NRC accepts University of Illinois microreactor permit for review

The U.S. Nuclear Regulatory Commission has accepted the University of Illinois Urbana-Champaign’s construction permit application for the KRONOS micro modular reactor, pushing the campus project into formal safety, environmental and technical review. That acceptance matters because it means the regulator judged the filing complete enough to begin the hard part, and the agency said it will publish a Federal Register notice that opens a 30-day window for nearby communities and the public to request a hearing.

For a microreactor, that is the first real gate-crossing. The NRC’s project materials describe the proposal as a non-power high-temperature gas-cooled research reactor in Champaign County, Illinois, based on NANO Nuclear Energy Inc. technology. The filing is listed as a single-unit research reactor application, and the review now underway will test whether a campus-built advanced reactor can clear the same licensing discipline that governs larger commercial projects. If it does, the Illinois case could become a template for other university and institutional reactor efforts that want to move from concept to construction without losing credibility along the way.

The path to this point has been long. The University of Illinois submitted a letter of intent to the NRC in May 2021 for a high-temperature gas-cooled reactor, then the university and NANO Nuclear publicly announced a strategic collaboration in April 2025 to build the first research KRONOS micro modular reactor on campus. The NRC also issued a safety evaluation in April 2025 approving the fuel qualification methodology for the KRONOS fuel design, cutting one major licensing uncertainty before the construction permit filing landed on March 31, 2026.

The design itself is built around familiar advanced-reactor hardware: TRISO fuel, helium gas coolant and a graphite moderator, with a molten-salt secondary loop for campus power conversion. University and company materials describe the KRONOS MMR as a 15 MWe, 45 MWth system using passive helium cooling. In October 2025, the partnership marked the start of geotechnical drilling for the prototype site, a sign that the project had already moved from paper to dirt before the permit review formally began.

The university says the reactor is meant to support demonstrations in hydrogen production, desalination and microgrid distribution, while also serving as a training ground for future nuclear engineers and regulators. NANO Nuclear says it expects the NRC review to be completed in 2027. For now, the important milestone is simpler than the technology around it: the NRC has accepted the file, and the KRONOS project is finally past the intake desk and into the review room where campus microreactors have to prove they belong.