Environmental Impact Statement for the Construction Permit for the Kairos Hermes Test Reactor – Final Report (NUREG-2263)

On this page:

Download complete document

Publication Information

Manuscript Completed: August 2023
Date Published: August 2023

Office of Nuclear Material Safety and Safeguards
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

Availability Notice


The U.S Nuclear Regulatory Commission (NRC) has prepared this environmental impact statement (EIS) in response to an application submitted by Kairos Power, LLC (Kairos) for a construction permit (CP) for a non-power test reactor termed Hermes at a site in Oak Ridge, Tennessee. Kairos plans to build and operate Hermes to demonstrate key elements of the Kairos Power Fluoride Salt-Cooled, High Temperature Reactor technology for possible future commercial deployment. This EIS includes the analysis that evaluates the environmental impacts of the proposed action and considers the following two alternatives to the proposed action: (1) the no-action alternative (i.e., the CP is denied) and (2) building the proposed Hermes non-power test reactor at a site near Idaho Falls, Idaho.

After weighing the environmental, economic, technical, and other benefits against environmental and other costs, and considering reasonable alternatives, the NRC staff recommends, unless safety issues mandate otherwise, that the NRC issue the CP to Kairos once the NHPA Section 106 process is complete. The NRC staff based its recommendation on the following factors:

  • the NRC staff’s review of Kairos’s environmental report (included as part of the CP application and revised in March 2023) and associated responses from Kairos to requests from the NRC staff for clarifying information;
  • the NRC staff’s review of comments received as part of the scoping process;
  • the NRC staff’s review of comments received on the draft EIS;
  • the NRC staff’s communications with, and comments received from, Federal, State, and local agencies, as well as Tribal officials; and
  • the NRC staff’s independent environmental review.

Page Last Reviewed/Updated Thursday, August 17, 2023