Regulatory Activities

Since 2020, the NRC staff has been developing and implementing strategies to enhance licensing efficiency and to provide additional regulatory clarity for microreactors.

Section 208 of the Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy Act of 2024 (the ADVANCE Act) 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. Further, Executive Order (EO) 14300 Section 5(e), directs the NRC to establish a process for high-volume licensing of microreactors and modular reactors. More information can be found on the EO 14300 and ADVANCE Act page.

In response to this direction, the staff began developing a proposed rule to address licensing requirements for microreactors and other reactors with comparable risk profiles, as discussed in the public meetings held on July 14, July 17 and July 18, 2025. This rulemaking proposes amendments to the NRC’s regulations to establish a flexible regulatory framework for microreactors and other reactors with comparable risk profiles. Information related to staff considerations for the proposed rule is available in the meeting notices and the meeting summary (ML25223A181). More information related to the rulemaking can be found at the Part 57 rulemaking webpage.

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.

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)