Some 70 kilometres from Geneva as the crow flies, Bugey, in the Ain department, is one of France’s oldest nuclear power plants, having come into service in 1972.
The site creates about 4.5 percent of France's electricity using pressurized water reactors that harness water from the nearby Rhône River.
It has been the subject of controversy before, notably in 2013 when Greenpeace activists broke in to the plant to highlight alleged security weaknesses at the facility.
The current Swiss legal action is a joint initiative by Geneva’s city and cantonal authorities, which have teamed up on an issue that has preoccupied the region for some time, reports Swiss daily 24 Heures.
Back in 2012, the canton placed an official objection to French energy company EDF’s authorization to create a nuclear waste depot at the Bugey site, but the complaint was rejected by the French government.
In March 2015 the city council engaged Corinne Lepage, environmental law specialist and a former French minister, to devise a legal strategy calling for the plant to be shut down.
This fresh Swiss campaign against Bugey, led by Lepage, comes as Switzerland decides to shut down one of its own nuclear plants, at Mühleberg.
The reactor in the canton of Bern will be disconnected from the Swiss electricity grid in 2019 and will be finally put out of service by September 2020 at the latest, its owner BKW Energy announced to the press on Wednesday.
Like Bugey, Mühleberg also dates from 1972, making it one of the oldest nuclear plants in the world.
No age limits
However, despite the old age of some of Switzerland’s nuclear installations, their lifespan should not be limited by law, the federal government said on Wednesday.
On Wednesday the Swiss parliament voted against a motion to set an age limit for nuclear plants.
A large majority of MPs felt it would be ineffective and even counterproductive to set a limit, reported the Swiss press.
Operators of the plants could seek financial damages if forced to shut their installations prematurely, said the Tribune de Genève.
Parliament also voted against recommendations by the Federal Inspectorate of Nuclear Security (ENSI) that nuclear plant operators should submit long-term security plans for ageing reactors, including details of how plants will be decommissioned.
Many on the political right judged the measure unnecessary, saying the ENSI already had the power to intervene over security issues.
'Worse than before Fukushima'
Quashing the proposal angered some on the political left, however, including president of the Greens, Adèle Thorens.
Speaking to Le Matin, she said: “Instead of moving away from nuclear power it’s been decided to prolong the life of nuclear plants instead.”
Worse, she said, was the fact that parliament “had refused the recommendations of our own monitoring organization!”
“We are now in a security situation worse than before Fukushima,” she added. “That’s the incredible paradox of our energy strategy.”