Hanford's "sister reactors," the K-East and the K-West Reactors, were built side-by-side in the early 1950s. The two reactors went operational within four months of each other in 1955. K-West was the seventh reactor built at Hanford; K-East was the eighth. The two reactors ran for more than 15 years before being shut down in 1970 and 1971.
Currently, The U.S. Department of Energy’s mission is to complete remediation of the 100 K Area waste sites, demolition of the K West Basin and other structures, and place the K East and K West reactors into Interim Safe Storage. The 100 K Area is the last reactor area in Hanford’s Columbia River corridor, where cleanup has not been completed yet.
For more information, please see the 100 K Area Fact Sheet.