The Department of Energy confirmed Thursday that “more likely than not” another underground tank at the Hanford Site in Washington state is leaking radioactive waste.
“Based on conservative estimates, it has been determined that T-101 is more likely than not leaking a small amount of contamination to the soil beneath the tank,” DOE managers at the former plutonium production complex said in a staff email Thursday. “This determination poses no increased health or safety risk to the Hanford workforce or the public.”
A copy of the email was viewed by Exchange Monitor.
“The decrease in liquid level in Tank T-101, which could be attributable to a number of factors, is relatively small and is the equivalent of as much as 200 gallons per year,” DOE said in the announcement. “To put this in some perspective, as many as 60 single shell tanks are assumed to have leaked an estimated total of 1 million gallons in the past.”
While the amount might be small, it is enough to trouble the Washington state Department of Ecology, a state regulator at Hanford.
“Evidence indicates that another underground storage tank is leaking highly radioactive waste at the Hanford Site,” and “this is deeply concerning … and needs to be addressed with urgency,” Washington Ecology Director Laura Watson said in a statement.
“Based on current information, we do not believe this tank poses an immediate risk to workers or the public,” Watson went on to say. The recent leak was first reported by the Tri-City Herald.
A deal was reached in May 2023 over how DOE and the state should handle tank leaks at Hanford.
The leaking tank has been watched by DOE for decades, a DOE spokesperson said in an email.
In 1992, Tank T-101 was classified as an “assumed leaker,” according to DOE. But in 1993 much liquid was pumped out and by 2019 it was deemed “sound” through a leak assessment. But monitoring continued and eventually led to reconsideration of the tank status, the DOE spokesperson said.
To protect the nearby Columbia River, there are pump and treat systems near T-101 to capture and remove contaminants that might reach the groundwater, the DOE spokesperson said. The federal agency plans to build a surface barrier over T Farm to block rain or snowmelt from seeping into the ground.
There are roughly 56 million gallons of radioactive liquid waste in Hanford’s underground tanks left over from decades of plutonium production.