PARIS — Security officials are investigating a mysterious wave of drone flights that have buzzed illegally over more than a dozen nuclear plants across France, raising security concerns around the country’s primary energy source.
Between Oct. 5 and Nov. 2, guards at 13 nuclear plants, many of which are operated by the French electricity giant EDF, spotted several drones flying over the sites, including in Le Blayais, in southwestern France, and Gravelines in the north.
A French government official said the drones were small and civilian or commercial, not military drones. “Our main concern is that the drones will take photos and video footage of the plants,” said the official, who spoke on the condition of anonymity to discuss security issues.
“One of our security concerns is to avoid having any precise images being taken of the nuclear plant,” the official added.
On Saturday, the Secretariat General for National Defense and Security, an interministerial body under the authority of the prime minister, issued a statement calling the drone flights an “organized provocation” aimed at “disrupting the surveillance chain and protection of these sites.”
The tension over the drones mounted recently when Ségolène Royal, the environment minister, said that she did not “have any lead” about who might be piloting the drones.
Some immediate suspicion fell on the environmental group Greenpeace, but it denied any involvement and raised the potential vulnerability of the nuclear sites to terrorism.
The government, the group said, had not taken adequate precautions to safeguard the sites, including pools where spent fuel is kept.
The French authorities said the nuclear plants were not vulnerable to the drones, and the interior minister, Bernard Cazeneuve, said that measures to “neutralize” the drones were in place.
But exactly what countermeasures had been taken, he and other officials would not say. Nor would they speculate on who might be behind the flights.
France has 19 nuclear plants and 58 nuclear reactors that supply nearly 75 percent of the country’s electricity. They are supposed to be built to withstand earthquakes and plane crashes.
Under French law, overflights of nuclear sites are illegal. They are punishable by a year in prison and a fine of 75,000 euros, or about $94,000, if an aircraft flies within a perimeter of 5 kilometers, or about 3 miles, around the site and 1 kilometer above it.