The radioactive substances detected by STUK in Helsinki and Kotka have no effect on the outdoor radiation situation
The Radiation and Nuclear Safety Authority (STUK) detected in an air sample collected in Helsinki on 16-17 June small amounts of radioactive isotopes of cobalt, ruthenium and cesium (Co-60, Ru-103, Cs-134 and Cs-137). The same radioactive substances were detected also in Kotka in a sample collected from 15 to 22 June. In addition, radioactive isotopes of zirconium and niobium (Zr-95, Nb-95) were also detected in the Kotka sample.
The radioactive particles in the air have had no effect on the radiation situation. STUK measures the radiation situation at 260 automatic measuring stations, and the measurement results of the stations can be viewed in real time on STUK's website. The radiation situation has been normal.
The composition of the detected radioactive substances suggests that they are derived from the nuclear reactor fuel. Due to the very low concentrations observed, the substances may be coming from normal operation or maintenance of nuclear reactors.
STUK has been in contact with domestic nuclear power plants. They have not detected substances detected by STUK in their own emission monitoring. It is therefore unlikely that the radioactive substances detected would be of domestic origin.
STUK monitors the concentrations of radioactive substances in the outdoor air in eight locations in Finland. Measurements at the Helsinki measuring station are always made on samples collected during 24 hour period. At other stations, measurements are made on samples collected over a week. Further information on the monitoring of outdoor radioactive substances and the measurement results of outdoor radioactive substances can be found on STUK's website.
Aleksi Mattila, Head of Laboratory +358 9 759 88 437
Media Services, tel. +358 10 850 4761