Application of 3D thermal analyses for loading and unloading procedures of spent fuel casks to ensure admissible temperatures and avoid undesired situations

摘要

3D thermal analysis is a powerful method to calculate time periods that are permissible for several operational steps during loading of a cask with spent nuclear fuel assemblies and the unloading procedure. With these calculations and the derived time periods it is possible to keep admissible temperatures in cladding tubes as well as other components like moderator rods and to avoid undesired situations like discharge of boiling water leading to uncontrolled contamination of the surroundings.