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      in Energy

      Team engineers nanoparticles using ion irradiation to advance clean energy and fuel conversion

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      MIT researchers and colleagues have demonstrated a way to precisely control the size, composition, and other properties of nanoparticles key to the reactions involved in a variety of clean energy and environmental technologies. They did so by leveraging ion irradiation, a technique in which beams of charged particles bombard a material.

      They went on to show that nanoparticles created this way have superior performance over their conventionally made counterparts.

      “The materials we have worked on could advance several technologies, from fuel cells to generate CO2-free electricity to the production of clean hydrogen feedstocks for the chemical industry [through electrolysis cells],” says Bilge Yildiz, leader of the work and a professor in MIT’s departments of Nuclear Science and Engineering and Materials Science and Engineering.

      Critical catalyst

      Fuel and electrolysis cells both involve electrochemical reactions through three principal parts: two electrodes (a cathode and anode) separated by an electrolyte. The difference between the two cells is that the reactions involved run in reverse.

      The electrodes are coated with catalysts, or materials that make the reactions involved go faster. But a critical catalyst made of metal-oxide materials has been limited by challenges including low durability. “The metal catalyst particles coarsen at high temperatures, and you lose surface area and activity as a result,” says Yildiz, who is also affiliated with the Materials Research Laboratory and is an author of an open-access paper on the work published in the journal Energy & Environmental Science.

      Enter metal exsolution, which involves precipitating metal nanoparticles out of a host oxide onto the surface of the electrode. The particles embed themselves into the electrode, “and that anchoring makes them more stable,” says Yildiz. As a result, exsolution has “led to remarkable progress in clean energy conversion and energy-efficient computing devices,” the researchers write in their paper.

      However, controlling the precise properties of the resulting nanoparticles has been difficult. “We know that exsolution can give us stable and active nanoparticles, but the challenging part is really to control it. The novelty of this work is that we’ve found a tool — ion irradiation — that can give us that control,” says Jiayue Wang PhD ’22, first author of the paper. Wang, who conducted the work while earning his PhD in the MIT Department of Nuclear Science and Engineering, is now a postdoc at Stanford University.

      Sossina Haile ’86, PhD ’92, the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern University, who was not involved in the current work, says:

      “Metallic nanoparticles serve as catalysts in a whole host of reactions, including the important reaction of splitting water to generate hydrogen for energy storage. In this work, Yildiz and colleagues have created an ingenious method for controlling the way that nanoparticles form.”

      Haile continues, “the community has shown that exsolution results in structurally stable nanoparticles, but the process is not easy to control, so one doesn’t necessarily get the optimal number and size of particles. Using ion irradiation, this group was able to precisely control the features of the nanoparticles, resulting in excellent catalytic activity for water splitting.”

      What they did

      The researchers found that aiming a beam of ions at the electrode while simultaneously exsolving metal nanoparticles onto the electrode’s surface allowed them to control several properties of the resulting nanoparticles.

      “Through ion-matter interactions, we have successfully engineered the size, composition, density, and location of the exsolved nanoparticles,” the team writes in Energy & Environmental Science.

      For example, they could make the particles much smaller — down to 2 billionths of a meter in diameter — than those made using conventional thermal exsolution methods alone. Further, they were able to change the composition of the nanoparticles by irradiating with specific elements. They demonstrated this with a beam of nickel ions that implanted nickel into the exsolved metal nanoparticle. As a result, they demonstrated a direct and convenient way to engineer the composition of exsolved nanoparticles.

      “We want to have multi-element nanoparticles, or alloys, because they usually have higher catalytic activity,” Yildiz says. “With our approach, the exsolution target does not have to be dependent on the substrate oxide itself.” Irradiation opens the door to many more compositions. “We can pretty much choose any oxide and any ion that we can irradiate with and exsolve that,” says Yildiz.

      The team also found that ion irradiation forms defects in the electrode itself. And these defects provide additional nucleation sites, or places for the exsolved nanoparticles to grow from, increasing the density of the resulting nanoparticles.

      Irradiation could also allow extreme spatial control over the nanoparticles. “Because you can focus the ion beam, you can imagine that you could ‘write’ with it to form specific nanostructures,” says Wang. “We did a preliminary demonstration [of that], but we believe it has potential to realize well-controlled micro- and nano-structures.”

      The team also showed that the nanoparticles they created with ion irradiation had superior catalytic activity over those created by conventional thermal exsolution alone.

      Additional MIT authors of the paper are Kevin B. Woller, a principal research scientist at the Plasma Science and Fusion Center (PSFC), home to the equipment used for ion irradiation; Abinash Kumar PhD ’22, who received his PhD from the Department of Materials Science and Engineering (DMSE) and is now at Oak Ridge National Laboratory; and James M. LeBeau, an associate professor in DMSE. Other authors are Zhan Zhang and Hua Zhou of Argonne National Laboratory, and Iradwikanari Waluyo and Adrian Hunt of Brookhaven National Laboratory.

      This work was funded by the OxEon Corp. and MIT’s PSFC. The research also used resources supported by the U.S. Department of Energy Office of Science, MIT’s Materials Research Laboratory, and MIT.nano. The work was performed, in part, at Harvard University through a network funded by the National Science Foundation. More

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      in Energy

      Dennis Whyte steps down as director of the Plasma Science and Fusion Center

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      Dennis Whyte, who spearheaded the development of the world’s most powerful fusion electromagnet and grew the MIT Plasma Science and Fusion Center’s research volume by more than 50 percent, has announced he will be stepping down as the center’s director at the end of the year in order to devote his full attention to teaching, engaging in cutting-edge fusion research, and pursuing entrepreneurial activities at the PSFC.

