The NRC announced proposed 10 CFR Part 57, 'Licensing Requirements for Microreactors and Other Reactors With Comparable Risk Profiles', on 24 April 2026 (News Release 26-047). It published the rule in the Federal Register on 1 May 2026 (91 FR 23628, FR Doc. 2026-08550, docket NRC-2025-0379, RIN 3150-AL36), with a correction on 15 May (C1-2026-08550); comments closed 15 June 2026. In section C, 'Utilization Facilities and General Licenses', the NRC says stakeholders had raised redefining 'utilization facility' to exclude some reactors from AEA section 103 licensing, and that it considered this. The proposal keeps the 1956 definition ('any nuclear reactor' other than plutonium or U-233 production reactors) and carries it into Part 57. The NRC's discussion of the AEA's safety and security prongs 'suggests that any nuclear reactor would meet both prongs' and so be a utilization facility regulated by the NRC. General licenses are proposed only for construction of certain components. The rule implements Executive Order 14300, which requires the final rule by 23 November 2026. The notice does not mention the lawsuit or any settlement. The proposal does not give the plaintiffs the redefinition they sued for; a final rule could differ.

• Licensing Requirements for Microreactors and Other Reactors With Comparable Risk Profiles (proposed rule), 91 FR 23628 (Federal Register (Nuclear Regulatory Commission), 2026-05-01) primary government “any nuclear reactor would meet both prongs and constitute a utilization facility”
• NRC Proposes a New Licensing Framework to Accelerate Safe, High-Volume Deployment of Microreactors (News Release 26-047) (U.S. Nuclear Regulatory Commission, 2026-04-24) primary government “Part 57 is designed to deploy microreactors with safety, scale, and speed.”