18 minute read | October.23.2026
New rule and accompanying NRC staff white paper outline how federal reactor demonstrations may support commercial licensing, but significant questions remain about the credit given to prior authorizations, safety evaluations, and testing.
Last year, the Department of Energy (DOE) and Department of War (DOW) launched several initiatives to accelerate nuclear reactor development and demonstration, including DOE's Reactor Pilot Program (RPP) and Nuclear Energy Launch Pad, and DOW's Project Janus. These programs rely on DOE and DOW statutory authority under the Atomic Energy Act to authorize reactor development and demonstration outside the Nuclear Regulatory Commission’s (NRC) traditional licensing framework for commercial nuclear reactors. Since their launch, the nuclear industry, federal regulators, and other stakeholders have been working to determine how these other federal authorizations—at DOE and DOW—can support and accelerate subsequent commercial licensing of these reactors by the NRC.
The NRC has now taken important steps toward addressing that question. In a newly issued final rule, NRC Reviews of Reactor Designs Previously Authorized by U.S. Department of Energy or Department of War, the NRC amends 10 CFR Part 50 and the new Part 53 to expressly allow applicants to leverage information from DOE- or DOW-authorized reactors that have been tested and demonstrated the ability to function safely. In a newly released NRC staff white paper, Leveraging Information from Previously Authorized Facilities, outlining an initial framework for determining how prior DOE safety evaluations, technical findings, and demonstration experience may support subsequent NRC licensing.
Together, these developments establish a clearer connection between federal reactor deployment under DOE and DOW authorizations and commercial deployment under NRC authorization, with the potential to reduce duplicative technical reviews, licensing costs, and deployment timelines. They may also have broader implications for developers pursuing traditional NRC licensing pathways by providing insight into how the agency evaluates testing, operational experience, and the maturity of advanced reactor designs.
The central question remains how much regulatory credit the NRC will give to prior federal authorizations, safety evaluations, and testing. The final rule establishes the regulatory pathway, while the white paper begins to define how it may be implemented. However, in its accompanying response to public comments, the NRC expressly declined to establish a presumption that prior DOE or DOW findings should be accepted in subsequent NRC licensing. Instead, the NRC noted that it will determine the appropriate degree of reliance on prior federal work through its independent, application-specific review. The white paper also remains preliminary and does not represent an approved NRC position at this time.
For developers, the implications are both regulatory and commercial. How demonstrations are designed, evaluated, and documented today could materially affect the cost, scope, and timing of subsequent NRC licensing. Establishing a clear regulatory crosswalk between federal demonstration activities and NRC requirements will therefore be critical to realizing the intended efficiencies.
We highlight the key developments and their practical implications below.
The final rule adds a new 10 CFR § 50.43(f), which provides that an NRC application:
may include consideration of relevant information gathered from a utilization facility that has been previously authorized by the Department of Energy or the Department of Defense and that has been tested and has demonstrated the ability to function safely.
When relying on this pathway, applicants must identify how attributes of the prior authorization satisfy NRC regulations, including the requirements of 10 CFR § 50.43(e) governing the demonstration of reactor safety functions. The Part 50 amendment also supports licensing under Part 52.
The NRC also amends 10 CFR § 53.440(a)(1)—under the NRC’s new Part 53 rulemaking (issued earlier this year)—to recognize the same approach under the Part 53 licensing framework.
Importantly, the rule does not eliminate the need for independent NRC review or reduce applicable safety standards. In its response to public comments, the NRC emphasized that applicants must continue to submit complete applications demonstrating compliance with NRC requirements and that the agency retains authority to request additional information and independently determine whether those requirements are satisfied.
The NRC also acknowledged that DOE and DOW authorizations may differ substantially in scope from commercial NRC licensing. For example, material qualification for a limited-duration federal demonstration may not establish the suitability of those materials for a commercial reactor intended to operate for 40 years.
