Southern Urals probable source region of ruthenium-106 detected in Europe

Air dust collector at the BfS monitoring station Schauinsland

The reason for the slight increase in readings of radioactive ruthenium-106 recently detected remains unclear. Most probably, the increase originates from the southern Urals, as suggested by calculations of the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS). However, other regions in the South of Russia must still be considered. An accident at a nuclear power plant can be ruled out as a possible cause, since solely ruthenium-106 has been detected. The concentrations of radioactivity in Germany are very low and do therefore pose no hazard to public health.

Considering that Russia must be assumed to be the region of origin of radioactive release, the Federal Minister for Environment, Nature Conservation, Building and Nuclear Safety (Bundesumweltministerium, BMUB) expects responsible Russian authorities, and IAEA, to provide robust information as soon as possible in order to help clarify the causes of the increased ruthenium readings.

Ruthenium-106 (Ru-106) is used as a radiation source for cancer therapy, among others. At times, ruthenium-106 is also used in so-called "Radioisotope thermoelectric generators" (RTG) to power satellites. In addition, ruthenium may occur during reprocessing of nuclear waste.

Trace measurements of Ruthenium-106 in Germany and Europe

Slightly elevated levels of ruthenium in the atmosphere have been detected at several trace monitoring stations in Europe since 29.09.2017, among others at six stations of Germany's National Meteorological Service (Deutscher Wetterdienst, DWD) and at several European stations such as in Austria and Italy. Recalculating the atmospheric dispersion of radioactive material allows to narrow down the areas where the release might have occurred. According to estimates, the radioactive material has been released during the last week of September.

The values measured in Europe are very low levels of radioactivity not hazardous to health. For example, the highest concentration of ruthenium measured in Görlitz amounts to about 5 Millibecquerels per cubic metre of air. Assuming constant inhalation of this activity concentration for the period of one week would result in a dose being lower than the dose within one hour due to the natural radiation background. The measurements at the other stations (Arkona/Rügen, Greifswald, Angermünde, Cottbus, and Fürstenzell/Bavaria) are even lower.

BfS is continuing to analyse all available measurements of radioactive substances in the atmosphere.