Sensitivity Study of Thermophysical Properties for LiF-BeF2 and Simulant Oils on a Natural Circulation Loop with MARS Code Implementation

Abstract

Molten salt is a good heat transfer and storage medium for nuclear applications. However, understanding molten salt properties is limited due to its challenging experimental conditions, such as high operating temperature, prevention of high temperature corrosion and toxicity, or large scaled facility. Therefore, simulant heat transfer fluid with scaling law can be used in a lab scale to avoid those challenges. In this paper, sensitivity study of thermophysical properties with simulant oils for LiF-BeF2 (FLiBe) molten salt was performed utilizing MARS code, the thermal-hydraulic safety analysis code. The sensitivity study for major thermophysical properties related to the heat transfer performance (density, thermal conductivity, viscosity, heat capacity) was performed with simulant oils (DOWTHERM RP and DOWTHERM A) to compare the tendency of the sensitivity effect on the mass flow rate in the natural circulation condition. For the MARS code simulation with FLiBe and simulant oils, their thermophysical properties were implemented into MARS code. The sensitivity effect of simulant oils was similar with those of FLiBe enough to be scaled.