Speaker
Description
The latest revision of the IAEA Regulations for the Safe Transport of Radioactive Material (SSR-6, Rev. 1) introduced a new group of surface contaminated objects (SCO-III) which shall be applied for objects, that – due to their size - can only be transported unpackaged. The classification as SCO-III is typically used for the transport of disused steam generators, that are contaminated on their internal surfaces with activity levels that exceed those permitted for SCO-I, but are below the limits given in §413 (c) in SSR-6, Rev. 1. Furthermore, the classification as SCO-III requires all openings to be sealed in order to prevent the release of radioactive material during conditions defined in para. 520(e), and for the inside of the object to be as dry as possible.
The transport of large contaminated components (as SCO-III or under special arrangement) requires a multilateral approval of the shipment in accordance with the dangerous goods regulations, based on SSR-6, Rev. 1. In Germany, the Federal Office for the Safety of Nuclear Waste Management (BASE) is the competent authority for issuing the approval after verifying compliance with the dangerous goods regulations. The technical assessment of BASE covers, in particular, the radioactive inventory determination carried out by the applicant, and the transport plan including the radiation protection measures for the transport itself and all associated handling operations. After receiving a commission from BASE, the Federal Institute for Material Research and Testing (BAM) assesses the mechanical and thermal properties of the SCO-III in transport configuration in terms of activity retention, as well as the management system including the quality assurance measures for all operations and conditions of the transport (design, preparation, transport).
Since the introduction of SCO-III, three shipments of disused steam generators with high levels of internal surface contamination have touched German territory:
• a transport of two disused steam deformers from the nuclear power plant Lingen, Germany, by road, inland waterways and sea to the USA in 2024,
• a transport of three lower parts of disused steam generators from the nuclear power plant Fessenheim, France, by road, inland waterways and sea to Sweden in 2025, and
• a transport of four disused steam generators from the nuclear power plant Unterweser, Germany, by road and sea to Sweden in 2025
All of the three shipments were partly accompanied by BASE and BAM, e.g. after preparation and during transshipments.
In this paper, we report on the most important insights gained by assessing the applications for shipment approval and accompanying these transports. These insights concern the preparation of the object, the form and content of the transport plan, the radiological characterization of the object, and the implementation of radiation protection measures.
