Simulation of Nuclear Fuel Cladding under Long Term Storage Cond.

Within a joint research project between the Institute for Energy (IE) and the Institute for Transuranium Elements (ITU) on the integrity of spent nuclear fuel cladding the ITU code TRANSURANUS was used to simulate creep of Zircaloy cladding tubes under long term storage conditions. Since TRANSURANUS is designed to model the mechanical, thermal and physical behaviour of fuel rods during reactor operation it was the objective of this study firstly to explore the limitations of the present creep models in TRANSURANUS for the simulation of long term creep processes under dry storage conditions. If the present creep models in TRANSURANUS were found to be inappropriate then the next objective was to formulate the properties of an "ideal" creep model for dry storage.