March 21, 2006
Tuesday

Scientists say evidence is mounting that the radioactive plutonium used in nuclear weapons could have a far longer useful life than previously estimated, raising questions about the need for an expensive Bush administration program to build more than a thousand replacement warheads.

With hundreds of billions of taxpayer dollars potentially at stake, the research on the aging of this dangerous and complex weapons ingredient, being conducted at the nuclear weapons laboratories, is being followed closely by Bush administration officials, lawmakers and nuclear weapons experts.

Although the results are preliminary, some scientists who have reviewed parts of the research say the fuel could be potent for a century or more, far longer than the 45- to 60-year minimum lifespan for the plutonium components - known as pits - previously estimated by the weapons labs.

If that is true, said a lawmaker whose committee oversees the weapons complex, Congress could decide that the new generations of replacement nuclear warheads sought by the Bush administration may not be needed for decades or that far fewer replacements would have to be built.

"This does have a direct correlation with the whole complex" of new weapons factories the administration is seeking, said Rep. Ellen Tauscher, D-Calif., a member of the House Energy and Water Appropriations Subcommittee.

The most expensive element in the administration's plan is expected to be a new pit factory that would be capable of building 120 per year. Tauscher said that if the plutonium is found to have a longer lifespan, "the need for 120 pits could be way off."

The issue may come to a head later this year. In debating the need for the replacement warheads, Congress required that the National Nuclear Security Administration, which oversees the weapons complex, report by this fall its latest assessment of the useful lifespan of plutonium. Research has been under way for several years at the weapons labs, Lawrence Livermore and Los Alamos, which are managed by the University of California, and the Sandia National Laboratories.

Portions of the research, though not finished, have been analyzed by some outside experts as part of the scientific peer review.

For now, the government refuses to release any lifespan estimates and would not comment on questions raised by the research. "Until the aging studies are complete, any further comment on plutonium aging would be purely speculative," said Bryan Wilkes, an NNSA spokesman.

But earlier this month Linton Brooks, the head of the NNSA, acknowledged during testimony before the House Strategic Forces Subcommittee that the lifespan could be longer. "It may turn out to be that it's 60 plus," said Brooks, as quoted by Global Security Newswire. "We're doing accelerated aging tests to find that out."

Previously, the weapons laboratories estimated that the plutonium remained potent for 45 to 60 years at a minimum. Eventually, scientists say, it would undergo radioactive decay, weakening the explosive force of the bombs.

But some scientists who sit on lab advisory committees or have followed some of the newer research say it appears the plutonium in pits may be reliable for at least 90 years.

Sidney Drell, a professor emeritus at the Stanford Linear Accelerator and a longtime government adviser on nuclear issues, said the new research suggested 60 years "is the lower limit, as far as I'm concerned."

"I wouldn't be surprised if 100 years is the new number," said Raymond Jeanloz, a physics professor at the University of California who has served as a government adviser and helps monitor research at the weapons labs.

"They've really agonized about every conceivable detail," added Jeanloz, who is also chairman of the Committee on International Security and Arms Control at the National Academy of Sciences. "It's been very hard to come to a consensus. But it looks like it could be years or decades or millennia before any serious degradation takes place."

Nuclear weapons production and underground testing halted with the end of the Cold War, but Bush administration officials have argued that concerns over the U.S. stockpile - some warheads are almost 40 years old - and the reliability of plutonium have increased the need for a new weapons factory and replacement warheads.

"Today, our weapons are aging and now are being rebuilt in life-extension programs that are both difficult and costly," Brooks said at the hearing on March 1.

The administration's proposal, called the Reliable Replacement Warhead program, or RRW, was funded for the first time by Congress last year with $25 million for the initial research.

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