The influence of the creep model parameters' variation on the fuel rod integral response

Nuclear Research Institute φe plc obtained a newest version of the TRANSURANUS computer code, which has been developed by the teams of Mr. K. Lassmann. As a new fuel, designed for the four year cycle is being introduced in the Dukovany VVER-440/213 type NPP, an extensive application of this code for the fuel behaviour analysis is planned. The main problem arisen is an insufficient base of a direct data on a Zr1Nb cladding material properties for high burn-up region. That is why the parametric study of a specific cladding material properties influence on the fuel rod integral behaviour has been started. The goal of this study was to gain physical feeling about the influence of the models like thermal-irradiation creep, irradiation growth and basic mechanical properties. As a first step to the solution, the analytical approach to the local creep model parameters variation sensitivity study was prepared. Then the TRANSURANUS computer code has been used for the evaluation of the global sensitivity study of the problem. (authors)