New Nuclear Reactor Generic Environmental Impact Statement (NR GEIS)

On this page:

• Abstract
• Overview of the NR GEIS and Revised Regulations
• Project Background
• Final Rule
• Key Documents
• Public Meetings
• Project Mailing List

Abstract

The U.S. Nuclear Regulatory Commission (NRC) staff prepared a generic environmental impact statement (GEIS) in accordance with the National Environmental Policy Act of 1969 (NEPA), as amended, to address the NRC licensing of the building and operation of new nuclear reactors in the United States. The NRC staff has published a final rule that amends the regulations that govern the NRC’s environmental reviews under NEPA by codifying the findings of the Generic Environmental Impact Statement for Licensing of New Nuclear Reactors, NUREG-2249. In this GEIS, the NRC staff uses the values and assumptions in a technology-neutral plant parameter envelope (PPE) for a new nuclear reactor to evaluate the environmental impacts of constructing and operating a nuclear reactor. In addition, this GEIS assumes that a new reactor might be built anywhere in the United States that meets the requirements of the NRC’s siting regulations. To accommodate this broad range of siting possibilities, the staff developed a site parameter envelope (SPE) that provides limiting values and assumptions related to the site. The generic findings from this GEIS are codified in Title 10 of the Code of Federal Regulations Part 51.

Overview of the NR GEIS and Revised Regulations

On April 24, 2026 the NRC published the final Generic Environmental Impact Statement for Licensing of New Nuclear Reactors (NR GEIS, NUREG-2249) (91 FR 22394), and associated changes to its regulations in 10 CFR Part 51. The GEIS presents impact analyses for environmental issues that are common to many new nuclear reactors and that can therefore be addressed generically, streamlining the environmental review process to allow applicants and the NRC staff to focus their environmental reviews on project- and site-specific issues. The NRC uses a similar approach for nuclear reactor license renewal application reviews, relying on the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (NUREG-1437).

The GEIS may be used in support of various types of reactor licensing actions including construction permits (CPs), operating licenses (OLs), limited work authorizations (LWAs), early site permits (ESPs) and combined licenses (COLs). An applicant for a new reactor may choose to rely on findings from the GEIS if it meets certain conditions (discussed below). If an applicant relies on any of the findings from the GEIS in its application, then the NRC staff will prepare its environmental document as a supplement to the GEIS.

In the GEIS, the NRC staff identified environmental issues associated with building, operating and decommissioning a new nuclear reactor. The staff determined that for many of the issues (referred to as Category 1 issues) it could reach a generic conclusion of SMALL impacts if the project could meet a set of values and assumptions associated with the plant design (plant parameter envelope, or PPE) and the project site (site parameter envelope, or SPE). SMALL impacts are defined as environmental effects that are not detectable or are so minor that they will neither destabilize nor noticeably alter any important attribute of the resource. However, there were other issues (referred to as Category 2 issues) for which the NRC staff determined that a generic finding regarding the environmental impacts cannot be reached because the issue requires the consideration of project-specific information that can only be evaluated once the proposed site is identified. In addition, there were 2 issues (referred to as Category Not Applicable, or N/A) related to the human health effects of electromagnetic fields for which the state of the science is currently uncertain, and no generic conclusion on human health impacts is possible.

The GEIS presents the analysis supporting a finding of SMALL environmental impacts for each Category 1 issue for which the NRC staff could reach a generic conclusion if the values and assumptions of the PPE and SPE are met. It also lists the Category 2 issues for which a generic conclusion could not be reached, explaining the basis for that conclusion. In the GEIS, the NRC staff identified 100 Category 1 issues, 19 Category 2 issues, and 2 Category N/A issues.

Project Background

On November 15, 2019, the NRC staff issued a Federal Register notice (84 FR 62559) announcing an exploratory process and soliciting comments to determine the possible utility of developing a GEIS for licensing advanced nuclear reactors (ANRs). The exploratory process included two public meetings, a comprehensive public workshop attended by multiple stakeholders, and a site visit to the Idaho National Laboratory, one location that is being contemplated for some ANRs. As part of the exploratory process, the staff considered its experience with previous NRC GEIS documents that support power reactor license renewals, in situ uranium recovery facilities, and decommissioning. The staff gathered information to determine whether a GEIS for construction and operation of ANRs might be viable. The exploratory process concluded with an information paper to the NRC Commission concluding that the staff decided to pursue a GEIS using a technology-neutral approach, and that a GEIS would generically resolve many environmental issues, saving resources and providing predictability for potential applicants.

In Staff Requirements Memorandum (SRM) SECY-20-0020, dated September 21, 2020, the Commission approved the development of a GEIS for the construction and operation of ANRs using a technology-neutral, performance-based approach, and directed staff to codify results in the Code of Federal Regulations. The NRC issued a notice of intent to prepare the GEIS on April 30, 2020 (85 FR 24040), carried out a scoping process, and held a scoping meeting to receive public comments on the GEIS on May 28, 2020. After considering the comments received from various sources during the scoping process, the NRC staff initially developed this GEIS as a document that would be applicable to only ANRs.

Because this GEIS was initially developed using a technology-neutral, performance-based approach, its analyses can be used by any reactor. In SRM SECY-21-0098, dated April 17, 2024, the Commission directed the NRC staff to change the limited applicability of the GEIS from solely “advanced nuclear reactors” to any new nuclear reactor licensing application, provided the application meets the values and the assumptions of the plant parameter envelopes and the site parameter envelopes used to develop the GEIS. As such, the GEIS was broadened to include all new nuclear reactors and therefore referred to as the NR GEIS.

Final Rule

Generic Environmental Impact Statement for Licensing of New Nuclear Reactors Rulemaking

Key Documents

NRC Docket NRC-2020-0101
Includes proposed and final rule language and stakeholder comments.

• Final Generic Environmental Impact Statement for Licensing of New Nuclear Reactors, NUREG-2249 (NR GEIS) 
• Federal Register Notice-Generic Environmental Impact Statement for Licensing of New Nuclear Reactors Final Rule 
• Regulatory Guide 4.2, Revision 4, "Preparation of Environmental Reports for Nuclear Power Stations" (Final Rule - GEIS for Licensing New Nuclear Reactors)
• Interim Staff Guidance COL-ISG-030, “Environmental Considerations Associated with New Nuclear Reactor Applications that Reference the Generic Environmental Impact Statement (NUREG- 2249)”
• Recommendations for an Applicant to Calculate Activity Data for Greenhouse Gases Estimates (GHG White Paper)
• Energy and System Design Mitigation Alternatives White Paper
• Regulatory Analysis for the 10 CFR Part 51 Generic Environmental Impact Statement for Licensing of New Nuclear Reactors Final Rule

Project Meetings

Project Mailing List

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