RODNEY C. EWING (1946-2024)

BY SIEGFRIED HECKER, SULGIYE PARK, AND CAMERON TRACY

RODNEY CHARLES EWING, a leading expert on mineralogy, materials science, and nuclear waste management, died on July 13, 2024, at age 77.

Rod was born on Sept. 20, 1946, in Abilene, Texas, to Mary and Charles Ewing. From his early days, Rod showed a keen interest in earth materials; by high school, he had amassed a small collection of minerals and fossils. But it was only when he attended a field trip to Big Bend National Park, as an undergraduate student at Texas Christian University, that he decided to become a mineralogist. Rod made his first foray into scientific research as an intern at the mineralogy wing of the Smithsonian Institution. He graduated summa cum laude with a bachelor’s degree in geology from Texas Christian University in 1968. At the same time, Rod began a lifelong journey of political activism. He often reminisced about turning his back on his graduation ceremony’s commencement speaker, President Lyndon B. Johnson, in protest of U.S. actions in the Vietnam War.

Shortly after starting graduate school at Stanford University on a National Science Foundation fellowship, Rod was drafted into the Army. He served for two years, including seven months in Vietnam as an interpreter and interrogator. Rod would later state that, while he opposed the war, he did not try for a deferment, saying that “if I didn’t go, the next guy to get called up would be someone who was poor, and probably not as well educated as I was, and who wouldn’t have a chance.”

With significant support from Richard Jahns, the dean of Stanford’s School of Earth Sciences, Rod was able to obtain an early discharge and resume his Ph.D. studies. Back at Stanford University, Rod continued his dissenting political streak by leading an effort to convince the university to cut its ties with oil companies, after learning that they funded opposition to a state ballot initiative to direct some of California’s gas tax revenues to address air pollution and support public transportation. At the same time, he launched a long-term research effort to understand the physics and chemistry of metamict minerals whose formerly well-ordered atomic crystal structures became disordered by radiation damage caused by the presence of radioactive elements. Rod would later justify his decision to focus on this esoteric group of minerals by stating, in typical Ewing fashion, that “there was no interest and no application. It was perfect.”

But Rod believed that so long as one conducted careful, rigorous scientific research on a novel topic, interest and applications would follow. They did. In 1974, his study of small, spherical regions of atomic ordering in an otherwise metamict sample of a niobium-tantalum-titanium oxide mineral was featured on the cover of Science. That same year, he received his Ph.D. from Stanford and joined the Earth and Planetary Sciences faculty at the University of New Mexico. There, his work turned to the engineering applications of metamict minerals.

In a 1976 article in Science, Rod argued that minerals that demonstrated the ability to withstand irradiation over geologic timescales provided a roadmap for the development of synthetic materials able to safely contain nuclear waste from energy and weapons programs. He maintained this focus on the materials science of nuclear waste disposal for the remainder of his career, co-authoring a patent for a method of disposing of excess weapons plutonium in 1995. In 2001, this work was recognized by the U.S. Department of Energy as one of the top 101 innovations of the previous quarter century.

While at the University of New Mexico, Rod became deeply involved in the geological study of the Harding Pegmatite Mine, located 20 miles southwest of Taos, New Mexico. The mine was known for its significant deposits of critical metal-bearing minerals, including spodumene, lepidolite, microlite, and beryl.

Mining ceased shortly after World War II, but Rod’s tireless work documenting the site’s geology prompted efforts to preserve the mine for teaching and research purposes. He facilitated the transfer of the mine’s ownership to the University of New Mexico in 1978 through an act of Congress. For decades, Rod brought his students to the Harding mine as a unique outdoor geologic laboratory. He would set up camp atop piles of calcite and quartzite and enthusiastically describe the genesis of microlite, a relatively rare calcium tantalate belonging to the pyrochlore group — a complex group of cubic niobium-tantalum-titanium oxides that became one of his main areas of study. Today, the mine is open to the public at no charge, and it hosts thousands of visitors annually.

In 1997 Rod joined the faculty at the University of Michigan. The breadth of his expertise and the interdisciplinary nature of his work were evident in his appointment to simultaneous positions in the Departments of Nuclear Engineering & Radiological Sciences, Earth & Environmental Sciences, and Materials Science & Engineering. There, Rod’s continual search for untread scientific terrain led him to an interest in extremes: the behavior of structurally complex materials when subjected to temperatures of thousands of Kelvin, pressures approaching those encountered in Earth’s core, and intense particle irradiation. In 2017, his contributions in this arena were honored by the naming of the mineral ewingite, of chemical formula Mg8Ca8(UO2)24(CO3)30O4(OH)12(H2O)138, the most structurally complex mineral found on Earth. Crystallography, particularly of highly complex compounds, was one of Rod’s lifelong passions. Most shelves in his offices were adorned with wooden “ball-and-stick” models of atomic structures, many of which he had crafted.

Throughout this period, Rod continued his engagement with U.S. policy, this time in relation to nuclear waste management. At the time, the United States was developing the Yucca Mountain Nuclear Waste Repository, a disposal facility for spent nuclear fuel and high-level waste in southern Nevada. Assessing the geology of the site, Rod argued that proponents of the facility had overlooked key safety risks and significantly underestimated the difficulty of modelling the site’s geologic behavior over the extended timeframes (from 10,000 to 1,000,000 years) during which it was meant to effectively contain radioactive material.

