The tunnel, which housed eight rail cars of nuclear waste in Hanford – about 200 miles south of Seattle – left a 15-to-20-foot hole when it partially collapsed Tuesday. Although no one was hurt, some workers were evacuated and others sheltered in place while the air around the site was tested for radioactivity. Tests revealed that no radioactivity had leaked from the tunnel, and 50 truckloads of soil were brought in to plug the hole.
On Wednesday, the Washington State Department of Ecology (DOE) filed an enforcement action urging the federal government to immediately assess whether failure of other storage tunnels is likely and to submit a plan to the DOE for the safe storage of the materials as well as a plan for permanent cleanup.
“This alarming emergency compels us to take immediate action – to hold the federal government accountable to its obligation to clean up the largest nuclear waste site in the country,” DOE Director Maia Bellon said in a statement.
According to the Department of Energy, Hanford has produced more than 20 million pieces of uranium metal fuel for nine nuclear reactors along the Columbia River. The five plants at the Hanford site discharged an estimated 450 billion gallons of liquid waste in soil disposal sites and 53 million gallons of radioactive waste in 177 underground storage tanks. Most of the nation’s nuclear weapons, including the bomb dropped on Nagasaki, Japan, during World War II, used plutonium from Hanford.
The Hanford site stopped producing plutonium in the late 1980s, with cleanup efforts beginning in 1989. The cleanup currently employs approximately 11,000 workers.
“Our top priority is to ensure the safety of Hanford workers and the community,” Washington Gov. Jay Inslee said in a statement. “The collapse of this tunnel raises serious questions about how it happened and what can be done to make sure it doesn’t happen again. This enforcement order is necessary to make sure we get greater assurance about the condition of these tunnels and the Department of Energy’s plan to contain any further risks.”
In a press release, the DOE highlighted how the age of some of the storage areas at Hanford are of particular concern. The collapsed tunnel was built in 1956 of timber, concrete and steel and topped with eight feet of dirt. It was sealed with the nuclear-waste-filled rail cars in 1965.
“The infrastructure built to temporarily store radioactive waste is now more than a half-century old,” Bellon said. “The tunnel collapse is direct evidence that it’s failing. It’s the latest in a series of alarms that the safety and health of Hanford workers and our citizens are at risk.”
Workers returned to their jobs at Hanford on Thursday.