Mesoscale Simulations of Fission Gas Release: a Two-Dimensional Implementation of the Shell Porosity Model

Abstract

A 2D implementation of the shell porosity model [1], allows for time-dependent modelling of intergranular fission gas bubbles in mixed oxide nuclear fuels with potentially heterogeneous microstructures. The application of this implementation is the physically based, computationally efficient modelling of fission gas accommodation and release. In this work the theory and implementation aredescribed, followed by sample results demonstrating the model potential to simulate some observed fission gas behavior. Finally, simulations conducted on a network of simulated grains edges with heterogeneity in parameters such as interfacial energy, rate of fission gas release, and bubble contact angle, are discussed. Future applications of the model are discussed, as well as possible improvements.