CountryNuclear power in Japan
Japan has 15 reactors operating with 13,946 MW net installed capacity, 9.1 % of its electricity. 18 more units have their operation suspended. 2 under construction. 1 with halted construction. 27 shut down. First reactor connected in 1965.
Japan ranks 6th among the 32 countries with operating reactors by net capacity, and 8th by number of reactors. Its first reactor, Japan Power Demonstration Reactor, started operating in 1965, 61 years ago. Its operating fleet comprises 12 PWR and 3 BWR. The highest-capacity plant in operation is Takahama, with 3,220 MW net, and the oldest unit still in service is Takahama 1, operating since 1974. There are 2 units under construction at Ohma and Shimane.
BWR reactors in Japan · PWR reactors in Japan · FBR reactors in Japan · GCR reactors in Japan · HWLWR reactors in Japan · Rankings
Electricity generation mix
Share of electricity generation, 2025 (closest earlier year; 2026 has no data) · Ember
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Plants
| Plant | Units | Types | Status today | MWe operating |
|---|---|---|---|---|
| Kashiwazaki Kariwa | 7 | BWR | operating6 operation suspended | 7,965 |
| Hamaoka | 5 | BWR | 3 operation suspended2 shut down | 3,473 |
| Takahama | 4 | PWR | 4 operating | 3,220 |
| Genkai | 4 | PWR | 2 operating2 shut down | 2,254 |
| Ohi | 4 | PWR | 2 operating2 shut down | 2,254 |
| Tomari | 3 | PWR | 3 offline, awaiting restart | 1,966 |
| Sendai | 2 | PWR | 2 operating | 1,692 |
| Shika | 2 | BWR | 2 operation suspended | 1,613 |
| Onagawa | 3 | BWR | operatingoffline, no restart pendingshut down | 1,592 |
| Tsuruga | 3 | BWR, PWR, HWLWR | offline by regulatory decision2 shut down | 1,108 |
| Higashidori (Tohoku) | 1 | BWR | offline, awaiting restart | 1,067 |
| Tokai | 2 | GCR, BWR | offline, awaiting restartshut down | 1,060 |
| Ikata | 3 | PWR | operating2 shut down | 846 |
| Shimane | 3 | BWR | operatingunder constructionshut down | 789 |
| Mihama | 3 | PWR | operating2 shut down | 780 |
| Fukushima Daiichi | 6 | BWR | 6 shut down | — |
| Fukushima Daini | 4 | BWR | 4 shut down | — |
| Higashidori (Tepco) | 1 | BWR | construction halted | — |
| Japan Power Demonstration Reactor | 1 | BWR | shut down | — |
| Monju | 1 | FBR | shut down | — |
| Ohma | 1 | BWR | under construction | — |
Data: IAEA PRIS · Global Energy Monitor · Wikipedia · editorial review · updated on Sep 21, 2026