Abstract
Predicting fuel behavior in the reactor is a typical multi-physics coupling problem. The traditional fuel performance analysis adopts a decoupling way. To provide a higher fidelity tool for fuel performance simulation, the multi-physics coupling software COMSOL and 3D Monte Carlo neutron transport code RMC are coupled. The fuel rod thermo-mechanical coupling analysis module is constructed in COMSOL. RMC is innovatively wrapped as a component of COMSOL to communicate with the fuel performance module. Grid mapping algorithm is set up using COMSOL’s functionality. A carefully designed segregation solver sequence is used to control the coupling process. The fine power distribution calculated by RMC is transferred to COMSOL fuel thermal calculation, and the fuel temperature and the coolant temperature and density calculated by COMSOL are transferred to RMC. In a Picard iterative way, the fuel rod lattice level neutron thermomechanical tight coupling is realized. The coupling is demonstrated in a fuel rod BOL steady state case. The fuel performance analysis is enhanced by the higher fidelity neutron flux solution.