      “The reason I came to MIT as a faculty member in ’06 was because of the PSFC and the very special place it held and still holds in fusion,” says Whyte, the Hitachi America Professor of Engineering in the Department of Nuclear Science and Engineering. When he was appointed director of the PSFC in 2015, Whyte saw it as an opportunity to realize even more of the PSFC’s potential: “After 10 years I think we’ve seen that dream come to life. Research and entrepreneurship are stronger than ever.”

      Whyte’s passion has always been for fusion — the process by which light elements combine to form heavier ones, releasing massive amounts of energy. One hundred years ago fusion was solely the provenance of astronomers’ speculation; through the efforts of generations of scientists and engineers, fusion now holds the potential to offer humanity an entirely new source of clean, abundant energy — and Whyte has been at the forefront of that effort.

      “Fusion’s challenges require interdisciplinary work, so it’s always fresh, and you get these unexpected intersections that can have wild outcomes. As an inherently curious person, fusion is perfect for me.”

      Whyte’s enthusiasm is legendary, especially when it comes to teaching. The effects of that enthusiasm are easy to see: At the start of his tenure, only a handful of students chose to pursue plasma physics and fusion science. Since then, the number of students has ballooned, and this year nearly 100 students from six departments are working with 15 faculty members.

      Of the growth, Whyte says, “It’s not just that we have more students; it’s that they’re working on more diverse topics, and their passion to make fusion a reality is the best part of the PSFC. Seeing full seminars and classes is fundamentally why I’m here.”

      Even as he managed the directorship and pursued his own scholarly work, Whyte remained active in the classroom and continued advising students. Zach Hartwig, a former student who is now a PSFC researcher and MIT faculty member himself, recalled his first meeting with Whyte as an incoming PhD student: “I had to choose between several projects and advisors and meeting Dennis made my decision easy. He catapulted out of his chair and started sketching his vision for a new fusion diagnostic that many people thought was crazy. His passion and eagerness to tackle only the most difficult problems in the field was immediately tangible.”

      For the past 13 years Whyte has offered a fusion technology design class that has generated several key breakthroughs, including liquid immersion blankets essential for converting fusion energy to heat, inside launch radio frequency systems used to stabilize fusing plasmas, and high-temperature superconducting electromagnets that have opened the door to the possibility of fusion devices that are not only smaller, but also more powerful and efficient.

      In fact, the potential of these electromagnets was significant enough that Whyte, an MIT postdoc, and three of Whyte’s former students (Hartwig among them) spun out a private fusion company to fully realize the magnets’ capabilities. Commonwealth Fusion Systems (CFS) both launched and signed a cooperative research agreement with the PSFC in 2018, and the founders’ vision parlayed into significant external investment, allowing a coalition of CFS and PSFC researchers to refine and develop the electromagnets first conceived in Whyte’s class.

      Three years later, after a historic day of testing, the magnet produced a field strength of 20 tesla, making it the most powerful fusion superconducting electromagnet in the world. According to Whyte, “The success of the TFMC magnet is an encapsulation of everything PSFC. It would’ve been impossible for a single investigator, or a lone spin-out, but we brought together all these disciplines in a team that could execute innovatively and incredibly quickly. We shortened the timescale not just for this project, but for fusion as a whole.”

      CFS remains an important collaborator, accounting for approximately 20 percent of the PSFC’s current research portfolio. While Whyte has no financial stake in the company, he remains a principal investigator on CFS’s SPARC project, a proof-of-concept fusion device predicted to produce more energy than it consumes, ready in 2025. SPARC is the lead-up to ARC, CFS’s commercially scalable fusion power plant planned to arrive in the early 2030s.

      The collaboration between CFS and MIT followed a blueprint that had been piloted more than a decade prior, when the Italian energy company Eni S.p.A signed on as a founding member of the MIT Energy Initiative to develop low-carbon technologies. After many years of successfully working in tandem with MITEI to advance renewable energy research, in 2018 Eni made a significant investment in a young CFS to assist in realizing commercial fusion power, which in turn indirectly funded PSFC research; Eni also collaborated directly with the PSFC to create the Laboratory for Innovative Fusion Technologies, which remains active.

      Whyte believes that “thoughtful and meaningful collaboration with the energy industry can make a difference with research and climate change. Industry engagement is very relevant — it changed both of us. Now Eni has fusion in their portfolio.” The arrangement is a demonstration of how public-private collaborations can accelerate the progress of fusion science, and ultimately the arrival of fusion power.

      Whyte’s move to diversify collaborators, leverage the PSFC’s strength as a multidisciplinary hub, and expand research volume was essential to the center’s survival and growth. Early in his tenure, a shift in funding priorities necessitated the shutdown of Alcator C-Mod, the fusion research device in operation at the PSFC for 23 years — though not before C-Mod set the world record for plasma pressure on its last day of operation. Through this transition, Whyte and the members of his leadership team were able to keep the PSFC whole.

      One alumnus was a particular source of inspiration to Whyte during that time: “Reinier [Beeuwkes] said to me, ‘what you’re doing doesn’t just matter to students and MIT, it matters to the world.’ That was so meaningful, and his words really sustained me when I was feeling major doubt.” In 2022 Beeuwkes won the MIT Alumni Better World Service Award for his support of fusion and the PSFC. Since 2018, sponsored research at the PSFC has more than doubled, as have the number of personnel.