Scope of the Rule. The new licensing pathway applies to previously authorized reactor designs and does not establish a corresponding framework for fuel cycle facilities, including uranium enrichment, conversion, or fuel fabrication facilities licensed under 10 CFR Parts 40 and 70. Although information developed under DOE authorization may support subsequent NRC fuel cycle licensing, the regulatory credit afforded that information remains subject to the applicable licensing requirements and NRC review.
Why it matters: Developers now have an express regulatory basis for leveraging prior DOE or DOW demonstration experience in commercial licensing. But a successful demonstration does not automatically establish that a larger, modified, or differently situated commercial reactor satisfies NRC requirements. The applicability of that experience, and the evidence supporting it, will be critical.
One of the most significant issues raised during the rulemaking was how prior DOE and DOW authorizations would be evaluated in subsequent NRC licensing proceedings. Industry stakeholders sought greater predictability regarding which aspects of prior federal reviews could satisfy NRC requirements, how completed safety evaluations would be treated, and what additional information applicants would need to provide.
The NRC's response to public comments is particularly instructive. One commenter proposed establishing a rebuttable presumption that DOE or DOW technical conclusions would provide an adequate basis for corresponding NRC findings where the underlying determinations were materially similar. Under that approach, the NRC would focus its review on new or increased risks arising from differences in design, operation, or siting, while retaining authority to revisit prior conclusions where warranted.
It explained that DOE and DOW apply their own standards and make determinations for the purposes of their respective programs, rather than applying NRC regulations. Nevertheless, the NRC acknowledged that those standards, analyses, and testing may be sufficient to satisfy particular NRC requirements. The agency stated that it intends to leverage overlapping technical information to the maximum extent practical, including by adjusting the focus and depth of its reviews.
This distinction is significant. The NRC has established a pathway for crediting prior federal work, but applicants must affirmatively demonstrate how that work satisfies applicable NRC requirements. The agency has not established a presumption of equivalency or a requirement to limit its review to risks that were not previously evaluated.
As 158 pages, the NRC's new white paper provides considerably more detail on how this framework may operate. It identifies two principal approaches:
The second approach is particularly significant. The NRC staff acknowledges that directly leveraging DOE findings would represent a more novel approach than historical NRC practice, under which DOE-generated information has generally been used to support discrete technical evaluations.
However, this approach must be understood in light of the NRC's response to public comments. Directly leveraging a prior DOE finding would not mean automatically accepting that finding or substituting DOE's regulatory determination for the NRC's own. The applicant would still need to establish the finding's relevance and adequacy under NRC requirements.
The white paper identifies five factors the NRC staff would consider when determining how extensively prior DOE work can be leveraged:
Based on these factors, the white paper describes three potential levels of leveraging:
| Level | Potential NRC Treatment |
| Maximum Leveraging | Prior DOE technical information or findings may provide a direct basis for NRC determinations, subject to confirmation of their applicability and adequacy. |
| Moderate Leveraging | DOE information may support NRC findings but requires additional evaluation, analysis, or justification. |
| Limited Leveraging | DOE information may inform the NRC review but would not constitute a significant part of the technical basis for its safety determination. |
These categories are intended to guide application-specific and technical-area-specific assessments. They do not establish automatic regulatory credit or predetermined outcomes.
The white paper also identifies specific information applicants should provide when seeking to leverage a prior DOE authorization, including:
The white paper also includes 17 technical appendices addressing major licensing topics, including quality assurance, licensing-basis events, principal design criteria, source terms, fuel performance, emergency preparedness, security, analytical methods, and cybersecurity.
The NRC's response to public comments also addresses industry requests for more detailed implementation guidance. The agency confirmed that it will use its existing licensing application review procedures together with the draft interim staff guidance, NRC Application Pathway for Reactor Designs Previously Authorized by the U.S. Department of Energy or Department of War (published in the Federal Register on April 17, 2026). The NRC will assess, based on licensing experience, whether additional or more detailed guidance is warranted.
This leaves important questions regarding the degree of regulatory credit, evidentiary expectations, and consistency across applications to be resolved through implementation. The staff white paper offers a potentially valuable framework, but it has not undergone NRC management or legal review, does not represent an official agency position, and expressly cautions prospective applicants against relying on its contents when preparing applications.
