Dozens of Greenpeace activists have snuck into a nuclear power plant in eastern France at dawn.
It’s the latest break-in by the environmental group to highlight alleged security weaknesses at atomic facilities.
The activists broke into the Fessenheim plant and hung a banner reading “Stop risking Europe” on the side of one of its reactors.
They did this “to denounce the risk of French nuclear power for the whole of Europe,” the group said in a statement on Tuesday.
A spokesman for state-run power firm EDF, which runs the plant, said it was functioning normally despite the break-in.
“These actions will not have any impact on the working of the plant which is functioning normally,” the spokesman said.
Police detained 56 activists, he said, but 20 remained on top of the dome of one of the reactors as a police helicopter hovered above.
France, the world’s most nuclear-dependent country, operates 58 reactors and has been a leading international proponent of atomic energy.
But in a deal with the Greens before the 2012 parliamentary and presidential elections, President Francois Hollande’s Socialist party promised to cut reliance on nuclear energy from more than 75 per cent to 50 per cent by shutting 24 reactors by 2025.
Hollande has pledged to close Fessenheim, which was commissioned in 1977, by the end of 2016.
The plant, located on the banks of the Rhine, is close to the Swiss and German borders and is considered vulnerable to seismic activity and flooding.
The Greenpeace protest stunt comes ahead of a meeting by European leaders to discuss the future of the continent’s energy policy.
Greenpeace wants Hollande and German Chancellor Angela Merkel to push Europe towards a real energy transition, complaining that France relies too much on nuclear power, and Germany on coal, for electricity supplies.