The numerical analysis of the impact of CASTOR-1500 cask model simplifications on temperature distribution in the cask

Nuclear fuel is the most important component in a nuclear reactor that has a limited-service life and needs to be reprocessed or carefully handled before the geological disposal which would be the final step in its management. In order it could be disposed of in a geological repository, spent nuclear fuel activity and decay heat should be reduced. For this purpose, it is stored in water pools and interim storage facilities. In interim storage facilities, spent nuclear fuel very often is placed in spent nuclear fuel casks. All storage casks must fulfil safety requirements. The main thermal parameter for cask safety is fuel load temperature which must not exceed the maximum defined value. In this paper, thermal processes in the CASTOR RBMK-1500 storage cask are numerically analyzed using 2D and 3D models. Several simplifications were applied to the cask numerical models and the effects on the internal temperature distribution were analyzed.