Radioactive leaks have been reported in at least six underground nuclear waste tanks in one of the most contaminated nuclear site on earth - in northwestern US state of Washington - raising concerns about delays in emptying the ageing tanks.
However the governor of Washington state, Jay Inslee, who said that 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.
"I met with Secretary Chu in Washington, DC, this afternoon, and he told me that the department of energy has now confirmed there are six tanks leaking radioactive waste at Hanford," Inslee said. Chu is US' energy secretary.
There are a total of 177 tanks at this site in Hanford, 149 of which are single-shell tanks.
"This is disturbing news for all Washingtonians. 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.
"This certainly raises serious questions about the integrity of all 149 single-shell tanks with radioactive liquid and sludge at Hanford.
"I believe we need a new system for removing waste from these aging tanks, and was heartened to hear that the Department of Energy is looking at options for accelerating that process," he said.
Hanford houses millions of gallons of radioactive waste left over from plutonium production for nuclear weapons.
It is considered one of the most contaminated sites on Earth, according to US government.
Senator Ron Wyden, chairman of the Energy and Natural Resources Committee, who toured the site this week said that the conditions there "an unacceptable threat to the Pacific Northwest for everybody".
Before Friday's announcement, scientists with the not-for-profit Hanford Challenge claimed that over one million gallons of radioactive waste has already leaked into the ground at Hanford.
"The T-111 tank is one of the 177 underground nuclear waste tanks containing an estimated 56 million gallons of high-level nuclear waste.
"Sixty-seven Hanford tanks have leaked over one million gallons into the soil, which is right next to the Columbia River," it alleged.
"Hanford is in a tough place. The tanks are failing left and right, and the facility that is supposed to treat this waste, the Waste Treatment Plant, is plagued with mismanagement and technical problems. It won't be ready anytime soon," said Tom Carpenter, executive director of Hanford Challenge.
He said that the State of Washington should not wait for the US Department of Energy to take months to confirm that the tank waste has contaminated the environment, but instead begin emptying the tank immediately.