State takes legal action against U.S. government after Hanford nuclear site tunnel collapses

OLYMPIA, Wash. – The state of Washington is taking legal action against the U.S. government after a tunnel full of mixed radioactive and chemical waste collapsed at the Hanford Nuclear Reservation, the state Department of Ecology said Wednesday.

“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,” said Department of Ecology Director Maia Bellon.

Ecology is requiring the federal Department of Energy, through an enforcement order, to immediately assess the integrity of the tunnels, one of which partially collapsed on Tuesday, and take swift corrective action.

“Our top priority is to ensure the safety of Hanford workers and the community. 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,” Gov. Jay Inslee said.

“The infrastructure built to temporarily store radioactive waste is now more than a half-century old. 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,” Bellon said.

The enforcement order legally requires the U.S. Department of Energy to determine the cause of the tunnel collapse, assess the risk of further collapses, ensure the radioactive and chemical waste in the tunnels is stored safely, and submit a plan for permanently cleaning up waste in the tunnels.

Ecology oversees and regulates the federal government’s cleanup work at the Hanford Nuclear Reservation.

Thousands of workers at the Hanford Nuclear Reservation were told to stay home Wednesday as efforts began to plug a hole that developed in the partial collapse of a tunnel containing dangerous radioactive waste from the building of nuclear bomb materials.

A gravel road was built to the site of the roof collapse, and workers were expected to begin filling the hole with dirt on Wednesday, said Destry Henderson, a spokesman for the U.S. Department of Energy.

"We intend to start filling the hole today," Henderson said Wednesday.

Hanford, located in southcentral Washington state, has about 9,000 employees and most of them were told to stay home Wednesday, Henderson said.

A 400-square foot (37 square meters) section of the tunnel roof was discovered to have collapsed Tuesday morning, forcing thousands of workers to shelter-in-place for several hours.

Officials have detected no release of radiation and no workers were injured in the collapse of the unoccupied tunnel, Henderson said.

The rail tunnel was built in 1956 out of timber, concrete and steel, and topped by eight feet of dirt. It was 360 feet long (109.73 meters).

Radioactive materials were brought into the tunnel by rail cars for about a decade. The tunnel was sealed in 1965, with eight rail cars loaded with nuclear waste stored inside.

Hanford, built by the Manhattan Project in World War II, contains the nation's greatest volume of radioactive waste left over from the production of plutonium for nuclear weapons. The most dangerous are 56 million gallons of waste stored in 177 aging underground storage tanks, some of which have leaked.

The tunnel roof collapse caused soil on the surface above to sink 2 to 4 feet (half to 1.2 meters) over a 400 square foot (37 square meters) area, officials said.