      Whyte’s determination to build and maintain a strong community is a prevailing feature of his leadership. Matt Fulton, who started at the PSFC in 1987 and is now director of operations, says of Whyte, “You want a leader like Dennis on your worst days. We were staring down disaster and he had a plan to hold the PSFC together, and somehow it worked. The research was important, but the people have always been more important to him. We’re so lucky to have him.”

      The Office of the Vice President for Research is launching a search for the PSFC’s next leader. Should the search extend beyond the end of the year, an interim director will be appointed.  

      “As MIT works to magnify its impact in the areas of climate and sustainability, Dennis has built the PSFC into an extraordinary resource for the Institute to draw upon,” says Maria T. Zuber, MIT’s vice president for research. “His leadership has positioned MIT on the leading edge of fusion research and the emerging commercial fusion industry, and while the nature of his contributions will change, … the value he brings to the MIT community will remain clear. As Dennis steps down as director, the PSFC is ascendant.”  More

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      in Environment

      Forging climate connections across the Institute

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      Climate change is the ultimate cross-cutting issue: Not limited to any one discipline, it ranges across science, technology, policy, culture, human behavior, and well beyond. The response to it likewise requires an all-of-MIT effort.

      Now, to strengthen such an effort, a new grant program spearheaded by the Climate Nucleus, the faculty committee charged with the oversight and implementation of Fast Forward: MIT’s Climate Action Plan for the Decade, aims to build up MIT’s climate leadership capacity while also supporting innovative scholarship on diverse climate-related topics and forging new connections across the Institute.

      Called the Fast Forward Faculty Fund (F^4 for short), the program has named its first cohort of six faculty members after issuing its inaugural call for proposals in April 2023. The cohort will come together throughout the year for climate leadership development programming and networking. The program provides financial support for graduate students who will work with the faculty members on the projects — the students will also participate in leadership-building activities — as well as $50,000 in flexible, discretionary funding to be used to support related activities. 

      “Climate change is a crisis that truly touches every single person on the planet,” says Noelle Selin, co-chair of the nucleus and interim director of the Institute for Data, Systems, and Society. “It’s therefore essential that we build capacity for every member of the MIT community to make sense of the problem and help address it. Through the Fast Forward Faculty Fund, our aim is to have a cohort of climate ambassadors who can embed climate everywhere at the Institute.”

      F^4 supports both faculty who would like to begin doing climate-related work, as well as faculty members who are interested in deepening their work on climate. The program has the core goal of developing cohorts of F^4 faculty and graduate students who, in addition to conducting their own research, will become climate leaders at MIT, proactively looking for ways to forge new climate connections across schools, departments, and disciplines.

      One of the projects, “Climate Crisis and Real Estate: Science-based Mitigation and Adaptation Strategies,” led by Professor Siqi Zheng of the MIT Center for Real Estate in collaboration with colleagues from the MIT Sloan School of Management, focuses on the roughly 40 percent of carbon dioxide emissions that come from the buildings and real estate sector. Zheng notes that this sector has been slow to respond to climate change, but says that is starting to change, thanks in part to the rising awareness of climate risks and new local regulations aimed at reducing emissions from buildings.

      Using a data-driven approach, the project seeks to understand the efficient and equitable market incentives, technology solutions, and public policies that are most effective at transforming the real estate industry. Johnattan Ontiveros, a graduate student in the Technology and Policy Program, is working with Zheng on the project.

      “We were thrilled at the incredible response we received from the MIT faculty to our call for proposals, which speaks volumes about the depth and breadth of interest in climate at MIT,” says Anne White, nucleus co-chair and vice provost and associate vice president for research. “This program makes good on key commitments of the Fast Forward plan, supporting cutting-edge new work by faculty and graduate students while helping to deepen the bench of climate leaders at MIT.”

      During the 2023-24 academic year, the F^4 faculty and graduate student cohorts will come together to discuss their projects, explore opportunities for collaboration, participate in climate leadership development, and think proactively about how to deepen interdisciplinary connections among MIT community members interested in climate change.

      The six inaugural F^4 awardees are:

      Professor Tristan Brown, History Section: Humanistic Approaches to the Climate Crisis  

      With this project, Brown aims to create a new community of practice around narrative-centric approaches to environmental and climate issues. Part of a broader humanities initiative at MIT, it brings together a global working group of interdisciplinary scholars, including Serguei Saavedra (Department of Civil and Environmental Engineering) and Or Porath (Tel Aviv University; Religion), collectively focused on examining the historical and present links between sacred places and biodiversity for the purposes of helping governments and nongovernmental organizations formulate better sustainability goals. Boyd Ruamcharoen, a PhD student in the History, Anthropology, and Science, Technology, and Society (HASTS) program, will work with Brown on this project.

      Professor Kerri Cahoy, departments of Aeronautics and Astronautics and Earth, Atmospheric, and Planetary Sciences (AeroAstro): Onboard Autonomous AI-driven Satellite Sensor Fusion for Coastal Region Monitoring

      The motivation for this project is the need for much better data collection from satellites, where technology can be “20 years behind,” says Cahoy. As part of this project, Cahoy will pursue research in the area of autonomous artificial intelligence-enabled rapid sensor fusion (which combines data from different sensors, such as radar and cameras) onboard satellites to improve understanding of the impacts of climate change, specifically sea-level rise and hurricanes and flooding in coastal regions. Graduate students Madeline Anderson, a PhD student in electrical engineering and computer science (EECS), and Mary Dahl, a PhD student in AeroAstro, will work with Cahoy on this project.

