Washington, Feb 24 (IANS): Six underground radioactive waste tanks at America's most contaminated nuclear site in Washington State in the Pacific Northwest region are leaking, according to the state governor Jay Inslee.

Inslee made the announcement Friday after a meeting with US Energy Secretary Steven Chu who told him that the US Department of Energy has determined there are six, single-shell tanks leaking radioactive waste at Hanford.

Last week, the governor was told about one of those tanks, according to a statement issued by his office. There are a total of 177 tanks at the Hanford site, 149 of which are single-shell tanks.

Chu "told me that the Department of Energy has now confirmed there are six tanks leaking radioactive waste at Hanford," Inslee said.

But "there is no immediate or near-term health risk associated with these newly discovered leaks, which are more than five miles from the Columbia River," he said.

Calling it "disturbing news for all Washingtonians" Inslee said "This certainly raises serious questions about the integrity of all 149 single-shell tanks with radioactive liquid and sludge at Hanford.

Located in southeastern Washington State, Hanford is a 586-square-mile site created in 1943 as part of America's effort to develop the atomic bomb, called the Manhattan Project.

The complex was decommissioned by 1987, but remains the biggest nuclear waste repository in the US, storing 53 million gallons of radioactive waste, including 30 million gallons in the 149 single-shell tanks, according to the State of Washington Department of Ecology.