Sendai 1 is an 846 MWe (net) Kyushu Electric PWR that in August 2015 became the first Japanese reactor restarted under the post-Fukushima NRA rules, ending almost two years with zero nuclear generation. It is operating, with NRA approval to run beyond 40 years granted in November 2023.
Background: Palisades fuel loading: Holtec restart timeline and what comes next · NRC reactor licensing process, explained
Current state
| Status | Restarted |
| Country | Japan |
| Location | Satsumasendai, Kagoshima Prefecture |
| Plant | Sendai |
| Unit | 1 |
| Operator | Kyushu Electric Power |
| Reactor type | PWR |
| Net capacity (MWe) | 846 |
| Restart type | Post-Fukushima restart |
| Shut down | 2011-05 |
| Restarted | 2015-08-11 |
| Years offline | 4.2 |
| Regulator | NRA conformity approval 2014-09-10; beyond-40-year operation approved 2023-11-01 |
Notes
Net capacity from WNA (JAIF lists 890 MWe gross). restarted is reactor startup; power generation began 2015-08-14. years offline measured shutdown (May 2011, mid-month assumed) to restart.
Timeline
- 2011-05 — Kyushu took Sendai 1 offline for a periodic inspection. (source)
- 2013-07-08 — Kyushu applied for an NRA review against the new regulatory requirements. (source)
- 2014-09-10 — The NRA officially approved the unit as meeting the new requirements. (source)
- 2015-08-11 — Sendai 1 restarted, the first Japanese reactor to do so under the post-Fukushima rules. (source)
- 2015-09-10 — The unit resumed commercial operation. (source)
- 2023-11-01 — The NRA approved operation of Sendai 1 beyond 40 years. (source)
The timeline is append-only: corrections are added as new entries. Stated targets appear in the current-state table, never as milestones.
Related units
- Genkai Unit 3 Restarted · Japan
- Genkai Unit 4 Restarted · Japan
- Hamaoka Unit 3 Cancelled · Japan
- Hamaoka Unit 4 Cancelled · Japan
- Higashidori Unit 1 (Tohoku Electric) Under review · Japan
- Ikata Unit 3 Restarted · Japan
- Kashiwazaki-Kariwa Unit 6 Restarted · Japan
- Kashiwazaki-Kariwa Unit 7 Approved · Japan
See all 45 units in the Nuclear Plant Restarts Tracker →
Sources
- Current Status of Nuclear Power Plants in Japan as of August 7, 2026 — Japan Atomic Industrial Forum (JAIF) (primary), checked 2026-10-11
- Nuclear Power in Japan — World Nuclear Association, checked 2026-10-11
- Japan restarts Sendai Unit 1 (Today in Energy) — U.S. Energy Information Administration (primary), checked 2026-10-11
- Second Japanese reactor restarted — World Nuclear News, checked 2026-10-11