Future arms control agreements may require trusted verification mechanisms aimed at confirming the authenticity of items presented as nuclear warheads. In the last five years, our team has been pioneering a warhead verification approach based on the cryptographic concept of zero-knowledge proofs. This approach could allow the authentication of nuclear warheads without sharing any design information.
The original idea was published in Nature in June 2014. Since then, we have been working on the development of a zero-knowledge object-comparison system and the procedures for its use in nuclear warhead inspections. The demonstration of such a system is now outlined in a Nature Communications article published on September 20, 2016.
For more information, you can check our zero-knowledge warhead verification project page. The Princeton Plasma Physics Laboratory has made a video about the experiments (see the press release here).
Alex Wellerstein has written a nice story about our work and experiments in the New Yorker.
The Nuclear Futures Lab has recently established a presence at StudioLab — a new 2500 sq. ft space on campus developed by the Council on Science and Technology to bring together students, faculty and staff, independent of area of concentration, to explore the intersections and shared creativity across STEM, the arts, humanities, and social sciences. Programmatic initiatives within the StudioLab will include courses, labs, studios, research, projects, workshops and events.
The NFL recently installed its Full Motion Virtual Reality (FMVR) system in the space, which will give students and faculty new opportunities to conduct research through virtual reality. The NFL is currently using the system to design and examine new treaty verification systems and architectures for nuclear arms control. Notional facilities and weapons are built as 3D models, and when these are brought to life in FMVR, researchers are able to conduct live, immersive simulations that will help to hone effective verification options for future treaties.
For this first demonstration, we tried to implemented all key steps of a zero-knowledge inspection using 14-MeV DT neutron radiography with test items represented by patterns of steel and aluminum cubes. We were able to preload the bubble detectors with the complement of the radiograph of a reference item and, by subsequent irradiation, verify whether items presented for inspection were identical to the reference item or not. We confirmed that the results yielded “zero information” when valid items were tested and successfully identified tampered items for four different diversion scenarios.
Watch this space for updates as we evaluate new measurements and write up the journal version of the paper.
In April 2015, Iran and the E3+3 nations negotiated a framework for a “comprehensive solution that will ensure the exclusively peaceful nature of the Iranian nuclear program.” The final settlement, expected by July 2015 or soon after, would constrain Iran’s activities for various extended periods in return for the lifting of sanctions and affirm Iran’s right to pursue its nuclear program free of the limits on its uranium enrichment capacity a decade or more from now. What happens when these restrictions begin to phase out?
In our recent Science Perspective piece, we outline one approach to limit the long-term risk by using the next 10 years to convert Iran’s national enrichment plant into a multinational one, possibly including as partners some of Iran’s neighbors and one or more of the E3+3 countries.
Here is a summary of our current areas of research:
Nuclear Disarmament Verification. Our research focuses on new concepts and technologies that can help support verification approaches for nuclear disarmament in two main areas: the treatment of fissile materials in future arms-control regimes and the verification of nuclear warheads slated for dismantlement. We are also part of the new Consortium for Verification Technology and PhD projects could involve internships at a U.S. National Laboratory.
Research on disarmament verification places a strong emphasis on warhead counting and on verified nuclear warhead dismantlement, which might become necessary for deep-cuts arms control regimes. We pursue several technical approaches in this area. Our work combines neutron physics, computer modeling, and experimental work at the Princeton Plasma Physics Laboratory (PPPL).
Nuclear Power. Our research explores the shapes of alternative nuclear futures looking in particular at emerging technologies, many still in the R&D stage, that may be potential game changers for nuclear power. The main emphasis is currently on analyzing and assessing proposed small modular reactor (SMR) designs, which are potentially better suited for a modern electric grid with more distributed power generation and could also offer increased safety and security through underground siting. Some designs also envision much longer core-lives and promise lower proliferation risks.
Please write to Alexander Glaser if you have questions about admission procedures, the Laboratory’s activities and possible topics for a thesis.
In the negotiation over Iran’s nuclear program there currently appears to be an unbridgeable gap between Iran’s minimum requirement for enrichment capacity, the equivalent of the approximately 10,000 IR-1 centrifuges currently operating at Natanz, and the U.S. upper limit, which appears to be considerably lower. But there is another variable which also determines how quickly Iran could produce enough 90% enriched uranium for a nuclear explosive if it broke its commitment to stay below 5% enrichment. This variable is the size of Iran’s stockpile of up-to-5%-enriched uranium. Having a large stockpile of low-enriched uranium to feed into its centrifuge cascades shortens by a factor of three, e.g. from six to two months, the time that it would take to produce enough 90% enriched uranium for a bomb.
In this memo, first circulated in late September, Frank von Hippel and Alex Glaser show that it would be possible to reduce Iran’s current stockpile of 5,000 kg of low-enriched UF6 to about 200 kg made possible by using a smaller (12-inch) cylinder for enriched uranium. This would make it possible to recover the factor of three in breakout time and might make it possible for the P5+1 to raise their upper limit on Iran’s centrifuge capacity.
Our book is finally out, and we had the opportunity to present it yesterday at the Carnegie Endowment for International Peace in Washington, DC. Our argument is based on a very simple premise: Banning nuclear weapons will not end the threat of nuclear war and nuclear explosions if countries continue to make, stockpile, and use the fissile materials that make nuclear weapons possible. International efforts to abolish nuclear weapons and to prevent proliferation and nuclear terrorism so far have been acting largely in parallel with no comprehensive underlying strategy. With now enough fissile material around for about 200,000 nuclear weapons, we propose a new framework that puts these materials front and center. We propose a set of policies to drastically reduce fissile material inventories worldwide with a view to their total elimination as irreversibly as possible. Put simply, no material, no problem.
