Mihama
Mihama, nuclear power plant in Japan, operates one pressurized water reactor with 780 MW net installed capacity and has been in service since 1970.
Unit Mihama 3 has been operating for 50 years, since 1976. Its 780 MW net are enough to supply about 2,460,000 households.
- Country
- Japan
- Units
- 3
- Technology
- PWR
- Net capacity
- 780 MWe
- First grid connection
- 1970
- Operator
- Kansai Electric Power
- Owner
- Kansai Electric Power Co
- Status
- Operating
See also: alerts for this plant · every plant in Japan · Vendor: Westinghouse · Vendor: Mitsubishi Heavy Industries · every PWR reactor · how a PWR works

Units
| Unit | Type | Model | Status | MWe | MWt | Construction start | Grid connection | Closure | Load factor |
|---|---|---|---|---|---|---|---|---|---|
| Mihama 1 | Pressurized water (PWR) | Westinghouse 2-loop (WH 2LP) | Shut down | 320 | 1,031 | Feb 1967 | Aug 1970 | Apr 2015 | — |
| Mihama 2 | Pressurized water (PWR) | Mitsubishi 2-loop (M 2LP) | Shut down | 470 | 1,456 | May 29, 1968 | Apr 1972 | Apr 2015 | — |
| Mihama 3 | Pressurized water (PWR) | Mitsubishi 3-loop (M 3LP) | Operating | 780 | 2,440 | Aug 7, 1972 | Feb 19, 1976 | — | 87.4 % (2024) |
Data: IAEA PRIS · Wikipedia · updated on Sep 17, 2026
Mihama 1, a 320 MWe PWR (Westinghouse 2-loop (WH 2LP)), started construction in 1967 and operated from 1970 to 2015.
Mihama 2, a 470 MWe PWR (Mitsubishi 2-loop (M 2LP)), started construction in 1968 and operated from 1972 to 2015.
Mihama 3, a 780 MWe PWR (Mitsubishi 3-loop (M 3LP)), started construction in 1972, was connected to the grid in 1976 and is still operating, with a 87.4% load factor in 2024.
Operator: Kansai Electric Power.
Owner: Kansai Electric Power Co (Mihama 1, Mihama 2, Mihama 3).