A series of warnings by state and federal experts, stretching back more than thirty years, preceded this week’s cave-in of a tunnel in Hanford, Washington, that holds lethally radioactive debris from the U.S. nuclear weapons program, according to government documents.
A report in 1980 for the Energy Department, which oversees safety and cleanup work at the site, said that wooden beams holding up the tunnel had lost a third of their strength by then. A contractor for the department pointed to the issue again in 1991, warning that by the year 2001, the beams would be further degraded.
A group of academic experts, working under contract to the department, said more alarmingly in a 1,969-page report in August 2015 that the roof of the tunnel in question had been seriously weakened and that a “partial or complete failure” could expose individuals even 380 feet away to dangerous levels of radiation.
No action was taken by the department in response, and earlier this month — the precise date remains uncertain because conditions at the site were not closely monitored — a portion of the roof collapsed at the tunnel, creating a 20-foot square hole. Afterward, the managers of the Hanford site were forced on May 9 to order 3,000 workers to shelter indoors. But instead of shoring up the beams inside the tunnel in question, they poured in 54 new truckloads of dirt.
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.
“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,” Maia Bellon, director of the Washington Department of Ecology, said Wednesday in a written statement.
“It’s not acceptable that the hole could have been open for four days,” said Alex Smith, the nuclear waste manager for the Ecology Department, according to an AP report.
In the 1991 report, by Los Alamos Technical Associates, Inc., the authors made clear after conducting an internal inspection of the tunnel that the DOE knew the timbers holding up the roof had been substantially weakened as early as 1980. It predicted that by 2001, they would be at 60 percent of their original strength and recommended another evaluation in 2001. But records indicate that it never happened.
A Department of Ecology inspection in 2015 noted that because the tunnels were closed up, “no permanent emergency equipment, communications equipment, warning systems, personal protective equipment, or spill control and containment supplies” were located inside — deficiencies that could complicate emergency efforts in the case of a tunnel fire or other safety incident.
A Government Accountability Office estimate in 2016 placed the total cost of cleaning up the toxic legacy of the U.S. nuclear weapon program at more than $250 billion.
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