Development of Transport and Long-Term Storage Casks for Spent Fuel with High Enrichment and High Burn up

GNB is introducing two representatives of the new CASTOR cask generation based on the proved, tested and already licensed CASTOR base concept. The main characteristics of this concept are: 1 ) Cask body made of ductile cast iron with machined fins for heat dissipation 2) The neutron moderator material is integrated inside the cask wall. 3) In order to fulfill the storage requirements the design of the lid system is based on the detectable double-lid principle 4) Shock absorbers to limit stresses caused by type-S-tests With the new generation of the CASTOR casks, the following aims are pursued: 1) Transport and storage of uranium and MOX-fuel assemblies with maximum enrichment, maximum burn-up and acceptable cooling time, to consider future demands of fuel assembly characteristics 2) Maximum capacity of the cask while guaranteeing safe handling in nuclear power plants and casks interim storage sites as well as transport on public routes. 3) Meeting the requirements for the Type-B packages and the requirements for interim storage sites in Germany. 4) Using the upper bound values for the outer dimensions and a reasonable handling weight the cask concept is an optimised relation between costs and fuel masses per cask.