Quoted exactly and dated only as precisely as the source. Copies of one release count as one origin. A withdrawn statement stays visible and is labelled.
13 October 2020 · Financing · Whole project
Announced
DOE Advanced Reactor Demonstration Program initial award to TerraPower (cost-shared; later funding subject to appropriations)
Government record U.S. Department of Energy, Office of Nuclear Energy · Counterparty: U.S. Department of Energy · Government cost share · USD 80m
“DOE is awarding TerraPower LLC (Bellevue, Washington) and X-energy (Rockville, Maryland) $80 million each in initial funding to build two advanced nuclear reactors that can be operational within seven years.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
16 November 2021 · Financing · Whole project
Announced
DOE's stated plan to invest in the Natrium demonstration (licensing, construction, demonstration)
Government record U.S. Department of Energy, Office of Nuclear Energy · Counterparty: U.S. Department of Energy · Government cost share · About USD 2bn
“The U.S. Department of Energy is extremely excited about this project and plans to invest nearly $2 billion to support the licensing, construction and demonstration of this first-of-a-kind reactor.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
14 May 2024 · Permissions · Whole project
Application submitted
Construction permit application, Kemmerer Power Station Unit 1 (applicant US SFR Owner, LLC, a TerraPower subsidiary)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The application for the construction permit was received on March 28, 2024, and a supplement to the application was submitted on May 2, 2024.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
29 March 2024 · Technical milestones · Whole project
Design disclosed
Storage boost claim (power and duration; no MWh figure stated)
Company reported TerraPower
“The Natrium storage technology can boost the system’s output to 500 MWe for more than five and a half hours when needed.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
4 June 2024 · Permissions · Whole project
Application accepted for review
Construction permit application accepted for review and docketed (Docket No. 50-613)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“Nuclear Regulatory Commission (NRC) has accepted for review and docketed an application from US SFR Owner, LLC (USO) for a construction permit for the Kemmerer Power Station, Unit 1 reactor to be built in Lincoln County, Wyoming.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
10 June 2024 · Construction · Whole project
Site work
Start of non-nuclear construction at the site; nuclear construction deferred until the permit
Company reported TerraPower
“Due to its unique design, non-nuclear construction is beginning, while nuclear construction will begin after this application is approved.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
14 January 2025 · Permissions · Whole project
Permission issued
State industrial siting permit for activities outside NRC jurisdiction (non-nuclear facilities incl. energy island)
Company reported TerraPower · Authority: Wyoming Industrial Siting Council · Jurisdiction: Wyoming (state)
“received approval from the Wyoming Industrial Siting Council (ISC) on its permit for the first Natrium1 plant, Kemmerer Power Station Unit 1. The permit covers all construction and operational activities on the Natrium plant that are not under the jurisdiction of the U.S. Nuclear Regulatory Commission (NRC).”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
8 May 2025 · Permissions · Whole project
Permission issued
NRC exemption allowing non-safety construction on the energy island during the permit review (not a construction permit)
Company reported TerraPower · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“TerraPower is pleased with the U.S. Nuclear Regulatory Commission’s (NRC) official exemption decision that allows us to construct the energy island while they continue completing the construction permit application review process of the Natrium plant.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
23 October 2025 · Technical milestones · Whole project
Design disclosed
Plant design as described in the NRC final environmental impact statement notice
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register)
“The proposed facilities would house one 840-megawatt thermal, pool-type, sodium-cooled fast reactor connected to a molten salt energy storage system that enables variable energy supply up to 500 megawatts electric net.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 18 June 2025 · Permissions · Whole project
Target: permission issued, 2026
Expected NRC approval of the nuclear reactor (as of June 2025)
Company reported TerraPower · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The company began non-nuclear construction activities on the site of the first plant last year and expects regulatory approval for the nuclear reactor next year.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
16 March 2026 · Permissions · Whole project
