Secrecy News

NNSA Moves to Expand Plutonium Pit Production

The National Nuclear Security Administration said last week that it will proceed with a plan to sharply expand production of plutonium “pits” — the explosive triggers for thermonuclear weapons — without performing a full “programmatic” environmental review.

NNSA envisions producing “no fewer than 80 pits per year by 2030,” including a minimum of 30 pits per year at Los Alamos National Laboratory and a minimum of 50 pits per year at the Savannah River Site. Currently, “less than 20 per year” are produced, all at Los Alamos.

It is “NNSA’s determination that no further NEPA [National Environmental Policy Act] documentation at a programmatic level is required,” the agency said in a January 8 Federal Register notice. (Site-specific assessments will still be prepared for plutonium pit production at Los Alamos National Lab and the Savannah River Site.)

Environmental and anti-nuclear groups cried foul. “NNSA’s refusal to complete programmatic environmental review before plunging ahead with plans to more than quadruple the production authorization for plutonium bomb cores flies in the face of our country’s foundational environmental law, the National Environmental Policy Act, and a standing federal court order mandating that the government conduct such a review,” said Marylia Kelley of Tri-Valley CAREs.

In response to public comments challenging the basis for increased pit production, NNSA said that it is obliged by law to pursue the goal of producing “no fewer than 80 plutonium pits per year by 2030.” (The exact numbers are classified.)

“These requirements are contained in federal law and national policy,” the agency said. “Contentions that there is no need for new pits are not consistent with federal law, the 2018 NPR [Nuclear Posture Review], and national policy.”

That doesn’t mean that the new pit production goal is sensible (or achievable). “The 80 pits/year requirement comes from dividing 4,000 pits by 50 years,” said Frank von Hippel of Princeton University. “We have fewer than 2,000 pits deployed. Do we need to refabricate twice as many?” (See also “Why 80? Defense leaders discuss the need for plutonium pits,” Aiken Standard, December 28).

Meanwhile, Congress has substantially increased funding for new pit production. Details of recent budget action in this area were described in “Energy and Water Development Appropriations: Nuclear Weapons Activities,” Congressional Research Service, updated January 6, 2020 (see esp. “strategic materials,” pp. 10-11).

NNSA explained its view of the need to proceed with expanded pit production, including responses to public comments, in a December 2019 Final Supplement Analysis.

“The size and composition of the U.S. nuclear weapons stockpile is determined annually by the President,” NNSA said. The agency “lacks discretion to consider alternatives outside of national policy.”

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Plutonium aging and its implications for new pit production were discussed by the JASON science advisory panel in a new letter report to the Department of Energy. See Pit Aging, November 23, 2019.

The JASONs affirm that plutonium pit aging — which can result in degraded performance over the long term — is a real phenomenon, but they said that for now this does not create any “impending issues” for the nuclear weapons stockpile. They note that there are uncertainties in the data on aging and in the corresponding modeling, and that there are steps that can be taken to reduce those uncertainties and to mitigate the effects of aging. Nevertheless, they say, pit manufacturing should be reestablished as expeditiously as possible.

The letter report, which is an unclassified overview of a longer classified report, is not the JASONs’ most illuminating work.

It is conclusory and “it provides no data at all on anything” to support its call for expedited pit production, said Stephen Young of the Union of Concerned Scientists. “It is completely different than the ground-breaking 2007 [JASON] report, which gave a clear, concrete assessment of pit lifetime that was far beyond previous public estimates.”

Still, some insight can be gleaned from the new report, said Steve Fetter of the University of Maryland.

“The most interesting sentence in this unclassified JASON summary is: ‘A focused program of experiments, theory, and simulations is required to determine the timescales over which Pu [plutonium] aging may lead to unacceptable degradation in primary performance’.

“This implies that experiments, theory, and simulations conducted to date have not established such timescales,” Fetter said. “In other words, there is still no answer to the question, ‘at what point does Pu aging degrade primary performance’?”

According to the 2007 JASON report, “Most primary types have credible minimum lifetimes in excess of 100 years as regards aging of plutonium.” Nearly all currently stockpiled pits were produced between 1978 and 1989.

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Recently updated reports from the Congressional Research Service on nuclear weapons include the following.

U.S. Strategic Nuclear Forces: Background, Developments, and Issues, updated January 3, 2020

Russia’s Nuclear Weapons: Doctrine, Forces, and Modernization, updated January 2, 2020

A Low-Yield, Submarine-Launched Nuclear Warhead: Overview of the Expert DebateCRS In Focus, updated January 10, 2020

Defense Primer: Strategic Nuclear ForcesCRS In Focus, updated January 10, 2020

Defense Primer: Command and Control of Nuclear ForcesCRS In Focus, updated January 10, 2020

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For the second year in a row, the Department of Defense has refused to reveal the current size of the U.S. nuclear arsenal.

The nuclear weapon stockpile numbers had previously been declassified and disclosed for each year through 2017. No justification for the change in disclosure policy was provided.

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