Electricite de France SA will limit planned maintenance at nuclear reactors near the English Channel and Atlantic Ocean as the driest spring in about 50 years reduces river water for cooling inland plants.
EDF, Europe’s biggest power generator, operates France’s 58 nuclear reactors that provide about three quarters of the country’s power needs. Most require river water for operations, prompting the utility and the country’s nuclear safety watchdog to step up monitoring.
Measures being taken by the utility include the “limitation of summer outages in seaside nuclear plants,” EDF said in a presentation last week. The dozen French reactors that rely on seawater for cooling include Gravelines, Penly, Paluel, Flamanville and Blayais.
EDF schedules planned refueling and maintenance sometimes years in advance to coincide with a greater need for base nuclear power during cold winter months and hot summer months. The utility was forced to reduce output at some riverside reactors during a 2003 heat wave that left 14,000 people dead.
“We have to pay attention to reactor operations. A decline in water flow and increase in temperatures have an impact on cooling,” French Environment Minister Nathalie Kosciusko- Morizet said at a news conference today. “If the water flow becomes too low, a reactor will be halted.”
Swiss authorities would like to maintain the water level of Lake Geneva by adjusting flows into the Rhone River, she said, adding that this could affect French reactors.
The current dry spell, which has prompted water restrictions in some areas, hasn’t had an impact on nuclear output, EDF spokeswoman Jill Coulombez said by telephone. French law requires plants to reduce output when water levels drop below a certain level or shut down if temperatures rise too high.
Dry conditions lowered EDF’s hydroelectric power production by 2.1 terawatt-hours last quarter, EDF said in a May 12 statement.
The availability of water for EDF power generation started to fall below average in the middle of January and remained through March below the minimum recorded over the past decade, according to last week’s presentation.
France may have “one of the driest” months of May on record, Michele Blanchard, a researcher at forecaster Meteo France, said in an interview in Paris today. No significant rain is forecast for the next two weeks and temperatures will start rising.
France’s nuclear safety watchdog is reviewing guidelines that would need to be followed in the event of a drought in the coming months, Andre-Claude Lacoste, head of the Autorite de Surete Nucleaire, said last week. Reactors that may be affected include those located on the Loire and Rhone Rivers, he said.
EDF will also carry out weekly “stress tests based on historical temperature models,” as part of water management measures as well as “cautious” management of the water in dams, according to the presentation.
Hydroelectric reserves in France are 9 percentage points below the same week last year and 11 points lower than in 2009, according to data on the website of Reseau de Transport d’Electricite, a unit of EDF. France gets about 20 percent of its power capacity from running water through turbines.