STUK supervises STUK supervises

STUK supervises

STUK supervises

Monitoring of environmental radiation in nuclear power plants

Monitoring of environmental radiation in nuclear power plants

Environmental studies of Finnish nuclear power plants started already before the plants were commissioned with surveys of the underlying conditions in the area, and now a diverse and comprehensive environmental radiation surveillance is carried out in the surroundings of nuclear power plants.

Radioactivity in the surroundings of nuclear power plants is monitored by STUK and the licensees, i.e. nuclear power companies. STUK Guide YVL C.7 sets forth the detailed requirements for the licensee concerning the monitoring of environmental radiation in the surroundings of nuclear facilities. The licensee must prepare a programme for the monitoring of environmental radiation in the surroundings of the nuclear facility and report the results to STUK. According to STUK Guide YVL C.7, STUK carries out monitoring of environmental radiation in the surroundings of the nuclear facility during use independently from the licensee by taking and analysing environmental samples from the surroundings of the nuclear facility.

In its regulatory control programme, STUK analyses approximately 300 samples taken from the land and sea environment of the Loviisa and Olkiluoto plants annually. Similar sample types are collected from the surroundings of both of the nuclear power plants, while paying attention to the local conditions. The sampling sites and sample types have been selected so that they reflect the environment surrounding the facilities to the greatest extent possible. Samples are taken from an area that covers several kilometres around the facility. Release routes of radionuclides, the spread of emissions to the environment, lifestyles of local people and location of residential areas are considered when selecting the sampling points. The radionuclide concentrations in the samples are compared with samples taken elsewhere in Finland as well as with the observations made in previous years.

Taking samples from marine environment near Olkiluoto nuclear power plant.

In the terrestrial environment, samples are taken from the soil, reindeer lichen, haircap moss, needles, ferns, mushrooms, plant milk, pasture grass, grains, root vegetables, household water, groundwater and sludges. Marine environment samples are used to monitor the spread of power plant emissions in the marine environment and the accumulation of emissions in plants and animals. In the marine environment, samples are taken from the sea water, periphyton, bladder wrack, elodeids, aquatic plants, benthic macroinvertebrates, fish, fish fry, bottom sediments and sedimenting material. Furthermore, radioactive substances in outdoor air and radioactive substance concentrations in people living near the power plant are regularly monitored. The environmental samples are analysed at STUK’s laboratory. