Around 70 per cent of French electricity is derived from the splitting of atoms, and no other country produces more nuclear power per capita.

More than a means of keeping the lights on, France’s prowess in the nuclear space is also a source of national pride – the amalgamation of decades of research that stretch back to the discovery of polonium and radium by Marie Skłodowska Curie and Pierre Curie in Paris in the late 1890s.

Today, nuclear energy earns the country more than $3 billion per year in electricity exports. This has taken on fresh saliency as global energy prices spike in response to Russia’s invasion of Ukraine.

Yet the nuclear energy industry in France is facing significant challenges. Climate change, for example, is already hampering French nuclear output. An especially hot and dry summer has warmed the country’s rivers and lowered water levels, reducing the ability of its energy companies to use the water to cool nuclear reactors.

Some power plants are beginning to show their age and require extensive maintenance for corrosion damage, which could end up taking years. All of this has conspired to force half of France’s nuclear reactors offline for now. This couldn’t have come at a worse time: Europe’s energy prices and supplies are already under immense pressure following the invasion of Ukraine.

Politics is also at play. In the wake of presidential and parliamentary elections this year, the future of nuclear energy in France seems less certain.

Critics of centrist President Emmanuel Macron, who was re-elected in April for a second five-year term, accuse him of being inconsistent on nuclear policy. He previously promised to reduce France’s reliance on nuclear energy, and two years ago he pushed ahead with shutting a 42-year-old plant in Fessenheim, close to the border with Germany.

Macron’s tone has since shifted: in February, he announced plans to build 6 new reactors at an estimated cost of $50 billion, with the first coming online by 2035.

To achieve this, however, he will need the backing of parliament, which is likely to be difficult following legislative elections in June. The coalition that includes Macron’s Renaissance party won 42.5 per cent of seats – more than any other party, but not enough to keep a governing majority. Voters instead endorsed parties from the far right and left.

The coalition of left-wing parties, led by anti-nuclear politician Jean-Luc Mélenchon, gained 22.7per cent of seats. The far right, led by pro-nuclear politician Marine Le Pen, took 15.4 per cent – but cutting a deal with Le Pen, who is a long-time presidential rival of Macron, could prove politically problematic.

Those who work in or study nuclear power in France are wondering what this means for the industry. Nature spoke to four specialists, each with their own perspective on what this political climate could mean for the future of nuclear power.

Today’s nuclear power infrastructure was born out of the French government’s efforts in the 1950s and 1960s to develop a nuclear bomb during the cold war, and so a lot of resources were poured into nuclear research.

That created the expertise, then in the 1970s the oil-price shock turned attentions towards nuclear-power development. Countries began to rethink their energy strategies as they tried to reduce dependence on foreign oil.

For France, the answer was nuclear power and, in 1974, prime minister Pierre Messmer even expressed a desire that all of France’s electricity should come from nuclear power. Although that didn’t happen, the 1980s and 1990s saw a rapid expansion of nuclear power capacity in France: 56 reactors were built in just 15 years. This created a critical mass of both knowledge and infrastructure that really allowed nuclear power to establish itself, but not everyone agreed it was a good thing.

A lot of people still don’t want nuclear. Activists in the environmental movements say they want only renewable energy, but that’s technically a very difficult thing to pull off. I don’t think Macron was particularly interested in this topic during his first term, so he just followed the political precedent set by his socialist predecessor, François Hollande, who closed a nuclear power station in the final months of his presidency.

But the question of climate change and how to manage greenhouse-gas emissions has become increasingly pertinent. In a 2022 paper I published with collaborators, we investigated the environmental impacts of four electricity-production scenarios with differing levels of nuclear output.

Solar and wind systems take quite a bit of power to install and require more building materials than do the scenarios that lean more heavily on nuclear. Of course, nuclear power in France also has the advantage of a well-established existing network.

We concluded that the scenarios with a large percentage of nuclear power, such as France’s current nuclear portfolio, have the lowest environmental impact. If we don’t want to produce energy from fossil fuels, which is essentially the problem we’re all trying to solve here, then the most stable answer is nuclear energy. We don’t necessarily need to be at 70 per cent, but perhaps 50 per cent will be required.

I think Macron has now come around to this point of view, which is clear in his speeches when he talks about energy policy, but Mélenchon’s coalition might try to prevent the reactors from being built.

The history of nuclear energy in France is very interesting because it has created constraints. It has made the pro-nuclear side of the argument into the status quo. The industry has worked hard to normalise the use of nuclear energy, and that shapes the whole policy debate – any time you want to reduce the percentage of nuclear energy, you must take on this normalised culture.

Last year, I co-authored a paper in which we interviewed 28 people about their attitudes towards nuclear energy. Eleven of the participants were anti-nuclear activists, 13 were professionals who work in the nuclear industry and four worked for independent monitoring organisations that inform the public about nuclear radiation.

We found that the anti-nuclear people are pretty pessimistic. The movement has been going for decades and they’ve been protesting for a long time without any real change. They’re frustrated.

When it comes to discussing the risks around nuclear power, this takes a back seat in comparison to the economic and political arguments. The debate is framed as one of energy independence.

• A Nature report