Thermophysics Imaging of Molten Actinide/Alkali Salts

January 31, 2023
Thermophysics Imaging of Molten Actinide/Alkali Salts
Grey scale neutron radiograph (left) of UCl3-NaCl-KCl salt at final temperature 800 °C. Extracted neutron transmission profiles (right) for this sample as function of temperature (yellow to blue sequence of traces). Inhomogeneities in neutron transmission, likely caused by voids, persist below 750 °C. Vertical axis units are detector pixel numbers with pixel size equaling 42.7 µm.

Scientific Achievement

Accurate density profiles were obtained in molten sodium, magnesium, potassium, and uranium chloride salt mixtures as function of temperature, revealing the formation of voids and surface wetting of the quartz tube containment.

Significance and Impact

The work establishes neutron radiography as viable method for accurately determining density profiles in actinide/alkali halide blends, which is essential for understanding thermophysical properties in molten salt nuclear reactors and third generation solar energy storage.

Research Details

  • Measured densities of single salts and binary blends are in good agreement with estimates from Redlich-Kister modeling.
  • UCl3−NaCl−KCl ternary mixture deviates from model estimate and suggests void formation.
  • The radiographs also provide contact angles, quantifying molten salt wetting of the quartz containment.

“Density Measurements of Various Molten Sodium, Magnesium, Potassium, and Uranium Chloride Salt Compositions Using Neutron Imaging”
Jisue Moon, Hunter Andrews, Can Agca, Jean-Christophe Bilheux, Alexander Braatz, Abbey McAlister, Joanna McFarlane, Jake McMurray, Kevin Robb, and Yuxuan Zhang,
Industrial & Engineering Chemistry Research 61, 17665–17673 (2022). DOI: