Current state
| Status | Suspended |
| Design | ABWR (BWR) |
| Net capacity | 1,325 MWe |
| Country | Japan |
| Vendor | Hitachi-GE |
| Owner / operator | J-Power |
| Construction start | 2010 |
| Original COD target | — |
| Current COD estimate | FY2030-FY2031 |
| Schedule slippage | — |
Notes
Construction paused post-Fukushima; full-MOX ABWR. No restart of construction; WNA/PRIS/WNISR all list as suspended or under-construction-without-date (JAIF 2026-07: 'Under Construction, TBD'). J-Power COD signal drifted FY2030 (WNISR 2025) to FY2031 (REI, Apr 2026). Key gate: safety improvement plan submission autumn 2026, then NRA approval of the 2014 installation-change filing (still 'In review' Jan 2026); full-MOX fuel supply partly covered by Orano contract.
Milestone log
- 2025-09 — WNISR 2025 (J-Power spokesperson): no construction work ongoing; safety improvement plan submission postponed to autumn 2026 (to Aomori Prefecture and Ohma Town), then final NRA approval; operation target FY2030 (source)
- 2026-01-22 — NRA review of Ohma reactor installation change (filed 2014-12-16) still 'In review', per JANSI licensing-status chart (source)
- 2026-04-24 — Renewable Energy Institute column citing J-POWER: Ohma (1,383 MW) could be operational in FY2031 given commissioning-works and safety-review progress (source)
- 2026-06-16 — Listed as under construction in the WNA world table (source)
The milestone log is append-only: corrections are recorded as new entries, never rewrites. Full history via /api/v1/changes.
Sources
- https://world-nuclear.org/information-library/current-and-future-generation/plans-for-new-reactors-worldwide
- https://pris.iaea.org/pris/
- https://www.worldnuclearreport.org/World-Nuclear-Industry-Status-Report-2025-HTML-version
- https://www.genanshin.jp/english/facility/map/
- https://www.renewable-ei.org/en/activities/column/REupdate/20260424.php
- https://www.jaif.or.jp/cms_admin/wp-content/uploads/2026/07/jp-npps-operation20260708_en.pdf