2004–2026
Commercial fission, dated.
14 fission power reactors are on record. 15 dated steps run from 2004–2026. HTR-PM demonstration plant, Shidao Bay connected to the grid on 20 December 2021.
A date is taken from the plant's timeline, or from a licensing decision that names the plant. Research reactors and fusion results stay on the timeline. Filings are on licensing.
- Power reactors
- 14
- Dated steps
- 15
- On the grid
- 1
The plants
9 of the 14 have a stored date. A dash means that step has no stored date.
| Plant | Status | Construction | Permit | Criticality | Grid | Operating licence | Denial |
|---|---|---|---|---|---|---|---|
| Prototype Fast Breeder Reactor Kalpakkam, India · Sodium fast reactor Completion was expected in 2010 when the project was sanctioned in September 2003; first criticality came in April 2026. Criticality date is from Wikipedia; no AERB, DAE or BHAVINI page could be opened (AERB reset the connection; BHAVINI returned 404). | Commissioning | 2004 | — | 6 April 2026 | — | — | — |
| HTR-PM demonstration plant, Shidao Bay Rongcheng (Shidao Bay), China · High-temperature gas-cooled reactor | Operating | December 2012 | — | 12 September 2021 | 20 December 2021 | — | — |
| CAREM-25 CNEA · Lima (Zárate), Argentina · Pressurised water reactor Conflicting status: IAEA RRDB lists "CANCELLED"; Wikipedia (revised 2026-09-16) says construction is halted and the project "heavily paralyzed". No CNEA statement was opened. No status is assigned; slip history is in the description. | No status recorded | February 2014 | — | — | — | — | — |
| BREST-OD-300 Seversk, Russia · Lead fast reactor | Under construction | 8 June 2021 | — | — | — | — | — |
| Linglong One demonstration unit, Changjiang CNNC · Changjiang, China · Pressurised water reactor | Under construction | 13 July 2021 | — | — | — | — | — |
| Aurora-INL Oklo · Idaho National Laboratory, United States · Sodium fast reactor DOE steps are reported by Oklo only; no DOE document was opened this run. | Planned | — | — | — | — | — | 6 January 2022 |
| Darlington New Nuclear Project Unit 1 Ontario Power Generation · Clarington, Canada · Boiling water reactor Licence to construct issued 2025-04-04 (CNSC). Ground-breaking date is Wikipedia's; site preparation preceded the licence to construct. | Under construction | December 2022 | 4 April 2025 | — | — | — | — |
| Kemmerer Power Station Unit 1 TerraPower · Kemmerer (Lincoln County), United States · Sodium fast reactor Construction permit CPAR-1 issued 2026-03-09 (NRC). Construction dates are from Wikipedia, not a regulator document. No operating licence. | Under construction | June 2024 23 April 2026 claimed | 9 March 2026 | — | — | — | — |
| Palisades Nuclear Plant Holtec International · Covert Township (Van Buren County), United States NRC reauthorised power operation 2025-07-24. No source opened this run confirms the reactor has restarted or reconnected to the grid. | Commissioning | — | — | — | — | 24 July 2025 | — |
The dates
2004
-
Construction start
2012
-
December 2012 · Construction start
2014
-
February 2014 · Construction start
2021
-
8 June 2021 · Construction start
-
13 July 2021 · Construction start
-
12 September 2021 · First criticality
-
20 December 2021 · Grid connection
2022
-
6 January 2022 · Application denied
NRC denies Aurora combined licence application
achieved verified
-
December 2022 · Construction start
2024
-
June 2024 · Construction start
2025
-
4 April 2025 · Construction permit issued
Darlington New Nuclear Project Unit 1
CNSC licence to construct one BWRX-300 at the Darlington New Nuclear Project
achieved verified
-
24 July 2025 · Operating licence issued
Palisades: NRC reauthorises power operation (exemption, licence transfer and amendments to DPR-20)
achieved verified
2026
-
9 March 2026 · Construction permit issued
NRC construction permit CPAR-1 issued for Kemmerer Power Station Unit 1 (Natrium)
achieved verified
-
6 April 2026 · First criticality
-
23 April 2026 · Construction start
Kemmerer Unit 1: nuclear construction begins (reported)
claimed
Without a stored date
5 power reactors have a record here and no dated step in the table above.
- Akademik Lomonosov Operating Pevek, Russia
Russia's floating nuclear power plant, a barge with two KLT-40S reactors (300 MWt in total, 70 MWe gross) moored at Pevek, Chukotka. It began operating in December 2019 and was fully commissioned in May 2020.
- Clinch River Nuclear Site Unit 1 Planned Tennessee Valley Authority · Oak Ridge (Roane County), United States
A planned GE Vernova Hitachi BWRX-300 at TVA's Clinch River site in Oak Ridge, Tennessee. The NRC docketed the construction permit application (Docket 50-615) in July 2025; no permit has been issued.
- Long Mott Generating Station Planned Calhoun County (Seadrift), United States
A planned four-unit X-energy Xe-100 plant (800 MWt in total) at Dow's Seadrift site in Calhoun County, Texas. The construction permit application (Docket 50-614) is under NRC review; no permit has been issued.
- Pioneer Unit 1 (Palisades SMR-300) Planned Holtec International · Covert, United States
A planned Holtec SMR-300 at the Palisades Energy Center in Covert, Michigan. Part 1 of a phased construction permit application was docketed in February 2026 (Docket 50-616); no permit has been issued.
- Pioneer Unit 2 (Palisades SMR-300) Planned Holtec International · Covert, United States
A planned Holtec SMR-300 at the Palisades Energy Center in Covert, Michigan. Part 1 of a phased construction permit application was docketed in February 2026 (Docket 50-617); no permit has been issued.