Proposed NRC Rule Leverages DOE and DOW Authorizations for More Efficient Licensing

On April 2, 2026, the U.S. Nuclear Regulatory Commission (NRC) issued a proposed rule to leverage prior Department of Energy (DOE) and Department of War (DOW) reactor authorizations for commercial reactor deployment. Under the proposed rule, an applicant could use aspects of a prior DOE or DOW authorization to demonstrate compliance with certain NRC safety requirements.

By linking the federal government’s various reactor approval processes, this proposed rule could improve licensing efficiency for developers able to take advantage of DOE and DOW authorization pathways. We cover the proposed rule in more detail below.

Background on DOE and DOW Authorizations

As we’ve recently outlined, DOE and DOW have narrow, mission-specific authority to construct and operate nuclear reactors without NRC licenses.

• DOE may authorize reactors “under contract with and for the account of” DOE, but not reactors operated as part of an electric-utility system for industrial or commercial purposes.
• DOW has broader authority to manufacture, produce or acquire nuclear reactors for “military purposes,” possibly including selling limited electricity off-base.

Both DOE and DOW have begun flexing these infrequently exercised reactor authorization powers, set forth in the Atomic Energy Act, based on a series of Executive Orders issued from the White House.

• DOE created the Reactor Pilot Program, under which it selected 11 reactor projects to move forward under DOE authorization, with reportedly three companies on track to go critical by July 4, 2026. Further, DOE recently announced the DOE Launch Pad to extend the Reactor Pilot Program to more projects that will move forward under DOE authorization.
• Meanwhile, DOW plans to deploy microreactors at several military installations across the United States under Project Janus. Nine installations are under consideration for the pilot, including Fort Benning, Fort Bragg and Fort Campbell. The initiative aims to meet a deadline imposed by Executive Order 14299 for a fully operational reactor by September 30, 2028. Unlike the similar Project Pele (a DOW program that focuses on mobile, experimental reactor prototypes), Project Janus focuses on commercializing microreactor technology at permanent U.S. military bases under DOW authorization.

While helpful to demonstrate first-of-a-kind nuclear reactor designs, the ultimate use-cases of DOE and DOW are inherently and statutorily limited. For commercial, civilian deployments, the Atomic Energy Act requires entities to obtain an NRC license—which is where this proposed rule comes in.

What’s in the Proposed Rule

This proposed rule implements Executive Order 14300, which directed the NRC to leverage prior DOE and DOW reactor authorizations to support subsequent commercial reactor licensing by the NRC. Specifically, Section 5(d) ordered the NRC to establish an expedited pathway to approve reactor designs that the DOE or DOW have tested and demonstrated the ability to function safely. It instructed the NRC to focus solely on risks that may arise from new NRC-licensed applications, not risks already addressed under DOE or DOW processes.

The NRC proposes to allow applicants to reference a prior DOE or DOW reactor authorization by adding a provision to 10 CFR Part 50 (for two-step traditional reactor licensing)—which would also apply to Part 52’s one-step licensing per 10 C.F.R. § 52.47(c)(2)—and the newly approved but not yet effective Part 53 (for advanced reactor licensing).

In particular, an applicant could reference the prior authorization to demonstrate that a reactor design accomplishes its safety functions. This presents an alternative to the analysis, prototype testing and operating experience currently required under 10 CFR 50.43(e) (for Part 50 and 52 applicants) and the recently approved 10 CFR 53.440 (for Part 53 applicants).

Specific requirements for using prior DOE or DOW authorization include:

• The reactor must have been tested and must have demonstrated the ability to function safely.
• An applicant must identify how the attributes of the DOE or DOW authorization satisfy NRC regulations.
• An applicant must address how any key differences—changes to the design, its functionality, associated hazards, siting information or underlying safety assumptions—meet NRC requirements.

The NRC plans to issue guidance for review of applications that reference DOE or DOW authorizations. Additionally, the NRC will include an analogous provision in its upcoming proposed Part 57 for microreactor and other low consequence reactor licensing.

Takeaways and Implications for Developers

This proposed rule offers real potential for licensing efficiency gains, as it would limit duplication of efforts and link the federal government’s multiple reactor approval pathways. To get the most out of this proposal, developers and their deployment partners who are considering relying on a DOE or DOW authorization should consider the following: 

• While an applicant can leverage prior approval, it must still demonstrate safety and compliance with NRC requirements. Prior DOE/DOW authorization does not offer a blank check to NRC licensing—the NRC retains its role as an independent safety regulator. When transitioning to NRC licensing, an applicant must identify how the DOE or DOW authorization maps onto the NRC’s regulations. This may require additional analysis to bridge the gap between frameworks.
• Developers should limit design changes after DOE/DOW authorization—or at least prepare to justify differences for commercial deployment. Because an applicant must address how key differences meet NRC requirements, developers may be disincentivized to make substantial changes to the design basis or safety case once the DOE or DOW issue their authorization. However, some changes may be necessary to transition a reactor design from the limited, mission-driven DOE/DOW use-case to the commercial uses under NRC licensing authority. The sooner developers consider or address these changes, the more effectively they can manage the transition.
• Light-water and advanced reactor designs will benefit, but the use-case for microreactors is still in flux. The DOW is focusing on deploying microreactors in the near term under Project Janus. While microreactors can be licensed under current NRC licensing frameworks, the NRC is also developing a separate licensing framework for these and other low-consequence designs. The NRC promises to introduce a comparable provision to that rule—Part 57—but what that looks like is still unknown.

Conclusion

As the NRC finds ways to streamline its licensing requirements—and DOE and DOW increasingly rely on their statutory authorities—this proposed rule offers a way to synthesize multiple agency authorities.