The Ruthenium-106 spike detected by several European atmospheric monitoring networks in late September could have originated at a nuclear processing plant in Russia, although officials at the plant said that they had not experienced a leak at the plant.
A senior executive at the plant, according to Reuters, admitted that Ruthenium-106 was a by-product of of the spent fuel processing at the Mayak nuclear plant in the Ural Mountains. However, the official also said that no operation at the plant that could have leaked the isotope at that location “for many years.” The plant spokesman Yuri Mokrov also said that Ruthenium-106 was commonly produced in the process, but that levels were so small “we can only see it in the chimney,” Reuters quoted Mokrov as saying at a Internet conference on Wednesday.
The Mayak facility in 1957 was the site of a waste tank explosion that contaminated 9,200 square miles of land and caused 10,000 residents to leave their homes in a regional evacuation.
While the spike in late September was detected as far away as France, monitors said that only a few milliBecquerels per cubic meter of air were found – a level too light to be harmful to humans.
Monitors at the time – although the spike was not made public until early November – suspected the Ural Mountain region as the source of the spike, which Russia still denies.