In Purex process modifications, two cold runs with mixer-settlers were made on the extraction and stripping of ruthenium and zirconium without the presence of uranium. Efforts in actinide recovery from solids were directed toward the determination of dissolution parameters in various reagents for /sup 241/Am and /sup 239/Pu oxide mixtures, /sup 233/U oxide, /sup 237/Np oxide, /sup 244/Cm oxide, /sup 232/Th oxide, and PuO/sub 2/. Studies in americium-curium recovery with OPIX (oxalate precipitation and ion exchange), Talspeak, and cation exchange chromatography focused on the feasibility of forming oxalate precipitates in continuous systems, the effects of zirconium on Talspeak, and methods for removing solvent degradation products of the Talspeak system. In studies of americium-curium recovery using bidentate extractants, additional distribution coefficients for actinides and other key elements between reduced synthetic LWR waste solution and 30 percent dihexyl-N, N-diethyl-carbamylmethylene phosphonate in diisopropylbenzene were measured. Studies in the americium-curium recovery using inorganic ion exchange media to determine the pH dependence of lanthanide ion affinity for niobate, titanate, and zirconate ion exchange materials have been completed. A modified flowsheet for the extraction of uranium, neptunium, plutonium, americium, and curium from high-level liquid waste is presented. Evaluation of methods for measuring actinides from incinerator ash is continuing. A preliminary evaluation of methods for treatment of salt waste and waste waters was completed. In thermal reactor transmutation studies, waste actinides from an LWR lattice containing mixed uranium-plutonium assemblies were recycled in separate target assemblies. (LK)
