For more than 40 years, facilities at the Hanford Site produced plutonium
critical to the nation’s defense during World War II and throughout the Cold War. This effort resulted in the production of 56 million gallons of radioactive and chemical wastes, which are currently stored in 177 underground tanks. The tanks range in capacity from 55,000 gallons to over one million gallons.
The tank waste is a complex and diverse combination of radioactive and chemical waste that takes the physical form of sludges, salts and liquids with varying combinations of chemical properties. Much of the waste is stored in 149 aging single-shell tanks, first constructed in the mid 1940’s. The remainder is stored in 28 double-shell tanks of newer construction. DOE has minimized the risk of waste leaking from the 149 single-shell tanks by removing pumpable liquids and transferring those liquids to the double-shell tanks. To date, DOE has retrieved the solid waste from 14 of the single shell-tanks and work continues on retrieving the waste from three additional tanks.
DOE is working toward the ultimate solution of treating and immobilizing the tank waste for permanent disposition. The Waste Treatment and Immobilization Plant (WTP) is a key component of that effort. It will allow for vitrification of radioactive waste, which means turning the tank waste into a solid glass form for disposal.