They revealed the origin of the mysterious radioactive cloud that has spread in Europe and Asia.

In 2017, a vast radioactive cloud has crossed Europe, part of Asia and the Arabian Peninsula. Although the countries of the affected regions were able to detect the phenomenon, the origin of this phenomenon could not be clearly determined. Two years later, a scientific study ends the mystery and concludes that the material it came from the Russian nuclear reprocessing plant Mayak, located south of the Urals.

According to a statement issued this week by the Technical University of Vienna (TU), the research entitled "Concentrations in the air and chemical considerations of radioactive ruthenium from a large undeclared nuclear emission in 2017", had the participation of 69 experts from different countries.

In dialogue with the agency EFEGeorg Steinhauser, project manager at Olivier Mbadon, explains that the level of radioactivity detected in the atmosphere At no time did this pose a risk to human health. However, the airborne detection of ruthenium-106 – an artificial substance – in such a large geographical area is "very unusual" and causes concern.

"It was a very compact cloud, in each place it stayed for a maximum of two days and continued to move, so we can see that the release took place very quickly, all of a sudden," he said. scientist. In addition, he added that the phenomenon is from Russiaand expressed the wish to receive official explanations from this country about what happened.

"The Russians have not accepted it yet, but on the basis of scientific evidence we are very sure that it was an accident in Mayak. On the other hand, there is no alternative, "said Steinhauser, who was able to determine the origin of the cloud by badyzing the data collected. for 176 radiation measurement stations in 29 countries.

In addition, the researcher stated that his intention was not to file a complaint against Russia, but to propose a joint work between nations in order to inform him of what had happened and to be able to improve with a view to the future. "The scientific community is interested in learning from accidents"he explained.

Already in November 2017, the Institute of Radiation Protection and Nuclear Safety (IRSN) of France had designated a Russian zone, between the Volga and Ural rivers, as the place of origin of Ru-106 detected in previous weeks in Europe. However, Moscow, who admitted to record unusually high concentrations of this isotope, denied that in Mayak there was an accident that explained the phenomenon.

According to the UT statement, the badysis of more than 1,300 measurements of Ru-106 concentrations detected in many European countries has inferred that the total volume of the leak was between 250 and 400 terabecquerel (a unit that measures the radioactive activity). Maximum values ​​of 176 millibecquerels per cubic meter of air were also badyzed, 100 times higher than the total measured concentrations in Europe after the serious Fukushima accident.

The calculations made it possible to date the time when the radioactive releases occurred between September 25 and September 26, 2017. The main conclusion is that it was an accident. accident at a nuclear fuel reprocessing plant in use, and not in a reactor, and the evaluation of the distribution of isotope concentration highlights "a site of rejection in the southern Urals".

"The fact that no radioactive substance other than ruthenium has been measured clearly indicates that the source must be a nuclear reprocessing plant," said Steinhauser, who described as "remarkable" the 39, extended geographical extent of the cloud.

The union recalls that the Mayak plant already had a large radioactive "release" in 1957, the largest before the Chernobyl nuclear accident (1986), following the explosion of the nuclear power plant. a tank containing liquid waste from the production of plutonium.