Impacts of constraints and uncertainties on projected amount of Hanford low-activity waste glasses

Abstract

A systematic evaluation of Hanford low-activity waste (LAW) loading in alkali-aluminoborosilicate glasses was performed. A set of 22 waste compositions were selected to represent the range of wastes anticipated across the Hanford mission. Glass composition was formulated for each waste to simultaneously satisfy a full cadre of property and composition constraints while maximizing waste loading. Glass properties were estimated using property models recently developed for Hanford LAW Facility operation. The impacts from the property and composition constraints on the glass mass to be produced were calculated and compared. Electrical conductivity, Vapor Hydration Test and SO3 melter tolerance, and canister-centerline cooling crystal constraints have a large effect on reducing total glass mass, while the impacts from Product Consistency Test, viscosity, and isothermal crystal constraints are relatively small. Additionally, effects of model prediction and process/composition uncertainties were quantified. The results identified areas of future research that could be useful to improve the efficiency of plant operation.