Transport and storage solutions for defective spent fuel

The fuel assemblies can become a defective fuel during the irradiation cycle in reactor or during the storage in cooling pool, for example due to a galvanic corrosion of the cladding. There are two main categories defining the defective fuel: - The leaking fuel rods, - The damaged fuel rods. Currently, there is no internationally accepted definition of ‘defective fuel’ but decisions are made directly in each country depending on the local regulatory requirements, available technologies and the stage of the fuel cycle, i.e. wet or dry storage, transportation, disposition in a repository or reprocessing. In the first part of this presentation, the general definitions, classifications and current approaches for the management of defective spent fuel are presented. Depending on the different criteria to be respected and functions to be fulfilled for the transport and/or the dry storage of defective fuel rods, following approaches may be implemented: - No encapsulation - “Material” encapsulation - “Gas-leak-tight” encapsulation Transportation of defective fuel assemblies is today being performed. Various cask designs exist for that purpose and specific operations are implemented for preparing the defective fuel for transport. Interim dry storage of defective fuel assemblies has been implemented for decades in the USA. Specific operations are performed for preparing the defective fuels which are then stored along with intact spent fuel assemblies in the dry storage system. Solutions for the long-term dry storage defective fuel, compliant with direct disposal safety requirements, have been already implemented or are still in the qualification phase. In the second part of this presentation, technologies and solutions to be proposed worldwide by Orano TN for the transportation and/or the dry storage of defective fuels are presented. The hydrogen risk generated by radiolysis of residual moisture is of great importance during transportation and/or storage of defective spent fuel. Eventually this paper will present the current status on Orano TN dedicated R&D programs, started around 10 years ago, to prevent and/or limit this risk. References [1] IAEA Nuclear Energy Series No. NF-T-3.6: Management of Damaged Spent Nuclear Fuel, issue IAEA 2009