Coupled neutronics and thermal-hydraulics simulation of molten salt reactors based on OpenMC/TANSY

•Two-step scheme for simulation of MSRs based on OpenMC/OpenFOAM.•Accurate geometry modeling capability for both cross sections generation and full-core simulation.•Development of a multi-region and multi-physics code for MSRs based on OpenFOAM.•Calculation and analysis of safety-related parameter βeff and critical fuel concentration.