Recycle stream impacts on feed treatment flowsheets and glass formulation for the Hanford Waste Vitrification Plant

The Hanford Waste Vitrification Plant (HWVP) is being designed to vitrify high-level radioactive wastes stored on the Hanford site. The vitrification flowsheet is being developed to assure that low-level effluent streams will be sufficiently low in TRU and gamma activity to allow direct disposal in shallow land burial. To achieve this goal, the process is being designed to separate high activity components from off-gas treatment decontamination waste streams, thereby creating a recycle stream which must be combined with the plant food. The intent of this paper is to consider the impacts of such a recycle stream on glass formulation, melter operability, redox control upsets due to the recycle of nitrates, and the ability of a single composition frit to accommodate shifts in the recycle flowsheet