Property Measurements of NaCl-UCl₃ and NaCl-KCl-UCl₃ Molten Salts (Rev.1)

Technical Report · Fri May 26 04:00:00 EDT 2023

DOI:https://doi.org/10.2172/1985295· OSTI ID:1985295

Rose, M. A. ^[1]; Gardner, L. D. ^[1]; Lichtenstein, T. T. ^[1]; Thomas, S. A. ^[1]; Wu, E. ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)

Thermochemical and thermophysical property values of several salt compositions of interest are needed by molten salt reactor (MSR) developers to design, license, and operate their reactors. Thermochemical and thermophysical properties being measured at Argonne include thermal transitions, phase behavior, heat capacity, density, volumetric thermal expansion of the liquid phase, thermal diffusivity, thermal conductivity, and viscosity. Several properties of eutectic compositions in the ternary NaCl-KCl-UCl₃ and binary NaCl-UCl₃ systems that may be used by MSR developers as fuel bearing salts are being measured. A 65.8 mol % NaCl–34.2 mol % UCl₃ mixture and a near-eutectic mixture of 50.9 mol % NaCl–24.4 mol % KCl–24.7 mol % UCl₃ were synthesized and the thermochemical properties of the mixtures were measured by using differential scanning calorimetry (DSC). The measured transition temperatures were compared to transition temperatures predicted using two models. A thermodynamic model of the binary NaCl-UCl₃ system was constructed using data in the Molten Salt Thermal Properties Database–Thermochemical Version 2.0 (MSTDB-TC V2.0). A ternary NaClKCl-UCl₃ system model constructed at Argonne and was described in a previous report. These comparisons can be used to validate the models. Thermophysical property values of molten salts are needed to model how salt retains and transfers heat in an MSR system. These property values are essential to the entire MSR design because molten salt is used as both the fuel and the coolant material in a salt fueled reactor. Heat capacity of the synthesized NaCl-UCl₃ and NaCl-KCl-UCl₃ salt mixtures was measured by using DSC and thermal diffusivity was measured by using laser flash analysis (LFA) at temperatures spanning the typical operating range of an MSR.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1985295
• Report Number(s): ANL/CFCT--22/45-Rev.1; 182815
• Country of Publication: United States
• Language: English

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