Evaluation of Salt Coolants for Reactor Applications

Molten fluorides were initially developed for use in the nuclear industry as the high-temperature fluid fuel for the Molten Salt Reactor (MSR). The U.S. Department of Energy Office of Nuclear Energy is exploring the use of molten salts as primary and secondary coolants in a new generation of solid-fueled, thermal-spectrum, high-temperature reactors. This paper provides a review of relevant properties for use in evaluation and ranking of salt coolants for high-temperature reactors. Nuclear, physical, and chemical properties were reviewed, and metrics for evaluation are recommended. Chemical properties of the salt were examined to identify factors that affect materials compatibility (i.e., corrosion). Some preliminary consideration of economic factors for the candidate salts is also presented.