Development and Pilot Testing of New Flow Diagrams for Plutonium Purification at the RT-1 Plant

To modernize the extraction facility of the RT-1 plant, two flow diagrams for plutonium purification have been developed. In the first flow diagram, the Pu(IV)–Np(IV) valence pair is stabilized and both Pu and Np are stripped and, in the second flow diagram, the Pu(IV)–Np(V) valence pair is stabilized and only Pu is stripped. The problem of stabilizing the pair of the desired components in the required valence state is solved using reagents that had already been used at the RT-1 plant: hydrogen peroxide, hydrazine nitrate, and a catalyst (Fe). Both flow diagrams are adapted to the extraction facility of the plant with minimum changes in equipment and successfully pass extended process tests. As the result of this work, the volume and salt content of the raffinate are reduced.