On 15 February, the DOE's Office of River Protection (ORP) and its Tank Farms operations contractor Washington River Protection Solutions (WRPS) confirmed that the liquid levels in one tank (SST) T-111 were decreasing. This number was later raised to six, after data was misunderstood.
"One week ago, Secretary Chu told me there was one tank leaking. But he told me today that his department did not adequately analyze data it had that would have shown the other tanks that are leaking," Inslee said in a 22 February statement.
"This certainly raises serious questions about the integrity of all 149 single-shell tanks with radioactive liquid and sludge at Hanford."
There are a total of 177 tanks at the Hanford site, including 149 single shelled tanks.
The Hanford site was established in 1943 as part of the Manhattan Project to produce plutonium for the first atomic bomb. Plutonium production continued there until 1987 when the last reactor ceased operation. In 1989, the U. S. Department of Energy (DOE), Environmental Protection Agency (EPA), and Washington State Department of Ecology entered into a legally binding accord, the Tri-Party Agreement (TPA), to clean up the Hanford Site.