Radiation enhanced diffusion processes in UO2 and (U,Pu)O2

Abstract

The diffusion mechanisms and migration characteristics of point defects in the fluorite structures of UO2 and (U, Pu) O2 were analyzed. The possibility of complex migration mechanisms of anionic and cationic vacancy and interstitial Frenkel defects depending on the stoichiometry of materials was shown.The statistical analysis of published data on the radiation-enhanced diffusion (RED) characteristics of metal atoms in UO2 and (U, Pu)O2 for temperatures 1303-1673 K was carried out. An approximate temperature dependence of RED coefficient was obtained. Within the framework of understanding of the mechanisms of diffusion processes in fluorite structure, the approximate temperature dependence of the RED coefficient of oxygen for UO2 and (U, Pu)O2 was proposed.