Coupled neutronics/thermal-hydraulics for analysis of molten salt reactor

The Generation IV International Forum (GIF) selected molten salt reactor (MSR) among six advanced reactor types. It is characterized by a liquid circulating fuel that also serves as coolant. In this study, a multiple-channel analysis code (MAC) is developed and it is coupled with MCNP4c to analyze the neutronics/thermal-hydraulics behavior of molten salt reactor experiment (MSRE). The MAC calculates thermal-hydraulic parameters, such as temperature distribution, flow distribution and pressure drop. MCNP4c performs the analysis of effective multiplication factor, neutron flux and power distribution. A linkage code is developed to exchange data between MAC and MCNP to implement coupling iteration process until the power convergence is achieved. The coupling calculation can achieve converged solution after a few iterations. The results are in reasonable agreement with the analytic solutions from the ORNL. For further design analysis, parametric studies are performed to provide valuable information for new design of MSR. The effect of inlet temperature, graphite to molten salt volume ratio (G/Ms) from varying channel diameter and different power levels on the effective multiplication factor, neutron flux, graphite lifetime and temperature distribution are discussed in detail.

► A multiple-channel analysis code (MAC) is developed to be coupled with MCNP.
► 1/8 of core is simulated in MCNP and thermal-hydraulic code.
► The coupling calculation can achieve stable state after a few iterations.
► The coupling calculation results are in reasonable agreement with the analytic solutions of the ORNL.
► Parametric studies of MSR are performed to provide valuable information for future design MSR.