Navy Never Received Refurbished W-76 Warhead

(May. 29) -Technical obstacles have delayed U.S. efforts to extend the life of W-76 nuclear warheads. One such weapon is depicted in the above diagram (Los Alamos National Laboratory image).
(May. 29) -Technical obstacles have delayed U.S. efforts to extend the life of W-76 nuclear warheads. One such weapon is depicted in the above diagram (Los Alamos National Laboratory image).

The first W-76 warhead said to have been refurbished and delivered months ago to the U.S. Navy today remains disassembled at a nuclear components facility in Texas, the Los Angeles Times reported (see GSN, March 4).

The United States intends to eventually replace decades-old parts inside hundreds of W-76 warheads, which fit onto submarine-launched Trident ballistic missiles and comprise more than half of the nation's launch-ready nuclear deterrent. The successful refurbishment of one of the weapons, therefore, was considered a key achievement in efforts to maintain the U.S. stockpile without the use of nuclear test detonations.

The National Nuclear Security Administration announced in February that the "first refurbished W-76 nuclear warhead had been accepted into the U.S. nuclear weapons stockpile by the Navy" (see GSN, Feb. 24). However, Navy spokesman Lt. Clay Doss yesterday challenged the Energy Department agency's assertion.

"We have not received delivery of any refurbished W-76 warheads. The answer is none," Doss told the Times yesterday.

A federal entity had by February approved the warhead's final blueprint, thus officially incorporating the refurbished weapon into the stockpile, argued NNSA spokesman Damien LaVera.

Delays in the warhead's delivery stem at least partially from problems replicating a secret part of the original weapon. The component, known as "Fogbank," is believed to be made from an unusual substance and is considered key in helping the weapon reach its intended energy intensity before detonating (see GSN, Aug. 15, 2008).

U.S. nuclear engineers found they could not create new Fogbank with the same qualities as those produced in the 1970s and 1980s, congressional investigators said in a March report.

"I don't know how this happened that we forgot how to make Fogbank. It should not have happened, but it did," said Philip Coyle, a former assistant defense secretary who also held a senior position at the Lawrence Livermore National Laboratory in California.

The W-76 problem illustrates the dilemma faced by the Energy Department as it seeks to keep the U.S. stockpile viable even as experienced scientists and engineers take their expertise with them into retirement.

"I wouldn't say the deterrent has been affected at all," Coyle said. "It is, however, a reminder that expertise about nuclear weapons is a precious thing and needs to be maintained."

Technicians have solved the Fogbank problem, but they were still addressing minor issues involving other components of the refurbished warhead, according to the National Nuclear Security Administration.

"It is inaccurate to say that we are unable to ship the weapons because there is an issue or problem," LaVera said (Ralph Vartabedian, Los Angeles Times, May 29).

May 29, 2009
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The first W-76 warhead said to have been refurbished and delivered months ago to the U.S. Navy today remains disassembled at a nuclear components facility in Texas, the Los Angeles Times reported (see GSN, March 4).