      Professor Priya Donti, Department of Electrical Engineering and Computer Science: Robust Reinforcement Learning for High-Renewables Power Grids 

      With renewables like wind and solar making up a growing share of electricity generation on power grids, Donti’s project focuses on improving control methods for these distributed sources of electricity. The research will aim to create a realistic representation of the characteristics of power grid operations, and eventually inform scalable operational improvements in power systems. It will “give power systems operators faith that, OK, this conceptually is good, but it also actually works on this grid,” says Donti. PhD candidate Ana Rivera from EECS is the F^4 graduate student on the project.

      Professor Jason Jackson, Department of Urban Studies and Planning (DUSP): Political Economy of the Climate Crisis: Institutions, Power and Global Governance

      This project takes a political economy approach to the climate crisis, offering a distinct lens to examine, first, the political governance challenge of mobilizing climate action and designing new institutional mechanisms to address the global and intergenerational distributional aspects of climate change; second, the economic challenge of devising new institutional approaches to equitably finance climate action; and third, the cultural challenge — and opportunity — of empowering an adaptive socio-cultural ecology through traditional knowledge and local-level social networks to achieve environmental resilience. Graduate students Chen Chu and Mrinalini Penumaka, both PhD students in DUSP, are working with Jackson on the project.

      Professor Haruko Wainwright, departments of Nuclear Science and Engineering (NSE) and Civil and Environmental Engineering: Low-cost Environmental Monitoring Network Technologies in Rural Communities for Addressing Climate Justice 

      This project will establish a community-based climate and environmental monitoring network in addition to a data visualization and analysis infrastructure in rural marginalized communities to better understand and address climate justice issues. The project team plans to work with rural communities in Alaska to install low-cost air and water quality, weather, and soil sensors. Graduate students Kay Whiteaker, an MS candidate in NSE, and Amandeep Singh, and MS candidate in System Design and Management at Sloan, are working with Wainwright on the project, as is David McGee, professor in earth, atmospheric, and planetary sciences.

      Professor Siqi Zheng, MIT Center for Real Estate and DUSP: Climate Crisis and Real Estate: Science-based Mitigation and Adaptation Strategies 

      See the text above for the details on this project. More

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      in Energy

      Engineers develop an efficient process to make fuel from carbon dioxide

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      The search is on worldwide to find ways to extract carbon dioxide from the air or from power plant exhaust and then make it into something useful. One of the more promising ideas is to make it into a stable fuel that can replace fossil fuels in some applications. But most such conversion processes have had problems with low carbon efficiency, or they produce fuels that can be hard to handle, toxic, or flammable.

      Now, researchers at MIT and Harvard University have developed an efficient process that can convert carbon dioxide into formate, a liquid or solid material that can be used like hydrogen or methanol to power a fuel cell and generate electricity. Potassium or sodium formate, already produced at industrial scales and commonly used as a de-icer for roads and sidewalks, is nontoxic, nonflammable, easy to store and transport, and can remain stable in ordinary steel tanks to be used months, or even years, after its production.

      The new process, developed by MIT doctoral students Zhen Zhang, Zhichu Ren, and Alexander H. Quinn; Harvard University doctoral student Dawei Xi; and MIT Professor Ju Li, is described this week in an open-access paper in Cell Reports Physical Science. The whole process — including capture and electrochemical conversion of the gas to a solid formate powder, which is then used in a fuel cell to produce electricity — was demonstrated at a small, laboratory scale. However, the researchers expect it to be scalable so that it could provide emissions-free heat and power to individual homes and even be used in industrial or grid-scale applications.

      Other approaches to converting carbon dioxide into fuel, Li explains, usually involve a two-stage process: First the gas is chemically captured and turned into a solid form as calcium carbonate, then later that material is heated to drive off the carbon dioxide and convert it to a fuel feedstock such as carbon monoxide. That second step has very low efficiency, typically converting less than 20 percent of the gaseous carbon dioxide into the desired product, Li says.

      By contrast, the new process achieves a conversion of well over 90 percent and eliminates the need for the inefficient heating step by first converting the carbon dioxide into an intermediate form, liquid metal bicarbonate. That liquid is then electrochemically converted into liquid potassium or sodium formate in an electrolyzer that uses low-carbon electricity, e.g. nuclear, wind, or solar power. The highly concentrated liquid potassium or sodium formate solution produced can then be dried, for example by solar evaporation, to produce a solid powder that is highly stable and can be stored in ordinary steel tanks for up to years or even decades, Li says.

      Several steps of optimization developed by the team made all the difference in changing an inefficient chemical-conversion process into a practical solution, says Li, who holds joint appointments in the departments of Nuclear Science and Engineering and of Materials Science and Engineering.

      The process of carbon capture and conversion involves first an alkaline solution-based capture that concentrates carbon dioxide, either from concentrated streams such as from power plant emissions or from very low-concentration sources, even open air, into the form of a liquid metal-bicarbonate solution. Then, through the use of a cation-exchange membrane electrolyzer, this bicarbonate is electrochemically converted into solid formate crystals with a carbon efficiency of greater than 96 percent, as confirmed in the team’s lab-scale experiments.

      These crystals have an indefinite shelf life, remaining so stable that they could be stored for years, or even decades, with little or no loss. By comparison, even the best available practical hydrogen storage tanks allow the gas to leak out at a rate of about 1 percent per day, precluding any uses that would require year-long storage, Li says. Methanol, another widely explored alternative for converting carbon dioxide into a fuel usable in fuel cells, is a toxic substance that cannot easily be adapted to use in situations where leakage could pose a health hazard. Formate, on the other hand, is widely used and considered benign, according to national safety standards.

