DOE contractor CPCCo recently completed construction of a protective cocoon over the former K East Reactor building at Hanford. (Photo: DOE)
The Department of Energy’s Office of Environmental Management (EM) announced that construction of Hanford’s K East Reactor cocoon has been completed ahead of schedule and under budget. Cocooning of K East—enclosing it in a protective steel structure while the reactor’s radioactivity naturally decays—was one of EM’s key construction priorities for 2022.
K East, which operated from 1955 to 1971, is the seventh of nine former plutonium production reactors to be cocooned at the Hanford Site near Richland, Wash. The nearby K West Reactor will be the eighth. The ninth, the B Reactor, has been preserved as the world’s first full-scale plutonium production reactor and is part of the Manhattan Project National Historical Park.
Year-long project: Workers with EM contractor Central Plateau Cleanup Company (CPCCo) broke ground on the project last fall after awarding a subcontract in August 2021 to a local business for the work.
Earlier this year, crews finished backfilling and compacting the area around the former reactor with approximately 34,000 cubic yards of sand and gravel to level the site before pouring a 6-foot-thick concrete foundation to support construction of the cocoon. The first steel columns for the enclosure were placed in mid-May with construction of the frame and installation of metal sheeting on the walls and roof continuing through the summer. Completion of construction was announced on October 26.
Design features: The cocoon’s design allows for routine inspections of the reactor every five years. During this “checkup,” radiation technicians will confirm that no contamination is leaving the sealed reactor core and that nothing is entering the building from the outside. Additional safety features include new lighting between the structure and the reactor building, as well as upgraded lighting inside the building.
