Photochemical separation of plutonium from uranium

Abstract

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) Pu⁴⁺ → Pu³⁺ and UO₂²⁺ → U⁴⁺ photoreduction proceeded in HCl_(aq) and HNO_3(aq) and (2) photogenerated Pu³⁺_(aq) and U⁴⁺_(aq) could be separated using anion exchange chromatography (high yield, >90%; good separation factor, 322).