USED FUEL ASSEMBLY TRANSPORTCASK TN®G3 FAMILY

TN International has extensive experience in domestic (in France) and international transport of used fuel assemblies (in France about 2,400 fuel assemblies are transported each year). Compared with the first transport cask designs of the early 1980s, the fuel characteristics (enrichment, burn-up) have significantly evolved. Meanwhile, the requirements of the regulations and the Competent Authorities have also significantly increased. To deal with these evolutions and continue to satisfy customer needs for the transport of used fuel assemblies over the next 40 years, TN International has developed a new generation of transport casks. The TN®G3 cask family has been designed with four main purposes: Transport a wide scope of fuel types, with high enrichment (up to 5%), high burn-up (up to 70,000 MWd/tU), even with a short cooling time (as low as 2 years). Such content results in high radiation sources, especially neutron sources for high burn-up fuel. Used MOX fuel can also be transported. The TN®G3 cask is designed to mitigate the radiation level surrounding the package. Secure a design compliant with the highest safety level requirements. In particular, the TN®G3 design includes a double leaktight barrier complying with the latest IAEA regulations. The leaktightness of the barriers will be demonstrated by a drop test campaign with a package model including, in particular, the delayed impact effect. Minimize changes of interfaces with the hosting facilities (nuclear power plants and recycling facilities in France) and transport means (trucks, wagons…). Most of the heavy tools are unchanged for the operation of the casks, such as the cask lifting yoke, the transport skid, or the skirt to prevent contamination during pool immersion. Integrate TN International’s 50 years of experience in the shipment, operation and maintenance of transport casks into the design. The TN®G3 cask is also compatible with the latest NPP design such as the EPRTM reactor. This paper presents the TN®G3 cask family, and the technical solutions to comply with this challenging scope of work.