Processing of Mark-42 Target Materials for Recovery of Americium and Curium

Heavy actinides have a number of research and development applications. For example, californium-252 (Cf-252) is a radioactive neutron source with widespread industrial applications. Heavy elements are produced in high-flux reactors using unique and irreplaceable heavy curium (Cm) feedstock, which was produced by long-term irradiation of plutonium (Pu) in a high-flux reactor at the Savannah River Site (SRS). Oak Ridge National Laboratory (ORNL) is developing plans to recover Cm and americium (Am) from Mark-42 (Mk-42) target materials as feedstock for heavy actinide production and is testing improved flow sheets for the recovery process. The objective of this work is to identify the most effective flow sheet with which to process stored Am/Cm/Ln (lanthanide) oxides to recover and purify the Am/Cm for future heavy actinide production. This paper describes a proposed processing plan for recovering the Am/Cm from Mk-42 materials and summarizes the results of a series of small processing runs being conducted at ORNL to demonstrate an optimized process for separation of Ln fission products from the Am/Cm elements.