Separation of Americium, Curium, and Plutonium from Irradiated Targets

The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL) processes highly irradiated targets for the Mark 42 program to separate Am, Cm, and Pu. The target feed material for each assembly was 3.3 kg of plutonium (78% 239 Pu) that was irradiated at the Savannah River Site to yield approximately 100 g each of 243 Am and 244 Cm, and 100-g quantities of 242 Pu for special DOE projects. The REDC has plans to process ten of these target assemblies over the next few years. The first assembly has been dissolved, and approximately 1/4 of this material has been used to test the processing flowsheet. Various aqueous processes developed at the REDC over the past years were utilized to dissolve the target segments, separate the bulk of the impurities from the transuranics, separate the plutonium from the transplutonium actinides, and separate the rare earth fission products from the Am-Cm. The separation of the Am-Cm products to the desired purity levels presented new processing challenges for REDC operations. Through a combination of precipitation and cation-exchange operations, an Am product containing part-per-million levels of Cm was obtained. Standard REDC processing techniques were used to prepare the products as oxides for shipment. Future processing will focus on the reduction of waste solutions, improvement of yields, and application of new technologies for improved processing.