The successful development of advanced Molten Salt Reactors (MSRs) heavily relies on our understanding of the detailed structure of chloride molten salts, enabling us to predict the behavior of the melt in the presence of fission and corrosion products. Chromium (Cr) is the most reactive element in nuclear MSRs, yet its solvation structure in the highly ionic medium is unknown. Our research seeks to provide atomic-level insights into the solvation shell structure around Cr3+ metal ion in molten MgCl2-KCl salt by applying synchrotron X-ray scattering and ab-initio molecular dynamics simulations. Our analysis shows the existence of well-defined outer solvation shells extending beyond the immediate coordination environment of Cr3+. The addition of a small amount of the highly charged Cr3+ metal ion in MgCl2-KCl salt changes the local structure of the melt, restructuring constituent ions around it. This finding is expected to improve our understanding of metal ion solvation in inorganic molten salts and may potentially have implications for liquid-fueled nuclear reactors, since the structure of Cr corrosion products influences the macroscopic properties of molten salts used as coolants and solvation medium for actinide fuel salts.

Atomic insights into metal ion solvation structure in molten chloride salts through high-energy X-ray scattering

ACS Fall 2020 Virtual Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.