Formation of β-UO from UCl Salt Compositions under Oxygen Exposure.

Complementary X-ray absorption fine structure (XAFS) and Raman spectroscopy studies were conducted on various UCl concentrations in alkali chloride salt compositions. The samples were 5 mol % UCl in LiCl (S1), 5 mol % UCl in KCl (S2), 5 mol % UCl in LiCl-KCl eutectic (S4), 50 mol % UCl in KCl (S5), and 20 mol % UCl in KCl (S6) molar concentrations. Samples were heated to 800 °C and allowed to cool to room temperature with measurements performed at selected temperatures; the highest temperatures showed the most stability and will be primarily referenced for conclusions.

Identification and Decomposition of Uranium Oxychloride Phases in Oxygen-Exposed UCl Salt Compositions.

Complementary X-ray absorption fine structure (XAFS) spectroscopy and Raman spectroscopy studies were conducted on several UCl concentrations in several chloride salt compositions. The samples were 5% UCl in LiCl (S1), 5% UCl in KCl (S2), 5% UCl in LiCl-KCl eutectic (S3), 5% UCl in LiCl-KCl eutectic (S4), 50% UCl in KCl (S5), and 20% UCl in KCl (S6) molar concentrations. Sample S3 had UCl sourced from Idaho National Laboratory (INL), and all other samples were UCl sourced from TerraPower.

Determination of Speciation and Local Structure of NaCl-SrCl and LiF-ZrF Molten Salts.

Understanding the local environment of the metal atoms in salt melts is important for modeling the properties of melts and predicting their behavior and thus helping enable the development of technologies such as molten salt reactors and solar-thermal power systems and new approaches to recycling rare-earth metals. Toward that end, we have developed an approach for measuring the coordination of metals in molten salt coupling X-ray absorption spectroscopy (XAS) and Raman spectroscopy. Our approach was demonstrated for two salt mixtures (1.