Permission issued
Construction Permit No. CPAR-1, Kemmerer Power Station Unit 1, immediately effective (not an operating licence)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The U.S. Nuclear Regulatory Commission (NRC or the Commission) is providing notice of the issuance of Construction Permit (CP) No. CPAR-1 to US SFR Owner, LLC (USO) for the Kemmerer Power Station Unit 1 reactor facility and the associated record of decision (ROD).”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
23 May 2026 · Construction · Whole project
Construction
DOE account of the permit and the start of plant construction
Government record U.S. Department of Energy, Office of Nuclear Energy
“TerraPower received its construction permit in March 2026 — the first ever issued by the NRC for a commercial non-light-water power reactor — and broke ground on the Natrium plant construction the following month.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
23 April 2026 · Construction · Whole project
Construction
Official start of construction on the Kemmerer Unit 1 plant (after the construction permit)
Company reported TerraPower
“TerraPower, a nuclear innovation company, today, announced the official start of construction on its flagship Natrium® plant1, Kemmerer Unit 1. Kemmerer Unit 1 is on track to be the first utility-scale advanced nuclear power plant in the United States.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Date not disclosed · Customer / offtake · Whole project
Interest disclosed
Intended service to PacifiCorp's Rocky Mountain Power customers (no offtake agreement described)
Company reported TerraPower (Wyoming page) · Counterparty: PacifiCorp (Rocky Mountain Power) · Bindingness not stated
“The plant will provide power to support PacifiCorp’s Rocky Mountain Power customers in Wyoming and throughout the region.”
Source: TerraPower (Wyoming page) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Date not disclosed · Technical milestones · Whole project
Design disclosed
DOE Advanced Reactor Demonstration project profile
Government record U.S. Department of Energy, Office of Nuclear Energy
“Location: Kemmerer, Wyoming, near the retiring Naughton coal plant
Size: Single-unit, 345 MWe-net plant
Technology: Natrium is a sodium‐cooled fast reactor design that leverages decades of reactor technology and fuel development.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 14 January 2025 · Permissions · Whole project
Target: permission issued, December 2026
Target date for NRC construction permit approval (as of January 2025)
Company reported TerraPower · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“That application was submitted in March 2024 and is on track for approval in December 2026.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated Date stated not shown on the source · Permissions · Whole project
Target: application submitted, 2028
Operating licence application
Company reported TerraPower (FAQ) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“This is the first commercial-scale, advanced nuclear power plant to ever receive this permit. TerraPower anticipates submitting the operating license application in 2028.”
Source: TerraPower (FAQ) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 15 December 2022 · Operational delivery · Whole project
Target: commercial operation, 2028
Original in-service target (2028), announced as slipping at least two years because of HALEU fuel supply
Secondary report World Nuclear News
“TerraPower has said it expects operation of the Natrium demonstration reactor to be delayed by at least two years because there will not be sufficient commercial capacity to manufacture high-assay low-enriched uranium fuel in time to meet the proposed 2028 in-service date.”
Source: World Nuclear News ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 16 August 2023 · Operational delivery · Whole project
Target: commercial operation, 2030
Revised operation date (2030), as of August 2023
Company reported TerraPower
“In July, TerraPower announced an MOU with Centrus Energy Corp. to significantly expand their collaboration to ensure the Natrium demonstration reactor has access to high-assay, low-enriched uranium (HALEU) to meet the project’s 2030 operation date.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 2 July 2025 · Operational delivery · Whole project
Target: commercial operation, 2030
Project completion target (2030), as of July 2025
Company reported TerraPower
“That project is expected to be completed in 2030 and will be the first utility-scale advanced nuclear power plant in the United States.”
Source: TerraPower ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 9 March 2026 · Operational delivery · Whole project
Target: commercial operation, 2030
Project completion target (2030), as stated by DOE after the permit
Government record U.S. Department of Energy, Office of Nuclear Energy
“The Natrium project is expected to be completed in 2030.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
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