Speaker
Description
The CERUS project was developed by the Argentinean National Atomic Energy Commission (CNEA) according to the strategies of spent fuel management policy declare at the National report for the Joint convention on the safety of spent fuel management and on the safety of radioactive waste management, in order to achieve a predisposal treatment to the conditioning of $U_{3}Si_{2}$-Al clad spent fuel. Research Reactor Spent Fuel (RRSF) management is challenging due to the enrichment at discharge higher than 11% of $^{235}U$. Due to criticality considerations and susceptibility to materials degradation, direct disposal cannot be a viable option for $U_{3}Si_{2}$-Al clad RRSF management (IAEA-TECDOC-1508, 2006). The main idea of the process consists of the use of natural (or depleted) uranium oxide to achieve the isotopically dilution down to 1% $^{235}U$ and seeking for a monolithic ceramic wasteform with uranium octoxide ($U_{3}O_{8}$) as immobilization matrix.
Previous research works carried out at the Bariloche Atomic Center (CAB) focused on the characterization of a mixture of natural $U_{3}O_{8}$ and, calcined and milled aluminium clad-uranium silicide (natural) plate (Russo et.al. 2002). This study proposes the continuity of the research of $U_{3}O_{8}$ precursor powders that began with the study of densification behaviour by Chavez et.al. (2018). Several samples 9 mm in diameter, uranium oxide pellets, cold-pressed and sintered, were obtained by two routes of powder synthesis: AUC-ammonium uranyl tri-carbonate (Argentina’s $UO_{2}$ industrial process), and ADU-ammonium diuranate. Finally, were characterized by Archimedes method of immersion to obtain the porosity as well as ceramography, optical and electronic microscopy to reveal the shape and morphology of the ceramic matrix.
This work addresses the response of micro-indentations on the sintered pellets. Indentation measurements of Vickers and Knoop were done to relate with the hardness of $U_{3}O_{8}$ ceramic matrices. Lastly, samples were observed in a Scanning Electron Microscope (SEM) to characterize the fractures initiated in the notches.
| Speaker's title | Mr |
|---|---|
| Affiliation | Comisión Nacional de Energía Atómica (CNEA) |
| Do you wish to participate as a Young Professional? | Yes |
| Do you wish to be considered for a Young Professional grant? | Yes |
