Application of full-core three-dimensional multi-physics calculation to the EBR-II SHRT-45R benchmark

A full-core three-dimensional multi-physics calculation framework is developed for steady-state and transient analyses of liquid metal reactors. This framework comprises 3 modules: the SPH-corrected multi-group cross-section library module, the neutronics module, and the thermal hydraulics module. In this framework, the multi-group cross-sections are generated using the Monte Carlo code OpenMC and corrected using the SPH factors. The neutronics module uses the MORPHY neutron transport solver and is capable of performing three-dimensional neutronic kinetics simulations. In the thermal hydraulics module, the subchannel code COBRA-YT is modified and enhanced for liquid metal reactor simulations, integrating thermophysical properties and empirical correlations related to liquid metals. The neutronics and thermal hydraulics modules are coupled through the fixed-point iteration scheme. We applied this framework to simulate the unprotected loss of flow test of the Experimental Breeder Reactor II (EBR-II). The simulation results show that the SPH correction significantly improved the k_eff error from 3939 pcm to 26 pcm in the neutronic calculations of the EBR-II core. The root mean square of the assembly power relative errors is 2.04% compared to reference results. For transient simulation, the fission power and temperature results exhibit changing trends consistent with the reference results. The simulation results demonstrate the capability of the constructed multi-physics calculation framework to accurately simulate the transient behaviors of liquid metal reactors.