PARIS (Reuters) - A cloud of radioactive pollution over Europe in recent weeks indicates that an accident has happened in a nuclear facility in Russia or Kazakhstan in the last week of September, French nuclear safety institute IRSN said on Thursday. 
 
 FILE PHOTO: An employee looks at equipment in a new facility at a nuclear waste disposal plant in the town of Fokino in Russia's far-eastern Primorsky region June 24, 2014. REUTERS/Yuri Maltsev 
 
 The IRSN ruled out an accident in a nuclear reactor, saying it was likely to be in a nuclear fuel treatment site or center for radioactive medicine. There has been no impact on human health or the environment in Europe, the IRSN said. 
 
 IRSN, the technical arm of French nuclear regulator ASN, said in a statement it could not pinpoint the location of the release of radioactive material but that based on weather patterns, the most plausible zone lay south of the Ural mountains, between the Urals and the Volga river. 
 
 This could indicate Russia or possibly Kazakhstan, an IRSN official said. 
 
 “Russian authorities have said they are not aware of an accident on their territory,” IRSN director Jean-Marc Peres told Reuters. He added that the institute had not yet been in contact with Kazakh authorities. 
 
 A spokeswoman for the Russian Emergencies Ministry said she could not immediately comment. It was not immediately possible to reach authorities in Kazakhstan or the Kazakh embassy in Moscow. 
 
 Peres said that in recent weeks IRSN and several other nuclear safety institutes in Europe had measured high levels of levels of ruthenium 106, a radioactive nuclide that is the product of splitting atoms in a nuclear reactor and which does not occur naturally. 
 
 IRSN estimates that the quantity of ruthenium 106 released was major, between 100 and 300 teraBecquerels, and that if an accident of this magnitude had happened in France it would have required the evacuation or sheltering of people in a radius of a few kilometers around the accident site. 
 
 The ruthenium 106 was probably released in a nuclear fuel treatment site or center for radioactive medicine, Peres said. Because of its short half-life of about a year, ruthenium 106 is used in nuclear medicine. 
 
 The IRSN ruled out an accident in a nuclear reactor, as that would have led to contamination with other radionuclides too. It also ruled out the crash of a ruthenium-powered satellite as an IAEA investigation has concluded that no ruthenium-containing satellite has fallen back on earth during this period. 
 
 Measurement from European stations showed high levels of ruthenium 106 in the atmosphere of the majority of European countries, at the beginning of October, with a steady decrease from Oct. 6 onwards. 
 
 The IRSN said that the concentrations of ruthenium 106 in the air that have been recorded in Europe were of no consequence for human health and the environment. 
 
 The institute also said that the probability of importation into France of foodstuffs, notably mushrooms, contaminated by ruthenium 106 near the site of the accident is extremely low. ||||| TexteZone1 
 
 Read our Update from February 6, 2018 
 
 Ruthenium 106 has been detected in late September by several European networks involved in the monitoring of atmospheric radioactive contamination, at levels of a few milliBecquerels per cubic meter of air. IRSN's investigations make it possible to provide information on the possible location of the source of the release as well as the order of magnitude of the quantities released. 
 
 As soon as it became aware of the first detections of Ruthenium 106 in the atmosphere in Europe, IRSN mobilized all its means of radiological monitoring of the atmosphere and conducted regular analysis of the filters from its monitoring stations. For the period from September 27 to October 13, 2017, only the stations of Seyne-sur-Mer, Nice and Ajaccio revealed the presence of Ruthenium 106 in trace amounts. Since October 13, 2017, Ruthenium 106 is no longer detected in France. 
 
 Measurement results from European stations communicated to the Institute since October 3, 2017, have confirmed the presence of Ruthenium 106 in the atmosphere of the majority of European countries. The results obtained for sampling periods later than October 6, 2017, showed a steady decrease in Ruthenium 106 levels, which is currently no longer detected in Europe. 
 
 The concentration levels of Ruthenium 106 in the air that have been recorded in Europe and especially in France are of no consequence for human health and for the environment. 
 
 Based on the meteorological conditions provided by Météo France and the measurement results available in European countries, IRSN carried out simulations to locate the release zone, to assess the quantity of ruthenium released, as well as the period and the duration of the release. 
 
 The map below summarizes the results obtained and confirms that the most plausible zone of release lies between the Volga and the Urals without it being possible, with the available data, to specify the exact location of the point of release. Indeed, it is in this geographical area that the simulation of a ruthenium release makes it possible to better reproduce the measurements obtained in Europe. 
 
 Map showing the plausibility of the origin of the release: 
 
 For the most plausible zone of release, the quantity of Ruthenium 106 released estimated by IRSN simulations is very important, between 100 and 300 teraBecquerels. The release, accidental with regard to the quantity released, would have occurred during the last week of September 2017. 
 
 Because of the quantities released, the consequences of an accident of this magnitude in France would have required to implement locally measures of protection of the populations on a radius of the order of a few kilometres around the location of the release. 
 
 For foodstuffs, the exceeding of maximum permitted levels (1250 Bq/kg for Ruthenium 106 for non-milk products) would be observed over distances of the order of a few tens of kilometres around the location of the release. 
 
 The possibility of exceeding maximum permitted levels near the accident site led IRSN to study the scenario of importing foodstuffs from this area. From this analysis, IRSN considers, on the one hand, that the probability of a scenario that would see the importation into France of foodstuffs (especially mushrooms) contaminated by Ruthenium 106 near the source of the release is extremely low and, on the other hand, the potential health risk associated with this scenario is also very low. It does not therefore appear necessary to introduce systematic controls on the contamination of imported foods. 
 
 Download IRSN information report from Novembre 9, 2017 « Detection of Ruthenium 106 in France and in Europe: Results of IRSN’s investigations » (PDF)
– A nuclear accident happened somewhere in Russia or Kazakhstan during the last week of September and was kept very quiet, the French nuclear safety institute IRSN has concluded after analyzing a mysterious radioactive cloud that appeared over Europe last month. IRSN researchers say they detected high levels of ruthenium 106, a type of atom that does not occur in nature and is only found when atoms are split in reactors, Reuters reports. The cloud was at its peak during the first week in October and dissipated until it could not be detected in France by Oct. 13, according to IRSN, which says its analysis of weather patterns points to a source between the Ural mountains and the Volga river. The institute, which says other European nuclear regulators have made similar findings, has ruled out the crash of a radioactive satellite or an accident at a nuclear reactor as the source of the cloud. It says the most likely source was either a facility dealing with spent nuclear fuel or a facility for radioactive medicine. Russian authorities say they're not aware of any accident in the area, while Kazakh authorities haven't been reached for comment yet, IRSN says. The institute says the cloud itself is harmless and is unlikely to contaminate food, though it says there must have been a very large amount of ruthenium 106 released at the accident site, enough that would have theoretically warranted an evacuation of a radius of several miles.