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Former White House Coordinator for Arms Control and WMD Terrorism
News Analysis: Officials Air Views on Key Stockpile Issue

Tom Z. Collina and Daniel Horner

As the U.S. Nuclear Posture Review (NPR) moves toward completion in the coming months, the Obama administration is grappling with a major question about the U.S. nuclear arsenal. Given the stated need to maintain the arsenal for the foreseeable future, can the United States reliably maintain existing warhead designs, or will the country eventually need new ones?

Public statements by senior officials from the departments of Defense and State appear to be at odds on this point, and officials from other parts of the government apparently have weighed in as well.

The debate reveals what some observers see as a tension born from President Barack Obama’s Prague speech in April, where he called for “a world without nuclear weapons” while also saying, “As long as these weapons exist, the United States will maintain a safe, secure and effective arsenal to deter any adversary.”

Inside the Obama administration, this debate is not about nuclear testing; the administration strongly supports the Comprehensive Test Ban Treaty (CTBT) and opposes additional tests. Nor is it about developing weapons with new military capabilities.

At issue is how long nuclear warheads “last.” During the Cold War, nuclear warheads were continually replaced with new, more-lethal types, developed with the help of more than 1,000 nuclear tests. The United States has not conducted a nuclear test since 1992. Since then, no new warhead types have been introduced into the arsenal. As a result, existing designs are getting older.

Secretary of Defense Robert Gates has said repeatedly that the United States probably needs to replace at least some existing weapons with new designs. He told the Air Force Association Sept. 16 that the United States should “continue to make investments, and I think larger investments, in modernizing [its] nuclear infrastructure.” That would include programs to extend the life of nuclear warheads “and in one or two cases probably new designs that will be safer and more reliable,” he said.

He added, “We have no desire for new capabilities. That’s a red herring. This is about modernizing and keeping safe a capability that everyone acknowledges we will have to have for some considerable period into the future before achieving some of the objectives of significant arms reduction and eventually no nuclear weapons at all.”

According to knowledgeable sources, the NPR has not reached a conclusion about the need for new warhead designs. Gates supported a similar effort in the Bush administration called the Reliable Replacement Warhead (RRW) program, which was canceled by Congress.

A top Department of State official has publicly opposed the idea of any program that would pursue new designs, even if they would not provide new capabilities. In an Oct. 21 interview with Arms Control Today (see page 6), Undersecretary of State for Arms Control and International Security Ellen Tauscher declined to comment specifically on whether the NPR would include a new version of the RRW program. She said she does not “consider RRW to be anything other than something from the past.” Noting that she chaired the House subcommittee that had oversight of the program and that she led the effort to kill it, she said, “When I kill something, it stays dead.”

In comments to The Cable in September, she said, “I think there are a lot people that still hope for the return of [the] RRW [program], and they are going to be sadly disappointed.”

A former congressional staffer who followed the RRW issue closely said Oct. 27 that there was “an apparent disconnect” between the public comments of Gates and Tauscher.

Eric Edelman, who served as undersecretary of defense for policy under Gates, said in a separate Oct. 27 interview that his impression is that Gates “is not wedded to something called RRW” but does strongly support modernization of the U.S. stockpile.

Noting that he no longer has day-to-day contact with Gates, Edelman, now a distinguished fellow at the Center for Strategic and Budgetary Assessments, said he believes that Gates views such an effort as necessary if the Obama administration is to get Senate approval for a new strategic arms control agreement and the CTBT.

Edelman, who held senior positions in the State and Defense Departments, said his sense was that the administration “has not come to closure yet” on this issue. However, it is not “bad” to have differing views within the administration, he said. “Those disagreements get ironed out because, at the end of the day, it’s the president’s decision,” he said.

Tauscher’s position reportedly has some backing in the White House. At a high-level meeting in June, Vice President Joe Biden opposed the idea of a resurrected RRW program on the grounds that the perception that the United States was upgrading its nuclear warheads could undermine the administration’s credibility on nuclear disarmament and nonproliferation, according to an Aug. 18 report by Global Security Newswire.

The Department of Energy’s National Nuclear Security Administration (NNSA), which, along with the Defense Department, is responsible for maintaining the U.S. nuclear arsenal, is also pushing for the ability to design new warheads, as is the U.S. Strategic Command (STRATCOM).

RRW Redux?

