An underground tank holding some of the worst radioactive waste at the nation's most contaminated nuclear site might be leaking into the soil.
The U.S. Energy Department said workers at Washington's Hanford Nuclear Reservation detected higher radioactivity levels under tank AY-102 during a routine inspection Thursday.
Spokeswoman Lori Gamache said the department has notified state officials and is investigating the leak further. An engineering analysis team will conduct additional sampling and video inspection to determine the source of the contamination, she said.
State and federal officials have long said leaking tanks at Hanford do not pose an immediate threat to the environment or public health. The largest waterway in the Pacific Northwest -- the Columbia River -- is still at least 5 miles away and the closest communities are several miles downstream.
However, if this dangerous waste escapes the tank into the soil, that raises concerns about its traveling to the groundwater and someday potentially reaching the river.
Washington Gov. Jay Inslee said the potential leak "raises very troubling questions." He said additional testing is expected to take several days, but he also said the state will be insisting on an accelerated plan to deal with all the waste at Hanford -- something the state and federal government will be discussing in the coming weeks.
"If we do not receive satisfaction in those meetings in the next few weeks, we have several legal options available to us," Inslee said. "And we'll act accordingly."
The state says there is no immediate public health threat and that the river is not at immediate risk of contamination.
Tom Carpenter, executive director of the Seattle-based advocacy group Hanford Challenge, said, "This is really, really bad. They are going to pollute the ground and the groundwater with some of the nastiest stuff, and they don't have a solution for it."
Downriver from Hanford in Oregon, Ken Niles was somber.
"These last few months just seem like one body blow after another," said Niles of Oregon's Energy Department. "It's true this is not an immediate risk, but it's one more thing to deal with among many at Hanford."
Two radionuclides comprise much of the radioactivity in Hanford's tanks: cesium-137 and strontium-90. Both take hundreds of years to decay, and exposure to either would increase a person's risk of developing cancer.
Mike Geffre, an instrument technician who works for contractor Washington River Protection Solutions, said Thursday's inspection came from a pit under the tank, like a saucer under a teacup. Water samples from the pit had an 800,000-count of radioactivity and a high dose rate, which means that workers must reduce their time in the area.
"Anything above a 500 count is considered contaminated and would have to be disposed of as nuclear waste," Geffre said. "Plus, the amount of material we've seen from the leak is very small, which means it's a very strong radioactive isotope."
Meanwhile, the Energy Department recently notified Washington and Oregon that it may miss two upcoming deadlines to empty some single-shell tanks.