France halts three nuclear reactors, reduces output at eight as heatwave hits 41C
Three reactors were shut down and eight others were throttled as temperatures soared to 41C, with the government issuing a temporary environmental waiver for one plant.
Reactor shutdowns amid heatwave
On Sunday, July 12, state-owned energy utility EDF announced the temporary shutdown of three nuclear reactors and power reductions at eight others as a severe heatwave pushed temperatures to 41C across swathes of France. The halted units were reactor No. 2 at Golfech on the Garonne, No. 3 at Bugey on the Rhone, and No. 2 at Chooz on the Meuse. The eight others running at reduced output included units at Saint-Alban (reactors 1 and 2), Blayais (1 and 3), Bugey (4 and 5), Chooz (1), and Tricastin (3), EDF detailed to AFP. Temperatures had already reached 40C in nearly 70 communes, and more than a third of France was placed under the national weather service’s highest heat alert. The operational changes were required to comply with regulations limiting how much warm water can be discharged back into rivers already heated by the extreme weather.
Due to the weather conditions and to comply with regulations on [cooling water] discharges, and thus to protect the environment.
Waiver gives Bugey breathing room
A day earlier, on Saturday, the government published a decree temporarily modifying thermal discharge limits for the Bugey plant, following a request from EDF and a decision by the Nuclear Safety and Radiation Protection Authority (ASNR). The waiver allows the plant to release water that is up to 1 degree Celsius warmer than the upstream temperature into the Rhone, valid until July 20. EDF had proposed the temporary 1C limit alongside an enhanced environmental monitoring program, arguing that without the change it would have to cut output further or stop the reactors entirely. The move was authorized to maintain a minimum level of electricity production from reactors No. 4 and No. 5, which grid operator RTE deemed necessary to ensure the security of the electricity network, and was confirmed as a public necessity by the energy ministry in a letter on Thursday.
- Government issues environmental waiver for Bugey nuclear plant
- EDF shuts three reactors and reduces output at eight others
- Bugey waiver expires
Heatwave impacts mount
This is the third heatwave to hit France since May, with more than 25 million people exposed to forecast highs of 41C, according to an AFP tally based on population data. Tourist hotspots such as Paris landmarks were forced to close early, outdoor events were cancelled, and a stage of the Tour de France was shortened. Wildfires have proliferated across several regions, and deaths by drowning have spiked as people sought relief in rivers and lakes. The repeated episodes of intense heat since late May have also caused excess mortality, authorities indicated, and exposed how infrastructure is ill-adapted to extreme weather events that are becoming more frequent.
- Shut down
- 3
- Reduced power
- 8
- Normal operation
- 46
Climate change and future resilience
The reactor shutdowns mark the second time in recent weeks that EDF has had to halt units because of heat, following a record-breaking June heatwave. Scientists have linked the increasing frequency and intensity of such heat episodes to man-made climate change. France’s fleet of 57 reactors provides about 70% of the country’s electricity, and all are sited beside rivers or the sea to use water for cooling. Repeated stress on the fleet from warming rivers raises questions about the long-term resilience of critical energy infrastructure in a warming climate, particularly when heatwaves are no longer isolated events but recurrent seasonal phenomena.