      Several improvements account for the greatly improved efficiency of this process. First, a careful design of the membrane materials and their configuration overcomes a problem that previous attempts at such a system have encountered, where a buildup of certain chemical byproducts changes the pH, causing the system to steadily lose efficiency over time. “Traditionally, it is difficult to achieve long-term, stable, continuous conversion of the feedstocks,” Zhang says. “The key to our system is to achieve a pH balance for steady-state conversion.”

      To achieve that, the researchers carried out thermodynamic modeling to design the new process so that it is chemically balanced and the pH remains at a steady state with no shift in acidity over time. It can therefore continue operating efficiently over long periods. In their tests, the system ran for over 200 hours with no significant decrease in output. The whole process can be done at ambient temperatures and relatively low pressures (about five times atmospheric pressure).

      Another issue was that unwanted side reactions produced other chemical products that were not useful, but the team figured out a way to prevent these side reactions by the introduction of an extra “buffer” layer of bicarbonate-enriched fiberglass wool that blocked these reactions.

      The team also built a fuel cell specifically optimized for the use of this formate fuel to produce electricity. The stored formate particles are simply dissolved in water and pumped into the fuel cell as needed. Although the solid fuel is much heavier than pure hydrogen, when the weight and volume of the high-pressure gas tanks needed to store hydrogen is considered, the end result is an electricity output near parity for a given storage volume, Li says.

      The formate fuel can potentially be adapted for anything from home-sized units to large scale industrial uses or grid-scale storage systems, the researchers say. Initial household applications might involve an electrolyzer unit about the size of a refrigerator to capture and convert the carbon dioxide into formate, which could be stored in an underground or rooftop tank. Then, when needed, the powdered solid would be mixed with water and fed into a fuel cell to provide power and heat. “This is for community or household demonstrations,” Zhang says, “but we believe that also in the future it may be good for factories or the grid.”

      “The formate economy is an intriguing concept because metal formate salts are very benign and stable, and a compelling energy carrier,” says Ted Sargent, a professor of chemistry and of electrical and computer engineering at Northwestern University, who was not associated with this work. “The authors have demonstrated enhanced efficiency in liquid-to-liquid conversion from bicarbonate feedstock to formate, and have demonstrated these fuels can be used later to produce electricity,” he says.

      The work was supported by the U.S. Department of Energy Office of Science. More

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      in Energy

      Rafael Mariano Grossi speaks about nuclear power’s role at a critical moment in history

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      On Sept. 22, Rafael Mariano Grossi, director general of the International Atomic Energy Agency (IAEA), delivered the 2023 David J. Rose Lecture in Nuclear Technology at MIT. This lecture series was started nearly 40 years ago in honor of the late Professor David Rose — a nuclear engineering professor and fusion technology pioneer. In addition to his scientific contributions, Rose was invested in the ethical issues associated with new technologies. His widow, Renate Rose, who spoke briefly before Grossi’s lecture, said that her husband adamantly called for the abolishment of nuclear weapons, insisting that all science should serve the common good and that every scientist should follow his or her conscience.

      In his prefatory remarks, MIT Vice Provost Richard Lester, a former PhD student of David Rose, said that even today, he still feels the influence of his thesis advisor, many decades after they’d worked together. Lester called it a “great honor” to introduce Grossi, noting that the director general was guiding the agency through an especially demanding time. “His presence with us is a reminder that the biggest challenges we face today are truly global challenges, and that international organizations like the IAEA have a central role to play in resolving them.”

      The title of Grossi’s talk was “The IAEA at the Crossroads of History,” and he made a strong case for this being a critical juncture, or “inflection point,” for nuclear power. He started his speech, however, with somewhat of an historical footnote, discussing a letter that Rose sent in 1977 to Sigvard Eklund, IAEA’s then-director general. Rose urged the IAEA to establish a coordinated worldwide program in controlled fusion research. It took a while for the idea to gain traction, but international collaboration in fusion formally began in 1985, eight years after Rose’s proposal. “I thought I would begin with this story, because it shows that cooperation between MIT and the IAEA goes back a long way,” Grossi said.

      2023 David J. Rose Lecture in Nuclear TechnologyVideo: MIT Department of Nuclear Science and Engineering

      Overall, he painted a mostly encouraging picture for the future of nuclear power, largely based on its potential to generate electricity or thermal energy without adding greenhouse gases to the atmosphere. In the face of rapidly-unfolding climate change, Grossi said, “low-carbon nuclear power is now seen as part of [the] solution by an increasing number of people. It’s getting harder to be an environmentalist in good faith who is against nuclear.”

      Public acceptance is growing throughout the world, he added. In Sweden, where people had long protested against radioactive waste transport, a poll now shows that more than 85 percent of the people approve of the nation’s high-level waste handling and disposal facilities. Even Finland’s Green Party has embraced nuclear power, Grossi said. “I don’t think we could imagine a pro-nuclear Green Party five years ago, let alone in 1970 or ’80.”

      Fifty-seven nuclear reactors are being constructed right now in 17 countries. One of the world’s newest facilities, the Barakah nuclear power plant in the United Arab Emirates, “was built on ground rich in oil and natural gas,” he said. In China, the world’s first pebble-bed high-temperature reactor has been operating for two years, offering potential advantages in safety, efficiency, and modularity. For countries that don’t have any nuclear plants, small modular reactors of this kind “offer the chance of a more gradual and affordable way to scale up nuclear power,” Grossi noted. The IAEA is working with countries like Ghana, Kenya, and Senegal to help them develop the safety and regulatory infrastructures that would be needed to build and responsibly operate modular nuclear reactors like this.

