Photochemical separation of plutonium from uranium.

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 4+ → Pu 3+ and UO 2 2+ → U 4+ photoreduction proceeded in HCl (aq) and HNO 3(aq) and (2) photogenerated Pu 3+ (aq) and U 4+ (aq) could be separated using anion exchange chromatography (high yield, >90%; good separation factor, 322).