The U.S. Nuclear Regulatory Commission announced on January 29, 2026, the issuance of Interim Staff Guidance DRA-ISG-2026-01, titled "Content of Risk Assessment and Severe Accident Information in Light-Water Power Reactor Construction Permit Applications." This guidance clarifies the scope and depth of NRC staff reviews for descriptions of risk assessments and severe accident information included in the Preliminary Safety Analysis Report for construction permit applications involving light-water power reactors. Effective March 2, 2026, the document responds to growing interest from applicants planning submissions in the coming years, marking a step to streamline reviews under the two-step licensing process outlined in 10 CFR part 50. By providing this clarity, the NRC aims to ensure that preliminary design information meets regulatory standards without requiring the full detail needed for operating licenses, potentially facilitating renewed activity in nuclear power development amid evolving energy needs.
Background on NRC Licensing Processes
The NRC's two-step licensing framework under 10 CFR part 50 allows applicants to secure a construction permit based on preliminary design information before finalizing details for an operating license. This contrasts with the one-step combined license process under 10 CFR part 52, which demands a complete design upfront. The last power reactor construction permit was issued in the 1970s, with recent approvals focusing on combined licenses guided by NUREG-0800, the Standard Review Plan, and Regulatory Guide 1.206.
Anticipating new applications, the NRC developed this ISG following preapplication engagements with prospective applicants. As noted in the Federal Register notice, "The NRC is aware of one applicant's interest in submitting a CP application within the next few years." This guidance supplements earlier efforts, such as DNRL-ISG-2022-01 issued in October 2022, which addressed general safety reviews for light-water reactor construction permits but lacked specifics on probabilistic risk assessments and severe accident evaluations.
Historical context reveals that regulatory guidance has evolved since the 1970s. Regulatory Guide 1.70, last revised in 1978, provides some insights into Preliminary Safety Analysis Report content, but it does not incorporate subsequent requirements or technical advances. The new ISG bridges these gaps by focusing on risk-related elements, ensuring reviews align with current standards without mandating final design finality at the construction permit stage.
Key Elements of the Guidance
The ISG specifies that it applies to light-water reactor construction permit applications using risk assessment and severe accident information, excluding non-light-water designs. It emphasizes a limited safety review at the construction permit phase, allowing flexibility for applicants to begin building with preliminary data. As the notice states, "The licensing process under 10 CFR part 50 allows an applicant to begin construction with preliminary design information instead of the final design required for a COL under 10 CFR part 52."
Central to the guidance is the clarification of review scope for the Preliminary Safety Analysis Report. Applicants must describe risk assessments and severe accidents, but the depth is tailored to preliminary stages. The ISG draws from the Standard Review Plan and Regulatory Guide 1.206 to define acceptable approaches, ensuring that submissions identify potential risks without the exhaustive analysis required for operating licenses. Public comments on the draft, summarized in Appendix A of the ISG (ADAMS Accession No. ML25099A053), were considered and resolved, refining the final version.
This approach reflects broader NRC efforts to adapt to modern applications. For instance, it acknowledges that while combined licenses under part 52 involve detailed final designs, construction permits permit iterative development, with changes documented in the Final Safety Analysis Report during the operating license phase.
Legal and Regulatory Framework
The guidance operates within established regulations, including 10 CFR part 50, which governs domestic licensing of production and utilization facilities. It aligns with the Backfit Rule in 10 CFR 50.109, as the notice confirms that issuance "would not constitute backfitting as defined in 10 CFR 50.109" and does not affect existing licensees or approvals under part 52.
Precedents from past NRC actions, such as the updates to Regulatory Guide 1.206 in 2018, inform this ISG. The notice references NUREG-0800 as the primary review guidance, supplemented by this document to address risk-specific content. No new requirements are imposed. Instead, the ISG clarifies expectations, potentially reducing uncertainty for applicants. Perspectives from industry stakeholders, evident in the public comment process, highlight a desire for predictability, while regulatory advocates emphasize maintaining safety rigor.
The Congressional Review Act classification underscores the guidance's non-major rule status, as determined by the Office of Management and Budget, indicating minimal economic impact but procedural importance.
Implications for Stakeholders
For applicants, the ISG offers a roadmap to prepare effective submissions, potentially accelerating the path to construction amid interest in nuclear energy for carbon-free power. Short-term implications include enhanced preapplication dialogues, as the NRC anticipates submissions "over the next few years." Long-term, it could influence the revival of the two-step process, providing more flexibility than combined licenses but requiring thorough Final Safety Analysis Report reviews later.
Different viewpoints emerge. Proponents of nuclear expansion see this as a facilitative step, aligning with energy policy goals. Critics, however, may argue for stricter preliminary reviews to prevent safety oversights, drawing from historical incidents like those informing post-1970s regulations. The guidance balances these by adhering to verifiable standards without endorsing expansion.
The ISG's issuance also signals NRC adaptability, incorporating public input and aligning with Executive Order 12866's emphasis on regulatory efficiency.
In summary, this guidance equips the NRC to handle emerging construction permit applications effectively. Potential next steps include applicant submissions leveraging the ISG, with ongoing debates centering on balancing innovation with safety. Future challenges may involve integrating advanced risk assessment technologies or addressing non-light-water applications separately, while trajectories could see increased nuclear development if economic and policy conditions align.
