Plutonium host phases derived from high-level waste at the Idaho Chemical Processing Plant

The National Academy of Sciences recommended dissolution in a silicate matrix, with fission products to provide a protective radiation field, as one option for dispositioning excess weapons-grade plutonium. Candidate materials and processing conditions have been developed to pursue this option using high-level waste stored at the Idaho Chemical Processing Plant. Devitrification of glassy host materials achieves increased plutonium loading by partitioning plutonium into durable crystalline host phases. Results of devitrification experiments are summarized, and several unique plutonium host phases are reported. These phases were initially synthesized and characterized using cerium as a plutonium surrogate, to simplify operational requirements. Tests using plutonium were performed to validate results obtained with surrogate materials. Characterization and leach test results are reported.