By Suzanne Dahl, Tank Waste Treatment manager, Nuclear Waste Program
For the last 16 years, Washingtonians have expected that Hanford’s low-activity waste will be immobilized in glass (vitrified). The 2010 settlement agreement between the Tri-Party agencies also requires vitrification of some type. This stable waste form is so important to us because low-activity waste is destined to stay onsite in a landfill—above the groundwater that feeds the Columbia River. Vitrified glass is proven to successfully capture the contaminants and protect human health and the environment. For these reasons, I believe this is the best solution for low-activity waste disposal at Hanford.
The U.S. Department of Energy (USDOE) is considering a new technology called steam reforming to treat a portion of the low-activity waste. Steam reforming uses super-heated steam and charcoal to bind liquid radioactive wastes into clay. USDOE hopes the process will save money.
Although steam reforming is used commercially and is planned at USDOE’s Idaho site, neither of these scenarios compare to Hanford. Commercial processes don’t produce mineral waste, as is proposed for Hanford, and Idaho’s steam reforming non-mineral waste will go to a deep geologic repository, not an onsite landfill.
Between 2003 and 2006, USDOE tested a variety of other waste forms. Ultimately, nothing proved to be as durable and protective as glass, and none of the technologies were cheaper or faster. All of the options considered would cost as much and have similar implementation schedules as vitrification.
In the news recently, USDOE admitted they would abandon the idea if it could not be proven in the next 1 to 3 years. We question the ability to complete all the necessary testing and demonstrate that it is as protective a waste form as vitrified glass in 3 years.
Let’s keep our commitment to glass for the waste staying in Washington. Continuing to look at new technology is important, but, with limited resources, we should focus on solutions for existing problems, perhaps exploring melter technologies or vitrification advancements.