Numerical Simulation Of The Operational Characteristics Of The Nitrate Salt Natural Circulation Loop

Molten salt reactor is one of the six Generation IV advanced reactor concepts thathas good economy, safety, sustainability and nuclear nonproliferation features. Moltensalt reactor adopts passive residual heat removal system based on natural circulations.Fluoride salt-cooled high-temperature reactor (FHR) is one kind of the molten saltreactors. It uses the direct reactor auxiliary cooling system (DRACS) for the passiveresidual heat removal. The DRACS uses atmosphere as the ultimate heat sink. Ittransfers the heat from the primary loop to the natural circulation loop, and eventuallyto the atmosphere via the salt-air heat exchanger. In order to study the flow and heattransfer characteristics of the DRACS, and to understand the issues of standby, startupand operation of the DRACS, Shanghai Institute of Applied Physics (SINAP) has builta nitrate salt natural circulation test loop to conduct experiments.This thesis is based on the test loop that has already been designed and constructedat SINAP. We calculated the heat transfer coefficients of the heat exchangers, the flowresistance of the loop, and analyzed the transients of the loop by using CFD softwareFLUENT and system analysis software RELAP5. The results of our work may be usedto compare with experimental data from the loop, to guide the experiments and toimprove the design of the DRACS.