Replacement warhead program poses challenges for weapons complex

April 24, 2007

An independent study group, convened by AAAS's Center for Science, Technology and Security Policy, has issued a report on the proposed Reliable Replacement Warhead (RRW) and its role in the future U.S. nuclear weapons program.

Bruce Tarter, head of the study group and a former director of the Lawrence Livermore National Laboratory, will discuss the report in a teleconference with reporters at 10:00 a.m. EDT on Tuesday, 24 April.

All details from the teleconference will remain under embargo until 11:00 a.m. EDT, Tuesday, 24 April, 2007. Dial-in numbers: Toll Free - 1-800-619-7628 Toll Number for International -- 1-210-234-0019. Leader Name: Ben Somers, passcode: AAAS. (Participants are requested to RSVP to Benjamin Somers prior to the teleconference at or 202-326-6414.)

The panel concluded that most of the anticipated benefits of the proposed RRW program -- more easily maintained nuclear weapons with enhanced performance margins, improved safety and security properties, and greater ease of manufacture -- would occur in the long term subsequent to modernization of the weapons production complex.

However, the panel noted that the next one to two decades will be a very challenging period for the nuclear weapons program as it simultaneously undertakes construction at many sites, maintenance and refurbishment of existing weapons, and potentially the building of RRWs.

For example the first RRW is provisionally scheduled for delivery in 2012 using the existing production complex which will require a greatly enhanced capability for the manufacture of plutonium pits, or triggers, at the Los Alamos National Laboratory. In addition, certification of both the method and the design for the first RRW will still need to go through a rigorous implementation and demonstration process.

In addition to Tarter, the study group included other former nuclear weapons Lab directors and senior weapons scientists, former senior DOE officials, and university experts. Two panel members elected to add brief personal comments at the end of the report.

The panel found that surveillance information from systematic measurements of the stockpile shows evidence of age-related findings. However, it also noted that the frequency of such findings has not trended upward, and the recent data on plutonium metal indicates it may have a longer functional lifetime than previously demonstrated. Despite these encouraging results it is not yet possible to predict the future aging behavior of the stockpile.

In the absence of detailed plans on scope, schedule, and costs, the panel said that it is not possible to judge the trade-offs in the weapons and the complex among stockpiles with varying mixes of RRWs and existing legacy weapons. Such assessments can only be achieved, the panel noted, when stockpile requirements have been set and cost and schedule predictions have been made in response.

The panel also concluded that a continuing commitment to stockpile stewardship -- the basis of the current nuclear weapons program -- is essential, whether or not the future stockpile includes RRWs as well as the legacy weapons. They noted that stockpile stewardship has succeeded politically because of the dual bipartisan commitment to a sound nuclear weapons program and to one that proceeds without nuclear testing.

The panel also observed that the Administration has yet to clearly lay out the role of nuclear weapons in a post-Cold War, post 9/11 world "that makes the case for and defines future stockpile needs" and that argues the case for the replacement warheads. Based on past experience, they argued, there cannot be a major transformation of the sort envisioned by the RRW proposal without greater White House leadership to produce substantial bipartisan support. Since the transformation is expected to take 25 years, involving several Administrations and a dozen Congresses, a successful program will almost certainly require an approach that balances weapons program goals with those of nonproliferation and arms control.

The panel said there were risks in all future approaches, but pursuing the initial phases of the RRW path could be a prudent hedge against the uncertainties of an all-legacy future, and an opportunity that might result in a better long term posture. But, it will be crucial to continually re-evaluate the risks, costs, and benefits of the different possible futures.

Dr. Tarter will participate in a public briefing on the report on Capitol Hill at 11:00 a.m., 24 April, 2007, in Room 2118 of the Rayburn House Office Building.
The American Association for the Advancement of Science (AAAS) is the world's largest general scientific society, and publisher of the journal, Science ( AAAS was founded in 1848, and has 262 affiliated societies and academies of science, serving 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The non-profit AAAS ( is open to all and fulfills its mission to "advance science and serve society" through initiatives in science policy, international programs, science education and more. For the latest research news, log onto EurekAlert!,, the premier science-news Web site, a service of AAAS.

American Association for the Advancement of Science

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