NRC proposes reactor licensing overhaul with 40-year renewals and smaller emergency zones, 91 FR 44560

What the record shows

The rule amends 10 CFR parts 2, 50, 51, 52, 53, 54, 71 and 100 and runs from page 44560 to page 44716 [1]. Its provisions fall into a few groups that matter for different readers.

License renewal. Section 54.31(b) now caps a renewed license at 20 years past the existing expiration date [1]. The NRC proposes 40, “consistent with the maximum license period in section 103 of the AEA” [1]. The agency writes that the 40-year term in the Atomic Energy Act was adopted for antitrust and financial reasons rather than safety, quoting its own 1991 rule [1]. Because a renewed license that adds 40 years on top of the time left on the current one would exceed that statutory limit, the NRC says it would switch from the “supersession” license it uses now to a “tack-on” license that takes effect when the current term ends [1]. It is seeking comment on how to condition pre-operation aging management work under a license that is not yet in effect [1].

The arithmetic is spelled out in the rule. A plant in its first renewal period, years 40 to 60, could seek a 40-year subsequent renewal to reach 100 years; a plant already approved to 80 years could apply for a third renewal to reach 120 [1]. The rule would also delete the bar in 10 CFR 54.17(c) on applying more than 20 years before expiration, letting licensees file at any time during the current term [1]. A new 10 CFR 54.21(a)(4) would let applicants propose risk-informed and performance-based alternatives to the existing aging management review [1].

Construction before a license. The NRC would narrow the definition of “construction” in 10 CFR 50.10, 51.4 and 53.020 to structures, systems and components whose construction can affect a safety-related or safety-significant function [1]. Separately, new 10 CFR 50.10(h) and 53.1130(e) would use section 109 of the Atomic Energy Act to issue a general license to begin construction once a construction application is docketed [1]. That license would cover only plants that reference a design the NRC has given “generic finality” and that has already been built and placed into operation, and it would exclude “the reactor vessel, the reactor coolant system, and associated reactivity control and heat removal systems” [1]. Work done under it would be “entirely at the risk of the general licensee” [1].

Emergency planning zones. Proposed changes to 10 CFR 50.33(g), 50.47(c)(2) and 53.1109(g) would set the plume exposure pathway zone at “generally about 2 to 10 miles” in radius, provide a site-boundary zone for facilities with an authorized power level below 300 MWt, and allow case-by-case determinations for any facility [1]. In support, the NRC cites its SOARCA and Level 3 PRA work and a July 2025 report, SAND2025-08913, on dose exceedance distances [1].

Siting. Part 100 would split power reactors into Tier 1 and Tier 2 [1]. A Tier 1 reactor, one that shows an unmitigated consequence below 25 rem at the exclusion area boundary, could use the less prescriptive subpart A criteria now reserved for testing reactors and pre-1997 applications [1]. The rule keeps the agency’s preference for low population density but would let applicants justify sites near population centers of more than about 25,000 residents by comparing societal risks with benefits, such as reuse of “existing infrastructure for a retired fossil fuel power plant” [1].

Other changes. The rule would let light-water reactors use fuel enriched above 5.0 weight percent uranium-235 “in most cases, without the use of exemptions” [1]; allow decommissioning cost estimates below the 10 CFR 50.75(c) formula for some new reactors [1]; extend manufacturing licenses and their renewals to 40 years [1]; drop the expiration date on early site permits [1]; and add a voluntary appendix T quality assurance standard as an alternative to appendix B [1].

The draft regulatory analysis puts undiscounted net savings to the NRC and industry at $1.86 billion, or $802.10 million at a 7 percent discount rate [1]. The NRC proposes a finding of no significant environmental impact, so no environmental impact statement would be prepared [1].

Where does the proposed rule sit in the process?

Executive Order 14300 told the NRC to publish proposed rules for a “wholesale revision” of its regulations within 9 months of May 23, 2025, and to issue final rules within 18 months [2]. Section 5 lists ten directives; this rule takes up three of them: thresholds for NRC-demanded design changes once construction is underway (5(f)), “determinate and data-backed thresholds” for safety assessments (5(h)), and longer renewal terms (5(i)) [2]. The NRC also cites section 501(a) of the ADVANCE Act, which directed it to update its mission statement so that licensing “does not unnecessarily limit” civilian nuclear deployment [1, 5].

A day earlier, at 91 FR 43456, the NRC published a separate proposed rule under section 5(b) of the order that would remove ALARA requirements from 10 CFR Chapter I and apply a 10-rem design-basis accident acceptance criterion [3]. Its comment deadline is also August 31 [3].

Comments on the licensing rule go through regulations.gov [1]. The NRC says it will hold public meetings on the proposal and post the location, time and agenda of each on its public meeting website within 10 calendar days of the meeting [1]. It poses numbered questions, including whether a general license to begin construction should require reference to a completed plant, which would exclude first-of-a-kind applicants [1]. A final rule would follow review of comments.

Who is affected now?

