Neutronics/thermal-hydraulics/fuel-performance coupling for light water reactors and its application to accident tolerant fuel

To accurately assess the in-pile performance of the accident tolerant fuel (ATF) over the whole life for the light water reactors (LWR), a full coupling of neutronics/thermal-hydraulics/fuel-performance is needed. In this paper, a multiphysics coupling code system named NECP-CLAMPERL is developed based on the high-fidelity neutronics code NECP-X, the sub-channel thermal-hydraulics code CTF, the finite-element fuel performance code NECP-CALF and the multiphysics object-oriented simulation environment (MOOSE). The code system is then applied to evaluate the performance of U₃Si₂ fuel, one of the most promising ATFs, by simulating a typical fuel assembly in pressurized water-cooled reactors (PWR). The quantities of interest including the reactivity, power distribution, fuel temperature, clad stress, fission gas release, plenum pressure, fuel radial displacement, gap width and PCMI are presented and analyzed in comparison with the traditional UO₂ fuel. Future works and other potential applications are also identified.