Rod contended that any containment method, including nuclear waste form materials and other engineering barriers, would fail over such a long timescale, leaving the site’s geology as the sole means of containment. However, he found its geology insufficient for this task. Rod highlighted several technical issues, including the risk of radionuclide transport due to water movement through the unsaturated zone and issues related to the long-term integrity of waste packages, which would corrode and release the radioactive materials they contained. Additionally, Rod criticized the top-down governmental approach of selecting Yucca Mountain as the sole site for U.S. nuclear waste disposal without first obtaining adequate community consent, viewing it as a failure in the regulatory process.

He emphasized the need for a consent-based approach that ensured affected communities would be actively involved in the decision-making process. Rod’s opposition reflected his dedication to ensuring that nuclear waste management practices were based on rigorous scientific standards and a deep understanding of public needs. A 2003 Scientific American article on the subject dubbed Rod the “man against a mountain.” In 2006, he co-edited with A. MacFarlane the book Uncertainty Underground: Yucca Mountain and the Nation’s High-Level Nuclear Waste (MIT Press), which detailed the unresolved technical concerns surrounding the repository.

In 2014 Rod made the final move of his career to the place where it began, Stanford University, as a professor of both nuclear security and geological sciences. From 2017 until his death, Rod was the Frank Stanton Professor in Nuclear Security and a professor in the Department of Earth & Planetary Sciences. He also served as co-director of the university’s Center for International Security and Cooperation, where he advanced the cause of integrating the physical sciences, engineering, and policy studies.

Rod’s scientific accomplishments were truly prodigious, with more than 750 publications across over 100 different journals. His extensive body of work traversed multiple disciplines, spanning mineralogy, geochemistry, materials science, nuclear engineering, physics, chemistry, and policy — a remarkable breadth of research that highlights Rod’s profound impact on a wide range of scientific domains. His work was cited in the scholarly literature over 50,000 times. But Rod’s impact also extended far beyond fundamental scientific research.

In his 2019 acceptance speech for the Distinguished Public Service Award of the Mineralogical Society of America, he proposed that “we should all spend at least 10% of our time working on subjects that have a social impact…I think our role is not only to create new knowledge, but to push that new knowledge into areas that improve the public good.” Rod dedicated well over one-tenth of his time to serving the public.

Throughout his career, he served on 12 National Research Council committees on issues of nuclear waste and nuclear weapons, and 29 national and international advisory committees and boards, including those of the Geochemical Society (2012-15) and the Bulletin of the Atomic Scientists (2012-22). He was a member of numerous scientific journals’ editorial boards and was a founding editor of both Elements and Geochemical Perspectives Letters. He served on governmental committees for agencies including the U.S. Department of Energy and Environmental Protection Agency, the French Commissariat à L’Energie Atomique, and the European Commission. In 2012, President Obama appointed him to the Nuclear Waste Technical Review Board, which advises the U.S. Congress and Department of Energy on the science of waste management. He chaired the board until 2017. That year, he was elected to the National Academy of Engineering.

Alongside his dedication to serving the public, Rod demonstrated a profound commitment to education and his students. He was always eager to create opportunities for teaching and learning. His commitment to advancing knowledge was also evident in his establishment of the Richard T. Liddicoat Postdoctoral Fellowship Program at the Gemological Institute of America, which significantly expanded its research capabilities. Rod served on the Board of Governors from 2006 to 2015.

As a teacher, this commitment was evident in every interaction with his students, from his open-door policy to meticulously designed curricula and thoughtful responses to every question. While Rod always held strong views on a wide range of science and policy issues, he took pride in never simply providing prescriptive answers, but in instead encouraging critical thinking. His many courses on the nuclear fuel cycle and waste management, for instance, often featured student-led debates on the potential roles of nuclear energy as an environmental threat or an effective solution to climate change.

To members of his research group, Rod was a beacon of unwavering support and genuine care. He created opportunities that went beyond the conventional, ensuring that his mentees could explore diverse topics and fields of interest. Although he was often a tough advisor with high expectations, he never hesitated to provide personal guidance on projects and offered a compassionate ear during challenging times. His belief in his students’ potential never wavered, and his efforts to offer meaningful opportunities left a lasting impact on their lives.

Rod’s work was influential in many fields of science, engineering, and public policy. While his awards and honors are too numerous to list, they include a Guggenheim Fellowship (2002), the Lomonosov Gold Medal of the Russian Academy of Sciences (2006), and an honorary doctorate from the Université Pierre et Marie Curie (2007). He served as president of the Mineralogical Society of America, the International Union of Materials Research Societies, and the American Geoscience Institute. In addition to his accolades, Rod maintained extensive international connections. He held visiting faculty and scientist positions at institutions worldwide, including the Hahn-Meitner-Institut in Berlin, Germany; the University of Queensland in Australia; the Centre D'Études Nucléaires de Fontenay-Aux-Roses in France; Charles University in Prague, Czechia; and the University of Tokyo in Japan, among others.

Rod is survived by his wife, Helga Fuchs; his children, Travis and Allison; stepdaughter Franziska; four grandchildren; and his 99-year-old mother, Mary Ewing.

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Image credits: Photo 1 (top): Andrew Brodhead (Stanford, California, June 2024); Photo 2 (bottom): Sulgiye Park (New Mexico, March 2022)