The NRC just proposed the biggest overhaul of nuclear reactor rules in years

The Nuclear Regulatory Commission proposed rewriting nine separate parts of its federal reactor rulebook on September 11, calling it a modernization that replaces decades-old requirements with a risk-based approach across licensing, decommissioning and day-to-day plant oversight. NRC Chairman Ho Nieh described the scope himself in the agency’s own release: this is “a major modernization of the NRC’s reactor regulations” intended to swap outdated mandates for “smarter, risk-informed approaches that reflect today’s technologies, knowledge and operating experience.” The proposal cleared its next procedural hurdle on September 24, when it was formally published in the Federal Register and the clock started on public comment.

Release 26-077 and a New Docket Number

The commission tracks its own announcements by release number, and this one carries the internal designation 26-077, dated September 11, 2026. Two weeks later, the substance of that announcement reached its formal legal form: a 339-page proposed rule, filed under Docket ID NRC-2025-1138, that spells out exactly which regulations change and how. Federal rulemaking runs on that kind of paper trail, and the gap between a press release and a Federal Register filing is normal, since an agency typically announces a rulemaking’s substance before the formal notice clears the government’s publication process.

Reading the two documents together tells a more complete story than either alone. The agency’s own news release supplies the plain-language framing and the chairman’s quote, while the formal filing supplies the legal text a licensee’s lawyers actually have to parse. Both carry the same September dates, and both point back to the same docket number, so there is no ambiguity about which rulemaking either document describes.

Nine Parts of the Federal Code, Rewritten

The Federal Register notice amends Parts 20, 21, 50, 52, 53, 55, 70, 72 and 75 of Title 10 of the Code of Federal Regulations, the sections covering everything from radiation protection and defect reporting to reactor licensing, operator qualifications, and spent-fuel storage. Individually, none of those nine parts is unfamiliar to the nuclear industry; together, amending all of them in a single rulemaking is what makes this a broad overhaul rather than a routine technical fix. The changes include grading earthquake design requirements by a plant’s actual seismic risk instead of a uniform standard, eliminating the 15-year expiration NRC currently places on standard design approvals, giving control rooms more flexibility on operator staffing, and rewriting how licensees report defects and nonemergency events.

The commission’s own numbers frame the proposal as a cost-cutting measure as much as a safety recalibration. NRC projects the changes will produce net averted costs of $311 million to $411 million over 30 years, or roughly $15 million to $22 million annually depending on the discount rate used, savings the agency attributes to cutting duplicative paperwork rather than to loosening the underlying safety margins the rules protect.

An Executive Order Sets the Deadline Clock

The rulemaking did not originate inside the commission on its own initiative. It traces back to Executive Order 14300, signed in 2025, which directed the NRC to reform and modernize its regulations and guidance documents on an accelerated timetable, and to the ADVANCE Act, the bipartisan 2024 law meant to streamline how the agency licenses new reactor designs. That lineage matters for how the rule gets read: it is less a response to a specific safety incident than a mandated, top-down rewrite with an external deadline attached.

The commission has since opened a running wholesale revision of its regulations in response to the order, of which the September rulemaking is the largest single piece to reach the Federal Register so far. Other pieces of the same wholesale-revision effort have already touched radiation-protection rules and nuclear-security requirements this year, meaning the reactor-licensing rulemaking is one chapter in a broader project rather than an isolated proposal that appeared without warning.

Forty-Six Days to Object

The public comment period runs 46 days from the Federal Register’s September 24 publication date, closing November 9, and the agency plans a virtual public meeting during that window, though it will not accept formal comments during the meeting itself; those still have to go through regulations.gov under the docket number. Nuclear Newswire’s coverage for the American Nuclear Society put the proposed rule’s length at 339 pages and flagged decommissioning trust-fund requirements and reactor licensing changes as among its most consequential sections for utilities already operating plants.

What happens after November 9 depends on how the commission weighs the comments it receives against the executive order’s own push for speed. A proposed rule of this size rewriting nine parts of the federal code at once has no fixed precedent for how long finalization takes, and until the commission acts on the record built during the comment window, the changes Nieh described remain exactly that: proposed, not yet the law that governs how a U.S. reactor operates.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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