Experts and analysts believe the ruthenium-106 detected in Europe was released by accident from a Russian site engaged in chemical reprocessing of old nuclear fuel or a facility producing isotopes.
Weeks after French nuclear watchdog IRSN reported a mysterious cloud of radioactive material over Europe, Russian authorities have confirmed that “extremely high” levels of the isotope ruthenium-106 were found in several parts of the country.
Experts and analysts believe the ruthenium-106 detected in Europe was possibly released by accident from a Russian site engaged in chemical reprocessing of old nuclear fuel or a facility producing isotopes used in nuclear medicine.
The Russian Meteorological Service said in a statement on Tuesday that it recorded the release of ruthenium-106 in the southern Urals in late September and classified it as “extremely high contamination”.
The highest concentration was registered in Argayash, a village in Chelyabinsk region in the southern Urals, which had levels of the isotope exceeding natural background pollution by 986 times, the service said.
“Probes of radioactive aerosols from monitoring stations Argayash and Novogorny were found to contain radioisotope Ru-106” between September 25 and October 1, the service said. It added the isotope was detected in Tatarstan and southern Russia, eventually reaching “all European countries, starting in Italy and toward the north of Europe” from September 29.
After an investigation, France’s Institut de Radioprotection et de Surete Nucleaire (IRSN) concluded the “most plausible zone of release (of the radioactive material) lies between the Volga (river) and the Urals”. It had also said the levels recorded in Europe were of “no consequence for human health and for the environment”.
Following the initial reports, Russia’s state-controlled Rosatom corporation had said in a statement last month that the radiation had not come from its facilities.
The Argayash station referred to by the Russian Meteorological Service is about 30 km from the Mayak nuclear facility, which was the site of one of the worst nuclear disasters in history in 1957. Mayak is now a reprocessing site for spent nuclear fuel.
Greenpeace Russia on Monday called on Rosatom to open “an in-depth inquiry and publish the results about the incidents at Mayak”, according to The Guardian. “Greenpeace will send a letter asking prosecutors to open an inquiry into potential concealment of a nuclear incident,” it said in a statement.
Ruthenium-106 is a radioactive isotope that is a by-product of a nuclear reaction and it is not found in nature. It is also used in certain medical treatments.
“It’s an unusual isotope,” Anders Ringbom, research director of the Swedish Defence Research Agency, was quoted as saying by NPR. “I don’t think we have seen it since the Chernobyl accident.”