Some are seeking to achieve certain goals of the earlier RRW program by folding the basic idea—that new-design warheads will be needed in the future—into the definition of “stockpile management.” The fiscal year 2010 defense authorization bill states that the top objectives of the Stockpile Management Program are “to increase the reliability, safety, and security of the nuclear weapons stockpile of the United States” and “to further reduce the likelihood of the resumption of underground nuclear weapons testing.” Some see new warhead designs as serving both of these goals.

The idea of certifying new warhead designs for the arsenal without the help of nuclear tests now seems feasible, thanks to new diagnostic tools in the Stockpile Stewardship Program that have led to greater understanding of the basic physics of nuclear weapons. STRATCOM and the NNSA are now making the case that new, untested weapons designs would be more reliable than well-tested, older designs.

“Confidence in [the] reliability of [the] aging stockpile is decreasing,” say STRATCOM viewgraphs, and STRATCOM wants the option to “replace” existing warheads with new designs. The STRATCOM viewgraphs, originally obtained by The Washington Times and published in September, describe a “range of options to manage the stockpile” into the future, from least intrusive to most, as follows:

Refurbish: Rebuild the warhead nuclear components as close to the original as possible.

Reuse: Mix and match the best nuclear components of different warheads; may have to remanufacture parts.

Replace: Manufacture new nuclear components similar to those previously nuclear tested.

The last option is STRATCOM’s new version of the RRW program. STRATCOM is evaluating a new design option for a common warhead to replace the W78 (Minuteman ICBM) and W88 (Trident submarine-launched ballistic missile) warheads for the post-2020 time frame.

NNSA viewgraphs released in September by Nuclear Watch New Mexico, a local group that tracks Los Alamos National Laboratory, include a similar list of the three options, stating that “[r]eplacement is essential for a viable modernized stockpile with increased flexibility and diversity.”

This RRW-style approach to stockpile maintenance is controversial in part because it would involve the design of new warheads whose performance would not be confirmed with nuclear tests—something that has never been done in the age of modern U.S. weapons. RRW critics are concerned that new, untested designs may turn out to be less reliable than current designs, eventually leading to calls for renewed nuclear testing.

Warhead Lifetimes

Because nuclear warheads are no longer being replaced with new designs, as they were during the Cold War, the average age of the nuclear arsenal is increasing beyond previous experience.

That is not a major concern for the non-nuclear parts of warheads, which can be replaced under the Life Extension Program (LEP) and fully tested without nuclear explosions. But nuclear parts of warheads—primaries (plutonium pits) and secondaries (lithium-deuteride components)—cannot be explosively tested.

RRW skeptics counter that the aging of the arsenal is not a near-term problem because recent studies show that the pits can last a very long time.

The NNSA had estimated as recently as April 2006 that the pits would last roughly 45-60 years. In November 2006, Lawrence Livermore and Los Alamos National Laboratories concluded that plutonium pits in current nuclear weapons have a shelf life of 85 years to perhaps 100 years or more. That conclusion was endorsed by the JASON group of senior defense consultants and by the NNSA. “These studies show that the degradation of plutonium in our nuclear weapons will not affect warhead reliability for decades,” then-NNSA Administrator Linton Brooks said in a November 2006 press release. “It is now clear that although plutonium aging contributes, other factors control the overall life expectancy of nuclear weapons systems,” he said. Given the arsenal’s current age, the newer estimates indicate that it will be more than 50 years before any plutonium parts in the 2009 stockpile start facing significant aging issues.

For now, it appears that independent weapons scientists have more confidence in existing, well-tested designs than new, untested ones. In an April 2008 paper, Sidney Drell, a JASON member and former director of the Stanford Linear Accelerator Center, and Marvin Adams of Texas A&M University found that “[w]e still have far to go before answering whether new designs can be created that incorporate all the desired attributes, can be fielded without [underground tests], and provide confidence as high as or higher than we have currently in the legacy weapons.”

A new JASON report on the LEP has been completed, and an unclassified summary has been prepared but not yet released by the NNSA, according to an administration official.

Congress in October included $223 million for the LEP in the fiscal year 2010 energy and water development appropriations act. All of the money is to go to refurbishment, but not replacement, of the W76 warhead, which is used on Trident submarines. The act also provides $32.5 million to study refurbishing non-nuclear parts of the B61 bomb. Seeking to avoid any appearance of designing new nuclear weapons, the law’s language states that no funding was requested to study refurbishment of the nuclear parts of the B61 and that any funds to be used for that purpose require prior congressional approval.