France Shuts Down Nuclear Reactors as Heatwave Intensifies

EDF, France’s state-owned energy giant, shut down three nuclear reactors on Sunday and warned that seven more may soon operate at reduced capacity, not because the plants themselves are overheating, but because the rivers that cool them have grown dangerously warm.

The reactors taken offline include Unit 2 at Golfech on the Garonne, Unit 3 at Bugey on the Rhône, and Unit 2 at Chooz on the Meuse.

Together they represent roughly 6% of France’s total nuclear capacity, though grid operator RTE has confirmed that electricity supplies remain secure.

The shutdowns stem from environmental regulations that cap the temperature of water discharged back into rivers after cooling the reactors.

With Europe’s third major heatwave of the year pushing river temperatures toward critical thresholds, around 28°C at some sites, releasing additional warm water would threaten fish and other aquatic life.

An EDF spokesperson stressed that the reactors themselves can handle the heat without any safety concern, calling the precaution purely an environmental protection measure.

This marks the second time in recent weeks that EDF has halted reactors due to extreme heat, following a record-breaking June heatwave that saw temperatures shatter records dating back to 1947.

More than a third of France currently sits under the national weather service’s highest heat alert, with temperatures forecast to reach up to 41°C.

Based on current forecasts, Bugey’s reactor should restart around July 19, Golfech around July 22, and Chooz around July 25,  though those dates could shift if the weather refuses to cooperate.

The broader picture remains sobering. EDF estimates that climate-related restrictions currently shave about 0.3% off annual nuclear production, a figure that could climb to 1.5% by 2050 without significant adaptation.

The utility plans to invest €8.7 billion by 2040 to climate-proof its nuclear and hydroelectric fleet — a tacit acknowledgment that what was once an exceptional event is fast becoming a recurring summer ritual.