Regulatory Activities

The NRC staff has identified a series of activities to enhance microreactor licensing efficiency and provide additional regulatory clarity. These activities were informed by interactions with a broad range of stakeholders and the NRC staff will continue to engage with stakeholders and other interested parties on microreactor topics. The NRC staff has prioritized the various actions from near term to longer term and is ensuring that potential policy issues are identified for resolution.

The NRC staff generated the Integrated Microreactor Activities Plan (ML25225A024), to provide a comprehensive view of microreactor licensing and regulatory topics. The plan includes actions the staff identified to enhance the flexibility of the regulatory framework to support the diverse technologies and deployment models being considered by microreactor developers and potential applicants. Subsequently, as directed by Executive Order (EO) 14300 Section 5(e), the staff began developing a proposed rule to address licensing requirements for microreactors and other low consequence reactors, as discussed in the public meetings held on July 14, July 17 and July 18, 2025. Information related to staff considerations for the proposed rule is available in the meeting notices and the meeting summary (ML25223A181). The staff is using the Microreactor Activities Plan to inform the rulemaking effort and going forward, updates to microreactor activities will be made through the other avenues (such as the rulemaking) in lieu of the above Activities Plan.

Additionally, on December 9, 2025, staff issued a memo discussing a regulatory approach for the oversight of microreactors during the operational phase (ML25329A275). This strategy leverages lessons learned from established oversight programs for large light water reactors and research and test reactors, to the extent practical, while incorporating innovative inspection methodologies and a scalable inspection footprint informed by licensee performance and risk insights, as appropriate. The memo and strategy are intended to facilitate further stakeholder engagement to support readiness to implement the program prior to the first operating microreactor.

Further, on December 16, 2025, SECY-25-0103, "Update on Development of the U.S. Nuclear Regulatory Commission's Advanced Reactor Construction Oversight Program" was issued (ML25024A241). This program was developed to be scalable so that it adequately covers construction oversight of all advanced reactors, including microreactors. The NRC staff is developing detailed inspection procedures to support program implementation in early 2026.  

The above activities also address the requirements in Section 208 of the Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy Act of 2024 (the ADVANCE Act). This section directs the NRC to develop and implement risk-informed and performance-based strategies and guidance to license and regulate microreactors in eight topical areas: (1) staffing and operations, (2) oversight and inspections, (3) security and safeguards, (4) emergency preparedness, (5) risk analysis methods, (6) decommissioning funding assurance, (7) transportation of fueled microreactors, and (8) siting. The NRC staff have developed strategies and guidance for the above eight topical areas by January 9, 2026, and will implement these strategies by July 9, 2027. More information can be found on the ADVANCE Act page.

Additional resources supporting microreactor licensing and regulation can be found below:

• SECY-20-0093: Policy and Licensing Considerations Related to Micro-Reactors (ML20254A363)
• SECY 23-0048: Vision for the Nuclear Regulatory Commission’s Advanced Reactor Construction Oversight Program (ML23061A086)
• SECY-24-0008: Micro-Reactor Licensing and Deployment Considerations: Fuel Loading and Operational Testing at a Factory (ML23207A252) and SRM-SECY-24-0008 (ML25168A133)
• SECY-25-0045: Recommendations for Revising the Reactor Oversight Process (ML25127A212)
• SECY 25-0052: Nth-of-a-Kind Microreactor Licensing and Deployment Considerations (ML24309A266), and SRM-SECY-25-0052 (ML25317A650)

The NRC staff will continue to identify opportunities to strengthen the regulatory framework for microreactors as technologies and deployment models evolve. In addition, the staff remains committed to engaging with stakeholders and other interested parties on licensing and deployment topics listed in the Integrated Microreactor Activities Plan.