Armed security agents posing as terrorists broke into a secure area at a nuclear weapons laboratory during a recent test, exposing flaws in the protection of stockpiles of plutonium and uranium coveted by terrorist groups and rogue nations seeking to become nuclear powers.
The "force-on-force" exercise at Lawrence Livermore National Laboratory in California pitted two teams of special-operations-trained commandos: one that attacked use of simulated explosives, and a team of defenders who tried to keep them out, said Bush administration officials familiar with the test.
The test was part of regular drills designed to test nuclear defenses and included the attackers' use of all-terrain vehicles and torches to cut through metal barriers, the officials said.
A spokesman for the National Nuclear Security Administration (NNSA), the Energy Department unit that oversees the laboratory 50 miles from San Francisco, said the security problems were revealed in the penetration test, which was first reported by Time magazine.
NNSA spokesman Bryan Wilkes declined to comment on the details of the exercise but stated in an interview that the initial results were "disappointing" and "highlighted the need for improvement."
"This is precisely the reason why we have these kinds of assessments done to test our security," Mr. Wilkes said. "We are constantly testing our security ... to find areas for improvement."
"The nuclear material at the site is secure, and we have the best security in the government," he said.
The "attackers" were commandos who are part of security teams that guard other U.S. nuclear facilities in the country and were part of a seven-week review of laboratory security at Lawrence Livermore. The simulated attack took place in late April.
The attacking force also began the exercises inside the laboratory's perimeter fences and other defenses inside an area called the Superblock, where nuclear material is stored, the administration officials said.
"The attackers were given tremendous insider knowledge, personnel, site access, facility information and communications advantages that would be highly improbable in a real-world scenario," one official said.
Defenders were limited from firing their weapons inside the area, another advantage for the simulated terrorists.
A Dillon Aero Gatling Gun, capable of firing at high rates, also did not work properly for the defenders because of a hydraulic problem, but the problem has been remedied, the officials said.
Four areas during the security inspection were found to be "effective," while four had ratings showing the need for improvement, Mr. Wilkes said.
One key lesson was that the laboratory"s protective forces need to train more often within the actual area they are protecting, he said.
"Immediate compensatory measures were put in place after the inspection, including additional security police officers and relocation of material to more secure storage locations," he said.
"No material or sensitive information at Lawrence Livermore National Lab is at risk, and the security at the site remains strong," he said.
All plutonium at the facility will be removed in four years, he said.
The NNSA said in a statement Friday that a recent "security assessment" identified several areas needing improvement.
Lawrence Livermore is part of the nuclear weapons complex and conducts research on plutonium pits used in nuclear weapons.
Laboratory spokeswoman Susan Houghton said some personnel were reassigned as a result of the security review and one immediate step will be to increase the training of the protective force officers. "We've accelerated training, and we're training against more real-world threats," she said.
The anti-nuclear group Project on Government Oversight (POGO), which monitors security at Energy Department facilities, said in a statement that the penetration drill shows the problems of security at the facility.
"The hydraulic system used to raise the gun from its hiding place inside the back of a small truck failed, making it impossible for the gun to be fired," POGO said, noting that the group has been critical of the deployment of the gun because of its one-mile range that poses a danger to nearby residences.
The group also stated that special response teams of armed security guards were involved in tactical failures during the drill.
"It is important to emphasize that Livermore's security problems are not the fault of the guard force, who have complained about their lack of training and poor tactics," said POGO senior investigator Peter Stockton. "In fact, two security officers were fired for raising these problems."
Time magazine, which first reported the penetration drill in its Monday editions, stated that the attacking force was able to penetrate Building 332, which contains about 2,000 pounds of plutonium and weapons-grade uranium.
The mock terrorists gained access to a payload of simulated fissile material inside the facility.
A POGO report on Lawrence Livermore security problems last year stated that contract security guards are not equipped to adequately secure the site and have limited capabilities to communicate with local police.
"As a result, coordinating an effort to recapture stolen [special nuclear material] is virtually impossible," the report said.
A POGO report from March stated that the laboratory has been unable to meet U.S. government security requirements and was given a waiver from the Energy's nuclear security administration.
"This action comes at a time when experts warn that the threat of nuclear terrorism is growing," the report said.
Michael Leiter, acting director of the National Counterterrorism Center, told a Senate hearing last week that al Qaeda in particular is continuing to seek unconventional weapons.
"Most troubling is the judgment they will continue to try to acquire and use chemical, biological, radiological or nuclear materials in attacks," Mr. Leiter said.
Other senior U.S. intelligence officials have said that one threat scenario is for terrorists to set off a radiological bomb — a conventional bomb laced with nuclear material to enhance its lethality.
Stealing or constructing a nuclear bomb for use in an attack would be more difficult but not impossible.
"More than anywhere else in the nuclear weapons complex, it is essential to prevent terrorists from accessing the nuclear materials at Livermore," said Danielle Brian, POGO's executive director. "Suicidal terrorists would not need to steal the materials; they simply could detonate them into an improvised nuclear device on the spot. That is why it is urgent to remove those materials from the lab, rather than settling for the [Energy Department's] drawn-out timetable of removing the materials by 2012. We hope this debacle will finally light a fire under [the Energy Department] and accelerate their schedule."