Molten salt reactors (MSRs) are often advocated as a radical but worthwhile alternative to traditional reactor concepts based on solid fuels. In a paper published in the Annals of Nuclear Energy in January 2015, Ali Ahmad, Edward McClamrock and Alexander Glaser study the resource requirements and proliferation-risk attributes of denatured molten salt reactors.
The analysis presented in the paper confirms that MSRs could offer significant advantages with regard to resource efficiency compared to conventional thermal reactors based on light-water reactor technology. Depending on specific design choices, even fully denatured reactors could reduce uranium and enrichment requirements by approximately a factor of 3–4, even when operated on an open fuel cycle. As for the implications associated with proliferation risk, fully denatured single-fluid reactors using low-enriched make-up fuel appear as the most promising candidate technology minimizing overall proliferation risks and should, in our view, therefore receive particular attention despite being less attractive from the perspective of resource utilization.
We have put together a webpage summarizing the main challenges of nuclear disarmament verification and the concept of the template approach for warhead authentication, which is the basis for the Nature article from June 2014. The page also provides a brief overview of other verification projects currently underway and includes a list of useful readings.
Zia Mian and Alex Glaser presented at the 2014 NPT Prepcom in New York on behalf of the International Panel on Fissile Materials on next steps the nuclear weapons states can take to increase transparency of their nuclear weapon and fissile material stockpiles as part of meeting their obligations under the NPT 2010 “Action Plan on Nuclear Disarmament.”
The presentation (PDF) was co-sponsored by the Missions of the Netherlands and of Japan, represented by Ambassador Henk Cor van der Kwast of the Netherlands and Ambassador Toshio Sano of Japan.
We are happy to announce that we are part of the consortium that has been awarded the $25 million five-year grant to improve nuclear arms control verification technology (see NNSA press release from March 31, 2014). The consortium will be led by the University of Michigan, and also involves MIT, Columbia, North Carolina State, University of Hawaii, Pennsylvania State, Duke, University of Wisconsin, University of Florida, Oregon State, Yale, and the University of Illinois at Urbana Champaign.
Princeton leads a key research thrust of the consortium focused on the relevant policy dimensions: “Treaty Verification: Characterizing Existing Gaps and Emerging Challenges.” Together with PPPL, we will also be able to expand our technical work on zero-knowledge approach to nuclear warhead verification and will be developing a virtual environment to support development, testing, and demonstration of verification approaches for these treaties. We will report regularly at nuclearfutures.princeton.edu on the progress of this exciting opportunity. Watch this space.
We have recently published an article on Iran’s Arak reactor in the April 2014 issue of Arms Control Today, proposing technical steps that would provide assurance that Iran could not quickly make sufficient plutonium for a nuclear weapon with the Arak reactor (A Win-Win Solution for Iran’s Arak Reactor, by Ali Ahmad, Frank von Hippel, Alexander Glaser, and Zia Mian). The suggested redesign of the Arak reactor would reduce plutonium production to less than one kilogram per year, comparable to the reduction that would be accomplished by replacing the Arak reactor with a light-water research reactor. At the same time, the proposed changes would not reduce the usefulness of the reactor for making radioisotopes and conducting research. We believe, this approach would meet Iran’s needs and would address the concerns of the international community as reflected by the P5+1.
The story has been picked up quite widely beginning on April 2, 2014, with a Reuters article.
Not only was the 2013 Nobel Peace Prize announced today, we are also happy to report that M. V. Ramana and Zia Mian were recognized this week for their work on global security issues. M. V. Ramana together with R. Rajaraman (Jawaharlal Nehru University, New Delhi) has received the American Physical Society’s 2014 Leo Szilard Award “for outstanding contributions to promote global security issues, through critical analyses of nuclear weapons and nuclear energy programs in India and associated risks in the subcontinent, and efforts to promote peace and nuclear security in South Asia though extensive engagements and writings.” The Leo Szilard Award was established to recognize outstanding accomplishments by physicists in promoting the use of physics for the benefit of society in such areas as the environment, arms control, and science policy. Zia Mian has been awarded the 2014 Linus Pauling Legacy Award on the occasion of the fiftieth anniversary of Linus Pauling’s receipt of the Nobel Peace Prize. The award was established in 2001 to honor individuals who have achieved in areas of interest to Linus Pauling.
The field of nuclear archaeology aims to develop the methods and tools to verify past production of fissile materials for military purposes, which may become necessary to support the verification of future arms control agreements that envision deeper cuts in the nuclear arsenals. So far, techniques have been successfully demonstrated for reconstructing historic plutonium production, especially in graphite-moderated reactors, but nuclear archaeology for uranium enrichment has proven much more challenging.
During the 2013 Annual INMM meeting, Sebastien Philippe and Alex Glaser presented a paper on nuclear archaeology for gaseous diffusion enrichment plant (GDEP). Gaseous diffusion was historically the most widely used technology for military production of highly enriched uranium. We propose a new approach to verify the production history of GDEP based on a mathematical model of a reference plant cascade and a nuclear forensic analysis of solid uranium particles deposited over time in the tubular separation membranes of the stage diffusers. Have a look (paper, slides).
Princeton University (and PPPL) recently ran a story about our nuclear warhead verification project, which has been picked up by some news media, including Gizmodo.
As a quick follow up: We will have a new paper with our most recent results, so far all based on MCNP computer calculations, at the INMM Annual Meeting this July in Palm Desert. In the meantime, here is a set of slides from a recent talk at Yale summarizing additional details of the proposed protocol and some initial simulated results.