Brennilis was a 70 MWe heavy-water, gas-cooled prototype that ran from 1967 to 1985 and has become a byword for slow French decommissioning. After a 2007 court annulment and partial work, a full dismantling decree was issued in September 2023; EDF began the final phase in December 2024 and targets a bare site by 2041.
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Current state
| Status | Active dismantling |
| Country | France |
| Location | Brennilis, Finistère |
| Site | Brennilis |
| Units | EL-4 |
| Unit count | 1 |
| Reactor types | HWGCR |
| Owner / licensee | EDF |
| Strategy | Mixed |
| Final shutdown | 1985-07-31 |
| Decommissioning start | 1985 |
| Target completion | 2041 |
| Spent fuel | All irradiated fuel removed by 1992. |
| Notable issue | Asbestos and mercury discoveries delayed handling-crane upgrades, but reactor fuel-channel removal is still planned to start in 2027. |
Notes
70 MWe capacity is commonly cited but not in the sources reviewed (capacity left not recorded). A press report puts full dismantling cost at about €850m (not recorded: date unclear).
Timeline
- 1966-12-23 — The reactor first went critical. (source)
- 1985-07-31 — Power production permanently ended. (source)
- 2007-06-06 — France's Conseil d'État annulled the 2006 decree authorising full dismantling. (source)
- 2011-07-27 — A decree authorised partial dismantling excluding the reactor block. (source)
- 2023-09-26 — Decree 2023-898 prescribed complete dismantling of the installation. (source)
- 2024-12 — The plant entered its final dismantling phase. (source)
The timeline is append-only: corrections are added as new entries. Stated targets appear in the current-state table, never as milestones.
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Related sites
- Chooz A Active dismantling · France
- Fermi Unit 1 (Enrico Fermi Atomic Power Plant) SAFSTOR · United States
- Fessenheim Nuclear Power Plant Active dismantling · France
- GE Vallecitos (VBWR and EVESR) Active dismantling · United States
- Kewaunee Power Station Active dismantling · United States
- La Crosse Boiling Water Reactor (LACBWR) License terminated · United States
- Rancho Seco Nuclear Generating Station License terminated · United States
- Sellafield (incl. Calder Hall) Active dismantling · United Kingdom
See all 72 sites in the Nuclear Decommissioning Tracker →
Sources
- Monts d'Arrée EL4-D (Centrale nucléaire de Brennilis) — ASNR (primary), checked 2026-10-11
- La centrale nucléaire de Brennilis — EDF (primary), checked 2026-10-11
- Centrale nucléaire de Brennilis : dernière étape de la déconstruction — Andra (primary), checked 2026-10-11