Operating plants are the near-term audience for the renewal change. On July 20, the NRC published notice that it had docketed Constellation Energy Generation’s June 17 application to renew Ginna’s license, No. DPR-18, for “an additional 20 years” beyond its current expiration of September 18, 2029 [4]. Hearing requests in Docket No. 50-244 are due September 18, 2026 [4].

Positions on the record

The proposed rule states the NRC’s own reasoning. The agency describes the changes as “the culmination of decades of combined experience” and says that while “some changes in this rule had not been advanced as regulatory priorities,” the order “catalyzed agency efforts to accelerate modernization” of parts 50 and 52 [1].

On renewal, the NRC states that most U.S. reactors already operate beyond 40 years and that it “has not identified any fundamental gaps in the understanding of aging” that the current process could not address [1]. On emergency planning, it writes that the zone determination “is not an analysis to reiterate the safety case of the design” and that the 1 rem threshold in 10 CFR 50.33(g)(2)(i)(A) is not a dose limit [1].

The executive order frames the same work in sharper terms. It directs the NRC to set “stringent thresholds for circumstances in which the NRC may demand changes to reactor design once construction is underway” [2]. The NRC’s answer is a revised set of change and departure processes for licensees that reference a certified design or manufacturing license under parts 52 and 53, and a question asking whether AP1000 construction flexibility should extend to the ABWR and ESBWR designs [1]. The comment window on that question, and on the rest of the rule, runs to August 31 [1].

Reading-room questions

Questions readers bring to this record, answered from the documents cited below.

When are comments due on the NRC's reactor licensing modernization proposed rule?

By 11:59 p.m. Eastern Time on August 31, 2026, through regulations.gov under Docket ID NRC-2025-0975 [1]. The NRC says it will consider later comments only if it is practical to do so [1].

How long would a renewed nuclear plant license last under the proposal?

Up to 40 years beyond the current license, instead of the 20-year limit in 10 CFR 54.31(b) [1]. The NRC says a plant in its first renewal period could apply for a subsequent 40-year term, bringing it to 100 years of operation, and a plant already approved to 80 years could seek a third renewal to 120 years [1].

Does the proposed rule change the 10-mile emergency planning zone?

Yes. It would set plume exposure pathway zones at generally about 2 to 10 miles in radius, give facilities under 300 MWt a site-boundary zone, and keep case-by-case determinations available to all facilities [1].

Would the R.E. Ginna renewal application get a 40-year term?

The July 20 notice describes Constellation's request as a 20-year subsequent renewal of License No. DPR-18, under the current rules [4]. The proposed rule does not say how applications already under review would be treated if the 40-year term is finalized [1, 4].

How much does the NRC estimate the rule would save?

The draft regulatory analysis estimates undiscounted net savings of $1.86 billion to the NRC and industry, or $802.10 million at a 7 percent discount rate and $1.26 billion at 3 percent [1].

Note on sourcing

This report rests on the proposed rule as published in the Federal Register and on the related executive order, statute and NRC notices. The draft regulatory analysis, draft environmental assessment, draft guidance documents (including DG-1454, DG-4036 and LR-ISG-2026-01) and the plain-language summary in the regulations.gov docket are referenced in the rule but are not separately examined here. The savings figures are the NRC's own estimates and have not been checked against an outside analysis. Public comments filed in Docket NRC-2025-0975 are not reflected here.

Sources

1. Modernizing Reactor Licensing, Safety Oversight, and Siting Practices, proposed rule, 91 FR 44560 (FR Doc. 2026-14341)Federal Register (Nuclear Regulatory Commission), July 16, 2026 · federalregister.gov
2. Executive Order 14300, Ordering the Reform of the Nuclear Regulatory Commission, 90 FR 22587Federal Register (Executive Office of the President), May 29, 2025 · federalregister.gov
3. Reforming and Modernizing the NRC's Radiation Protection Framework, proposed rule, 91 FR 43456 (FR Doc. 2026-14208)Federal Register (Nuclear Regulatory Commission), July 15, 2026 · federalregister.gov
4. Constellation Energy Generation, LLC; R.E. Ginna Nuclear Power Plant; Subsequent License Renewal Application, 91 FR 45288 (FR Doc. 2026-14565)Federal Register (Nuclear Regulatory Commission), July 20, 2026 · federalregister.gov
5. Public Law 118-67, Division B: Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy Act of 2024 (ADVANCE Act)U.S. Congress (Government Publishing Office), July 9, 2024 · govinfo.gov

Subject headings

• NRC
• nuclear
• license renewal
• emergency planning
• Executive Order 14300

Cross-references

Other register entries filed under the same subject headings.

1. Aug. 24, 2026No. 0016 · Report · 3 shared headingsNRC sets Sept. 22 mandatory hearing on Long Mott Xe-100 construction permit, 91 FR 53900
2. Oct. 14, 2026No. 0027 · Rule · 2 shared headingsNRC renews AP1000 design certification by direct final rule, adopting Revision 20, 91 FR 65091
3. Aug. 31, 2026No. 0019 · Report · 2 shared headingsNRC notices NextEra-Dominion application for indirect transfer of Dominion nuclear licenses, NRC-2026-4060