(263b) Hanford Hlw Sludge Processing in Crossflow Filtration

The Pretreatment Facility is the first step in the process of vitrifying Hanford’s tank waste. Filtration, washing and/or caustic leaching to pretreat the Hanford sludge is required before it undergoes high-level waste (HLW) vitrification. Samples of actual Hanford tank waste sludge were evaluated by the pretreatment processes of crossflow filtration, washing, caustic leaching, and rinsing. Filtration of the waste is necessary to remove components such as aluminum, chromium, sodium, and phosphorus that are soluble in water and often limit the waste loading in the glass. Data collected at 5 M Na and 20 ºC demonstrated flux increases dramatically with washing. Additionally, relationships between Na molarity, viscosity, and solids loading impacts on filter performance were used to develop an empirical fit that represents real waste testing as a function of the gel concentration