The Energy Department on Monday submitted its plans for closing four single-shell liquid-waste tanks at the Hanford Site near Richland, Wash., the Washington state Department of Ecology confirmed.
DOE was once supposed to deliver the closure schedule by March 30, but the state Department of Ecology and the U.S. Environmental Protection Agency — the two main regulators for cleanup at Hanford — agreed last year to extend the deadline to May 15.
The state agency confirmed it received DOE’s plans on Monday, but did not immediately share a copy of those plans. Ecology did share a May 15 letter from Glyn Trenchard, acting assistant manager of the Tank Farms Project at DOE’s Office of River Protection, to Alexandra Smith, program manager for Ecology’s Nuclear Waste Program, confirming the agency had delivered the plans as scheduled.
The schedule due was to provide closure dates for tanks C-201, C-202, C-203, and C-204: four of the 16 single-shell tanks in Hanford’s C Farm that were were once filled with liquid waste left over from Cold War-era plutonium production. The tanks are empty, as defined in the Tri-Party Agreement that governs Hanford cleanup, but DOE must formally decide how to close the containers. That means either removing the tanks from the site or leaving them where they are but filling them up with grout to prevent them from leaking.
There are 149 single-shell tanks and 28 newer, double-shell tanks at Hanford’s tank farm, which in total contain more than 55 million gallons of liquid waste that will eventually be turned into more easily storable glass canisters in the Waste Treatment Plant that Bechtel National is building at Hanford. The plant must start treating the site’s briny, low-activity waste by 2023 and its sludgy, high-level waste by 2036, a federal judge ruled last year.
