The energy provider insists there are no looming safety risks as three French regions face heatwave warnings.
EDF has reduced its electricity production at nuclear sites in France in response to soaring temperatures.
Three reactors are currently affected, although the energy provider has said “there is no safety risk”.
A reactor located at the Bugey nuclear power plant, a site near Lyon, has been closed since 12 August.
Also near Lyon, the Saint-Alban nuclear plant has experienced production cuts since 11 August, and similar measures are being taken at the Tricastin site. This is located in the South East of France, north of Avignon.
Heat-related incidents aren’t a new complication for EDF but rather a recurring problem, as exemplified when the firm published a climate change action plan last month.
The firm classed heatwaves as an “acute risk” but estimated that annual production losses linked to water resources would only amount to 1.5% in 2050.
Today, these losses amount to around 0.3% of production a year for EDF.
High temperatures can interfere with nuclear processes as reactors are heavily reliant on water.
Heat from nuclear reactions is used to transform water into steam, which then drives turbines to produce electricity.
Another current of water, outside of the closed loop system, is then drawn from surrounding rivers to cool the reactor.
This coolant, which doesn’t come into contact with the radioactive materials, absorbs excess heat and is then discharged back into the environment.
During periods of extreme heat, this can produce a number of complications.
If surrounding water sources are warmer than usual, reactors cannot be cooled as efficiently.
French regulations also prevent sites from discharging water that is too hot back into rivers and lakes, to avoid the accidental killing of fish and other wildlife.
EDF told Euronews that it had temporarily reduced production to “respect regulations relating to thermal discharges”.
The firm explained that “discharge limits are established individually for each plant” by the French Nuclear Safety Authority (ASN).
Three departments in France are currently affected by heatwave warnings, with storms now replacing hot weather in some areas.