Several EDF nuclear reactors have been forced to lower their production due to the high temperatures of the waterways used for their cooling, the company said on Friday, while the environmental exemptions enjoyed by certain sites are extended.
In addition to the potential damage to ecosystems, the problem is all the more acute as 27 nuclear reactors are shut down out of a fleet of 56 due to corrosion problems, France must already import electricity.
"The current exceptional climatic conditions result in a rise in the temperature of the Garonne which has reached 28 degrees", indicates EDF.
“At the request of the national electricity network operator (RTE), production unit No. 2 of the Golfech power plant, in Tarn-et-Garonne, remains in production (minimum power)”, continues the producer. of electricity.
This minimum power corresponds to approximately 300 MW, compared to 1,300 MW normally.
The plant's second reactor is in scheduled shutdown.
Standards specific to each plant
Each plant has its own regulatory water discharge temperature limits that must not be exceeded, so as not to heat up the surrounding waterways and to protect the fauna and flora.
The power plants indeed pump water to cool the reactors, before rejecting it.
The decrees setting the discharge limits also provide for higher thresholds "in exceptional climatic conditions", as is currently the case in Golfech.
In addition, temporary derogations can further raise the thresholds, which has been granted to four nuclear power plants, including that of Bugey (Ain), while France is going through a new heatwave episode.
"The exceptional climatic conditions that we have been experiencing for a few days have resulted in a rise in the temperature of the Rhône, which has reached more than 25 degrees", notes EDF in a separate point on the Bugey power station.
"Production units 2 and 5 have been maintained on the network in compliance with the provisions relating to exceptional climatic situations", indicates the group.
These two reactors “had to perform load reductions”, in other words reduce their power, said an EDF spokeswoman.
The other two reactors of the plant are shut down for scheduled maintenance.
Exemptions granted by the Nuclear Safety Authority
The Nuclear Safety Authority (ASN) has also extended until September 11 the environmental exemption, which initially ran until August 7, from which four power plants benefited so that they can continue to operate, indicated the Ministry of Health. Energetic transition.
pic.twitter.com/KWVdFpPSWN
– Nuclear Safety Authority (ASN) (@ASN) July 27, 2022
“ASN also authorized, yesterday (Thursday), a fifth authorization for derogation, concerning that of Tricastin”, we added to the ministry, which must still formally endorse this decision.
“When this decision is approved by the State, the power plants of Bugey, Blayais, Golfech, Saint-Alban and Tricastin will benefit from an exemption until September 11,” summarized the same source.
Discharges will be subject to "reinforced and daily" monitoring of the effects on fauna and flora, while EDF will draw up a report at the end of the period, the ministry stressed.
EDF had warned that it could be forced to lower its nuclear production in the coming days and even shut down a reactor at the Tricastin plant (Drôme) due to high river temperatures.
See also Rhône water could become too hot to cool the reactors of the Tricastin power plant
Drops in production for these reasons occur regularly in the summer period, although this year they occurred much earlier than usual - as early as May.
EDF puts the scope of these events into perspective, emphasizing that since 2000, production losses have represented an average of 0.3% of the fleet's annual production.
