Development of a 3D Multiphysics Coupled Computation Model for TRISO Fuel Particle

TRISO fuel particle is the area where fission reaction occurs for high-temperature gas-cooled reactor fuel and FCM accident-tolerant fuel pellet. To investigate the complicated behaviors of TRISO fuel particle under irradiation, a 3 D multiphysics-coupled computation model for fuel performance analysis was developed based on the COMSOL finite element software. Using the irradiation-dependent material properties and behavior models, this model is capable of simulating the complicated in-pile thermo-mechanical behavior under steady-state and accident conditions, important phenomena such as fission gas release, production of CO gas and diffusion of fission products, as well as failure probability of fuel particle. The IAEA CRP-6 benchmarks were employed to validate the model, which showed good agreement of the results between COMSOL and other codes; the simulation of TRISO fuel particle conducted by using BISON was also consistent with the results obtained by the COMSOL model, which indicated the reasonability of the model in the present study.