The development of next-generation molten salt reactors relies on accurate knowledge of the thermophysical properties of the candidate coolant and fueled molten salts. These thermophysical properties include density, viscosity, thermal conductivity, and heat capacity. Because of difficulties in measuring thermophysical properties of molten salts, there are many gaps in the current state of thermophysical property knowledge of these salts, particularly those that contain actinides or beryllium. Therefore, leveraging modeling techniques to estimate unknown molten salt thermophysical properties and guide future experimental measurements has high value for the nuclear industry. In this study, the densities of molten fluoride pseudo-ternary salt systems, which are of interest to the nuclear industry, were estimated using Redlich-Kister expansion and Muggianu interpolation techniques. The pseudo-ternary systems considered for estimation in this study were NaF-LiF-ZrF₄, LiF-BeF₂-ZrF₄, LiF-BeF₂-ThF₄, NaF-LiF-BeF₂, NaF-KF-BeF₂, NaF-ZrF₄-UF₄, and NaF-BeF₂-UF₄. This Redlich-Kister estimation approach accounts for nonideal mixing behavior based on pseudo-binary subsystem interaction parameters determined from experimentally measured pseudo-binary system density data sets. The Redlich-Kister estimation was compared with the method of additive molar volumes, which assumes ideal mixing. The Redlich-Kister approach was also used to determine previously unknown binary and ternary interaction parameters based on experimentally measured density data sets for select pseudo-ternary salt systems. The results of this study show improvement in density estimation using the Redlich-Kister approach for all systems considered compared with estimation by additive molar volumes. Furthermore, this analysis allowed for the estimation of nonideal density behavior in experimentally unstudied ZrF₄-UF₄ and BeF₂-UF₄, as well as the quantification of ternary interaction in NaF-LiF-ZrF₄, NaF-BeF₂-UF₄, and NaF-ZrF₄-UF₄.

下一代熔盐反应堆的开发依赖于对候选冷却剂和燃料熔盐的热物理特性的准确了解。这些热物理性质包括密度、粘度、热导率和热容量。由于熔盐的热物理性质测量困难，这些盐的热物理性质知识目前存在许多空白，特别是那些含有锕系元素或铍的盐。因此，利用建模技术估计未知的熔盐热物理特性并指导未来的实验测量对于核工业具有很高的价值。在这项研究中，核工业感兴趣的熔融氟化物伪三元盐系统的密度，使用 Redlich-Kister 扩展和 Muggianu 插值技术进行估计。本研究中考虑估计的伪三元系统是 NaF-LiF-ZrF₄、LiF-BeF ₂ -ZrF ₄、LiF-BeF ₂ -ThF ₄、NaF-LiF-BeF ₂、NaF-KF-BeF ₂、NaF-ZrF ₄ -UF ₄和NaF-BeF ₂ -UF ₄. 这种 Redlich-Kister 估计方法考虑了基于从实验测量的伪二元系统密度数据集确定的伪二元子系统交互参数的非理想混合行为。Redlich-Kister 估计与假设理想混合的加性摩尔体积方法进行了比较。Redlich-Kister 方法还用于根据选择的伪三元盐系统的实验测量密度数据集确定以前未知的二元和三元相互作用参数。这项研究的结果表明，与通过加性摩尔体积的估计相比，使用 Redlich-Kister 方法对所有考虑的系统进行密度估计有所改进。此外，该分析允许估计未经实验研究的 ZrF _{4中的非理想密度行为}-UF ₄和BeF ₂ -UF ₄，以及NaF-LiF-ZrF ₄、NaF-BeF ₂ -UF ₄和NaF-ZrF ₄ -UF ₄中三元相互作用的量化。