France reduced its nuclear power generation by 6.4 gigawatts due to a sustained heatwave that elevated river temperatures, compromising the cooling process essential for nuclear reactors. This reduction, representing about 14% of the country’s electricity demand, affected eight reactors across different sites.
The affected reactors include Saint Alban 1 and 2; Bugey reactors 3, 4, and 5; Golfech 2; and Blayais 1 and 3. Of these, Golfech 2 and Bugey 3 were taken offline completely, while the others continued operating but at diminished capacities. These measures reflect challenges nuclear plants face during extreme summer heat, which limits water availability and temperature parameters crucial for safe reactor function.
France relies heavily on nuclear energy, which accounts for approximately 70% of its electricity mix, making it Europe’s leader in nuclear power generation. Despite the current output restrictions, France remained a net exporter of electricity, sending over 10 gigawatts to neighboring countries according to grid operator RTE. However, concerns also extend to hydropower generation, which is vulnerable amid the ongoing heatwave expected to persist through midweek.
The heatwave has subjected France to temperature spikes exceeding 40 degrees Celsius for several days, prompting widespread red alerts and significant human health impacts. Thousands of heat-related deaths have occurred since late June, and the extreme weather disrupted major events like the Tour de France, which shortened one of its stages for the first time ever due to the intense heat conditions.