Russian officials on 8 December again denied the Mayak production association in Ozersk (Urals) was the source of radioactive ruthenium-106 (Ru-106) detected over Europe in September.
A scientific commission comprising representatives of Russian state nuclear corporation Rosatom, which owns the Mayak facility, the Nuclear Safety Institute of the Russian Academy of Sciences (IBRAE), and other groups, said that Ru-106 was at natural background level. "An examination of test samples did not identify the presence of ruthenium-106," the commission said. “The strength of gamma radiation and the intensity of beta rays are at their natural background level.”
"The substance was in the air — that’s a fact,” said IBRAE deputy director Rafael Arutyunyan. “But if the Mayak facility [were] the source, then we would have found concentrations hundreds of thousands of times the norm around it and in the soil.” The investigators suggested the radiation could have come from a satellite burning up in the atmosphere. "The source could be attributed, among other things, to the burning in the atmosphere of an artificial satellite or its fragment, on the board of which there was a source of ruthenium-106 with high total activity," says the document released by the inter-departmental commission. Arutyunian said while isotopes of plutonium, caesium or strontium are normally used as power sources for satellites, Ru-106 could also have been used in some satellite equipment. The assumption that the isotope came from a crashing satellite would explain its broad spread over Europe, he argued.
France’s Institut de Radioprotection et de Sûreté Nucléaire (IRSN), which initially detected the Ru-106 had ruled out the crash of a ruthenium-powered satellite as an International Atomic Energy Agency investigation had concluded that no ruthenium-containing satellite had fallen back on Earth during the relevant period. However, IRSN and other investigators all said that the concentrations of Ru-106 in the air were of no consequence for human health and the environment. Monitoring stations in Germany, Austria, Italy and Switzerland all detected very low levels of Ru-106 from late September.
IBRAE is now initiating the establishment of an international commission to investigate the incident, Tass reported. The government is also establishing a new interdepartmental group to study the wider situation concerning ruthenium-106. This will include Rosatom, Roshydromet (Federal Service for Hydrometeorology and Environmental Monitoring), Rostekhnadzor (Federal Service for the Supervision of Environment, Technology and Nuclear Management), Rospotrebnadzor (Federal Service for Supervision of the Consumer Rights and Human Well-Being), FMBA (Federal Medical-Biological Agency), and the Ministry of Industry and Trade.
“This is another large commission that will also have to draw its conclusions, this time, fortunately, not [concerning] the Mayak production association, but in regarding the overall situation," said Rosatom Communications Department, head Andrei Ivanov.