By Julia Sklar | MIT News

“Energy is incredibly fundamental to life,” MIT graduate student Ruaridh Macdonald says. “That’s why I keep studying it.”

This tenet has been the thread throughout Macdonald’s nearly eight years at MIT — first as an undergraduate, then as a master’s student, and now as a PhD student — all spent studying nuclear science and engineering. Though he has remained engaged in this one department, he’s participated in a variety of projects, first studying reactor design as he pursued his master’s degree and now working on a nuclear weapons verification project in the Laboratory for Nuclear Security and Policy.

Transportable reactors

Macdonald, who grew up in West London, spent his grade school days equally interested in the arts and humanities and in physics. But he ultimately chose physics when faced with the U.K.’s school system, which requires students to pick a concentration, similar to a major in college.

“I still have immense respect for the arts, but I asked myself which would allow me to help people most broadly, and I chose science,” Macdonald says.

His view of energy’s fundamental role in life is deeply rooted in the fact that so much of the world still doesn’t have access to it. Believing in the potential of nuclear energy as a clean, cheap source of power, Macdonald immediately dove into the subject at MIT. And as a master’s student, he worked on designing small, transportable nuclear reactors specialized to run in remote, isolated, and off-grid locations. The possibility of their widespread use invigorated him, but the slow movement from scientific discovery to real-world use frustrated him.

A timely pursuit

Moving on to the PhD program in MIT’s Department of Nuclear Science and Engineering, Macdonald resolved to find another, more readily applicable outlet for his interest in nuclear science, landing him in a lab that tackles an especially timely issue: how to ensure that countries with nuclear weapons abide by disarmament agreements.

The linchpin of these agreements is being able to verify that the signers are following the rules. But the trick, Macdonald says, is for both sides — or a third party — to be able to police weapons in a way that doesn’t give out too much information about them. If the U.S., for example, were to inspect a Russian weapon, in the process they might also be able to gather valuable information about how it was built — not information that governments want other countries to have.

Macdonald is involved in a project, called Zero Knowledge Warhead Verification, that tackles this problem with a beam of light, a scrambler, and a detector. Objects are made up of nuclei, which each give off a unique glow when hit with a gamma ray; the specific glow of an object acts like a fingerprint to identify what isotopes it’s made of. By carefully repeating this process from multiple angles, a nuclear weapon can be identified based on the composition and distribution of its isotopes.

To provide just enough of this identifying information, but no design information on a weapon, Macdonald says that the weapon is illuminated by the gamma ray beam; the resulting information is then passed on to a scrambler that mixes up the signals before reaching a detector. The resulting signal is then compared with one from a known weapon to see if they match. As both signals are scrambled, the inspector learns nothing useful about either, preserving the owner’s secrets — similar to the idea of “hashing” in digital cryptology.

Room for discovery

The project is one year into a five-year-long effort in which Macdonald and his colleagues are also working with Department of Energy labs to design such a verification device. And the lab work, necessarily, is acutely linked with on-the-ground politics.

While Macdonald remains focused on the science end of things, there are policy specialists — advisors and graduate students alike — among the lab members. Their job is to make sure that at the end of the day, the verification device he’s working to develop is not, as he says, “something that doesn’t actually matter, but is just scientifically interesting,” but is rather something that could be used by nations to uphold disarmament agreements.

Though Macdonald remains unsure exactly where his future will take him, he’s sure why he’ll stick with energy, and probably nuclear science: Apart from its role in creating an energy alternative, part of what drew him to nuclear science in the first place was its relative newness as a subject.

“If you think about it, nuclear engineering is really only 50 or 60 years old at this point,” Macdonald says. “That’s really young in the science world, and it leaves a lot of room for discovery.”


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AuthorLaboratory for Nuclear Security & Policy

Twenty-nine of the nation's leading scientists and nuclear arms-control experts—including former nuclear-weapon designers, White House science advisers, and Nobel laureates—co-signed a letter to President Obama on Saturday supporting the nuclear deal. Among them were MIT professors Frank Wilczek (physics) and R. Scott Kemp (nuclear science and engineering).

The letter, written by Richard L. Garwin, Robert J. Goldston, Rush D. Holt, R. Scott Kemp, and Frank N. von Hippel, highlights their judgment that before the agreement Iran was only a few weeks away from having fuel for a nuclear weapon, whereas under the agreement it would take Iran many months, leaving adequate time for international response. The letter concludes that the agreement, if accepted by Congress, would "advance the cause of peace and security in the Middle East and can serve as a guidepost for future nonproliferation agreements."

The five authors and 24 co-signers are some of the world's most knowledgeable experts about nuclear weapons. Garwin, a physicist who helped design the world's first hydrogen bomb, served as a science advisor to three presidents, both Democrat and Republican.

