Hot weather cuts French, German nuclear power output

A boy jumps into the sea on a hot summer day as a ferry sails past the beach in Sangatte, France, July 24, 2019. REUTERS/Pascal Rossignol

PARIS/FRANKFURT (Reuters) - Scorching temperatures across Europe coupled with prolonged dry weather has reduced French nuclear power generation by around 5.2 gigawatts (GW) or 8%, French power grid operator RTE's data showed on Thursday.

Electricity output was curtailed at six reactors by 0840 GMT on Thursday, while two other reactors were offline, data showed. High water temperatures and sluggish flows limit the ability to use river water to cool reactors.

In Germany, PreussenElektra, the nuclear unit of utility E.ON, said it would take its Grohnde reactor offline on Friday due to high temperatures in the Weser river.

Tourists shield themselves from the sun with umbrellas as temperatures reach new record highs in front of the Brandenburg Gate in Berlin, Germany, July 25, 2019. REUTERS/Fabrizio Bensch

The second heatwave in successive months to hit western Europe is expected to peak on Thursday with record temperatures seen in several towns in France.

Utility EDF, which operates France's 58 nuclear reactors, said that generation at its Bugey, St-Alban and Tricastin nuclear power plants may be curbed until after July 26 because of the low flow rate and high temperatures of the Rhone.

Its two reactors at the 2,600 megawatt (MW) Golfech nuclear power plant in the south of France were offline due to high temperatures on the Garonne river.

A child cools off as temperatures reach new record highs in a fountain in Berlin, Germany, July 24, 2019. REUTERS/Fabrizio Bensch

EDF's use of water from rivers as a coolant is regulated by law to protect plant and animal life and it is obliged to cut output in hot weather when water temperatures rise, or when river levels and flow rates are low.

Atomic power from France's 58 reactors accounts for over 75 percent of its electricity needs. Available nuclear power supply was down 1.4 percentage points at 65.3% of total capacity compared with Wednesday.

A spokeswoman for grid operator RTE said that although electricity demand was expected to rise due to increased consumption for cooling, France had enough generation capacity to cover demand. Peak power demand could be above 59.7 GW reached the previous day.

FILE PHOTO: General view of the EDF Bugey nuclear power plant in Saint-Vulbas, near Lyon, April 20, 2011. REUTERS/Robert Pratta/File Photo

Germany's PreussenElektra said in a statement it expected the closure of 1,430 MW Grohnde to last from midday on Friday July 26 to Sunday July 28, although plans could be revised if the weather changes.

PreussenElektra also operates the 1,485 MW Isar 2 reactor in Bavaria, which is due to finish a current routine maintenance standstill at the weekend, and the 1,440 MW Brokdorf plant on the river Elbe in the north.

Neither plants is currently expected to have to cut or halt operations because of the weather.

People cool off in the futuristically designed 'Badeschiff' (Pool ship) on the Spree river as temperatures reach new record highs in Berlin, Germany, July 24, 2019. REUTERS/Fabrizio Bensch

(Reporting by Bate Felix and Vera Eckert,; Editing by Keith Weir/David Evans)

French Republican Guards hold a bottle of water on a hot summer day in the courtyard of the Elysee Palace in Paris, France, July 24, 2019. REUTERS/Philippe Wojazer