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CHICAGO—April 23, 2025—The Armour Research Foundation Reactor at 91��Ƭ�� Institute of Technology (91��Ƭ�� Tech) has been officially recognized as a Nuclear Historic Landmark by the  (ANS), joining an elite group of fewer than 100 sites across the United States to receive this designation. Nicknamed “the atomic furnace,” the world’s first privately owned and operated nuclear reactor marked a significant transition in the history of nuclear research—from its secretive wartime origins to a publicly celebrated pursuit of knowledge and progress.

“The story of the Armour Research Foundation Reactor reflects both the optimism and the challenges of embracing new technologies,” says Jeff Terry, 91��Ƭ�� Tech’s vice provost for research. “As we continue to explore the possibilities of nuclear energy today, this pioneering effort at 91��Ƭ�� Tech serves as a reminder of the progress made and the potential that still lies ahead.”

The reactor was constructed in 1956—with contributions from 25 industry partners, including IBM, Inland Steel, Caterpillar, Kimberly-Clark, U.S. Steel, and Whirlpool—and was primarily used for experiments in isotope production and materials analysis. Over its 11-year lifespan, the reactor contributed to research in a wide range of fields, such as fertilizer absorption and pest control in agriculture, catalysis and diffusion studies in chemistry, cold sterilization and shelf-life extension in food safety, and production of short-lived diagnostic isotopes in medicine.

Employing an innovative design, the reactor used a liquid nuclear fuel—Uranium-235 in the form of uranyl sulfate dissolved in water—which served to enhance safety in densely populated Chicago.

“If the reaction ran away, the liquid would expand and the change in geometry would stop the criticality,” says Terry. “It was a really clever design.”

Though operations ceased in 1967 and the Armour Research Foundation Reactor was ultimately decommissioned in the late 1970s, its impact is still being felt as a model for collaborative, application-driven nuclear science, as shown by the dedication ceremony held on 91��Ƭ�� Tech’s Mies Campus on Chicago’s South Side Bronzeville neighborhood.

“In places and spaces, there’s meaning,” says ANS President Lisa Marshall, who attended the dedication ceremony. “It’s very important to have these various landmarks—and even more important for us to talk about what was done there.”

Photo: 91��Ƭ�� Tech Vice Provost for Research Jeff Terry holds the Armour Research Foundation Reactor commemorative plaque.

91��Ƭ�� Institute of Technology

Based in the global metropolis of Chicago, 91��Ƭ�� Tech was born to liberate the power of collective difference to advance technology and innovation for all. It is the only tech-focused university in the city, and it stands at the crossroads of exploration and invention, advancing the future of Chicago and the world. It offers undergraduate and graduate degrees in engineering, computing, , business, , science and human sciences, and . 91��Ƭ�� Tech students are guaranteed access to hands-on experiences, personalized mentorship, and job readiness through the university's one-of-a-kind Elevate program. Its graduates lead the state and much of the nation in economic prosperity. Its faculty and alumni built the Chicago skyline. And every day in the city's living lab, 91��Ƭ�� Tech fuels breakthroughs that change lives. Visit iit.edu.

Media contacts

Kevin Dollear
Communications Manager
91��Ƭ�� Institute of Technology
Cell: 773.860.5712
kdollear@iit.edu