Kemp, before founding MIT's Laboratory for Nuclear Security and Policy, served in Obama's State Department as the science advisor responsible for building the technical basis for a negotiated settlement with Iran. He is an expert on clandestine nuclear proliferation and centrifuge technology.

Holt, former deputy director of the Princeton Plasma Physics Laboratory (PPPL) and a former member of Congress, initiated the effort. He now leads the American Association for the Advancement of Sciences, the world’s largest general scientific society.

Frank von Hippel, a Princeton physicist, served as assistant director for national security in the White House Office of Science and Technology Policy during the Clinton administration and was previously instrumental in stemming the buildup of weapons between the Soviet Union and the West.

Among the co-signiners are Siegfried Hecker, a Stanford professor and former director of the Los Alamos nuclear-weapons laboratory; Freeman Dyson of the Institute for Advanced Study; Sidney Drell of Stanford; and Nobel laureates Philip Anderson, Leon Cooper, Sheldon Glashow, David Gross, Burton Richter, and Frank Wilczek.

The letter and a full list of signers can be viewed here.

Secretary of State John Kerry's Remarks citing the letter.


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AuthorLaboratory for Nuclear Security & Policy

LNSP received three grants to support new research directions related to its flagship projects on nuclear warhead verification and cargo inspection.

In May 2015, the Carnegie Corporation of New York awarded Prof. R. Scott Kemp a two-year grant to support interdisciplinary scholars working in nuclear security. The funds will support graduate students studying information transport, formal models, and U.S.-Russian cooperation related to LNSP's Zero Knowledge Warhead Verification System.

In June, MIT's Research Support Committee awarded Kemp an NEC Corporation Fund Award for Research in Computation and Communications. The award supports research on physical cryptography, the foundational method upon which LNSP's Warhead Verification System is built.

The Research Support Committee also awarded a Charles E. Reed Faculty Initiative grant to Prof. Areg Danagoulian for new work on monochromatic photon generation. The proposed experiment could improve the applicability of Nuclear Resonance Fluoresence techniques for isotope identification in nuclear security applications by reducing dose while dramatically improving signal-to-background rates.

"We are absolutely delighted to have received these awards," said Prof. Kemp, "The Carenegie and NEC awards will enable us to study a range of important interdisciplinary questions in warhead verification that go beyond the applied nuclear-physics program already supported by the National Nuclear Security Agency. The Reed Award will open up a new area of investigation for LNSP in photon sources related to both of our monochromatic-based projects."


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AuthorLaboratory for Nuclear Security & Policy

The U.S. drafted Parameters for a Joint Comprehensive Plan of Action (JCPOA) between the EU/E3+3 negotiators and Iran is a remarkable achievement. It has excellent specificity on technical constraints, timelines, and sequencing. The terms spell out a fair and equitable deal for all parties. JCPOA will allow Iran's peaceful nuclear program to grow at a natural pace, is effectively verifiable, and provides a solid fifteen year window during which the United States and other members of the P5+1 can build stronger relationships with Iran to reduce Iran's incentives for nuclear weapons. The negotiators are to be congratulated!

There are, however, important outstanding elements that must be clarified in the coming months. The text of the JCPOA says that no uranium enrichment will occur at Fordow, and that approximately two-thirds of the current 2976 centrifuges installed there will be removed. This leaves about 1000 centrifuges at Fordow, with some fraction enriching elements other than uranium. Although the Fordow capability is notionally a non-uranium capability, unless specifically designed to be incompatible, those centrifuges could be rapidly repurposed for enriching uranium under a breakout scenario. If those centrifuges are only first generation IR-1 centrifuges, they will not significantly affect the breakout calculation. U.S. officials have confirmed that this is their understanding, however, the text of the terms released leaves some ambiguity.

Other oustanding questions do not enter the breakout calculation, but are nonetheless important and will take considerable effort. For example, the extent of research allowed could be more carefully sepecified: will research on laser enrichment or other isotope separation and isotope breeding techniques be allowed at sites other than Fordow? Also, the mechanism by which Iran will maintain its LEU inventory below 300kg UF6 needs to be specified. The parameters for the redesign of the Arak reactor are already well in hand, but arrangements for exporting spent fuel will be difficult to negotiate. Principles for the long-term enrichment plan beyond 15 years needs to be resolved.

Many of these outanding areas are also issues for other emerging nuclear-power countries. The excellent work of the negotiating teams lays the ground not only for a peaceful resolution of the Iran nuclear issue, but can also help address the connection between nuclear power and nuclear proliferation more generally. If it takes up the charge, Iran can become a leader in securing a world free of nuclear weapons, helping to find ways for others to share in the fruits of nuclear energy.


