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 Debate, CRS In Focus, updated January 10, 2020
Defense Primer: Strategic Nuclear Forces, CRS In Focus, updated January 10, 2020
Defense Primer: Command and Control of Nuclear Forces, CRS 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.
DOE Seeks to End MOX Plutonium Disposal Program
The Trump Administration requested $220 million next year “to continue the orderly and safe closure of the Mixed Oxide (MOX) Fuel Fabrication Facility.”
The MOX Fuel Fabrication Facility was intended to eliminate excess weapons-grade plutonium by blending it with uranium oxide to produce a “mixed oxide” that is not suitable for nuclear weapons. The Administration proposes instead to pursue a “dilute and dispose” approach.
Termination of the MOX Facility in South Carolina had previously been proposed — but not approved — in budget requests for the last two years, due to mounting costs.
“Construction remains significantly over budget and behind schedule,” the Department of Energy said in a November 2017 report to Congress. “The MOX production objective was not met in 2015 or 2016 and will not be met in 2017.”
“Due to the increasing costs of constructing and operating the MOX facility, both the Department’s analysis and independent analyses of U.S. plutonium disposition strategies have consistently and repeatedly concluded that the MOX fuel strategy is more costly and requires more annual funding than the dilute and dispose approach,” the DOE report said. The report was released by DOE under the Freedom of Information Act.
Though disfavored by the Administration, the MOX program has a champion in South Carolina Senator Lindsay Graham. “I will fight like crazy” to preserve it unless he is convinced that a superior alternative exists, he said at a February 8 hearing of the Senate Armed Services Committee.
Detailed background on the MOX program can be found in Mixed-Oxide Fuel Fabrication Plant and Plutonium Disposition: Management and Policy Issues, Congressional Research Service, December 14, 2017.
The latest proposal to terminate the MOX program was reported in “Aiken County legislators unsurprised by Trump’s anti-MOX budget” by Colin Demarest, Aiken Standard, February 19.
Pluto Flyby Mission Powered by Plutonium
News of the Earth these days is such that one welcomes news from elsewhere, especially when it concerns a prospect as spectacular as the impending flyby of Pluto by the NASA spacecraft New Horizons that will take place on July 14.
In reality, of course, New Horizons also represents news from Earth, having been built by humans and launched from Cape Canaveral in January 2006. Moreover, the New Horizons probe is not simply a technological artifact; it is the result of a political process and a policy debate. At issue were not only the parameters of the mission — its scope, timing, budget, and so on — but also the fact it uses a nuclear power source fueled, appropriately if controversially, by plutonium.
The plutonium-238 isotope used by New Horizons is an exceptionally hazardous material that is dangerous to produce, manufacture into suitable form, handle, transport and launch. The hazards are sufficient, in the eyes of some, to preclude its use altogether.
NASA and Department of Energy engineers did not dismiss public concerns about the safety of plutonium-fueled power sources, but they argued that the risks could be mitigated to an acceptably low level by proper design.
“Safety was the principal design driver for the [plutonium-fueled General-Purpose Heat Source used aboard New Horizons],” according to a 2006 retrospective account of its development. “The main safety objective was to keep the fuel contained or immobilized to prevent inhalation or ingestion by humans.” See “Mission of Daring: The General-Purpose Heath Source Radioisotope Thermoelectric Generator” by Gary L. Bennett, et al.
In effect, the design of the plutonium power source was predicated on the assumption that a launch accident or other mishap would occur, and that any resulting health and safety impact had to be minimized. Simulations were performed to validate the design, but fortunately no real-world test of the safety of the device under extreme conditions ever came to pass.
The GPHS plutonium power source has been used successfully on some of the boldest and most productive missions of space exploration ever undertaken, including Galileo, Ulysses, Cassini, and New Horizons.
For the most part, these missions were conducted with commendable openness, especially in earlier years. When one young critic raised questions about the use of plutonium power sources and the hazards of high-velocity Earth flybys in the Galileo mission prior to its 1989 launch, project manager John Casani of NASA Jet Propulsion Laboratory forthrightly invited him to come inspect the spacecraft in its clean room at JPL and to discuss the alternatives.
“Pluto is going to change us,” wrote analyst Dwayne Day last month, anticipating the possible consequences of the New Horizons mission for science, art, culture, politics, and space policy. See “Deep in space, corner of No and Where,” The Space Review, June 15, 2015.