Why it matters: The NRC is moving beyond simply allowing applicants to reference DOE information toward identifying how that information may support specific NRC licensing findings. Its recognition that prior DOE findings may directly support NRC determinations is particularly significant.
At the same time, the NRC's refusal to establish presumptive credit places considerable importance on the quality of the applicant's regulatory crosswalk. Developers will need to demonstrate the applicability of prior federal findings to specific NRC requirements, rather than relying on the fact that DOE or DOW previously authorized the reactor. The first applications under the new rule will be important in establishing how this framework operates in practice.
Our experience advising advanced reactor developers pursuing DOE authorization through the RPP and Nuclear Energy Launch Pad underscores why a workable DOE-to-NRC regulatory crosswalk is so important. These programs offer opportunities to demonstrate new reactor technologies under DOE authorization, but obtaining DOE authorization and developing an NRC-ready commercial licensing basis are not necessarily the same exercise.
We have been incorporating the NRC's draft interim staff guidance into our assessment of proposed Launch Pad projects, with particular attention to how demonstration activities, safety analyses, and authorization documentation can support eventual commercial licensing. The new white paper provides additional insight into how the NRC staff is considering these issues.
The white paper distinguishes between limited-scope demonstrations and full-scale demonstrations of commercial reactor designs.
Limited-scope demonstrations may include zero- or low-power criticality testing or operation at appreciable power levels to generate information supporting a future NRC application. These demonstrations may provide valuable technical data, but their limited operating conditions or duration may constrain how broadly their findings can be applied.
Full-scale demonstrations involving reactor designs and operating conditions substantially similar to those proposed for commercial deployment may offer greater opportunities for regulatory leveraging, particularly where DOE's review scope, technical evaluations, and supporting documentation closely align with NRC requirements.
The NRC also recognizes that a short-duration DOE demonstration may not address issues relevant to decades of commercial operation, including materials aging, component degradation, fuel performance, inspection and maintenance programs, and other long-term safety considerations.
These distinctions reinforce the importance of designing federal demonstrations with the intended commercial licensing pathway in mind.
The NRC staff's white paper specifically addresses how information developed at successive stages of the DOE authorization process may support subsequent NRC licensing. The staff distinguishes among three principal DOE documents—the Nuclear Safety Design Agreement (NSDA), Preliminary Documented Safety Analysis (PDSA), and Documented Safety Analysis (DSA)—and identifies different opportunities for leveraging each based on the maturity of the design and supporting safety analyses.
Nuclear Safety Design Agreement (NSDA). The NSDA is an agreement between DOE and the developer that establishes the foundational requirements and approach for reactor safety design. It documents design requirements, the safety analysis methodology, regulatory engagement processes, key safety decisions, and the Code of Record identifying applicable engineering codes and standards. In its white paper, the NRC staff explains that the NSDA generally contains high-level design information with limited value for direct NRC licensing credit. However, the staff encourages early NRC engagement at this stage, including potential preapplication audits, to familiarize NRC reviewers with the design, regulatory approach, and any proposed exemptions from DOE requirements.
Preliminary Documented Safety Analysis (PDSA). The PDSA is the preliminary safety analysis developed to support DOE's authorization of construction. It documents the developing reactor design, hazard and accident analyses, and proposed safety controls. The NRC staff explains in the white paper that DOE generally considers the design approximately 50% complete at this stage. Although the PDSA and an NRC Preliminary Safety Analysis Report (PSAR) both address preliminary designs, the staff cautions that DOE's expectations for design maturity may differ significantly from NRC requirements. In particular, an NRC PSAR generally requires preliminary design information across the complete facility, while DOE's PDSA process may not require the same level of maturity for all design elements. Accordingly, the staff encourages developers intending to use a DOE PDSA to support an NRC construction permit application to arrange for NRC observation of DOE's PDSA review. This would allow NRC reviewers to understand DOE's findings, identify gaps, and determine what information can be leveraged rather than independently repeating the entire review.