R. Scott Kemp
Assistant Professor of Nuclear Science and Engineering
Massachusetts Institute of Technology


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AuthorLaboratory for Nuclear Security & Policy

Mareena Robinson | Nuclear Science and Engineering

On Nov. 19, the MIT chapters of Global Zero and Radius hosted a roundtable discussion on the status of negotiations between Iran and the E3+3 the United States, Russia, China, the United Kingdom, France, and Germany—about Iran’s nuclear program. The discussion covered the history of the diplomatic process, the forces influencing current negotiations, and the likelihood and implications of a successful agreement.

Prof. R. Scott Kemp, former Science Advisor at the U.S. Department of State's Office of the Special Advisor for Nonproliferation and Arms Control.

Prof. R. Scott Kemp, former Science Advisor at the U.S. Department of State's Office of the Special Advisor for Nonproliferation and Arms Control.

R. Scott Kemp, an assistant professor in the Department of Nuclear Science and Engineering (NSE) at MIT and director of the MIT Laboratory for Nuclear Security and Policy (LNSP), led the discussion. Before joining the faculty, Kemp served as science advisor in the U.S. State Department’s Office of the Special Advisor for Nonproliferation and Arms Control, where Iran was his primary responsibility. He has continued to participate in Track II talks—those involving non-state individuals and groups—since leaving government service.

Kemp brought a mix of technical and political insights to the discussion, covering many intricacies of the diplomatic constraints. The event opened with Kemp setting the stage for the current negotiations, beginning with the inauguration of President Hassan Rouhani and the appointment of Foreign Minister Mohammad Javad Zarif as Iran's chief negotiator. Kemp asserted that this change in leadership marked a political shift that opened up the possibility of engagement that was not possible with the previous Iranian administration. On November 24, 2013, the new leadership agreed to a Joint Plan of Action that froze escalatory actions on both sides. After an extension in July of this year, the one-year anniversary and putative deadline for an agreement is now just days away.

Kemp said it was very unlikely that a final agreement would be reached by the November 24, 2014 deadline. "I'm sorry to say, but there is virtually no chance that a final deal will happen by Monday,” Kemp said, “but that's not as bad as it sounds." It is still possible, he added, that negotiators might achieve agreement on a framework for the broad outlines of a deal. Kemp said the element of brinkmanship pushes important decisions to the deadline. He reported that the Nov. 9–10 meeting between Foreign Minister Zarif, U.S. Secretary of State John Kerry, and EU envoy Catherine Aston was unproductive beyond reaffirming that all sides continue to believe that a deal is in the best interest of all parties and that an extension of some sort seemed likely.

Kemp identified three primary issues that remain unresolved: the size of Iranian stockpiles of low-enriched uranium, the duration of the period for which Iran would accept restraints and special inspection provisions, and the number of centrifuges Iran would operate during that period. Based on his expertise in enrichment technology, Kemp explained the tradeoffs between these parameters. The mission of the E3+3 negotiators is to lengthen Iran's nuclear "breakout" time to something like 12 months by reducing the number of centrifuges in operation and the stockpile of enriched uranium in Iran's possession. Iran, by contrast, argues that it needs to retain a significant capability because of their future civil energy plans and face-saving considerations. Based on personal conversations with Foreign Minister Zarif, however, Kemp articulated reasons why believed these claims were not the entire story. Kemp had proposed to Zarif several ways Iran could retain its centrifuges by using them for non-provocative purposes, such as enriching molybdenum for medical purposes. Zarif appeared uninterested in non-uranium alternatives, suggesting that Iran saw its nuclear program as having a military-strategic value.

Aron Bernstein, a professor in the MIT Physics Department and faculty advisor for MIT’s Global Zero, echoed Kemp's view, arguing that Iran’s enrichment capabilities serve as a "virtual nuclear weapon," giving the Iranian leadership the option to arm themselves in the future. In addition to this, Kemp explained that nuclear capabilities, whether for civilian or military purposes, are an intense source of pride for the Iranian public, making it difficult for the leadership to relinquish these capabilities while preserving their dignity.

Many other issues were discussed during the 90-minute roundtable, including the response of Saudi Arabia to a successful deal between Iran and the West, and how a final agreement would impact the strategic calculus for Israel. While nobody in the room was confident in predictions about the future, participants did agree that a successful deal would be a productive step towards lowering the tension between Tehran and the West. Kemp articulated a large agenda of foreign-policy items for which a warming of relations with Iran would be useful, including the problems of ISIS and Middle East stability.

Mareena Robinson-Snowden, the president of the MIT chapter of Global Zero and a fourth-year doctoral candidate in the NSE department, described the event as "an opportunity to explore the various issues influencing the success of this deal and provide people with a forum to discuss the meaning and impact of this event at the ground level. The entire world is awaiting the outcome of these negotiations, and will be actively listening to the decisions announced on the morning of November 25th."


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AuthorLaboratory for Nuclear Security & Policy