UIUC submits MMR construction permit application

The University of Illinois-Urbana-Champaign, in partnership with Nano Nuclear Energy, has submitted a construction permit application to the Nuclear Regulatory Commission for construction of a Kronos micro modular reactor (MMR). This is the first major step in the two-part 10 CFR Part 50 licensing process for the research and test reactor and is the culmination of years of technical refinement and regulatory alignment.

The team chose to engage with the NRC in a preapplication readiness assessment, providing the agency with draft versions of the majority of the CPA's technical content for feedback, which is expected to ensure a high-quality application.

UIUC intends to use the reactor to support training the nuclear workforce; drive public engagement around nuclear power; and conduct research exploring microreactor operations, systems, and broader viability.

According to Nano Nuclear, with this submission, the company has become the first commercially ready microreactor developer to submit a CPA.

Successful partnership: "Through every step of the process thus far, we at the Grainger College of Engineering have worked diligently alongside our partners at Nano Nuclear Energy to ensure our goals in constructing the first Kronos [MMR] on the university's campus can become a reality. By submitting the construction permit application to the NRC, we are taking the next step in signifying that the work has been done correctly and precisely. And we continue to look forward to the possibilities of what can become the most advanced nuclear research platform on any U.S. campus," said Caleb Brooks, director of the Illinois Microreactor Project and a professor in the Department of Nuclear, Plasma, and Radiological Engineering at UIUC.

Project origins: The project was first announced in 2021 when the university submitted a letter of intent to the NRC. At the time, UIUC was applying for a license to construct Ultra Safe Nuclear's MMR, but when USNC declared bankruptcy in 2024, Nano Nuclear acquired its MMR technology, renaming it Kronos. UIUC and Nano Nuclear reached an agreement to continue the project in 2025.

Kronos is a high-temperature, gas-cooled reactor (HTGR). Each TRISO-fueled and helium-cooled unit is designed to produce up to 15 MWe (45 MWt), and the reactor stores heat in molten salt tanks for steam generation.

University research reactors: It has been about 30 years since a U.S. university deployed a new research reactor, and while UIUC has had a head start in the process, other U.S. universities are also pursuing campus reactors of different designs. Pennsylvania State University is working with Westinghouse on plans for a 15-MWt eVinci sodium-cooled heat pipe reactor, Abilene Christian University in Texas is partnered with Natura Resources with plans for a 1-MWt molten salt research reactor, Texas A&M University and ZettaJoule have proposed a 30-MWt HTGR, and the University of Missouri is developing NextGen MURR, a 20-MW light water research reactor that will produce medical isotopes for cancer treatments and be used for neutron science research.