Recovery of Thermal Conductivity of MOX Fuel with Fission Gas Release

摘要

The fuel performance code, COSMOS, was developed with various different irradiation tests with MOX fuel. The thermal behaviors were also well predicted except for a few in-pile tests. The significant discrepancy was observed only in the case of accompanying significant fission gas release. It was consequently proposed that the thermal behavior can be accurately predicted with the assumption of thermal conductivity recovery depending on the extent of fission gas release. The recovery was confirmed indirectly by the comparison between measured in-pile data and the temperature predicted by the COSMOS. The collective comparison between the measured and calculated fuel temperature revealed that the thermal behaviors were predicted accurately with adopting the recovery effect on the thermal conductivity.