Deformation analysis on HT-9 fuel rod according to the variations of temperature and neutron flux

MR fuel rod is irradiated under the high neutron flux and temperature operation conditions. The parameters affected on fuel rod deformation are fission gas release, rod pressure build-up, FCMI, and cladding creep on at the high pressure and temperature under long term operation condition. One of the most important factors among these parameters is cladding creep phenomenon due to gas pressure build-up within the fuel rod. In-reactor thermal and irradiation creep characteristics for HT9 and HT9M were analyzed, and these characteristics were modeled for MACSIS in this study. The results were installed into MACSIS-MOD1 code, and the creep deformation for KALIMER fuel rod were evaluated by the MACSIS-MOD1. It appears that the thermal creep under normal operation condition showed a lower creep rate which is not a function of burnup comparing with irradiation creep. However, the irradiation creep is continually increased with burnup, and it is very important performance parameter at high burnup