The Brennilis Nuclear Power Plant is a decommissioned site located in the Monts d'Arrée in the commune of Brennilis in Finistère, France. Starting in 1962, the Commissariat à l'énergie atomique undertook construction of this experimental reactor moderated with heavy water and cooled with carbon dioxide (HWGCR). The reactor was to have a power of 70 MWe. The startup occurred in 1967.
In 1971, however, the French government decided to use Pressurized water reactor (developed by the United States) technology as their primary reactor model.