“…a À C, a À T, and a À L are the thermal diffusivities obtained from the combined model, three layered model, and literature, respectively. The thermal conductivity, an important parameter, was studied by many researchers for FLiNaK molten salt [24,27,[29][30][31][32][33][34][35]. For example, Janz et al [29] compiles physical properties of different salt systems, and reported the thermal conductivity of FLiNaK molten salt was 2.97-4.43 W/(m K) in the range of 800-920 K by the modified parallel plate method, and the uncertainty was about ±25%.…”