Ohi nuclear power plant
Ohi nuclear power plant is a nuclear power station in Japan with 2 operating units totalling 2,360 MW gross. The site has 4 units on record in total.
Units
| Unit | Status | Type | Model | Gross MW | Online |
|---|---|---|---|---|---|
| Unit 3 | PWR | M (4-loop) | 1,180 | 1991 | |
| Unit 4 | PWR | M (4-loop) | 1,180 | 1993 | |
| Unit 1 | Retired | PWR | WH 4LP | 1,175 | 1979 |
| Unit 2 | Retired | PWR | WH 4LP | 1,175 | 1979 |
Unit by unit
Each unit's rating, type and milestone dates as recorded by the Global Nuclear Power Tracker, with any correction we made to it. A dash or "not disclosed" means the source does not give the value.
Ohi nuclear power plant 3
| Reactor type | Pressurised water reactor (PWR) |
|---|---|
| Model | Mitsubishi 4-loop |
| Size class | Large |
| Gross capacity | 1,180MW |
| Net capacity | 1,127MW |
| Thermal output | 3,423MWt |
| Enrichment | 3–5% U-235 |
| NSSS vendor | Mitsubishi Heavy Industries |
| Owner | Kansai Electric Power Co100% |
| Operator | Kansai Electric Power |
| Construction start | 3 Oct 1987 |
|---|---|
| First criticality | 17 May 1991 |
| Grid connection | 7 Jun 1991 |
| Commercial operation | 18 Dec 1991 |
Ohi nuclear power plant 4
| Reactor type | Pressurised water reactor (PWR) |
|---|---|
| Model | Mitsubishi 4-loop |
| Size class | Large |
| Gross capacity | 1,180MW |
| Net capacity | 1,127MW |
| Thermal output | 3,423MWt |
| Enrichment | 3–5% U-235 |
| NSSS vendor | Mitsubishi Heavy Industries |
| Owner | Kansai Electric Power Co100% |
| Operator | Kansai Electric Power |
| Construction start | 13 Jun 1988 |
|---|---|
| First criticality | 28 May 1992 |
| Grid connection | 19 Jun 1992 |
| Commercial operation | 2 Feb 1993 |
Ohi nuclear power plant 1 Retired
| Reactor type | Pressurised water reactor (PWR) |
|---|---|
| Model | WH 4LP |
| Size class | Large |
| Gross capacity | 1,175MW |
| Net capacity | 1,120MW |
| Thermal output | 3,423MWt |
| Enrichment | 3–5% U-235 |
| NSSS vendor | Westinghouse Electric Company |
| Owner | Kansai Electric Power Co100% |
| Operator | Kansai Electric Power |
| Construction start | 26 Oct 1972 |
|---|---|
| First criticality | 2 Dec 1977 |
| Grid connection | 23 Dec 1977 |
| Commercial operation | 27 Mar 1979 |
| Permanent shutdown | 1 Mar 2018 |
Ohi nuclear power plant 2 Retired
| Reactor type | Pressurised water reactor (PWR) |
|---|---|
| Model | WH 4LP |
| Size class | Large |
| Gross capacity | 1,175MW |
| Net capacity | 1,120MW |
| Thermal output | 3,423MWt |
| Enrichment | 3–5% U-235 |
| NSSS vendor | Westinghouse Electric Company |
| Owner | Kansai Electric Power Co100% |
| Operator | Kansai Electric Power |
| Construction start | 8 Dec 1972 |
|---|---|
| First criticality | 14 Sep 1978 |
| Grid connection | 11 Oct 1978 |
| Commercial operation | 5 Dec 1979 |
| Permanent shutdown | 1 Mar 2018 |
Ohi nuclear power plant in context
By gross operating capacity Ohi nuclear power plant is the 2nd largest of 9 operating nuclear sites in Japan, holding 16% of the country's operating capacity, and ranks 72nd of 172 worldwide.
Its operating units started up between 1991 and 1993; the median unit is 34.0 years old, younger than the median of 35.0 in Japan.
The 4 units with both construction and grid dates on record took 3.7 to 5.8 years (median 4.6) from construction start to grid connection; the median across all reactors connected in the 1990s is 8.0 years.
The nearest other tracked nuclear sites are Takahama nuclear power plant (14 km), Mihama nuclear power plant (33 km) and Shimane nuclear power plant (240 km).
Build time by unit
| Unit | Construction start | Grid connection | Years | Fleet median, same decade |
|---|---|---|---|---|
| Unit 1 | 1972 | 1977 | 5.2 | 5.4 (1970s) |
| Unit 2 | 1972 | 1978 | 5.8 | 5.4 (1970s) |
| Unit 3 | 1987 | 1991 | 3.7 | 8.0 (1990s) |
| Unit 4 | 1988 | 1992 | 4.0 | 8.0 (1990s) |
Nearest tracked nuclear sites
| Site | Country | Distance | Operating GW gross |
|---|---|---|---|
| Takahama nuclear power plant | Japan | 14 km | 3.4 |
| Mihama nuclear power plant | Japan | 33 km | 0.8 |
| Shimane nuclear power plant | Japan | 240 km | 0.8 |
How these are worked out: ranks use gross operating capacity; ages count from the start-up year on record, as on the age page; build times run from construction start to grid connection, as on the build-times page; ratings are the tracker's net and design net capacity, as on the uprates page. Distances are straight-line between exact positions, so a site with only an approximate position gets none. A unit missing a date or a rating is left out of the figure that needs it.
Earthquakes nearby
Loading the latest USGS check…
| Time (UTC) | Mag | Depth | Epicentre | Distance |
|---|
Magnitude 4.0 and above within 200 km of Ohi nuclear power plant's listed coordinates, past 30 days. This is distance, not shaking: it says nothing about damage or any change in operation. Every plant.
| Location | Fukui, Japan |
|---|---|
| Coordinates | 35.5424, 135.6544 |
| Elevation | about 35 mabove sea level |
| Setting | On the sea coast, 0.2 km from the water |
| Region | Eastern Asia |
| Units by status | Operating: 2 Retired: 2 |
Elevation is read at the listed coordinates from a 30 m terrain model (SRTM 30 m). Two independent models differ by a median of 6 m across our plants and by up to about 40 m on steep or coastal ground, and a point on a shoreline can read as sea level. Distance to the water is measured to a generalised 1:10 million coastline, so a few kilometres or less is not resolved. This is context, not a design-basis or flood-risk figure.
| Owners | Kansai Electric Power Co |
|---|---|
| Operators | Kansai Electric Power |
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Sources
- Global Nuclear Power Tracker, Global Energy Monitor, August 2026 release , CC BY 4.0 · retrieved 2026-09-06
- GEM.wiki entry (further reading) , CC BY-SA 4.0, linked, not quoted
How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data