Ohi
Reactor Data
Reactor Units
Every power reactor at this site as listed in the IAEA Power Reactor Information System (PRIS): reactor type and model, net electrical capacity, grid connection and commercial operation dates, and current status.
4 units: 2 operational, 2 permanent shutdown.
Net capacity in service: 2,254 MWe.
| Unit | Type | Model | Net MWe | Construction | Grid | Commercial Op | Shutdown | Status |
|---|---|---|---|---|---|---|---|---|
| Ohi 1 | PWR | WH 4LP | 1,120 | 1972-10-26 | 1977-12-23 | 1979-03-27 | 2018-03-01 | Permanent Shutdown |
| Ohi 2 | PWR | WH 4LP | 1,120 | 1972-12-08 | 1978-10-11 | 1979-12-05 | 2018-03-01 | Permanent Shutdown |
| Ohi 3 | PWR | M (4-loop) | 1,127 | 1987-10-03 | 1991-06-07 | 1991-12-18 | Operational | |
| Ohi 4 | PWR | M (4-loop) | 1,127 | 1988-06-13 | 1992-06-19 | 1993-02-02 | Operational |
Capacity, milestones and suppliers
| Unit | Design MWe | Gross MWe | Thermal MWt | First Criticality | Reactor Supplier | Turbine Supplier | Notes |
|---|---|---|---|---|---|---|---|
| Ohi 1 | 1,120 | 1,175 | 3,423 | 1977-12-02 | WESTINGHOUSE ELECTRIC CORPORATION | MITSUBISHI HEAVY INDUSTRIES, LTD. | |
| Ohi 2 | 1,120 | 1,175 | 3,423 | 1978-09-14 | WESTINGHOUSE ELECTRIC CORPORATION | MITSUBISHI HEAVY INDUSTRIES, LTD. | |
| Ohi 3 | 1,127 | 1,180 | 3,423 | 1991-05-17 | MITSUBISHI HEAVY INDUSTRIES, LTD. | MITSUBISHI HEAVY INDUSTRIES, LTD. | |
| Ohi 4 | 1,127 | 1,180 | 3,423 | 1992-05-28 | MITSUBISHI HEAVY INDUSTRIES, LTD. | MITSUBISHI HEAVY INDUSTRIES, LTD. |
Lifetime performance, through 2025
| Unit | Electricity Supplied | Load Factor | Energy Availability | Operating Factor |
|---|---|---|---|---|
| Ohi 1 | 213.3 TWh | 55.8% | 55.3% | 56.0% |
| Ohi 2 | 231.7 TWh | 61.6% | 60.9% | 61.4% |
| Ohi 3 | 227.9 TWh | 67.7% | 66.7% | 67.0% |
| Ohi 4 | 235.2 TWh | 72.3% | 71.0% | 71.2% |
Operator: Kansai Electric Power Co.
Owner: Kansai Electric Power Co.
Source: IAEA Power Reactor Information System (PRIS), as of 2026-11-02.
Working Here
Per Diem Rates FY 2026
Per diem covers lodging and meals & incidental expenses (M&IE) for government and contractor travel near this facility. Rates are from the U.S. State Department foreign per diem tables for FY 2026.
$208
Lodging/Night
$107
M&IE/Day
$315
Total/Day
Japan: rate for locations the State Department does not list separately
U.S. Department of State foreign per diem, for U.S. government and contractor travel.
Photos
Photos of this facility from the NukeWorker photo gallery. Click the header or any photo to browse the full album.
Facility Map
Interactive satellite map showing the facility's geographic location. Marker color indicates current status: green for online, red for offline, orange for reduced power. Click the header to open in Google Maps satellite view.
35.5429, 135.658
Location & Contact
Physical address, phone number, and website for this facility. Use the directions link to get driving directions via Google Maps.
Plant Facts
About This Site
Written by NukeWorker from public records: facts that do not change. Operator, status and capacity come from the live data elsewhere on this page. Sources: Wikipedia: Oi Nuclear Power Plant.
Ohi Nuclear Power Plant is in the town of Ohi, Fukui Prefecture, Japan, on the Sea of Japan coast.
Read more
Construction of Unit 1 began on 26 October 1972 and Unit 2 on 8 December 1972, both Westinghouse four-loop pressurized water reactors. Mitsubishi Heavy Industries four-loop reactors followed as Unit 3 (construction from 3 October 1987) and Unit 4 (13 June 1988). The units were connected to the grid in 1977, 1978, 1991 and 1992. In December 2017 the operator announced that Units 1 and 2 would be decommissioned, and both were permanently shut down on 1 March 2018.