CURRENT ANSTO RESEARCH ON WASTEFORM DEVELOPMENT

Current ANSTO scientific research on wasteform development for mainly high-level radioactive waste is directed towards practical applications. Titanate wasteform products we have developed or are developing are aimed at immobilization of: (a) tank wastes and sludges; (b) U-rich wastes from radioisotope production from reactor irradiation of UO2 targets; (c) Al-rich wastes arising from reprocessing of Al-clad fuels; (d) 99Tc; (e) high- Mo wastes arising from reprocessing of U-Mo fuels and (f) partitioned Cs-rich wastes. Other wasteforms include encapsulated zeolites or silica/alumina beads for immobilization of 129I. Wasteform production techniques cover hot isostatic and uniaxial pressing, sintering, and cold-crucible melting. In addition, building on previous work on speciation and leach resistance of Cs in cementitious products, we are studying geopolymers. Although we have a strong focus on candidate wasteforms for actual wastes, we have a considerable program directed at basic understanding of the wasteforms in regard to crystal chemistry, their dissolution behavior in aqueous media, radiation damage effects and processing techniques