Density Measurements of Molten Salts

The present study focused on the development of a method to measure the density of molten salt. The method was validated by measuring densities of molten LiF-ThF₄ and LiF-ThF₄-UF₄ salts and comparing them with ideal-mixture calculations and reference data. For LiF-ThF₄, densities obtained in this study showed deviations less than 3% from the previously reported densities and the calculated values obtained using the ideal-mixture formula. For LiF-ThF₄-UF₄, deviations from ideal-mixture calculations were within 3%. Densities of a molten NaF-KF-UF₄ and a molten NaF-BeF₂-UF₄-ZrF₄ were also measured from 813 to 1173 and 838 to 1073 K, respectively. The measured values of these salts showed less than 2% deviations from the ideal-mixture values. In addition, the measured densities of the NaF-KF-UF₄ and NaF-BeF₂-UF₄-ZrF₄ salts showed similar trends to the density-temperature correlations of NaF-KF-UF₄ and NaF-BeF₂-UF₄ salts, respectively, with similar compositions reported by previous studies.