By Michael Kern of OilPrice.com,

France’s nuclear power generation was slashed by 6.4 gigawatts (GW) on Monday amid a prolonged and intense heatwave that hiked river temperatures and limited the ability of the power plants to use the water to cool reactors.

As many as eight reactors in France, which is Europe’s leader in nuclear power generation, were forced to curtail power output, according to data from the plants’ operator EDF and grid operator RTE cited by Reuters.

The 6.4 GW of curtailed power output was equivalent to 14% of France’s overall power demand as of Monday morning. 

The reactors where output has been limited include Saint Alban 1 and 2, reactors 3, 4, and 5 at Bugey, Golfech 2, and Blayais 1 and 3.

The Golfech 2 and Bugey 3 reactors were taken fully offline, while the other six were operating at reduced rates as of Monday morning.  

This is not the first time France has had to curb output at reactors and limit the nuclear power production, due to high summer temperatures. 

France’s nuclear power generation accounts for around 70% of its electricity mix, and when its reactors are fully operational, it is a net exporter of electricity to other European countries. 

Despite the curbs of nuclear generation during the current heatwave, data from RTE suggests that France would remain a net exporter with over 10 GW of power exported to France’s neighboring countries on Monday. 

The hydropower generation would also be a concern amid the heatwave that has lasted a least a week and is expected to continue at least until Wednesday this week. 

With temperatures topping 40 degrees Celsius (104 F) for days, red alerts have been issued throughout France amid the heatwave, and thousands of people have died of heat-related conditions since late June, when the record-breaking extreme summer temperatures started to disrupt life. Even the most famous and prestigious cycling event, the Tour de France, held a shortened stage on Sunday for the first time ever, due to the extreme heat.