Multiphysics Coupling of PROTEUS-NODAL and SAM for Molten Salt Reactor Simulation

Abstract

Verification tests of the coupled system of PROTEUS-NODAL and SAM were performed using the steady state and transient problems derived from the MSFR benchmark problem. Since the radial crossflow is neglected in the current SAM model, the effect of this simplification was first examined by comparing the steady state results with those obtained by a manually coupled calculation of PROTEUS-NODAL and ANSYS CFX. The SAM calculation used four parallel axial channels and CFX performed the full 3D CFD calculation in the cylindrical geometry of the MSFR core. Due to the neglect of the radial velocity field in the SAM calculation, SAM underestimated the axial velocity at the core center slightly, and this resulted in a slightly top-skewed power distribution: 0.1% overestimation in the upper part and 0.2% underestimation in the lower part of the core. The UTOP, ULOF, and ULOHS accidents of the MSFR transient benchmark were analyzed by including the outer loop in the SAM model. The results were compared with the PSI solutions from a coupled PARCS and TRACE calculation and the TUDelft solutions obtained from a coupled neutron diffusion and CFD calculation. In general, the power and core-averaged fuel temperature solutions of the coupled PROTEUS-NODAL and SAM calculations agreed well with the other solutions.