ADDING WET TRANSPORT CAP ABILITIES TO A. DRY SPENT FUEL CASK- THE TN 13/2 EXAMPLE

The TN 13/2 cask was designed for the transport of spent fuel from 1300 MW reactors to reprocessing plants. It is capable of canying relatively short cooled high bum-up fuel and came into service in 1983. The TN 1312 nonnally transports fuel under 'dry' conditions, the cask cavity containing an inert gas at sub-atmospheric pressure during transport. The cask is designed for fuel loading operations under water and hence it is compatible with 'wet' environments. Some casks are designed to transport fuel with a water filled cavity, so called 'wet' transports. Fuel cladding temperatures tend to be lower in 'wet' transport casks but higher temperatures are of no consequence for fuel destined for reprocessing. However, in the case of fuel movements between reactors on the same site, it is desirable to limit the cladding temperature and 'wet' transport casks are the preferred option. Transnucleaire decided to add 'wet' transport capabilities to the TN 1312 cask and thereby give customers the option of using the cask in both wet and dry modes. This paper explains the particular challenge of applying wet transport parameters to a dry cask design and explains how this was achieved for the TN 13/2 without changing any of the cask components.