Evaluation of Phase II glass formulations for vitrification of Hanford Site low-level waste

A vendor glass formulation study was carried out at Pacific Northwest Laboratory (PNL), supporting the Phase I and Phase II melter vendor testing activities for Westinghouse Hanford Company. This study is built upon the LLW glass optimization effort that will be described in a separate report. For Phase I vendor melter testing, six glass formulations were developed at PNL and additional were developed by Phase I vendors. All the doses were characterized in terms of viscosity and chemical durability by the 7-day Product Consistency Test. Twelve Phase II glass formulations (see Tables 3.5 and 3.6) were developed to accommodate 2.5 wt% P{sub 2}O{sub 5} and 1.0 wt% S0{sub 3} without significant processing problems. These levels of P{sub 2}O{sub 5} and SO{sub 3} are expected to be the highest possible concentrations from Hanford Site LLW streams at 25 wt% waste loading in glass. The Phase H compositions formulated were 6 to 23 times more durable than the environmental assessment (EA) glass. They melt within the temperature range of 1160{degrees} to 1410{degrees}C to suit different melting technologies. The composition types include boron-free for volatilization sensitive melters; boron-containing glasses for coId-cap melters; Zr-containing, glasses for enhanced Iong-term durability; and Fe-containing glasses for reducing melting temperature and melt volatility while maintaining chemical durability.