PNNL

Abstract

This contribution addresses various aspects of nuclear waste vitrification. Composition of nuclear wastes varies in the number of components and their composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee that the glass is easily made and resists environmental degradation. Glass formulation is facilitated by developing property-composition models. The strategy of model development and application is reviewed. However, the large variability of waste composition presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slows down the process; molten salts may accumulate in container refractory walls; on cooling, the glass may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.