Repeated warnings preceded collapse of a Hanford tunnel storing deadly wastes

The tunnel was one of two at the Energy Department’s Hanford reservation used as dumping grounds from 1960 to 2000 for radioactive machine parts, vessels, and other equipment. It was, in short, a tangible expression of the department’s policy of covering over some of its nuclear bomb-making detritus and effectively pretending it isn’t there.

The neglect followed a blunt warning 26 years ago from the State of Washington — cited in a 1991 Energy Department contractor’s report — that the tunnels were not a safe repository and that the wastes should be moved elsewhere.

Under an agreement overseen by a federal court in eastern Washington, the department was supposed to start crafting a way to deal with the tunnel’s lethal dangers by September 2015, but it missed the deadline and promised to do it later this year as part of an overall agreement with the state and the Environmental Protection Agency to push back completion of the site’s overall cleanup from 2024 to 2042. (Hanford remains the most toxic site in America and the government’s most costly environmental cleanup task.)

“The Department of Energy has been aware for years that the…tunnels were a risk. They told the other agencies in charge of overseeing Hanford that it wasn’t a risk,” said Dan Serres, conservation director at Columbia Riverkeeper, an advocacy group in Washington state that has a seat on an Energy Department advisory panel about the site. “DOE assured the others that there was no immediate risk of a collapse like the one that happened.”

Asked for comment on the reports, and on the Energy Department’s failure to respond to the warnings, a spokesman in Washington did not respond. Secretary of Energy Rick Perry said in a statement on May 11, after the hole had been filled in, however that “thankfully, the system worked as it should and all are safe.” He promised the department would “identify and implement longer-term measures to further reduce risks.”

The tunnel with the collapsed roof was built in 1956 over a rail spur that extended 350 feet south from the east end of the complex’s massive factory for making plutonium, a key sparkplug for America’s nuclear weapons. Managers at the plant initially sought to use it as a storage locker for radioactive materials, and so they shored it up with creosoted railroad ties, and piled eight feet of dirt on top.

Within a few years, however, they started using it to store contaminated plant equipment. The tunnel was filled and sealed in 1964, and a second, parallel, and much longer tunnel was built next to it. That one was filled with radioactive equipment contaminated with plutonium, americium, cesium and strontium as the site’s bomb-making factory was dismantled. It was sealed in 2000.

It is unclear when contractors running the plant first became concerned that gamma radiation, which changes the molecular structure of wood cell walls, would significantly weaken the first tunnel’s timbers. As early as 1971 the integrity of the wood was checked and determined to be sound. The 1980 study said however that said the wood’s strength had deteriorated to 64.5 percent of its original strength. It predicted that the structure should be sound until at least 1982, by which time the authors anticipated it would be cleaned out.

A September, 1990, Department of Energy dangerous waste permit application for the two storage tunnels revealed that some of the parts stored inside were spewing radioactivity at the rate of 5 rem to 25 rem per hour. Since occupational health guidelines for workers in DOE plants limit workers to exposures of 50 rem a year, these would be serious exposures.

Washington state’s ecology department has now ordered the DOE to find the cause of the breach and take steps to fortify the tunnel. Citing its state toxic waste authorities, it gave the Energy Department until July 1 to assess the structural soundness of both tunnels, and until Oct. 1 to propose changes to its state-issued hazardous waste permit that involve strengthening the tunnels, according to the latest change to the DOE’s hazardous waste permit.

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