In southeastern Washington state, Bechtel is designing, constructing, and commissioning the world’s largest radioactive-waste treatment plant for the U.S. Department of Energy (DOE). When complete, the Hanford Tank Waste Treatment and Immobilization Plant will process and stabilize 53 million gallons (200 million liters) of radioactive and chemical waste currently stored at the Hanford Site.
The waste, a byproduct of plutonium-production during World War II and the Cold War era, is in 177 aging underground tanks. More than one-third of them have leaked, contaminating the subsurface and threatening the nearby Columbia River.
The $12.2 billion project will use vitrification technology, blending the waste with glass-forming materials and heating it to 2,100 degrees Fahrenheit (1,149 degrees Celsius). The mixture is then poured into stainless steel canisters to cool and solidify. In this glass form, the waste is stable and impervious to the environment and safe for long-term storage.
The project is the largest undertaking of its kind ever and one of DOE’s most technically challenging cleanup projects—equivalent to building two nuclear power plants. Its construction site spans 65 acres (26 hectares) and includes facilities for pretreatment, low-activity waste vitrification, and high-level waste vitrification, as well as an analytical laboratory.
Construction began in October 2001, and in August 2011, the plant was 60 percent complete.