By Laura Schmidt-Hong | The Tech
As much as nuclear technology and engineering are rooted in physics and radiation, reactors and weaponry, they also involve stories of politics and negotiation, history and diplomacy. The gray decades of the Cold War and today’s evolving landscape of nuclear stability and international relations are inextricable from the technology that drives them. This sort of interdisciplinary symbiosis inspires Scott Kemp’s work in MIT’s Laboratory for Nuclear Security and Policy (LNSP).
A physicist by training, Kemp first became interested in applying politics and history to nuclear science after working in international relations and realizing the need for technical expertise in policy making. Working in the State Department as a science advisor, he noticed that “there’s a tremendous amount of policy, especially in the security space, that just makes no scientific sense whatsoever.” He earned his PhD in Public and International Affairs from Princeton University, where he wrote two dissertation-length analyses: one in history and one in nuclear engineering. The works were “essentially on the same topic, but from two different perspectives,” he said.
Now, as an associate professor of nuclear science and engineering and director of the LNSP, Kemp brings the same interdisciplinary focus to the lab. He works alongside physicists and chemists whose combined expertise enables them to solve problems and develop strategic tools.
Since its inception six years ago, the lab’s research has focused primarily on developing effective methods for treaty verification. Such verification is necessary to ensure that each nation committed to a nuclear treaty truthfully reports the number of warheads in their arsenal. Ensuring accurate self-reporting requires both political and technological approaches.
Inspired by information theory and cryptography, Kemp and Areg Danagoulian ’99, professor of nuclear science and engineering, have developed direct warhead verification protocols that can, in principle, verify the authenticity of a nation’s warheads while maintaining the secrecy of their design. Kemp explained that computers are rather poor tools to carry out such protocols: “all that does is put the burden of confidence on a computer system, and no one can prove that a computer does only what it’s supposed to do and nothing else.” Rather than using computers, they built physical systems that can apply information protection concepts. One such system is a physical implementation of a one-time pad — an encryption technique that involves a single-use key shared between two parties. This method is “the only provably secure form of encryption,” said Kemp, making it uniquely useful for treaty verification. Another system, inspired by zero-knowledge proofs, returns a null result when it compares two identical objects.
The financial stakes of all these efforts are high. According to Kemp, the United States will spend over one trillion dollars over the next three decades revamping their nuclear arsenal. That spending hinges on the United States’s conception of other nations’ nuclear postures and doctrines.
Another necessary element of verification is reconstructing the history of nuclear weapons production programs, particularly secret ones. If one day the United States negotiates a disarmament agreement with North Korea in which it relinquishes its nuclear weapons, Kemp anticipates a new question: how can the United States know how many nuclear weapons North Korea should give up?
Analytical chemistry methods developed by the LNSP may provide the answer. In a collaboration with his colleague Michael Short PhD ’10, professor of nuclear science and engineering, Kemp took advantage of the science behind alpha radiation and its effects on the microstructure of nuclear hardware. Uranium-238, the most abundant isotope of uranium found in nature, and uranium-235, the predominant isotope used in nuclear weaponry, emit alpha particles of different energies when they radioactively decay. As a result, they deposit energy at different depths, in what are known as bragg peaks, inside the materials that make up physical equipment, he said. In turn, scientists can estimate which isotopes of gaseous uranium are present in nuclear machinery by quantifying the radiation damage inside and applying conservation laws.
Kemp noted that this research manifests itself in the lab just like any other research, with one key distinction. “it’s benchwork, and it’s dirty… and it looks like any other lab,” but “it’s been selected to have this particular national security impact.”
Ultimately, through their efforts, Kemp and Short have successfully developed a method to measure structural changes from radiation in the plastic gaskets used in nuclear plants. They are still working to apply the same approach to metal parts, whose chemistry makes them more difficult analytical targets.
The lab and its research have not been immune to recent changes in the politics of nuclear technology and security, however. Kemp had a hand in developing the Iran nuclear deal, through consultations with the State Department and meetings with Iranian officials. When the United States withdrew from the deal and Trump launched a dialogue with North Korea, the LNSP began exploring ways to bring North Korea “into the fold,” Kemp said. In particular, he hopes to develop cooperative opportunities to increase the safety of North Korean reactors, manage its nuclear waste disposal, and use these efforts as a first step in building trust, he said.
Down the road, Kemp envisions the lab similarly extending its focus beyond nuclear security to “any kind of role technology might have” in existential security.
As they begin to explore the security considerations of decarbonization technologies, for instance, energy policy has captured Kemp and the department of nuclear science’s interest. In seeking the “optimal path to decarbonizing the electricity sector,” they hope to determine whether decarbonization technologies create or solve security problems. According to Kemp, vulnerabilities in the United States’ electric grid can be secured with improved planning of how new generation and transmission technologies are deployed.
Through the lab’s current and future work, Kemp ultimately hopes to maintain the interdisciplinary lines of thinking that have always inspired his and the LNSP’s research. “In an era where technology has, in a sense, outpaced our morality,” he said, it is necessary to understand that the “ability to use technology for good or for evil is so powerful that we need institutions and policies to deal with it.”
In the long run, said Kemp, “if you want to use technology to effect positive change in the world, you first need to be equipped with the skills to understand how the world works.”