Investigation of Normal and Abnormal States of the Molten Salt Experimental Loop Using Computational Fluid Dynamics

The Experimental Molten FLiBe Salt Loop (MSL), which was previously damaged during operation, is currently undergoing renovation using a risk-based design approach. An important part of this approach is to reliably define and explore normal and abnormal states of the MSL in order to avoid repeating such failures. A numerical model consisting of heated walls and working fluid volume was created for the ANSYS Fluent code. The quality of this model was checked, and sensitivity analysis for mesh quality was performed. Moreover, another sensitivity analysis was performed for the heat transfer coefficient between the insulation and the surrounding air. A number of different normal and abnormal states were identified, investigated, and described, including the loop filling process, regular operation with natural circulation or forced circulation, heating cutoff without draining, and insulation failure. The results of these investigations will be used for the risk-based design of the MSL renovation; for precise establishment of operation and safety limits, conditions, rules, and procedures before the MSL commissioning; and consequently, on a regular basis, for the risk-based operation, experiments, and maintenance of the MSL.