      Grossi also discussed a number of lesser-known projects the IAEA is engaged in that have little to do with power generation. Seventy percent of the people in Africa, for example, have no access to radiotherapy to fight cancer. To this end, the IAEA is now helping to provide radiotherapy services in Tanzania and other African countries. At the IAEA’s Marine Environmental Laboratories in Monaco, researchers are using isotopic tracing techniques to study the impact of microplastic pollution on the oceans. The Covid-19 pandemic illustrated the potentially devastating effects of zoonotic diseases that can infect humans with animal-borne viruses. To counteract this threat, the IAEA has sent hundreds of reverse transcription-polymerase chain reaction (RT-PCR) machines — capable of detecting specific genetic materials in pathogens — to more than 130 countries.

      Meanwhile, new risks have emerged from the war in Ukraine, where fighting has raged for a year-and-a-half near the six nuclear reactors in Zaporizhzhia — Europe’s largest nuclear power plant. Early in the conflict, the IAEA sent a team of experts to monitor the plant and to do everything possible to prevent a nuclear accident that would bring “even more misery to people who are already suffering so much,” Grossi said. A major accident, he added, would likely stall investments in nuclear power at a time when its future prospects were starting to brighten.

      At the end of his talk, Grossi returned to the subject of fusion, which he expects to become an important energy source, perhaps in the not-too-distant future. He was encouraged by the visit he’d just had to the MIT spinoff company, Commonwealth Fusion Systems. With regard to fusion, he said, “for the first time, all the pieces of the puzzle are there: the physics, the policy drivers, and the investment.” In fact, an agreement was signed on the day of his lecture, which made MIT’s Plasma Science and Fusion Center an IAEA collaboration center — the second such center in the United States.

      “When I think of all the new forms of collaboration happening today, I imagine Professor Rose would be delighted,” Grossi said. “It really is something to hold [his] letter and know how much progress has been made since 1977 in fusion. I look forward to our collaboration going forward.” More

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      in Energy

      3 Questions: What should scientists and the public know about nuclear waste?

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      Many researchers see an expansion of nuclear power, which produces no greenhouse gas emissions from its power generation, as an essential component of strategies to combat global climate change. Yet there is still strong resistance to such expansion, and much of that is based on the issue of how to safely dispose of the resulting radioactive waste material. MIT recently convened a workshop to help nuclear engineers, policymakers, and academics learn about approaches to communicating accurate information about the management of nuclear waste to students and the public, in hopes of allaying fears and encouraging support for the development of new, safer nuclear power plants around the world.

      Organized by Haruko Wainwright, an MIT assistant professor of nuclear science and engineering and of civil and environmental engineering, the workshop included professors, researchers, industry representatives, and government officials, and was designed to emphasize the multidisciplinary nature of the issue. MIT News asked Wainwright to describe the workshop and its conclusions, which she reported on in a paper just published in the Journal of Environmental Radioactivity.

      Q: What was the main objective of the this workshop?

      A: There is a growing concern that, in spite of much excitement about new nuclear reactor deployment and nuclear energy for tackling climate change, relatively less attention is being paid to the thorny question of long-term management of the spent fuel (waste) from these reactors. The government and industry have embraced consent-based siting approaches — that is, finding sites to store and dispose nuclear waste through broad community participation with equity and environmental justice considered. However, many of us in academia feel that those in the industry are missing key facts to communicate to the public.

      Understanding and managing nuclear waste requires a multidisciplinary expertise in nuclear, civil, and chemical engineering as well as environmental and earth sciences. For example, the amount of waste per se, which is always very small for nuclear systems, is not the only factor determining the environmental impacts because some radionuclides in the waste are vastly more mobile than others, and thus can spread farther and more quickly. Nuclear engineers, environmental scientists, and others need to work together to predict the environmental impacts of radionuclides in the waste generated by the new reactors, and to develop waste isolation strategies for an extended time.

      We organized this workshop to ensure this collaborative approach is mastered from the start. A second objective was to develop a blueprint for educating next-generation engineers and scientists about nuclear waste and shaping a more broadly educated group of nuclear and general engineers.

      Q: What kinds of innovative teaching practices were discussed and recommended, and are there examples of these practices in action?

       A: Some participants teach project-based or simulation-based courses of real-world situations. For example, students are divided into several groups representing various stakeholders — such as the public, policymakers, scientists, and governments — and discuss the potential siting of a nuclear waste repository in a community. Such a course helps the students to consider the perspectives of different groups, understand a plurality of points of view, and learn how to communicate their ideas and concerns effectively. Other courses may ask students to synthesize key technical facts and numbers, and to develop a Congressional testimony statement or an opinion article for newspapers. 

      Q: What are some of the biggest misconceptions people have about nuclear waste, and how do you think these misconceptions can be addressed?

      A: The workshop participants agreed that the broader and life-cycle perspectives are important. Within the nuclear energy life cycle, for example, people focus disproportionally on high-level radioactive waste or spent fuel, which has been highly regulated and well managed. Nuclear systems also produce secondary waste, including low-level waste and uranium mining waste, which gets less attention.

      The participants also believe that the nuclear industry has been exemplary in leading the environmental and waste isolation science and technologies. Nuclear waste disposal strategies were developed in the 1950s, much earlier than other hazardous waste which began to receive serious regulation only in the 1970s. In addition, current nuclear waste disposal practices consider the compliance periods of isolation for thousands of years, while other hazardous waste disposal is not required to consider beyond 30 years, although some waste has an essentially infinite longevity, for example, mercury or lead. Finally, there is relatively unregulated waste — such as CO2 from fossil energy, agricultural effluents and other sources — that is released freely into the biosphere and is already impacting our environment. Yet, many people remain more concerned about the relatively well-regulated nuclear waste than about all these unregulated sources.

