The U.S. Department of Energy has determined one of the single-shell tanks storing radioactive waste at Hanford is leaking around 150 to 300 gallons of liquid per year.
DOE officials have not determined the cause of the leak.
The reported tank, the T-111 located in the T Tank Farm at Hanford, was built in the 1940s and was "stabilized" in February 1995. It currently contains approximately 447,000 gallons of sludge, a mixture of solids and liquids with a mud-like consistency. This is the first tank that has reportedly been leaking since the interim stabilization was completed in 2005.
There are a total of 177 tanks at the Hanford site, 149 of which are single shell tanks.
"Fortunately, I can report that there is no immediate health risk," Governor Jay Inslee said during a news conference Friday, adding that the leak is in one of the tanks farthest from the Columbia River.
Still, Inslee said he was" alarmed on many levels" by the "disturbing" news, which raises concerns not only about this leak but also the integrity of the other old single-shelled tanks, some of which have experienced prior leaks.
"One of the reasons this is disturbing news is we were told this problem was dealt with years ago and was under control, " Inslee said during a news conference Friday. "We cannot leave 149 single-shelled tanks with high level radioactive liquid and sludge in the ground for decades after their design life." (Watch Inslee's news conference live now on TVW).
"Let me be clear. Washington state has a zero tolerance policy on radioactive leaks," he said.
Department of Energy officials say wells monitoring the T Tank Farm have not detected significant concentrations of chemicals or radionuclides in the soil, but officials are continuing to monitor the network of wells and evaluating possible next steps.