NRC finalizes rule to reuse DOE and Department of War reactor authorizations in licensing

The U.S. Nuclear Regulatory Commission has issued a final rule that lets commercial reactor applicants draw on earlier Department of Energy or Department of War authorizations of demonstration reactors. The rule takes effect on November 25, 2026, and was published in the Federal Register as 91 FR 67195.

What the rule changes

The NRC is amending two sections of title 10 of the Code of Federal Regulations: section 50.43 and section 53.440. Together they set out a pathway for streamlined review of commercial reactor designs that DOE or the Department of War has authorized, and that have been tested and shown they can function safely.

The section 50.43 change covers licensing under part 50 and part 52. The section 53.440 change covers licensing under part 53, the risk-informed, technology-inclusive framework for commercial nuclear plants.

The NRC says the main aim is to improve the efficiency of its licensing reviews and, in turn, increase its capacity to conduct them. The rule also keeps room for the NRC to use a range of technologies, testing methods and information from designs that were previously authorized and evaluated, where an applicant supports that in its license application.

Executive order behind it

The rulemaking responds to Executive Order 14300, "Ordering the Reform of the Nuclear Regulatory Commission," which President Donald J. Trump signed on May 23, 2025. Section 5(d) of the order contemplates an expedited route to approve reactor designs that DOE or the Department of War has tested and that have shown they can function safely. The order says NRC review of such designs should focus only on risks arising from new applications permitted by NRC licensure, not on risks already addressed in the DOE or Department of War processes.

A similar provision appears in a separate proposed rule on licensing requirements for microreactors and other reactors with comparable risk profiles, published May 1, 2026 (91 FR 23628). If that rule is finalized, it would apply under the proposed part 57 framework.

The docket is NRC-2025-1503.