Study of Neutronics and Thermal-hydraulics Coupling with RMC/COBRA-EN System

Abstract

Neutronics and Thermal-hydraulics (N-TH) coupling plays an important role in high fidelity multi-physics simulation for nuclear reactor analysis. A coupled N-TH code system based on a continuous-energy Monte Carlo code RMC and the sub-channel code COBRA-EN has been developed. The temperature dependence of nuclear cross sections is handled with the Fast Doppler Broadening (FDB) capability embedded in RMC. This code system has been applied to a PWR fuel pin and a fuel assembly to investigate the effects of N-TH coupling and Doppler broadening. The results show that the coupling system with Doppler broadening is effective for the thermal-hydraulics feedback.