Extended Development of a Fission Gas Release Behavior Model Inside Spherical Fuel Grains for LWR Reactors

Fission gas plays a significant role in fuel rod performance following accidents. The amount of fission increases dramatically under accidental conditions. This leads to subsequent rise the internal pressure and temperature due aggravated gap conductance between pellet cladding. As result, degrades. Therefore, studying behavior is crucial for accident assessment evaluating performance. Minimizing Impact on rods essential maintaining their integrity safety within nuclear reactors. One important aspect ensuring predicting release (FGR). In this study, we presented an extended model be used light water reactors (LWRs). FGR can modeled using COMSOL Multiphysics with finite element method. modeling approach considers both normal abnormal conditions, latter categorized as Class-II type incidents. assumes that diffusion inside spherical grain varies over time. By examining perfect sinks production, without imperfect steady-state different initial boundary conditions are set. To validate accuracy universality expressions model, input parameters from other models experiments utilized. comparing model’s results these inputs, applicability confirmed. validation process ensures provides reliable predictions operating Based our findings, it evident fraction displays upward trend coefficients temperatures rise. Conversely, larger sizes higher linear heat generation rates associated reduction fraction. Notably, enhanced resolution postponed onset FGR. Furthermore, influence coefficient primarily stems interconnected effects rate.