In a letter last week to National Nuclear Security Administration director Tom D’Agostino, the Defense Nuclear Facilities Safety Board said the concerns involve “changes in the safety philosophy” that place too much reliance on untested procedures.
“The board believes these changes have weakened the safety posture, reduced the safety margin and increased the potential for both workers and the public to be exposed to higher consequences,” wrote board chairman Peter S. Winokur.
The tritium program, which employs about 450 workers, is one of the last nuclear weapons functions still based at SRS and includes periodic recharging of the tritium reservoirs in nuclear warheads. Tritium, a gas that increases explosive power, has a half-life of about 12 1/2 years and requires recharging.
Workers also extract tritium from fuel rods produced at Tennessee Valley Authority reactors and from both surplus and active warhead reservoirs.
The board’s concerns include a “shift in safety philosophy” that replaces preventative controls with “mitigative or administrative controls.”
Specifically, the program’s new calculations of the effects of a release through fire or explosion are inadequate to replace traditional conservative modeling. “By using these non-bounding, less conservative parameters, the dose to the public is underestimated,” the board wrote.
Site officials plan to review and respond to the report soon, but also believe the existing safety programs are appropriate.
“Since the board staff’s visit a year ago, earthquake drills have been developed and are being implemented in the tritium facilities,” site spokesman Jim Giusti said. “These drills provide awareness to employees regarding possible facility conditions after an earthquake and they provide training on immediate response actions required during and after a seismic event.”
The site’s tritium inventory, he added, is only one-third of what it was in the early 1990s, but many of the original safety systems remain in place today.
The safety board’s criticisms, which must be addressed within 90 days, come at a time when the National Nuclear Security Administration is implementing a money-saving consolidation of tritium facilities at several federal sites that will lead to a combined cost savings and cost avoidance of hundreds of millions of dollars over the next two decades.
Under the long-range Tritium Responsive Infrastructure Modifications plan, several older, Cold War-era buildings will be abandoned as the operations are consolidated in newer, more efficient facilities, and the program will shrink from eight nuclear facilities to five.
The modernization plan, officials said, is unrelated to a new management structure that will combine management of the SRS tritium facilities with management of the Y12 National Security Complex near Knoxville, Tenn., and Pantex Plant near Amarillo, Texas.
Tasks performed at Pantex include retrofitting and repairing of nuclear weapons, interim storage of plutonium pits and dismantling of surplus warheads.
The Y12 site was part of the World War II Manhattan Project. Its current missions include the reworking of nuclear weapon systems and components, surveillance of nuclear weapons and related materials, and prevention of the spread of weapons of mass destruction.
The SRS tritium facilities occupy approximately 29 acres in the northwest portion of H Area. Operations there began in 1955.
The board’s concern over the tritium program also raises concerns over the safety of other programs at the site, said Tom Clements, Southeastern Nuclear Campaign Coordinator with Friends of the Earth.
“We are concerned that a change in the safety philosophy related to the tritium facility could also indicate that other SRS facilities are likewise at risk of greater accident than calculated and call on the DNFSB to review the safety basis for other facilities handling radioactive materials at SRS,” he said, in an emailWednesday.