The Defense Nuclear Facilities Safety Board recently sent lab officials a report and letter saying board staff had identified a number of deficiencies in calculations that concluded any release would be below the threshold deemed safe to the public.
Board staff said its calculations indicate the potential for a radiation release from an earthquake-induced fire could instead be more than four times higher than levels considered safe for public exposure.
At issue are the lab’s efforts to shore up the 1970s-era facility — the nation’s primary site for working with dangerous plutonium used in nuclear weapons.
The board has been working closely with the Department of Energy and the National Nuclear Security Administration to upgrade the building’s structure, fire suppression and ventilation systems since new studies in 2007 showed the potential for a major earthquake along area faults to be 300 percent greater than previously believed.
During a public hearing in Santa Fe last year, members of the safety oversight board expressed concerns that the planned structural fixes were inadequate to protect the public from a major radioactive release.
The new calculations are significant in determining what safety controls need to be put in place as work continues on the building, board Chairman Peter Winokur told The Associated Press on Wednesday.
The board’s current assessment is the “calculations were not done conservatively and the assumptions are not justified,” he said. “This is an ongoing process.”
James McConnell, NNSA’s assistant deputy administrator for nuclear operations and safety in Washington, said public safety is the agency’s highest priority, and it was working with the oversight board.
“If necessary or prudent, we will take appropriate actions to further improve the safety basis that documents the hazards and specifies the controls to ensure safety,” McConnell said in a statement.
He also noted the current risk to the public from the facility remains small and it is operating well within established safety objectives.