Because of budget cuts and higher costs, Lawrence Livermore National Laboratory laid off 440 employees May 22 and 23. Over the past 2 1/2 years, attrition and layoffs have reduced the work force of 8,000 by about 1,800 altogether.
According to a list obtained by The Associated Press, about 60 of the recently laid-off workers were engineers, around 30 were physicists and about 15 were chemists. Some, but not all, were involved in nuclear weapons work or nonproliferation efforts, and all had put in at least 20 years at the lab.
Some lawmakers and others said they fear the loss of important institutional knowledge about designing warheads and detecting whether other countries are going nuclear.
Also, Sen. Dianne Feinstein, a California Democrat, said job reductions at Lawrence Livermore and two other big U.S. weapons labs represent "a national security danger point." These unemployed experts might take their skills overseas, Feinstein said.
"The fact is, these are all people who are human - they have homes, they have families, they have educations to pay for," she said. "And I very much worry where they go for their next job."
The possibility is also on the mind of the nation's top nuclear weapons official, National Nuclear Security Administration chief Tom D'Agostino.
"Always in a situation where people leave under less-than-ideal circumstances, we worry about that, and it's something I assure you we're looking at closely," D'Agostino said. "I'm always concerned about the counterintelligence part of our mission, and we have an active program to go make sure we understand where we're vulnerable and where we're not."
Asked to elaborate, NNSA spokesman Bryan Wilkes said the agency is "always on guard for foreign entities approaching our employees, active or retired, but it's their responsibility to alert us to those circumstances."
The NNSA is aware of no instance in which a U.S. nuclear weapons scientist had gone to work overseas, he said.
He said the agency regards the possibility of a hostile government picking up laid-off workers as "highly unlikely," in part because these are American citizens who have responsibly held high-level clearances for many years, and because federal law provide stiff penalties - which range as high as life in prison - for divulging nuclear secrets.
In an e-mail message, Wilkes said the very notion that these scientists would sell their country out is "an insult to their personal integrity and their patriotism."
Ken Sale, a physicist laid off from Lawrence Livermore on May 23, said that taking his knowledge of nuclear weapons overseas would be unthinkable, and that he knows of no laid-off colleague who would even consider it.
But "the recent history of spying has all been money-based," Sale said. "Being concerned about expertise you wouldn't want rattling around in the whole world, and workers being desperate for a job, is a reasonable concern."
Sale worked on nuclear weapons testing, nonproliferation and nuclear-detection projects.
"The specific experience you get doing that stuff doesn't have applications outside that narrow world," he said. "It's not obvious that I will be able to be fully employed."
Sale, 51, will receive one week's pay for each of his 23 years at the lab, which is in Livermore, about 50 miles (80 kilometers) from San Francisco.
For security reasons, laid-off workers like Sale immediately lost their access badges, their top-secret "Q" clearances were suspended, and they were promptly escorted off the grounds. Some, including Sale, may stay on for a few months doing unclassified work via telecommuting.
Lawmakers and others have expressed concern that wave after wave of work force reductions will diminish the lab's expertise. D'Agostino said he could not guarantee that national security would not be harmed.
With a self-imposed nuclear test ban in place since 1992, maintenance of the warhead stockpile - Lawrence Livermore's top responsibility - is performed on supercomputers. So is the task of designing a new generation of warhead, which Lawrence Livermore won the right to do last year.
The layoffs have reduced the lab's roster of experts with invaluable experience they had gleaned from taking part in actual nuclear tests, Sale and others said. "Designing, building and seeing a device go off is very different from designing a device and handing it to a computer jockey," Sale said.
Los Alamos, the New Mexico laboratory that built the atom bomb during World War II, cut its work force last year by about 550 through retirements and attrition, and Sandia, also largely in New Mexico, plans to shed dozens of workers.