A coupling methodology for mesoscale-informed nuclear fuel performance codes

摘要: This study proposes an approach for capturing the effect of microstructural evolution on reactor fuel performance by coupling a mesoscale irradiated microstructure model with finite element code. To achieve this, macroscale system is solved in parallel, fully coupled, fully-implicit manner using preconditioned Jacobian-free Newton Krylov (JFNK) method. Within JFNK solution algorithm, microstructure-influenced material parameters are calculated and passed back to calculation. Due stochastic nature model, dynamic fitting technique implemented smooth roughness parameters. The proposed methodology demonstrated simple pellet. In INL’s BISON code calculates steady-state temperature profile pellet thermal conductivity determined phase field microstructures. multiscale demonstrates good nonlinear convergence near ideal parallel scalability. By formation large voids interior, predicted irradiation-induced reduction commonly observed reactors.