Precipitation Of Plutonium(IV) Oxalate

The plutonium(III) oxalate precipitation process was developed at Los Alamos for the final plutonium purification step prior to the dry chemistry and metal reduction operations. As originated the process employed hydriodic acid for the reduction of plutoniuni(IV-VI) to the plutonium(III) state. However, the corrosiveness and cost of the hydriodic acid made its replacement desirable, and experimental programs pointed toward the development of alternate procedures were carried out at Los Alamos and at Hanford. The precipitation of plutonium peroxide was substituted for the plutonium(III) oxalate process at Los Alamos and was tested at Hanford When it was found that ei ther an alcohol wash or a slow, drying step was needed to prepare the peroxide for hydrofluorination, attention at Hanford was turned to the precipitation of plutonium(IV) oxalate. Work on the latter compound had been done by Brown and Reas, who showed that hydrogen peroxide could be used for the plutonium valence adjustment. The subsequent work in the 234-5 Development Laboratory is described in this report. It was done to find the best conditions for the precipitation of plutonium(IV) oxalate and to prove that the process could be used as the final step in the purification of plutonium.