Two of Los Alamos National Laboratory's facilities could expose the public to high radiation doses in an accident scenario—and the lab won't commit to lowering that risk.
At a Nov. 17 meeting in Santa Fe, members of the Defense Nuclear Facilities Safety Board chided LANL brass for failing to mitigate risks created by two of its facilities, the PF4 plutonium facility and the Area G material disposal area.
The DNFSB is an oversight board that advises LANL and other defense sites run by the National Nuclear Security Administration, a division of the US Department of Energy. One of its functions is to evaluate the risk of radiation exposure presented by nuclear facilities to the public, to each site's workers and to the environment. The board compares each facility's risk to a federal guideline, which stipulates that the public should not be exposed to more than 25 rems of radiation in an acute incident.
A rem is a unit of measurement of radiation dose that expresses the risk of adverse health effects caused by radioactivity. Materials used at LANL, including plutonium and uranium, give off radiation that can disrupt cell function and cause cancer or death.
The DNFSB estimates offsite radiation doses emitted by each facility under different hypothetical accident scenarios. The estimated doses that would be emitted by Area G, the lab's biggest radioactive material disposal area, are the most dramatic. In the hypothetical scenario of an airplane crashing into the domes at Area G, where radioactive waste is stored in metal drums and other containers, a person standing outside lab property could be exposed to a whopping 1,795 rems, usually from inhalation of radioactive particles.
That high dose is actually the estimated exposure to a person over a 50-year lifespan, Kim Kearfott, a professor of radiology at the University of Michigan, explains.
"The good news is this number is not as bad as it looks," Kearfott says. "The bad news is that person would be radioactive for a long time…the reality is, if you inhale plutonium, it's exposing you every year for the rest of your life."
In that hypothetical scenario, the exposed person would have about a 36 rem dose per year for 50 years, and a corresponding increased cancer risk. Each year, the exposed person's risk of cancer would increase by about 2 percent.
The 25 rem dose that the federal government recommends nuclear facilities not exceed presents a 1 percent increase in the exposed person's chance of getting cancer, Kearfott says. It's also the threshold above which an exposed person's blood will start to show changes, such as increased white blood cell count. By contrast, the maximum dose a nuclear facility worker should be exposed to over the course of a year is five rems.
"Twenty-five rems is a fairly high number," nuclear engineer John Till says. Till is the president of Risk Assessment Corporation, a private company that, like the DNFSB, estimates radiation exposure doses to the public caused by radioactive materials.
"It's higher than we allow people to get normally when they're working during the year," Till says. "On the other hand, it's set so that the likelihood of a health defect occurring from that exposure is fairly small."
LANL has more facilities that exceed the 25 rem guideline than any other NNSA site, DNFSB Chairman Peter Winokur said at the meeting. One facility at the Savannah River Site in South Carolina also exceeds radiation dose guidelines under some hypothetical accident scenarios.
But the guideline is only a recommendation, not an enforceable regulation. Last spring, US Energy Secretary Steven Chu rejected the DNFSB's recommendation to formalize the radiation dose guideline into a regulation. But the DNFSB itself has only an advisory role, and no regulatory power, as Board Member John Mansfield pointed out at the meeting.
LANL Director for Business and Operations Carl Beard said he felt the lab’s operations are “safer now than they’ve ever been,” adding that the safety goals of LANL and the DNFSB are “very well aligned, although we do discuss semantics and issues.”
"You're your own regulator, so you're the ones determining when these facilities are safe to operate," Mansfield told LANL and NNSA representatives. "We're just trying to understand your interpretation of this nuclear safety management rule."
The high estimated radiation dose for Area G is partly due to the volume of radioactive material stored there: approximately 10.8 million cubic feet of waste. The plutonium facility, for its part, needs new ventilation and fire-suppression systems. But at the meeting, NNSA Defense Programs Deputy Administrator Don Cook said upgrading facilities to decrease possible radiation doses isn't the agency's only priority at LANL, adding, "I can't make a commitment to what Congress will appropriate."
While recognizing the limitations of the DNFSB's power over LANL, the board members expressed frustration with LANL's failure to comply with the 25-rem recommendation, as well as the lab's attitude toward the problem. Los Alamos Site Office Manager Kevin Smith touted LANL's improvement in some areas and staff members' track record of self-reporting safety breaches. LANL Director for Business and Operations Carl Beard said he felt the lab's operations are "safer now than they've ever been," adding that the safety goals of LANL and the DNFSB are "very well aligned, although we do discuss semantics and issues."
From some board members' reactions, it's clear they consider LANL's nuclear safety shortcomings to be a matter of more than just semantics. Mansfield said he wanted to make sure he correctly heard Beard's statement that the lab is safer now than ever, asking how Beard reconciled that assertion with documentation of the lab's safety problems, the most egregious of which include lapses in hazard identification, staff compliance with safety procedures, and management "rationaliz[ing] the status quo rather than identifying root causes and fixes for the problems." But since the 25-rem limit isn't enforceable, LANL can sidestep such obvious contradictions between its own rosy portrayal of lab safety and documents pointing to profound problems, Los Alamos Study Group Executive Director Greg Mello says.
"Basically, NNSA wants to say something is safe or not just because they say," Mello says, indicating the lab's reluctance to commit to lowering the radiation dose to federally recommended levels. "That was the really shocking thing—the NNSA did not agree to protect the public and the workers to any standard whatsoever."