Onagawa nuclear power plant
Onagawa nuclear power plant is a nuclear power station in Japan with 1 operating unit totalling 825 MW gross. The site has 3 units on record in total.
Units
| Unit | Status | Type | Model | Gross MW | Online |
|---|---|---|---|---|---|
| Unit 2 | BWR | BWR-5 | 825 | 2024 | |
| Unit 1 | Retired | BWR | BWR-4 | 524 | 1984 |
| Unit 3 | Mothballed | BWR | BWR-5 | 825 | 2002 |
Onagawa nuclear power plant in context
By gross operating capacity Onagawa nuclear power plant is the 8th largest of 9 operating nuclear sites in Japan, holding 6% of the country's operating capacity, and ranks 157th of 172 worldwide.
Its operating unit started up in 2024; the unit is 2.0 years old, younger than the median of 35.0 in Japan.
The 2 units with both construction and grid dates on record took 3.4 to 3.7 years (median 3.5) 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 Kashiwazaki Kariwa nuclear power plant (277 km).
Build time by unit
| Unit | Construction start | Grid connection | Years | Fleet median, same decade |
|---|---|---|---|---|
| Unit 1 | 1980 | 1983 | 3.4 | 7.3 (1980s) |
| Unit 2 | 1991 | 1994 | 3.7 | 8.0 (1990s) |
Nearest tracked nuclear sites
| Site | Country | Distance | Operating GW gross |
|---|---|---|---|
| Kashiwazaki Kariwa nuclear power plant | Japan | 277 km | 1.4 |
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 Onagawa 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 | Miyagi, Japan |
|---|---|
| Coordinates | 38.3987, 141.5003 |
| Elevation | about 20 mabove sea level |
| Setting | On the sea coast, 0.1 km from the water |
| Region | Eastern Asia |
| Units by status | Operating: 1 Retired: 1 Mothballed: 1 |
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 | Tohoku Electric Power Co Inc |
|---|---|
| Operators | Tohoku 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