|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Ceramic Materials for Nuclear Energy Research and Applications
||Phase-field Modeling of Bubble Growth During High Burn-up Structure Formation in UO2
||Sudipta Biswas, Andrea M. Jokisaari, Larry K. Aagesen
|On-Site Speaker (Planned)
In UO2 fuel, regions exposed to high burn-up and low temperatures exhibit a fine-grained microstructure with large bubbles known as high burn-up structure (HBS). A phase-field model is developed to investigate the mechanisms facilitating the creation of such a structure. The model captures the formation of smaller grains due to defect accumulation overtime via recrystallization, employing a dislocation density based discrete nucleation algorithm. The model also accounts for existing fission gas bubbles and concurrently tracks the concentration of defects, such as vacancies and gas atoms, leading to further bubble growth. Additionally, it considers the role of recombination of defects, various diffusion mechanisms, and activation paths contributing towards coalescence of smaller bubbles into the larger ones. The model can generate realistic HBS structures, similar to what has been observed experimentally, that can be used to evaluate the effect of the structure on the thermo-mechanical properties and performance of the fuel.
||Nuclear Materials, Computational Materials Science & Engineering, Modeling and Simulation