Kansai Electric is decommissioning Mihama 1 and 2, early-1970s PWRs retired in April 2015, over about 30 years. As of June 2026 secondary-system dismantling (since 2018) and removal of equipment around the reactors (since October 2022) were under way; Mihama 3 remains in operation.
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Current state
| Status | Active dismantling |
| Country | Japan |
| Location | Mihama, Fukui Prefecture |
| Site | Mihama |
| Units | Unit 1, Unit 2 |
| Unit count | 2 |
| Reactor types | PWR |
| Net capacity (MWe) | 790 |
| Owner / licensee | Kansai Electric Power |
| Strategy | Immediate dismantling |
| Final shutdown | 2015-04 |
| Decommissioning start | 2018-03-12 |
| Notable issue | Kansai has surveyed the site for a possible new reactor. |
Notes
Net capacities 320 + 470 MWe per WNA (WNN cites 340/500 gross).
Timeline
- 2015-03 — Kansai decided to decommission Mihama 1 and 2 rather than seek restarts. (source)
- 2015-04 — Mihama 1 and 2 were officially taken out of service. (source)
- 2018-03-12 — Dismantling of Mihama 2 secondary-system equipment began. (source)
- 2022-10-24 — Dismantling of reactor peripheral equipment began at both units. (source)
The timeline is append-only: corrections are added as new entries. Stated targets appear in the current-state table, never as milestones.
Related sites
- Biblis Nuclear Power Plant (Units A and B) Active dismantling · Germany
- Brokdorf Nuclear Power Plant (KBR) Active dismantling · Germany
- Brunsbüttel Nuclear Power Plant (KKB) Active dismantling · Germany
- Chinshan Nuclear Power Plant Fuel removal · Taiwan
- Chooz A Active dismantling · France
- Crystal River Unit 3 Site restoration · United States
- Doel Nuclear Power Plant (Units 1-3) Shut down · Belgium
- Dounreay (DFR and PFR fast reactors) Active dismantling · United Kingdom
See all 72 sites in the Nuclear Decommissioning Tracker →
Sources
- Kansai amends Mihama decommissioning plans — World Nuclear News, checked 2026-10-11
- Kansai Electric Power Nuclear Plant Operations Update (as of June 30, 2026) — Kansai Electric Power IR (via BigGo Finance), checked 2026-10-11
- Nuclear Power in Japan — World Nuclear Association, checked 2026-10-11
- Site survey for new Mihama reactor — Nuclear Engineering International, checked 2026-10-11