Documented Safety Analysis (DSA). The DSA provides the final safety analysis supporting DOE authorization of reactor operations. It reflects the final design and demonstrates that the as-built facility satisfies the safety basis necessary for operation. The NRC staff states in the white paper that, because the DSA represents a more mature design, its technical information should generally be capable of greater leveraging than information contained in an NSDA or PDSA. The staff similarly encourages NRC observation of DOE's DSA review to facilitate subsequent reliance on relevant technical analyses and findings. However, the white paper acknowledges that NRC staff experience with DSAs for reactors intended for commercial licensing remains limited, particularly because many DOE demonstrations involve relatively narrow operational scopes.
Testing and Operating Experience. Beyond these documents, the NRC staff recognizes that testing and operating experience from a DOE-authorized reactor may support subsequent NRC licensing findings. The white paper emphasizes, however, that applicants must demonstrate the relevance of that experience to the proposed commercial facility, particularly where the DOE demonstration involves a limited configuration, operating duration, or scope of activities. The staff encourages NRC involvement during the DOE authorization process so reviewers can understand what the demonstration was designed to establish and how its results may support subsequent NRC licensing.
Transitioning an Existing DOE-Authorized Reactor to NRC Licensing. The white paper also identifies a distinct issue for developers seeking to transition an existing DOE-authorized reactor directly to NRC licensing. Because the NRC does not oversee construction under DOE authorization, it must independently establish reasonable assurance that the facility was constructed in accordance with the proposed NRC licensing basis. The NRC staff indicates that it intends to verify the quality of construction activities through a separate process, referencing prior NRC correspondence to prospective applicants (ML26268A085 and ML26259A330). This makes construction records, quality assurance documentation, inspection results, and evidence of design conformance particularly important for developers contemplating a direct transition.
For developers pursuing the RPP or Launch Pad, these developments reinforce several practical priorities.
These considerations extend beyond regulatory compliance. For developers seeking to use successful demonstrations to support commercial financing, customer commitments, or broader deployment programs, the ability to translate DOE authorization and testing into NRC licensing progress may materially affect project economics and execution risk.
A demonstration that validates the technology but leaves substantial NRC licensing questions unresolved may provide less commercial value than one designed from the outset to support both DOE authorization and eventual NRC licensing.
The significance of these developments extends beyond companies participating in federal demonstration initiatives.
As the NRC begins applying the new rule and developing its approach to leveraging prior federal evaluations, its treatment of testing, operational experience, technical maturity, and design differences may provide broader insight into the evidence necessary to support commercial licensing of advanced reactor technologies.
The white paper's discussion of risk-informed review, technical documentation, design maturity, and the relationship between testing and licensing findings may be particularly relevant to developers pursuing traditional NRC pathways, even where no prior DOE or DOW authorization exists.
Developers should therefore pay attention to how the NRC implements the new rule, finalizes its accompanying guidance, and applies these principles in the first commercial licensing reviews involving previously authorized reactor designs.
The NRC's final rule, staff white paper, and response to public comments collectively provide a clearer picture of how federal reactor demonstrations may support subsequent commercial licensing.
The rule establishes an express regulatory pathway, and the white paper outlines a framework for determining how prior DOE technical findings and safety evaluations may be leveraged. The NRC's comment responses, however, confirm that the agency will not presume those findings satisfy NRC requirements and will retain discretion to determine the appropriate degree of credit through independent, application-specific reviews.
For developers participating in the RPP, pursuing Launch Pad demonstrations, or otherwise advancing reactor technologies under federal authorization, the immediate priority is to build the regulatory crosswalk now. Aligning demonstration activities, technical documentation, and NRC licensing requirements early will be essential to maximizing the value of federal demonstration experience and reducing unnecessary duplication during commercial licensing.
Orrick's Nuclear Energy team advises reactor developers and other industry participants on DOE authorization, NRC licensing, advanced reactor demonstration programs, and the regulatory and commercial strategies necessary to bring new nuclear technologies to market.