kazatomprom. In Russian.
Speaker: Dr Alexander Boytsov (Uranium One Inc.)
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THE FUNDAMENTAL RESEARCH AND INDUSTRIAL APPLICATION OF THE CO2 AND O2 IN SITU LEACHING PROCESS IN CHINA