We monitor the aggregated unavailability of nuclear power in France, based on the availability data published individually for each nuclear plant by RTE (Réseau de Transport d’Électricité). This monitoring allows us to analyze trends in nuclear availability and contrast actual plant statuses with our own forecasted production models in order to improve reliability assessments and market outlooks.

Production has mostly followed reported unavailabilities, holding in the 42–48 GW range. As of 3 October, the outlook points to a steady climb toward ~60 GW this winter, before falling back to the mid-40s GW by spring 2026. In September, availability was affected by a series of short but significant disruptions: Paluel dropped ~2.4 GW between 4–6 September when jellyfish clogged cooling intakes, while Gravelines lost multiple units in mid-August for the same reason. Strike action on 3 September briefly cut about 2.1 GW fleet-wide, and Flamanville 1 was curtailed by ~1.1 GW during another strike on 18 September. Importantly, Civaux 2 returned to service in late July after its scheduled outage and inspection, so it no longer weighs on availability. These incidents were short-lived, but they underline the continued vulnerability of the fleet to environmental conditions and industrial action. Overall, EDF’s optimistic winter outlook near 60 GW may prove difficult to sustain, with a more realistic level closer to 55–57 GW.