Self-irradiation effect on thermal conductivity of (Pu0.91Cm0.09)O2

To clarify the dependence of thermal conductivity on storage time of MA containing oxide fuel, the thermal diffusivity of (Pu0.91Cm0.09)O2 was measured at 473, 523 and 573 K by a laser flash method using the sample stored for 48, 264, 504, and 960 h. The heat capacity was measured by a drop calorimetry to derive the thermal conductivity. It was confirmed that the degradation of the thermal conductivity was attributed to the accumulation of lattice defects caused by self-irradiation, because the dependence of thermal conductivity on storage time could be approximated by the equation used for self-irradiation lattice expansion model.