      Interestingly, many engineers — even nuclear engineers — do not know these facts. We believe that we need to teach students not just cutting-edge technologies, but also broader perspectives, including the history of industries and regulations, as well as environmental science.

      At the same time, we need to move the nuclear community to think more holistically about waste and its environmental impacts from the early stages of design of nuclear systems. We should design new reactors from the “waste up.”  We believe that the nuclear industry should continue to lead waste-management technologies and strategies, and also encourage other industries to adopt lifecycle approaches about their own waste to improve the overall sustainability. More

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      in Energy

      Printing a new approach to fusion power plant materials

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      When Alexander O’Brien sent in his application for graduate school at MIT’s Department of Nuclear Science and Engineering, he had a germ of a research idea already brewing. So when he received a phone call from Professor Mingda Li, he shared it: The student from Arkansas wanted to explore the design of materials that could hold nuclear reactors together.

      Li listened to him patiently and then said, “I think you’d be a really good fit for Professor Ju Li,” O’Brien remembers. Ju Li, the Battelle Energy Alliance Professor in Nuclear Engineering, had wanted to explore 3D printing for nuclear reactors and O’Brien seemed like the right candidate. “At that moment I decided to go to MIT if they accepted me,” O’Brien remembers.

      And they did.

      Under the advisement of Ju Li, the fourth-year doctoral student now explores 3D printing of ceramic-metal composites, materials that can be used to construct fusion power plants.

      An early interest in the sciences

      Growing up in Springdale, Arkansas as a self-described “band nerd,” O’Brien was particularly interested in chemistry and physics. It was one thing to mix baking soda and vinegar to make a “volcano” and quite another to understand why that was happening. “I just enjoyed understanding things on a deeper level and being able to figure out how the world works,” he says.

      At the same time, it was difficult to ignore the economics of energy playing out in his own backyard. When Arkansas, a place that had hardly ever seen earthquakes, started registering them in the wake of fracking in neighboring Oklahoma, it was “like a lightbulb moment” for O’Brien. “I knew this was going to create problems down the line, I knew there’s got to be a better way to do [energy],” he says.

      With the idea of energy alternatives simmering on the back burner, O’Brien enrolled for undergraduate studies at the University of Arkansas. He participated in the school’s marching band — “you show up a week before everyone else and there’s 400 people who automatically become your friends” — and enjoyed the social environment that a large state school could offer.

      O’Brien double-majored in chemical engineering and physics and appreciated “the ability to get your hands dirty on machinery to make things work.” Deciding to begin exploring his interest in energy alternatives, O’Brien researched transition metal dichalcogenides, coatings of which could catalyze the hydrogen evolution reaction and more easily create hydrogen gas, a green energy alternative.

      It was shortly after his sophomore year, however, that O’Brien really found his way in the field of energy alternatives — in nuclear engineering. The American Chemical Society was soliciting student applications for summer study of nuclear chemistry in San Jose, California. O’Brien applied and got accepted. “After years of knowing I wanted to work in green energy but not knowing what that looked like, I very quickly fell in love with [nuclear engineering],” he says. That summer also cemented O’Brien’s decision to attend graduate school. “I came away with this idea of ‘I need to go to grad school because I need to know more about this,’” he says.

      O’Brien especially appreciated an independent project, assigned as part of the summer program: He chose to research nuclear-powered spacecraft. In digging deeper, O’Brien discovered the challenges of powering spacecraft — nuclear was the most viable alternative, but it had to work around extraneous radiation sources in space. Getting to explore national laboratories near San Jose sealed the deal. “I got to visit the National Ignition Facility, which is the big fusion center up there, and just seeing that massive facility entirely designed around this one idea of fusion was kind of mind-blowing to me,” O’Brien says.

      A fresh blueprint for fusion power plants

      O’Brien’s current research at MIT’s Department of Nuclear Science and Engineering (NSE) is equally mind-blowing.

      As the design of new fusion devices kicks into gear, it’s becoming increasingly apparent that the materials we have been using just don’t hold up to the higher temperatures and radiation levels in operating environments, O’Brien says. Additive manufacturing, another term for 3D printing, “opens up a whole new realm of possibilities for what you can do with metals, which is exactly what you’re going to need [to build the next generation of fusion power plants],” he says.

      Metals and ceramics by themselves might not do the job of withstanding high temperatures (750 degrees Celsius is the target) and stresses and radiation, but together they might get there. Although such metal matrix composites have been around for decades, they have been impractical for use in reactors because they’re “difficult to make with any kind of uniformity and really limited in size scale,” O’Brien says. That’s because when you try to place ceramic nanoparticles into a pool of molten metal, they’re going to fall out in whichever direction they want. “3D printing quickly changes that story entirely, to the point where if you want to add these nanoparticles in very specific regions, you have the capability to do that,” O’Brien says.

      O’Brien’s work, which forms the basis of his doctoral thesis and a research paper in the journal Additive Manufacturing, involves implanting metals with ceramic nanoparticles. The net result is a metal matrix composite that is an ideal candidate for fusion devices, especially for the vacuum vessel component, which must be able to withstand high temperatures, extremely corrosive molten salts, and internal helium gas from nuclear transmutation.

