Tokai-1, Japan's first commercial reactor (a 160 MWe UK-designed Magnox), ran until 1998 and has been in decommissioning since 2001. Reactor dismantling has been repeatedly delayed, partly over graphite disposal; completion is now expected around 2030, and JAPC signed a graphite-decommissioning cooperation deal with Italy's Sogin in April 2026.
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Current state
| Status | Active dismantling |
| Country | Japan |
| Location | Tokai, Ibaraki Prefecture |
| Site | Tokai |
| Units | Tokai-1 |
| Unit count | 1 |
| Reactor types | Magnox (GCR) |
| Owner / licensee | Japan Atomic Power Company (JAPC) |
| Strategy | Mixed |
| Final shutdown | 1998 |
| Decommissioning start | 2001-12 |
| Target completion | 2030 |
| Cost estimate | JPY 93bn (as of 2026-03) |
| Notable issue | Disposal route for irradiated graphite is the key bottleneck. |
Notes
Cost JPY 93bn total (35bn dismantling + 58bn waste treatment) per WNA (page updated 2026-03). Strategy mixed: safe storage of reactor before deferred dismantling.
Timeline
- 1998 — Tokai-1 ended operation after 32 years. (source)
- 2001-12 — JAPC launched decommissioning after notifying its decommissioning plan. (source)
- 2026-04-15 — JAPC and Sogin signed a memorandum on decommissioning graphite-moderated reactors. (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
- Brennilis (Monts d'Arrée EL-4) Active dismantling · France
- Fermi Unit 1 (Enrico Fermi Atomic Power Plant) SAFSTOR · United States
- Fukushima Daiichi Nuclear Power Station (Units 1-6) Fuel removal · Japan
- Fukushima Daini Nuclear Power Station (Units 1-4) Fuel removal · Japan
- GE Vallecitos (VBWR and EVESR) Active dismantling · United States
- Genkai Units 1 and 2 Active dismantling · Japan
- Hamaoka Units 1 and 2 Active dismantling · Japan
- Ikata Units 1 and 2 Active dismantling · Japan
See all 72 sites in the Nuclear Decommissioning Tracker →
Sources
- Decommissioning Nuclear Facilities — World Nuclear Association, checked 2026-10-11
- Tokai-1 decommissioning project — IAEA INIS, checked 2026-10-11
- Agreement between Sogin and JAPC on the decommissioning of graphite-moderated nuclear reactors — Sogin (primary), checked 2026-10-11
- JAPC Delays Tokai Nuclear Power Plant Decommissioning Another Five Years — Industrial Info Resources, checked 2026-10-11