Recovery behaviors of thermal conductivities in self-irradiated MOX fuel

Morimoto, Kyoichi ; Kato, Masato   ; Ogasawara, Masahiro*

In MOX fuel stored for long term, the defects induced by self-irradiation (alpha decay) increase with an increase of storage time, and consequently its thermal conductivities decrease by an accumulation of these defects. Some investigators showed that these defects were decreased or annihilated by heat treatment, and then the lattice parameter, thermal conductivity, etc of fuel were recovered. In this study, we prepared the specimens divided from MOX fuels stored for about fifteen years. We investigated a recovery behavior of the thermal conductivities of this specimen and evaluated this behavior as functions of heating temperature and heating time.