By George Lobsenz

The nation’s aging nuclear warheads can be safely maintained by life extension methods similar to those now used by the Energy Department, but the agency’s warhead monitoring programs are becoming inadequate and the continued reliability of the nation’s stockpile overall is threatened by a “lack of program stability, perceived lack of mission importance and degradation of the work environment” in the nuclear weapons complex, an expert panel said in a report released last week.

The report by the JASONs, an independent panel of nuclear weapons experts, appears to undermine some past arguments made by the National Nuclear Security Administration (NNSA), DoE’s semi-autonomous weapons agency, that more aggressive warhead refabrication and replacement efforts are needed to address potential reliability issues raised by aging of plutonium and other warhead components.

Further, the JASONs said some warhead changes under consideration by NNSA to improve “surety” of warheads–meaning safety and security–need more research and development and would require reuse of warhead components in new ways or replacement with redesigned components.

Those more aggressive lifetime extension programs (LEP) are controversial because nonproliferation groups and some congressional Democrats have charged that NNSA and the Pentagon have been using the aging issue as a cover to try to develop new types of warheads. Such new U.S. warheads, the critics say, would undermine the credibility of U.S. nonproliferation policies aimed at persuading other nations not to build nuclear weapons.

NNSA and Pentagon officials deny they are trying to build new weapons, but say some redesign of warheads would make weapons safer and more secure and reliable–and that would enable the United States to reduce its arsenal even further than is currently being done under U.S.-Russia arms control agreements.

Those officials also say that significant reliability issues are raised even by the limited changes to the nation’s Cold War-era warheads from component aging and refabrication of components under existing LEP programs. They note that the nation no longer can conduct underground bomb testing to ensure those changes do not affect warhead performance.

However, the JASONs said NNSA’s current stockpile stewardship program–which uses advanced computer simulation and subcritical testing to evaluate warhead reliability–along with existing LEP procedures that refurbish existing components are fully capable of ensuring the continued certification of warheads as safe, secure and reliable.

“JASON finds no evidence that accumulation of changes incurred from aging and LEPs have increased risk to certification of today’s deployed nuclear warheads,” the expert panel said in an unclassified summary of its report released last week by NNSA.

“Lifetimes of today’s nuclear warheads could be extended for decades, with no anticipated loss of confidence, by using approaches similar to those employed in LEPs to date.”

Those findings track an earlier JASON report that said the aging of plutonium in warheads did not pose, by itself, a reliability threat requiring redesign of warheads.

While not providing much detail on its findings, the new JASON report revealed that some unspecified warhead aging issues have been resolved and others that have been identified can be addressed with LEP approaches similar to those now being used.

It also disclosed that military requirements for some warheads–the capabilities they must provide–have been changed to ensure the warheads can remain certified. However, the report said the changed military requirements “are the result of improved understanding of original weapon performance, not because of aging or other changes.”

Rather than warhead aging, the JASONs said they were most concerned about threats to the overall stockpile stewardship program posed by broader programmatic uncertainties and potential erosion of expertise within NNSA’s nuclear weapons complex, where many experienced weapons scientists are retiring or leaving for greener research pastures.

“All options for extending the life of the nuclear weapons stockpile rely on the continuing maintenance and renewal of expertise and capabilities in science, technology, engineering and production unique to the nuclear weapons program,” the report said. “This will be the case regardless of whether future LEPs utilize refurbishment, reuse or replacement.

“The study team is concerned that this expertise is threatened by a lack of program stability, perceived lack of mission importance, and degradation of the work environment.”

Although the unclassified summary did not elaborate on those concerns, the JASONs did specifically express concern about NNSA’s warhead “surveillance” program, which conducts detailed examination and testing of a small number of each type of warhead each year to ensure no reliability problems are developing.

“Surveillance of stockpile weapons is essential to stockpile stewardship,” the report said. “Inadequate surveillance would place the stockpile at risk.

“We find that the surveillance program is becoming inadequate. Continued success of stockpile stewardship requires implementation of a revised surveillance program.”

That finding is intriguing in light of an Aug. 20, 2009, report issued by DoE’s Office of Inspector General that revealed that NNSA in 2007 had made “fundamental changes” to the stockpile surveillance program, including the initiation of a new warhead testing approach.

The IG report said those changes “had the practical effect” of eliminating significant backlogs in testing that have been a focus of criticism by the IG office for several years. In previous audits, the IG said “significant” testing backlogs had left NNSA without certain information needed to assess the reliability of the stockpile “as well as vital information regarding potential weapon system anomalies and defects.”

NNSA officials said the new surveillance program was focused on aging issues and filling knowledge gaps about critical warhead performance parameters, as opposed to old methods that looked to identify problems with warheads due to faulty design, production or changes. NNSA officials also told the IG that the new surveillance program “provides flexibility by matching the number of units [examined] and the types of tests to the specific data needs of each weapons system.”

The IG auditors concluded that they saw nothing “inappropriate” about NNSA’s new surveillance approach, but said that because of the highly technical nature of the changes, they were unable to “independently determine whether previously backlogged tests were properly eliminated or appropriately absorbed into the new testing approach.”

NNSA officials declined to respond specifically to the JASONs’ concern about the surveillance program. But in a statement, the agency suggested that, in general, the unclassified summary released publicly did not tell the whole story, and that the full classified JASON report “validated” the agency’s stockpile program.

“While we endorse the [JASON] recommendations and consider them well-aligned with NNSA’s long-term stockpile management strategy, certain findings in the unclassified executive summary convey a different perspective on key findings when viewed without the context of the full classified report,” NNSA said.

“The full report addresses them comprehensively and validates our basic scientific approach to warhead life extension programs, specifically our commitment to evaluating each weapons system on a case-by-case basis and applying the best technological approach from a spectrum of options.”

The JASON report drew praise from leaders of the House Armed Services Committee’s subcommittee on strategic forces, which asked for the independent review. Subcommittee Chairman James Langevin (D-R.I.) and ranking Republican Rep. Michael Turner (Ohio) said they shared the JASONs’ concern about the threat of eroding expertise in the weapons complex and that the report backed their recent legislation establishing a stockpile management program within NNSA to guide warhead life extension decisions.