Electrochemical recovery of plutonium from aqueous carbonate waste solutions

Abstract

Recovery of plutonium from aqueous carbonate waste solutions generated during the reprocessing of spent nuclear fuel is a key concern for sustainable nuclear energy programmes and the remediation of radioactive waste. Reported methods proceed through secondary waste generation caused by acidification of carbonate waste and make the recovery process cumbersome. Herein, we report a simple method for the recovery of Pu as solid PuO₂ powder from carbonate waste solution in a two-step process. (i) Pu was selectively electrochemically precipitated as plutonium-hydroxide in the presence of interfering U, Th, Ru, Zr, Nb, Cs and the degradation products of tri-butyl phosphate by bulk electrolysis at −0.9 V using a Pt gauze electrode and (ii) the precipitate was annealed at 973 K for conversion to pure PuO₂ powder. The present approach is simple, avoids the generation of secondary waste and reduces the exposure of working personnel to radiation.