Self-irradiation effect on thermal conductivity of Zr_0.70Pu_0.25Cm_0.05N solid solution

This study evaluated the dependence of the thermal conductivity of Zr_0.70Pu_0.25Cm_0.05N on storage time and temperature. The authors prepared sintered samples of Zr_0.70Pu_0.25Cm_0.05N solid solution and measured thermal diffusivity at storage times of 0, 24, 72, 144, 240, 408, 552, 816, 1,680, and 2064 h, from which it was determined that the thermal conductivity decreased exponentially with increasing storage time. This result suggests that the decrease of the thermal conductivity could be attributed to the accumulation of lattice defects from self-irradiation. To confirm the thermal recovery behavior of Zr_0.70Pu_0.25Cm_0.05N under annealing, thermal diffusivity was also measured just after annealing. The thermal conductivity of Zr_0.70Pu_0.25Cm_0.05N was determined to be larger than that of Zr_0.58Pu_0.21Cm_0.21N but smaller than that of Zr_0.80Pu_0.10Cm_0.10N. - Highlights: •The authors prepared Zr_0.70Pu_0.25Cm_0.05N and measured thermal diffusivity. •Dependence of thermal conductivity on storage time was clarified. •After annealing at 1423 K in vacuum, thermal conductivity was recovered.