SUPPLEMENTARY INFORMATION:

I. Background

Congress enacted the National Environmental Policy Act of 1969, 42 U.S.C. 4321-4347 (NEPA) to encourage productive and enjoyable harmony between humans and the environment, recognizing the profound impact of human activity and the critical importance of restoring and maintaining environmental quality to the overall welfare of humankind. (42 U.S.C. 4321, 4331). NEPA seeks to ensure that agencies consider the environmental effects of their proposed major actions in their decision-making processes and inform and involve the public in that process. To comply with NEPA, agencies determine the appropriate level of review of any major Federal action—an environmental impact statement (EIS), environmental assessment (EA), or categorical exclusion (CATEX) (42 U.S.C. 4336). If a proposed action is likely to have significant environmental effects, the agency must prepare an EIS and document its decision in a record of decision (42 U.S.C. 4336). If the proposed action is not likely to have significant environmental effects or the effects are unknown, the agency may instead prepare an EA, which involves a more concise analysis and process than an EIS (42 U.S.C. 4336). Following the EA, the agency may conclude that the action will have no significant effects and document that conclusion in a finding of no significant impact. If the analysis concludes that the action is likely to have significant effects, then an EIS is required.

Under NEPA, a Federal agency may establish categorical exclusions—categories of actions that the agency has determined normally do not significantly affect the quality of the human environment—in its agency NEPA procedures. 42 U.S.C. 4336e(1). If an agency determines that a categorical exclusion covers a proposed action, the agency will then evaluate the proposed action for any extraordinary circumstances in which a normally excluded action may have a significant adverse effect. DA considers extraordinary circumstances pursuant to Department of War DoW NEPA Implementing Procedures dated 30 April 2026 Part 1.4(d) Applying Categorical Exclusions and will concurrently use the agency extraordinary circumstances for the adopted CATEXs as identified below. If an extraordinary circumstance exists, the agency nevertheless may apply the categorical exclusion if the agency conducts an analysis and determines that the proposed action does not in fact have the potential to result in significant effects notwithstanding the extraordinary circumstance or the agency modifies the proposed action to avoid or otherwise mitigate significant effects. If no extraordinary circumstances are present or if further analysis determines that the extraordinary circumstances do not involve the potential for significant environmental impacts, the agency may rely on the categorical exclusion to approve the proposed action without preparing an EA or EIS. 42 U.S.C. 4336(a)(2). If the extraordinary circumstances have the potential to result in significant effects, the agency is required to prepare an EA or EIS.

Section 109 of NEPA, enacted as part of the Fiscal Responsibility Act of 2023, allows a Federal agency to adopt another Federal agency's CATEX (42 U.S.C. 4336c). To use another agency's CATEX under section 109, the adopting agency must identify the relevant CATEX listed in another agency's (“establishing agency”) NEPA procedures that covers the adopting agency's category of proposed actions or related actions; consult with the establishing agency to ensure that the proposed adoption of the CATEX is appropriate for a category of actions; identify to the public the CATEX that the adopting agency plans to use for its proposed actions; and document adoption of the CATEX (42 U.S.C. 4336c).

This notice documents the DA's adoption of one DOE CATEX for DA use and provides public notice of the adoption. The DA NEPA procedures are contained within DoW NEPA Implementing Procedures dated 30 April 2026. The DoW NEPA Implementing Procedures include a list of categorical exclusions available to all DoW Components. After adoption of any CATEX, including this CATEX, it would be available to all DoW Components.

II. DOE Categorical Exclusion

DA is adopting the following DOE CATEX:

DOE CATEX B5.26: Advanced Nuclear Reactors.

Authorization, siting, construction, operation, reauthorization, and decommissioning of advanced nuclear reactors, provided DOE determines that:

(1) the project's attributes, including potential fission product inventory, fuel type, reactor design, and operational plans, reduce sufficiently the risk of adverse offsite consequences from the release of radioactive or hazardous materials, and

(2) the project demonstrates that any hazardous waste, radioactive waste, or spent nuclear fuel generated by the project can be managed in accordance with applicable requirements.

For the purposes of this category, a project may include multiple reactors within a nuclear facility. This CATEX is listed in DOE's NEPA Implementing Procedures, Appendix B, available at energy.gov/​nepa.

III. DA's Use of Adopted CATEX

DA expects to use the listed CATEX for authorization of the construction and operation of advanced reactors on Army installations that would enhance mission capabilities and effectiveness, improve safety, and increase operational efficiencies. DA has identified multiple Army installations as potential locations for deployments of microreactor nuclear power plants (MNPs) for installation energy. This CATEX would allow DA to execute construction and operation of MNPs on Army installations. DA's use of this DOE CATEX would not be limited to this example and could be used in other circumstances for which its use is appropriate.

IV. Consideration of Extraordinary Circumstances and Applicable Criteria

The DoW's NEPA Implementing Procedures guides its consideration of extraordinary circumstances. Further, DA will apply the originating agency's extraordinary circumstances as described in DOE's extraordinary circumstances listed at DOE NEPA Implementing Procedures, Section 5.4(c)(3). If an extraordinary circumstance is present, the DA will determine whether it is possible to modify the action to avoid significant adverse effects. If the action cannot be modified, DA will consider whether the application of the CATEX is still appropriate notwithstanding the presence of extraordinary circumstances, because even with the extraordinary circumstance, the proposed action does not have the potential to result in significant impacts. If DA determines that it cannot apply a CATEX to the proposed action, a particular proposed action due to extraordinary circumstances, DA will prepare an EA or EIS, consistent with DoW NEPA Implementing Procedures dated 30 April 2026 Part 1.4 Categorical exclusions.

Additionally, when applying this CATEX, DA will evaluate the proposed action to ensure consideration of ( printed page 56137) “Integral Elements” described in Appendix B of DOE's NEPA Implementing Procedures. DA will document each application of the above-listed CATEX and its consideration of extraordinary circumstances and integral elements within a Record of Environmental Consideration (REC).

V. Consultation With Establishing Agencies and Determination of Appropriateness

DA worked with DOE to identify the CATEX that could apply to DA proposed actions and consulted with DOE representatives on 29 July 2026. During the consultation, the agencies discussed whether the categories of DA proposed actions would be appropriately covered by the CATEX; the extraordinary circumstances that DA should consider before applying this CATEX to DA's proposed actions; the requirement to evaluate conditions listed as integral elements in DOE's NEPA Implementing Procedures; and what documentation DA should complete when applying this CATEX. The agencies also considered past use of the CATEX by DOE. At the conclusion of that process, the agencies determined that DA's proposed use of the CATEX as described in this notice would be appropriate.

VI. Notice to the Public and Documentation of Adoption

This notice serves to identify to the public the CATEX DA plans to use for its proposed actions, subject to the limitations described above (42 U.S.C. 4336c(3) and document DA's adoption of the CATEX listed in Section II in accordance with 42 U.S.C. 4336c(4), and identifies the types of actions to which DA contemplates applying the CATEX to at this time. In adopting this categorical exclusion, DA will make an administrative change to remove “DOE” from the categorical exclusion text, in alignment with recent Council on Environmental Quality (CEQ) guidance on categorical exclusions ^[1] . Upon issuance of this notice, the adopted CATEX is available for use by DA, effective immediately.

91 FR 56135