|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Materials Science and Engineering for Nuclear Energy
||Off-stoichiometric Cluster Dynamics in Irradiated Oxides
||Sarah Khalil, Todd Allen, Anter El-Azab
|On-Site Speaker (Planned)
A cluster dynamics model describing the formation of vacancy and interstitial clusters in irradiated oxides has been developed. The model, which tracks the composition of the oxide matrix and the defect clusters, was applied to the early stage formation of voids and dislocation loops in UO2, and the effects of irradiation temperature and dose rate on the evolution of their densities and composition was investigated. The results show that Frenkel defects dominate the nucleation process in irradiated UO2. The results also show that oxygen vacancies drive vacancy clustering while the migration energy of uranium vacancies is a rate-limiting factor for the nucleation and growth of voids. In a stoichiometric UO2 under irradiation, off-stoichiometric vacancy clusters exist with a higher concentration of hyperstoichiometric clusters. Similarly, off-stoichiometric interstitial clusters form with a higher concentration of hyperstoichiometric clusters. The UO2 matrix was found to be hyper-stoichiometric due to the accumulation of uranium vacancies.
||Planned: Supplemental Proceedings volume