{"abstract":"The U.S. Nuclear Regulatory Commission (NRC or the Commission) is issuing an environmental assessment (EA) and finding of no significant impact (FONSI) regarding the Kairos Power LLC (Kairos or the licensee) request to amend Construction Permit No. CPTR-6 for the Hermes test reactor facility in Oak Ridge, Tennessee. The amendment request seeks NRC approval to extend the latest date for completion of the construction of the Hermes test reactor facility from December 31, 2026, to April 30, 2029.","action":"Notice; issuance.","agencies":[{"raw_name":"NUCLEAR REGULATORY COMMISSION","name":"Nuclear Regulatory Commission","id":383,"url":"https://www.federalregister.gov/agencies/nuclear-regulatory-commission","json_url":"https://www.federalregister.gov/api/v1/agencies/383","parent_id":null,"slug":"nuclear-regulatory-commission"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2026/04/21/2026-07700.html","cfr_references":[],"citation":"91 FR 21335","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"The EA and FONSI referenced in this document are available on April 21, 2026.","disposition_notes":null,"docket_ids":["Docket No. 50-7513","NRC-2021-0193"],"dockets":[{"supporting_documents":[{"title":"Draft NUREG-2263 \"Environmental Impact Statement for the Construction Permit for the Kairos Hermes Test Reactor\"","document_id":"NRC-2021-0193-0012"}],"agency_name":"NRC","documents":[{"comment_count":null,"comment_start_date":null,"updated_at":"2026-04-21T09:57:22.017-04:00","comment_url":"https://www.regulations.gov/commenton/NRC-2021-0193-0023","allow_late_comments":false,"id":"NRC-2021-0193-0023","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":1,"id":"NRC-2021-0193","title":"Kairos Power, LLC"}],"document_number":"2026-07700","effective_on":null,"end_page":21337,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/04/21/2026-07700.xml","html_url":"https://www.federalregister.gov/documents/2026/04/21/2026-07700/kairos-power-llc-hermes-test-reactor-environmental-assessment-and-finding-of-no-significant-impact","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-07700?publication_date=2026-04-21","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-04-21/2026-07700/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":124,"last_updated":"2026-06-24 20:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-04-21/pdf/2026-07700.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-07700.pdf?1776689110","publication_date":"2026-04-21","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/04/21/2026-07700.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"Draft NUREG-2263 \"Environmental Impact Statement for the Construction Permit for the Kairos Hermes Test Reactor\"","document_id":"NRC-2021-0193-0012"}],"comments_count":0,"agency_id":"NRC","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=NRC-2021-0193","supporting_documents_count":1,"docket_id":"NRC-2021-0193","document_id":"NRC-2021-0193-0023","regulation_id_number":null,"title":"Kairos Power, LLC","checked_regulationsdotgov_at":"2026-04-22T11:55:03Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":21335,"subtype":null,"title":"Kairos Power LLC; Hermes Test Reactor; Environmental Assessment and Finding of No Significant Impact","toc_doc":"Kairos Power LLC; Hermes Test Reactor","toc_subject":"Environmental Assessments; Availability, etc.","topics":[],"type":"Notice","volume":91}