MOSCOW, November 22. /TASS/. Russian industrial safety watchdog Rostekhnadzor has not found any breaches at the Mayak nuclear facility in the south Urals during its check of media reports about ruthenium-106 levels detected in some European countries, Rostekhnadzor said on Wednesday.
"It was found during the check that the specific activity of radionuclides in the surface air, including the specific activity of the ruthenium-106 isotope on the territory of the Mayak production association, its sanitary protection zone and the observation area during August - October 2017 did not exceed permissible and control levels set for the enterprise," the industrial safety watchdog said in a statement.
"No violations related to radiation control of the sources of radioactive discharges and the operation of equipment and technological processes that could have been the cause of the discharge of the ruthenium-106 isotope into the atmosphere were found during the check," the statement says.
The inspection of the Mayak nuclear facility in the Chelyabinsk Region was conducted on October 26 - November 3, 2017, Rostekhnadzor said.
"The levels of the ruthenium-106 activity registered in Europe varied in a broad range of 10 mcBq (microbecquerels) to 100 mBq (millibecquerels) per cubic meter of the air, with the highest level of 145 mBq per cubic meter registered on September 30, 2017 in Bucharest," Rostekhnadzor said.
Russia’s Federal Service for Hydrometeorology and Environmental Monitoring (Rosgidromet) earlier reported about excessive ruthenium isotope levels in the samples collected from the observation posts of Argayash and Novogorny in the Chelyabinsk Region. It followed from Rosgidromet’s report that the ruthenium levels in the samples collected from these stations measured 76,100 and 52,300 microbecquerels per cubic meter, which exceeded the background of the previous month by 986 and 440 times and corresponded to the level of "extremely high contamination."
The Mayak production association, which makes part of the state-owned civil nuclear power corporation Rosatom and produces nuclear weapon components, has denied that it has anything to do with the excessive ruthenium levels in the atmosphere. Rosatom has confirmed that no incidents have occurred at facilities of the Russian nuclear sector.
Ruthenium-106 levels in Europe
Germany’s Federal Office for Radiation Protection (BfS) earlier reported about an increased concentration of ruthenium-106 in the air from September 29 to October 3. The BfS noted that the ruthenium concentration was very inconsiderable and posed no danger for the health of people. German specialists also said they were confident that no nuclear power accident could be the cause for the increased concentration of ruthenium-106. Later, the BfS reported that a discharge at one of enterprises in the south Urals could be the source of the isotope.
Rosatom has reported that no traces of ruthenium-106 were detected in the air samples taken on the territory of Russia, except the only measuring station located in St. Petersburg. Rosatom said Russian nuclear power facilities could not be considered as the source of the isotope’s discharge. Rosatom cited the data of the International Atomic Energy Agency (IAEA), pursuant to which the ruthenium-106 concentration reached 145,000 microbecquerels per cubic meter in Romania, 54,300 microbecquerels per cubic meter in Italy, 40,000 and 37,000 microbecquerels per cubic meter in Ukraine and Slovenia, respectively, over that period.
Deputy Governor of the Chelyabinsk Region Oleg Klimov also rejected on October 20 the claims by European experts that the region’s enterprises could allegedly be the source of ruthenium-106 in Europe.
Ruthenium-106 is used, in particular, in radiation therapy and can also be released in nuclear fuel reprocessing.