Coupled Thermal-Hydraulics and Neutronics Simulation using Sub-Channel CFD and SERPENT

Abstract

The novel coarse-mesh CFD tool Subchannel-CFD (SubChCFD) is coupled with the Monte Carlo neutron transport code SERPENT using a segregated multi-physics coupling algorithm. The multi-physics model is used to simulate a soluble-boron-free small modular reactor assembly from the design proposed by Alzaben et al. The coupled solution is found to converge within 4 iterations, with successive keff values of within 20 pcm. The final coupled SubChCFD solution shows good agreement with a full-scale CFD model from the CFD software STAR-CCM+, with the exception of a small gap region between two oversized control rod guide tube and burnable poison rods, which induces a periodic flow instability that SubChCFD is unable to model.