| Abstract Scope |
Molten salts play a key role in the pyrometallurgical processing of used nuclear fuel, as well as in molten salt reactors, owing to their capability to dissolve actinides and fission products, operate at elevated temperatures, and support electrochemical separations. A detailed understanding of the chemical behavior of species in molten salts, along with the development of reliable in situ measurement techniques, is critical for improving process control, ensuring material compatibility, and maintaining system safety. At the Nuclear Fuel Cycle Group at Seoul National University, our research focuses on the behavior of actinides and fission products in high-temperature molten salt systems, using electrochemical and spectroscopic approaches. This presentation will share recent findings, including: (1) the contrasting dissolution behavior of strontium in chloride- and fluoride-based molten salts, (2) the quantification of trace impurities such as moisture in molten salts, (3) the development of real-time, quantitative laser-induced breakdown spectroscopy (LIBS) for direct measurements in the molten salts, (4) the determination of active electrode area using machine learning approaches, and (5) the measurement of high-concentration uranium through temperature-resolved melting behavior, enabling the identification of uranium content via phase transition profiling. These integrated approaches aim to establish a robust framework for molten salt monitoring and characterization, supporting the advancement of pyroprocessing technologies for used nuclear fuel treatment. |