Genkai Unit 4

Genkai 4 is a 1,127 MWe (net) Kyushu Electric PWR that resumed generating power in June 2018 after six and a half years offline. It is operating and returned to commercial operation after its latest periodic inspection in November 2025.

Background: Palisades fuel loading: Holtec restart timeline and what comes next · NRC reactor licensing process, explained

Current state

Notes

JAIF gross 1,180 MWe; net from WNA.

Timeline

• 2011-12-25 — Genkai 4 went into an extended outage. (source)
• 2017-01-18 — The NRA officially approved Genkai 3 and 4. (source)
• 2018-06-16 — Kyushu began withdrawing control rods to restart Genkai 4. (source)
• 2018-06-19 — Genkai 4 resumed electricity generation, the ninth Japanese reactor to do so. (source)
• 2018-07-19 — The unit resumed commercial operation. (source)
• 2025-11-14 — Genkai 4 restarted commercial operation after a periodic inspection. (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
• 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
• Mihama Unit 3 Restarted · Japan

See all 45 units in the Nuclear Plant Restarts Tracker →

Sources

1. Current Status of Nuclear Power Plants in Japan as of August 7, 2026 — Japan Atomic Industrial Forum (JAIF) (primary), checked 2026-10-11
2. Current Status of Nuclear Power Plants in Japan as of March 14, 2019 — Japan Atomic Industrial Forum (JAIF) (primary), checked 2026-10-11
3. Nuclear Power in Japan — World Nuclear Association, checked 2026-10-11
4. Genkai unit 4 supplying power again — World Nuclear News, checked 2026-10-11