US SFR Owner, LLC; Kemmerer Power Station, Unit 1; Draft Environmental Impact Statement

Nuclear Regulatory Commission.

Notice; request for comment.

The U.S. Nuclear Regulatory Commission (NRC), in cooperation with the U.S. Department of Energy (DOE), is issuing for public comment a draft Environmental Impact Statement (EIS). The draft EIS is in response to an application submitted by TerraPower, LLC (TerraPower) on behalf of US SFR Owner, LLC (USO), a wholly owned subsidiary of TerraPower, for a construction permit (CP) for a Natrium advanced reactor at a site in Lincoln County, Wyoming, designated as Kemmerer Power Station, Unit 1 (Kemmerer Unit 1). USO plans to build and operate Kemmerer Unit 1 to demonstrate the Natrium advanced reactor while ultimately replacing electricity generation capacity in the PacifiCorp service area following planned retirement of existing coal-fired facilities. The draft EIS evaluates the environmental impacts of the proposed action of issuing a CP that would allow the construction of Kemmerer Unit 1, as well as the environmental impacts of the following alternatives to the proposed action: (1) the no-action alternative ( i.e., denying the CP application) and (2) building the proposed Natrium advanced reactor at a different location.

Submit comments on the draft EIS by August 4, 2025. Comments received after this date will be considered if it is practical to do so, but the NRC is able to ensure consideration only for comments received on or before this date.

You may submit comments by any of the following methods; however, the NRC encourages electronic comment submission through the Federal rulemaking website:

• Federal rulemaking website: Go tohttps://www.regulations.gov and search for Docket ID NRC-2024-0078. Address questions about Docket IDs in Regulations.gov to Bridget Curran; telephone: 301-415-1003; email: [email protected]. For technical questions, contact the individual listed in the FOR FURTHER IINFORMATION CONTACT section of this document.
• Email: Comments may be submitted to the NRC electronically using the email address [email protected].
• Mail comments to: Office of Administration, Mail Stop: TWFN-7-A60M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, ATTN: Program Management, Announcements and Editing Staff.

For additional direction on obtaining information and submitting comments, see “Obtaining Information and Submitting Comments” in the SUPPLEMENTARY INFORMATION section of this document.