      O’Brien’s work focuses on nickel superalloys like Inconel 718, which are especially robust candidates because they can withstand higher operating temperatures while retaining strength. Helium embrittlement, where bubbles of helium caused by fusion neutrons lead to weakness and failure, is a problem with Inconel 718, but composites exhibit potential to overcome this challenge.

      To create the composites, first a mechanical milling process coats the ceramic onto the metal particles. The ceramic nanoparticles act as reinforcing strength agents, especially at high temperatures, and make materials last longer. The nanoparticles also absorb helium and radiation defects when uniformly dispersed, which prevent these damage agents from all getting to the grain boundaries.

      The composite then goes through a 3D printing process called powder bed fusion (non-nuclear fusion), where a laser passes over a bed of this powder melting it into desired shapes. “By coating these particles with the ceramic and then only melting very specific regions, we keep the ceramics in the areas that we want, and then you can build up and have a uniform structure,” O’Brien says.

      Printing an exciting future

      The 3D printing of nuclear materials exhibits such promise that O’Brien is looking at pursuing the prospect after his doctoral studies. “The concept of these metal matrix composites and how they can enhance material property is really interesting,” he says. Scaling it up commercially through a startup company is on his radar.

      For now, O’Brien is enjoying research and catching an occasional Broadway show with his wife. While the band nerd doesn’t pick up his saxophone much anymore, he does enjoy driving up to New Hampshire and going backpacking. “That’s my newfound hobby,” O’Brien says, “since I started grad school.” More

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      in Energy

      Fast-tracking fusion energy’s arrival with AI and accessibility

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      As the impacts of climate change continue to grow, so does interest in fusion’s potential as a clean energy source. While fusion reactions have been studied in laboratories since the 1930s, there are still many critical questions scientists must answer to make fusion power a reality, and time is of the essence. As part of their strategy to accelerate fusion energy’s arrival and reach carbon neutrality by 2050, the U.S. Department of Energy (DoE) has announced new funding for a project led by researchers at MIT’s Plasma Science and Fusion Center (PSFC) and four collaborating institutions.

      Cristina Rea, a research scientist and group leader at the PSFC, will serve as the primary investigator for the newly funded three-year collaboration to pilot the integration of fusion data into a system that can be read by AI-powered tools. The PSFC, together with scientists from the College of William and Mary, the University of Wisconsin at Madison, Auburn University, and the nonprofit HDF Group, plan to create a holistic fusion data platform, the elements of which could offer unprecedented access for researchers, especially underrepresented students. The project aims to encourage diverse participation in fusion and data science, both in academia and the workforce, through outreach programs led by the group’s co-investigators, of whom four out of five are women. 

      The DoE’s award, part of a $29 million funding package for seven projects across 19 institutions, will support the group’s efforts to distribute data produced by fusion devices like the PSFC’s Alcator C-Mod, a donut-shaped “tokamak” that utilized powerful magnets to control and confine fusion reactions. Alcator C-Mod operated from 1991 to 2016 and its data are still being studied, thanks in part to the PSFC’s commitment to the free exchange of knowledge.

      Currently, there are nearly 50 public experimental magnetic confinement-type fusion devices; however, both historical and current data from these devices can be difficult to access. Some fusion databases require signing user agreements, and not all data are catalogued and organized the same way. Moreover, it can be difficult to leverage machine learning, a class of AI tools, for data analysis and to enable scientific discovery without time-consuming data reorganization. The result is fewer scientists working on fusion, greater barriers to discovery, and a bottleneck in harnessing AI to accelerate progress.

      The project’s proposed data platform addresses technical barriers by being FAIR — Findable, Interoperable, Accessible, Reusable — and by adhering to UNESCO’s Open Science (OS) recommendations to improve the transparency and inclusivity of science; all of the researchers’ deliverables will adhere to FAIR and OS principles, as required by the DoE. The platform’s databases will be built using MDSplusML, an upgraded version of the MDSplus open-source software developed by PSFC researchers in the 1980s to catalogue the results of Alcator C-Mod’s experiments. Today, nearly 40 fusion research institutes use MDSplus to store and provide external access to their fusion data. The release of MDSplusML aims to continue that legacy of open collaboration.

      The researchers intend to address barriers to participation for women and disadvantaged groups not only by improving general access to fusion data, but also through a subsidized summer school that will focus on topics at the intersection of fusion and machine learning, which will be held at William and Mary for the next three years.

      Of the importance of their research, Rea says, “This project is about responding to the fusion community’s needs and setting ourselves up for success. Scientific advancements in fusion are enabled via multidisciplinary collaboration and cross-pollination, so accessibility is absolutely essential. I think we all understand now that diverse communities have more diverse ideas, and they allow faster problem-solving.”

      The collaboration’s work also aligns with vital areas of research identified in the International Atomic Energy Agency’s “AI for Fusion” Coordinated Research Project (CRP). Rea was selected as the technical coordinator for the IAEA’s CRP emphasizing community engagement and knowledge access to accelerate fusion research and development. In a letter of support written for the group’s proposed project, the IAEA stated that, “the work [the researchers] will carry out […] will be beneficial not only to our CRP but also to the international fusion community in large.”

      PSFC Director and Hitachi America Professor of Engineering Dennis Whyte adds, “I am thrilled to see PSFC and our collaborators be at the forefront of applying new AI tools while simultaneously encouraging and enabling extraction of critical data from our experiments.”

      “Having the opportunity to lead such an important project is extremely meaningful, and I feel a responsibility to show that women are leaders in STEM,” says Rea. “We have an incredible team, strongly motivated to improve our fusion ecosystem and to contribute to making fusion energy a reality.” More