The dose rate of external radiation is measured by an automatic external-dose rate-monitoring network maintained by STUK and local rescue services. The network comprises about 260 stations. Measurement data is stored in the national data system. There they are available for several authorities almost in real time. The daily measurement data of automatic stations are displayed on these www pages. The automatic network receives measurement data also from other Nordic countries and from more than 20 stations in the environs of the Leningrad nuclear power plant. The rescue services and the Defence Forces have more than 100 stations where external radiation is monitored locally. Authorities have thousands of portable meters too. They are important as supplements to the automatic network. They are used for verifying the results of the automatic network as well. In Finland, external radiation varies from 0.05 to 0.30 microsieverts per hour (µSv/h). During the Chernobyl accident in 1986, the highest momentary dose rate measured in Finland was 5 µSv/h. It is necessary to shelter indoors if the external dose rate exceeds 100 µSv/h. |
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