Nuclear waste glass composition limitations

This paper discusses the primary considerations involved in nuclear waste glass composition development, explains why the maximum content of certain elements in those glasses is limited, and suggests some possible improvements in reprocessing and waste management practices that might reduce vitrification costs. The basic task is to formulate a glass that can be processed with an acceptably high waste loading and the best possible chemical durability. Problems encountered when certain elements are introduced at higher than acceptable levels include formation of crystalline sludges on the melter floor, increased off-gas system corrosion, and decreased product chemical durability. It is concluded that design decisions that result in reduced amounts of corrosion products and certain soluble neutron poisons, separations process chemicals, and waste handling chemicals in high-level waste (HLW) would, if feasible, reduce vitrification costs. 21 references, 6 figures, 2 tables