RUSSIA has admitted finding "extremely high” concentrations of a radioactive isotope in some parts of the country in September, amid reports of a nuclear accident.
The announcement confirmed findings earlier this month by French nuclear safety institute IRSN of a cloud of radioactivity above Europe.
Russian officials had denied any knowledge of a nuclear accident that could have caused the cloud.
In October, state nuclear company Rosatom said at the time of the proposed accident "radiation around all objects of Russian nuclear infrastructure is within the norm and at the level of background radiation”.
This week, however, Russia's weather bureau, Rosgidromet, said "probes of radioactive aerosols from monitoring stations Argayash and Novogorny were found to contain radioisotope Ru-106 (ruthenium-106)” between September 25 and October 1.
Ruthenium-106 is a form of ruthenium that results from splitting atoms in a reactor and does not occur naturally.
The isotope was found in Tatarstan and southern Russia and had reached "all European countries starting in Italy and toward the north of Europe” from September29, Rosgidromet said.
The service did not say where the pollution originated, but a concentration 986 times the natural level of other forms ruthenium was found at Argayash, a village close to the Russian border with Kazakhstan and about 30km from the Mayak nuclear facility.
A blast at Mayak in 1957 exposed almost half a million people to dangerous radiation. Mayak is now a nuclear fuel reprocessing site.
The French report on the cloud said the source of the pollution was probably an accident somewhere between the Volga river and the Ural mountains. It said the levels were so high that if the accident had been in France, authorities would have evacuated surrounding areas. But the concentrations in Europe did not pose a threat to health.
The institute said a nuclear reactor could not have been the source because other radioactive elements would also have been detected.
It said the pollution could have come from an installation linked to the nuclear fuel cycle.
- Harriet Agerholm, The Independent