Measurements of the liquidus surface and solidus transitions of the NaCl–UCl3 and NaCl–UCl3–CeCl3 phase diagrams

Abstract

NaCl–UCl3–PuCl3 is proposed as the fuel salt for a number of molten salt reactor concepts. No experimental data exists for the ternary system, and limited data is available for the binary compositions of this salt system. Differential scanning calorimetry is used in this study to examine the liquidus surface and solidus transition of a surrogate fuel-salt (NaCl–UCl3–CeCl3) and to reinvestigate the NaCl–UCl3 eutectic phase diagram. The results of this study show good agreement with previously reported data for the pure salt compounds used (NaCl, UCl3, and CeCl3) as well as for the eutectic points for the NaCl–UCl3 and NaCl–CeCl3 binary systems. The NaCl–UCl3 liquidus surface produced in this study predicts a 30–40 °C increase on the NaCl-rich side of the binary phase diagram. The increase in liquidus temperature could prove significant to molten salt reactor modeling.