Vendor glass durability study during evaluation of melter system technologies for vitrification of Hanford low-level wastes

The low level radioactive wastes (LLW) separated from the single-shell tanks and double-shell tanks at the Hanford Site will be immobilized into glass. A melter system technology testing, and evaluation program is being conducted to identify the demonstration, best overall melter system technology available to vitrify the Hanford LLW streams. The melter technologies being demonstrated use a variety of heating methods to melt the glass, including plasma torch, fossil-fuel-fired cyclone burner, carbon arc and joule-heating. The Phase I testing is a {open_quotes}proof of principle{close_quotes} test to demonstrate that a melter system technology can process a simulated highly alkaline, high nitrate/nitrite content LLW feed and produce a glass product of consistent quality. Target waste oxide loading of LLW simulant was specified to be about 25 wt%. Pacific Northwest Laboratory (PNL) is providing glass formulation support for this program. The five candidate vendor glasses at 20 wt% Na{sub 2}O level provided by PNL are alumino-borosilicate and aluminosilicate glasses with melting points around 1300{degrees}. Glasses adopted by vendors were tested at PNL to verify the required properties. The testing included durability evaluation through product consistency test, MCC-1 tests, and flow through tests and viscosity measurements.