A single-shell tank at Hanford is leaking up to 300 gallons a year of radioactive liquids, a disclosure that raises broader questions about the integrity of more than 140 other tanks that hold tens of millions of gallons of waste left over from decades of processing nuclear materials at the federal site in southeast Washington.
“We were told this problem was dealt with years ago, and was under control,” said Gov. Jay Inslee, who met with reporters Friday afternoon.
The leak disclosed Friday by the Energy Department is the latest setback in a long-troubled effort to clean up a federal site that ranks as one of the most contaminated places on Earth, according to a 2008 Government Accountability Office) report.
The tank under scrutiny was assumed to be leaking in past decades, so in 1995 pumpable liquids were removed in what was termed an “interim stabilization,” according to the Energy Department.
The tank currently holds about 447,000 gallons of sludge.
Inslee said that federal government needs to come up with funding to deal with the leaking tank, check the conditions of other tanks and build more interim storage with double-shelled tanks.
Long term, a $12 billion effort is under way to build a plant to treat high-level waste. The plant is designed to turn radioactive waste into glass logs through a vitrification process, but that effort has been beset by big technical challenges and repeated delays.
Inslee says the new leak lends added urgency to the cleanup at a time when budget cutting in Congress could make funding much harder to obtain.
“We will not tolerate any leaks of this material to the environment,” Inslee said.
In past decades, Hanford was a virtual dumping ground for wastes from the nuclear-processing effort. The new leak is minuscule compared to the site’s history.
The 2008 GAO report noted that the federal managers of the Hanford site intentionally discharged 121 million gallons of radioactive liquid waste directly into the ground between 1946 and 1966.
The storage tanks have leaked about 1 million gallons of waste into the ground over the years, according to the GAO report.
But a major stabilization effort completed in 2005 was supposed to curb the leaks by pumping out liquids and leaving behind thicker sludge.
Inslee said this is the first confirmed leak of a single-shelled tank since that stabilization effort was completed.
Inslee acknowledged there is no immediate threat from the leak, since it would likely take years to reach the groundwater.
Due to past pollution, there already are large radioactive plumes making their way through the soil and groundwater.
There is an extensive effort to monitor the plumes and a groundwater-treatment system also is in place, according to the Department of Ecology.