France is experiencing an exceptionally severe heatwave, with temperatures reaching as high as 43°C. The extreme conditions are expected to disrupt nuclear power operations because EDF relies on river water to cool reactors, and that cooling water must remain below set temperature limits.

EDF has already cut production at the Golfech nuclear plant in southwestern France due to high temperatures in the Garonne River. The company also announced operational restrictions for additional nuclear plants—intended to prevent river temperatures from exceeding allowable thresholds when heated cooling water is discharged back into the environment.

EDF says the electricity impact of these measures is “negligible” in the near term. However, the article notes that shutting down or throttling nuclear during heatwaves has reduced annual electricity output by an average of about 0.3% since 2000, and that the effect could grow if heatwaves become more frequent and intense.