Radioactivity source narrowed down

There are further indications that the release of the radioactive isotope ruthenium-106 could be traced back to the Mayak nuclear facility in the Ural region, a reprocessing site for spent nuclear fuel.

Russian meteorological service Rosgidromet confirmed on Monday the release of Ru-106 in the southern Urals in late September and early October, classifying it as an "extremely high contamination."

French nuclear safety institute IRSN reported on November 9 that radioactivity had been detected in France between September 27 and October 13, and that it likely stemmed from Russia or Kazakhstan.

At the Russian measuring station Argayash, the highest level measured was 986 times that of the previous month, the Russian weather service said in a statement. At the Novogorny station, the measured levels were 440 times higher.

In mid-October Russian nuclear agency Rosatom denied that any of its facilities experienced any incidents — today, it again denied this.

Officials at Mayak have said the dose of radiation is 20,000 times smaller than the "allowed annual dose," and therefore "poses no danger to human health and lives."

In a statement released on Tuesday, environmental group Greenpeace demanded an in-depth inquiry "into potential concealment of a nuclear incident" and an investigation into public health risks.

Mayak was the location of the Kyshtym disaster in 1957, which remains the third-most serious nuclear accident ever recorded.

sad/im (AFP, AP, Reuters)