Development of Subchannel Code SUBSC for high-fidelity multi-physics coupling application

Abstract PWR core phenomena can be simulated and predicted more precisely and in more details with high-fidelity neutronics and thermal-hydraulics coupling calculation. An in-house subchannel code SUBSC was developed as the thermal-hydraulics solver. The steady-state bundle benchmark of PSBT benchmark was calculated to validate SUBSC; the results showed that the channel-averaged quality provided by SUBSC agreed well with the measured data at various conditions. Then a coupling code written in python language was employed to couple SUBSC and the Monte Carlo code OpenMC. The coupling code SUBSC/OpenMC was applied for a typical PWR 3x3 pin cluster coupling calculation. The numerical results demonstrated that the subchannel code SUBSC developed in this paper is applicable for high-fidelity coupling calculation.