The meteorological service of Russia has confirmed that "extremely high" levels of the radioactive isotope ruthenium-106 were detected in certain areas of the country in September. It denies the increased concentration is the result of a nuclear accident.
On Nov. 9, French officials determined that a radioactive cloud detected in Europe may have stemmed from an incident at a nuclear facility in the southeastern Urals region of Russia or Kazakhstan, the Financial Times reports.
Rosgidromet, Russia's meteorological organization, waited 11 days to confirm the existence of the cloud, which it admits it detected in September. The delay in responding has made some suspect that Russia was attempting to cover up the incident, as it did with the Chernobyl nuclear accident in 1986.
One of the suspicious entities is Greenpeace, which said on Nov. 20 that it would be calling for an "in-depth inquiry" into "potential concealment of a nuclear incident."
A report by Rosgidromet said the highest levels of radioactivity were detected in late September and early October at the Argayash weather station in the Chelyabinsk region near the Urals, according to Radio Free Europe. The levels of Ru-106 were reportedly 986 times higher than normal, which is considered "extremely high contamination."
The closest nuclear plant, Mayak, denies it has anything to do with the nuclear spike. It said it has not made Ru-106 for years. It was the site of one of the world's worst nuclear disasters in 1957.
A separate report detected a level 440 times higher than the month before. That data was collected at the Novogorny meteorological station in the same region of the Urals.
Rosgidromet later published another report retracting its statement there had been "extremely high" levels of Ru-106, indicating in bold that the amount detected was several times lower than permissible.
It blamed environmental protection groups for trying to "increase their importance in the eyes of society" during the time when "their budgets for the next year are being drafted." It also said the reason for the dramatic spike in background detection levels was because it usually detected levels near zero.
Both Rosgidromet and France's Institute for Radioprotection and Nuclear Safety denied the isotope was a threat, reports the Financial Times. Nuclear expert Paddy Reagan, a professor at England's University of Surrey, also told The Guardian the levels of Ru-106 weren't dangerous.
The radiation will persist in the atmosphere for five or six years, but half of it will be gone by next year. It is unlikely to warrant an environmental cleanup operation.