FLiNaK salt was researched heavily during the late 1950s by Oak Ridge National Laboratory as potential candidate for a coolant in the molten salt reactor because of its low melting point, its high heat capacity, and its chemical stability at high temperatures. Ultimately, its sister salt, FLiBe, was  chosen as the solvent salt for the molten salt reactor due to a more desirable nuclear cross section.  FLiNaK still gathers interest as an intermediate coolant for a high-temperature molten salt reactor where it could transfer heat without being in the presence of the fuel.