The U.S. Department of Energy authorized Bechtel to resume engineering work on a facility at the Waste Treatment and Immobilization Plant--a facility that will treat some of the nation's liquid radioactive waste. The resumption comes after progress toward resolving technical matters for the High-Level Waste Vitrification Facility, where the most radioactive of the stored liquid will be processed. The government contracted Bechtel National to build the multi-facility complex at the Hanford Site in southeastern Washington. The plant will turn waste into a stable, solid glass form using a process called vitrification. Some 56 million gallons of radioactive waste await treatment there, stored in 177 underground tanks. The waste is a by-product of plutonium production from the 1940s Manhattan Project through the 1980s.