Companies seeking licenses for commercial nuclear reactors will be able to lean on test data and analyses from demonstration reactors that the Energy Department or the military has already authorized, under a Nuclear Regulatory Commission rule scheduled for Monday's Federal Register. The change takes effect Nov. 25.
The commission finalized the rule on Oct. 22 and called it the first major revision of its reactor regulations completed under Executive Order 14300, the directive President Trump signed in May 2025 ordering the agency to speed up licensing of safe nuclear technology. Section 5(d) of that order sought an expedited route for designs the Energy Department or the Department of War had tested and shown to work safely, with the NRC's review confined to risks introduced by commercial use rather than ones the other agencies had already examined.
"This rule delivers the EO 14300 vision for an expedited path from DOE and DOW projects to NRC commercial licensing," Chairman Ho K. Nieh said in the agency's announcement. He said applications that clearly show how federal test results satisfy NRC requirements would let the staff move through them more efficiently.
The legal change itself is compact. A new paragraph in the commission's rules, Section 50.43(f), allows an application for a newer reactor design, including one that relies on passive or other innovative safety features, to draw on relevant information from a facility the Energy Department or the Defense Department previously authorized and that "has been tested and has demonstrated the ability to function safely." The applicant has to identify how that authorization satisfies NRC regulations. A matching revision to Section 53.440 extends the option to Part 53, the commission's risk-informed, technology-inclusive licensing framework. The regulatory text keeps the Defense Department name for consistency with existing rules, while the notice treats it as interchangeable with the Department of War.
The commission was explicit about the limits. Nothing in the rule delegates the NRC's licensing evaluation to the Energy Department, the Department of War or any other agency, and nothing permits the NRC to skip an independent review, the final rule says. Applicants relying on a federal authorization must account for any differences in design, function, hazards, siting or safety assumptions from what the earlier review considered. The commission also conceded that a government authorization or test program may not reflect a commercial configuration or cover every analysis a commercial license needs, and it said applicants must close whatever gaps remain.
The commission wrote those assurances in response to objections raised after it proposed the rule on April 2. The agency received 136 unique comment submissions. Supporters included The Heritage Foundation and the reactor developers Valar Atomics and Deep Fission, while the Union of Concerned Scientists, the Oregon Department of Energy and the New York State Energy Research and Development Authority were among the skeptics, FedScoop reported. Opponents argued that because defense or energy data may carry classified restrictions, the rule could in effect route around independent civilian oversight, and others pointed to differences in risk thresholds and containment protocols between government reactors and civilian commercial ones.
Several commenters also warned that the wording the commission first proposed would set a lower safety bar than its existing rules. The final version rewrites that language and moves it into the new Section 50.43(f), states that the safety standard is not altered, and makes the federal record one option for satisfying all or part of requirements that are otherwise unchanged.
The rule arrives as federal demonstration programs begin producing the kind of evidence it contemplates. Four reactors authorized by the Energy Department reached criticality by July 4, beating the three-reactor goal set in a separate May 2025 order on reactor testing, and Oklo's Groves isotope test reactor in Lockhart, Texas, became the fifth on Aug. 5, POWER Magazine reported. Those were zero-power or low-power experiments that yield reactor physics data, not sustained electricity, and neither the Energy Department effort nor the Army's Janus microreactor program automatically qualifies a developer for the new pathway. In August the Army chose five companies for microreactor projects at military installations, and it plans to commit up to $2.2 billion through fiscal 2031, with its own reactor regulatory office overseeing safety authorizations.
The NRC expects the change to save money for applicants and for its own reviewers, because staff will not have to repeat technical work the Energy Department or the military already did when that work covers the same ground, according to the rule's economic analysis. It did not estimate the savings, saying they will depend on how many applications cite a federal authorization and how well applicants show it applies. The Office of Information and Regulatory Affairs at the Office of Management and Budget deemed the rule significant but not economically significant, and the commission classified it as deregulatory under the administration's executive order on reducing regulation.
The agency is taking on the work with a thinner bench. The NRC has seen above-normal attrition, and the White House's fiscal 2027 budget request would eliminate nearly 200 full-time positions, according to FedScoop. Commissioner Bradley Crowell told a congressional hearing in May that the people the agency had lost were "the very senior, most experienced folks." The commission says the rule's main purpose is to make its licensing reviews more efficient and, in turn, expand how many it can handle.
Guidance for using the pathway is still in draft. The NRC released draft interim staff guidance for comment in April and says it will announce new guidance documents in the Federal Register. A similar provision sits in a separate proposed framework for microreactors, which the commission has not finalized.