Recovery behaviours of thermal conductivities in self-irradiated MOX fuel

The thermal conductivities of MOX fuel pellets stored for about 15 years and their recovery behaviours by pre-heating were investigated in two types of experiments. The experimental thermal conductivities approached the analytical curve derived from the thermal conductivities of non-self-irradiated specimens with an increase of pre-heating temperature. The experimental results were analyzed by the modified classical phonon transport model. The recovery processes between the thermal conductivities in this study and the lattice parameters of UO2 and PuO2 were compared. It was found that both recovery processes were similar to each other.