Real-Time Quantification of Contaminants in Molten Salts via Aerosol Formation and Laser-Induced Breakdown Spectroscopy

The detection and quantification of trace (parts per million–level) contaminants (such as corrosion species or fission products) in molten salts in real time can be accomplished using aerosol formation and laser-induced breakdown spectroscopy (LIBS). Molten salts have applications in pyroprocessing of spent nuclear fuel, as energy efficient heat-transfer fluids, and as liquid fuel in advanced molten salt reactors. Online monitoring of molten salt composition is critical to the safe and effective implementation of molten salts for nuclear energy applications; however, there is a gap in the current methods available to address this problem. The main challenges in analysis of molten salts are the high temperature, corrosivity, and radioactivity of these materials and their associated environments. These challenges can be mitigated by analyzing frozen aerosols produced from the molten salt and diluting these aerosols in an inert gas stream. This gas stream can transport these aerosols to an isolated LIBS sensor that can determine the elemental composition of the salt and quantify trace contaminants. This lightning talk will discuss the advantages of this approach for monitoring the composition of molten salts, and limits of detection for representative analytes will be presented.