Thermal conductivity of UO2 and PuO2 from first-principles

Abstract

Based on our previously calculated phonon spectra from first-principles, in the present work, we have applied the Slack relation to obtain the thermal conductivity of UO2, PuO2, (Th, Pu) O2, and (U, Pu) O2 in temperature range of 300–1500K. Also, the mode Grüneisen parameters of PuO2 and UO2 were presented to analyze the anharmonic properties. Rapid decrease of the thermal conductivity for UO2 at low-temperature zone was observed. As for PuO2, its larger phonon group velocity results in better thermal transfer ability than ThO2, UO2, and AmO2 at high-temperature zone.