US-based NANO Nuclear Energy has announced that the US Nuclear Regulatory Commission (NRC) has formally accepted the previously submitted Construction Permit Application (CPA) for the deployment of the Company’s KRONOS MMR at the University of Illinois Urbana-Champaign (U of I).
The CPA was submitted to NRC on 31 March by the U of I for the planned full-scale KRONOS MMR reactor at the university. Acceptance of the CPA signifies the application contains sufficient information for NRC to begin its formal safety, environmental, and technical review process.
The KRONOS MMR Energy System is a high-temperature, gas-cooled microreactor that uses helium coolant and particle fuel. Its compact, modular architecture is intended to support flexible deployment and scalable power output, from single-unit configurations to gigawatt-class multi-reactor clusters capable of powering large industrial and civil campuses as well as other applications, including governmental requirements.
In January NANO Nuclear signed a memorandum of understanding with the Board of Trustees of the University of Illinois on behalf of U of I to collaborate on the development, construction, and operation of its KRONOS MMR on campus as an advanced research reactor. This extended NANO’s existing research agreement with U of I providing for support in design and regulatory licensing of the KRONOS MMR.
NANO Nuclear estimates that the NRC formal review will be completed in 2027, providing the opportunity for NANO Nuclear to begin nuclear construction activities at the U of I in the second half of 2027.
“Acceptance of the Construction Permit Application for review confirms that the NRC has determined the submission contains the information necessary to begin detailed technical evaluation,” said NANO, Chief Technical Officer Florent Heidet of Nuclear Energy. “Advancing to this stage reflects years of engineering, regulatory engagement, and disciplined execution, as well as the substantial work required to support formal review of an advanced reactor design. Entering the NRC review process is an important progression for the KRONOS MMR programme and further reinforces our transition from development toward deployment. We believe milestones such as this increasingly distinguish advanced reactor developers progressing toward deployment from those still early in the development pathway.”
Jay Yu, Founder and Chairman of NANO Nuclear, noted. “Since NANO Nuclear’s inception, our strategy has centred on building a platform designed for long-term, scalable deployment of advanced nuclear technologies. We believe entering formal NRC review reinforces the maturity of our approach and marks continued progress toward making microreactor deployments a commercial reality. As we advance through the regulatory process, our teams are increasingly focused on activities supporting future deployment readiness, including advancing supply chain engagement and procurement discussions for key reactor systems and long-lead components, as well as business development.”
He added: “At the same time, our engineering teams remain focused on developing a reduced-scale, non-nuclear KRONOS MMR™ engineering demonstration unit at our newly renovated technical facility in Oak Brook, Illinois, supporting continued design refinement and technology validation.”
Caleb Brooks, Professor and Donald Biggar Willett Faculty Scholar of Nuclear, Plasma & Radiological Engineering at the U of I’s Grainger College of Engineering, said: “At Grainger Engineering, we believe universities play a vital role in accelerating innovation, developing the next generation workforce, and demonstrating technologies that can address critical energy and national needs,” said. “We look forward to continuing our work with NANO Nuclear and our engagement with the NRC throughout the review process as we work to further position U of I as a leader in future advanced energy technologies.”
NRC is currently initiating its thorough safety and environmental evaluation. It will also publish a Federal Register notice to open a mandatory 30-day public window for legal hearing requests. NANO Nuclear estimates that the comprehensive NRC review will conclude mid-year, clearing the path to begin on-site nuclear construction during the second half of 2027. The project team at U of I Department of Nuclear, Plasma & Radiological Engineering aims to achieve fully operational status by 2030. The reactor will partially re-power the university’s coal-fired Abbott Power Station, demonstrating carbon-free district heat and electricity integration.
The 2027 construction target is entirely achievable because the regulatory path for the site has been meticulously laid out. However, hitting the 2030 operational date appears to be a best-case scenario. Going from breaking ground in late 2027 to a fully operational, grid-connected nuclear reactor by 2030 leaves virtually zero margin for error. Nuclear projects face systemic bottlenecks that NANO Nuclear will have to navigate perfectly to succeed.
NANO Nuclear must submit a completely separate Operating Licence Application (OLA) before the reactor can operate. The NRC review for an OLA typically takes an additional 1-2 years, which will severely compress the remaining time left before 2030. The KRONOS MMR relies on High-assay low-enriched uranium (HALEU) TriStructural-Isotropic (TRISO) fuel. HALEU supply chains are globally constrained and heavily bottlenecked. Securing a commercial allocation, fabricating the fuel, and getting it certified by 2030 is a logistical hurdle.
The KRONOS design is fundamentally new. Even with modular, factory-fabricated parts, first-of-a-kind builds routinely encounter engineering delays, component manufacturing flaws, and integration friction during on-site assembly. Industry experts, including former NRC Chair Allison Macfarlane, have labelled timelines of this speed for microreactors as incredibly difficult to meet.
