YAKIMA – Through years of cleanup at the Hanford Nuclear Reservation, one room has remained sealed, like a vault, preserving the scene of the worst nuclear contamination accident at the site.
The Aug. 30, 1976, explosion contaminated several workers and resulted in one man forever being dubbed the Atomic Man. Radioactivity levels in the room remained too high to salvage it years after the accident. Workers have briefly entered the room only a few times, and it has been sealed since 1989.
No longer. On Thursday, workers in protective gear entered the room for the first time in 16 years to begin the process of characterizing its condition and its hazards — marking the next step in cleaning up the nation’s most contaminated nuclear site.
The entry is a sign of the cleanup progress that has been made at Hanford and, specifically, in decontaminating and demolishing the so-called Plutonium Finishing Plant where the room is located, said Keith Klein, manager of the U.S. Department of Energy’s Richland Operations Office, which manages the 586-square-mile site.
The Plutonium Finishing Plant processed plutonium nitrate solutions into metallic form for shipment to nuclear weapons production facilities.
The workers’ entry into the sealed room also is significant from a historical standpoint, Klein said.
“This is the scene of our worst contamination accident, and we never totally cleaned up after the accident. There was some interim stabilization, but it was sealed off for 16 years,” Klein said. “We are now reaching closure by finishing the cleanup from this accident.”
The federal government created Hanford as part of the top-secret Manhattan Project to build an atomic bomb. For 40 years, the south-central Washington reservation made plutonium for the nation’s nuclear weapons arsenal.
The 1976 explosion occurred during a process in which plutonium and americium, a highly toxic radioactive substance used in exploratory oil drilling, are pulled from liquid waste.
An accident investigation later determined that resin in a glovebox column, which also contained about 100 grams of americium-241, reacted unfavorably to nitric acid when the chemical process was restarted following a worker strike.
The ensuing blast blew out the quarter-inch-thick lead glass shielding workers, showering Harold McCluskey, a 64-year-old chemical operator for Atlantic Richfield Hanford Co., with nitric acid, americium and contaminated shards of glass.
Within a few minutes, McCluskey inhaled the largest dose of americium-241 ever recorded, about 500 times the occupational standards for the element. Doctors isolated him for five months in a steel and concrete tank, where nurses wore respirators and protective clothing to monitor his recovery.
Doctors injected an experimental drug to flush the isotope out of his system, and by 1977, his radiation count had fallen by about 80 percent.
When McCluskey returned home after the accident, friends avoided him and church members shunned him until his minister told people it was safe to sit with him, according to newspaper accounts. He died in 1987 at age 75, forever known as the Atomic Man in media reports and scientific journals.
The team of workers who entered the sealed room Thursday volunteered for the assignment in what will be a months-long cleanup process, said Bruce Klos, vice president for the Plutonium Finishing Plant closure project for contractor Fluor Hanford.
The workers fogged the room with a fixative to adhere contamination to surfaces and reduce airborne contamination. They also began taking samples to determine the level of radioactivity and started assessing safety systems, such as sprinklers, to ensure they will operate as cleanup progresses, he said.
“There’s been a tremendous amount of planning, interviewing people who used to work there, trying to gather information and pick their brains about what to expect in the facility,” Klos said. “They know how to do this safely.”
The room is part of the 63-building complex that comprises the Plutonium Finishing Plant. Ten buildings already have been demolished. The complex is to be ready for demolition by the end of 2006.
Costs to clean up the entire Hanford site are expected to total $50 billion to $60 billion, with the work to be finished by 2035.