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Plutonium-based technologies would benefit if chemical hazards for purifying plutonium were reduced. One critical processing step where improvements could be impactful is the adjustment of plutonium oxidation-states during separations. This transformation often requires addition of redox agents. Unfortunately, many of the redox agents used previously cannot be used today because their properties are deemed incompatible with modern day processing facilities and waste stream safety requirements. We demonstrated herein that photochemistry can be used as an alternative to those chemical agents. We observed that (1) Pu

Molten salts have found use as solvents in numerous applications including nuclear reactors, batteries, and the extraction and purification of various metals. Unfortunately, understanding of the chemistry of molten salt solutions is limited. In this presentation we explore the use of molten salts as a testbed for understanding both outer and inner coordination sphere effects on dissolved metal ions. The electron transfer reactions available to lanthanides (Eu3+, Sm3+, and Yb3+) and actinides (U3+, U4+, and Th4+) were explored in a series of alkali and alkaline earth halide salts. We present electrochemical data that demonstrate significant shifts in the reduction potentials of these metal ions as a function of the anion and cation identities of the molten salt solvent. We hypothesize that effects on the reduction potential of these metals come from two sources: (1) the primary coordination sphere and (2) the secondary coordination sphere. The influence from the primary coordination sphere is dominated by the degree of covalency in the coordination bonds between the Lnn+ and Ann+ cations and the molten salt anions. The influence of the secondary coordination sphere is dominated by the electron-withdrawing character of the salt cations. EXAFS data and computational results that support these hypotheses are presented. Further, we provide insight into electrodeposition of the An0 metals under these conditions and highlight temperature and molten salt effects that influence these electrodepositions. Specifically, we propose that increased mobility of solid-state atoms at high temperature (> 800°C) influence the properties of electrodeposited metals.