Source of low-level European release remains unknown

Estonia, Finland and Sweden last week measured levels of ruthenium and caesium isotopes which were higher than usual. They also reported the detection of some other artificial radionuclides. The three countries said there had been no events on their territories that could explain the presence of the radionuclides, as did more than 40 other countries that voluntarily provided information to the IAEA.

Seeking to help identify their possible origin, the IAEA on 27 June contacted its counterparts in the European region and requested information on whether the particles were detected in their countries, and if any event there may have been associated with the atmospheric release.

By yesterday afternoon, 37 Member States in the European region (Albania, Austria, Belgium, Bosnia & Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine and the UK) had voluntarily reported to the IAEA that there were no events on their territories that explained the release. They also provided information about their own measurements and results. In addition, 10 countries which were not asked for such information - Algeria, Canada, Georgia, Japan, Kuwait, Morocco, Qatar, Tajikistan, the UAE and the USA - also voluntarily reported to the IAEA.

Based on its technical analysis of the mix of artificial radionuclides that were reported to it, the IAEA has concluded the release was likely related to a nuclear reactor, either in operation or in maintenance. The IAEA ruled out that the release was related to the improper handling of a radioactive source. It was also unlikely to be linked to a nuclear fuel processing plant, a used fuel pool or to the use of radiation in industry or medicine.

Based on the data and information reported to the IAEA, no specific event or location for the dispersal of radionuclides into the atmosphere has yet been determined. To do this, the IAEA depends on receiving such information from a country where the release occurred.

The IAEA stressed that the observed air concentrations of the particles were very low and posed no risk to human health and the environment.