Like other European countries, France has been baking in temperatures of up to 40 degrees Celsius (104 degrees Fahrenheit) for several weeks. Although that is putting French nuclear reactors under strain, this does not seem to be calling the country's nuclear-heavy energy strategy into question.
Nuclear power plants normally generate roughly 70% of electricity in France — making nuclear's share of the energy mix there higher than in any other country.
But more than half of the country's 56 reactors have been closed for several months due to planned or extraordinary maintenance.
And about a fifth of them would normally need to interrupt their activity or at least reduce it to a bare minimum, as the water temperature of the rivers into which plants discharge their cooling water exceeds a certain limit.
But the government has suspended that rule until at least September 11.
'Ripple effects throughout the food chain'
For Jean-Pierre Delfau, an environmental activist at local group FNE86, that is an exasperating decision.
"I just can't understand how they can keep the reactors running although that will have a disastrous impact on the ecosystem," he told DW, as he and two other environmentalists made their way through high grass on the bank of the Garonne river to take a water sample on a recent afternoon.
The Garonne supplies cooling water for the Golfech nuclear plant in southwestern France. One of the power station's two reactors has been standing still for months, after authorities found corrosion and small cracks on pipes relevant for the plant's safety. The second reactor is still functioning.
"Due to the heat, the Garonne's water throughput is already down to 50 cubic meters per second, from several thousand in normal times," Delfau said. "The Golfech plant makes that worse, as it uses 8 cubic meters for its cooling system but only discharges 6 cubic meters back, as some of the water evaporates during the process," he pointed out.
He added that the plant's cooling processes have increased the water's temperature by 6 degrees C, which has triggered ripple effects throughout the food chain.
"The warmer water destroys microalgae that are food for certain small fish, which bigger fish feed on," explained the 79-year-old, who has been an anti-nuclear protester for more than 50 years.
"Plus, warmer water contains more bacteria. In order to make it potable, we have to add a lot of chemicals, which people then drink."
Not an existential crisis for French nuclear power
Power company EDF, which runs all of France's nuclear power plants, declined an interview request with DW. A spokeswoman replied by email that the situation was "extraordinary" and that so far, environmental probes had not revealed any negative impact on the flora and fauna around the respective reactors.
Despite environmental concerns, current issues are not throwing French nuclear power into an existential crisis. The government is planning to soon nationalize EDF and construct additional nuclear plants.
That has Anna Creti, climate economy director at Paris University Dauphine, scratching her head.
"It's not quite clear how this strategy is supposed to work on a technology level, especially in the short run," she told DW.
Technology not ready
"France is banking on so-called small modular reactors (SMRs), for which there exist roughly 40 different technologies, all of them in a pilot phase," Creti said. "Getting them ready for deployment could take up to 10 years," she added.
"The government also plans to construct more pressurized-water, so-called EPR reactors — a model that has encountered numerous problems," she continued.
According to current predictions, the country's first EPR plant is to go live next year in Flamanville in the north of the country. According to developer EDF, building costs have so far at least tripled, to roughly €13 billion ($13.3 billion).
France's Court of Auditors puts that figure at €19 billion — with construction taking more than 10 years longer than planned. Other EPRs in Britain, China and Finland are reported to experience construction, conceptual or production problems.
"The government has nevertheless earmarked €150 billion for refurbishing existing nuclear plants and constructing new ones," Creti said, adding that no such funding boon was announced for renewables, although Paris is working on new rules to cut red tape for development of renewables.
"Putting more money into renewables would make sense, as they have become ever cheaper over the past few years, and their technology is sufficiently advanced for them to be deployed immediately across the country," she emphasized.
France is the only European country not to have reached its 2020 EU renewables targets. Renewable energies make up only roughly 19% of energy production, instead of the planned 23%.
Various reasons for France's approach
But Christian Egenhofer, associate senior research fellow at Brussels-based think tank Center for European Policy, says the EU's so-called strategic autonomy is one reason France is betting on nuclear energy. The EU is aiming for independence not only regarding defense, but also energy independence.
"We have roughly 100 nuclear power plants in Europe. We need nuclear scientists and engineers to take care of their maintenance work — or we will have to farm out these tasks to the US, China or Korea, which would pose security issues," he told DW.
He added that France's grid structure is additionally a stumbling block for a massive deployment of renewables.
"The country's electric grid is centralized around Paris, where most of the electricity is consumed. All the power is brought there and redispatched across the country. That's not suitable for decentralized renewables projects, and adapting the grid will take years," Egenhofer explained.
Nevertheless, he believes France will shift to more renewables in the long run.
Energy shortages expected in winter
Philippe Mante is strongly hoping for that. He's in charge of climate affairs at EELV, France's green party, which is opposed to constructing new nuclear plants. For the sake of energy security, the party is not in favor of immediately dismantling existing nuclear energy plants.
"Even supporters of nuclear energy must know, given the current situation, that we need to massively and right away deploy renewable energy projects," he said in an interview with DW.
But even Mante has little expectation of that happening right away.
"I think we should all quickly buy very warm pullovers, as we are likely to face electricity shortages this winter," he said gloomily.
Neighboring countries will be watching closely. Until now, France has been Europe's biggest net energy exporter. This year, however, the country will have to import more electricity than it's exporting.
That's likely to add even more pressure to energy prices, which are already skyrocketing, due among other things to Moscow's invasion of Ukraine and reduced delivery of Russian gas.
Edited by: Hardy Graupner