Like a faint, creeping fog, a wave of radioactive pollution spread across Europe in late September and early October, French nuclear safety officials said Friday.
They speculated that Russia or Kazakhstan could be the source of the radioactive material, but as The U.K. Telegraph reports, no one has admitted responsibility for the leak.
IRSN, France’s nuclear safety institute, revealed that radioactivity was picked up by three French monitoring stations in late September. Monitoring stations also recorded radioactivity levels in other European nations throughout the first week of October, after which readings began to fall.
France said radiation was recorded at Seyne-sur-Mer, Nice and Ajaccio from Sept. 27 to Oct. 13, but not since.
The IRSN, said that it detected ruthenium 106, which does not occur in nature
Germany, Austria, Italy and Switzerland also detected ruthenium. No radiation was detected in Britain.
French officials said there was no direct impact on human health.
French officials said that although Europe recorded low levels of ruthenium, at the source of the leak, it would have been a “major” event. They said if the leak had taken place in France, evacuations would have been required for “a few kilometers around the accident site”.
Germany’s Federal Office for Radiation Protection said an accident at a nuclear power plant could be “ruled out,” according to The U.K. Independent.
“Ruthenium-106 is used as a radiation source in cancer therapy for the treatment of ocular tumors. Ruthenium can also occur during the reprocessing of nuclear fuel elements,” the office said in a statement.
Jean-Christophe Gariel, director for health at the IRSN, said that the most likely site of the release would be a nuclear fuel treatment site or center for radioactive medicine.
He said that unless someone admits responsibility, there is little more than can be done.
“The matter is closed as far as France is concerned. It’s not a problem for France, what is not satisfactory is that ruthenium-106 has been detected across Europe and that poses a question,” Gariel said.
“We have come up with a plausible zone of where it could have come from; we can’t do any more. Russia is a vast country and we’re not aware of all the installations on its territory. The ball is now in the other camp.”
Jean-Marc Peres, IRSN’s director, said, “Russian authorities have said they are not aware of an accident on their territory.”
He revealed that officials in Kazakhstan had not yet been reached.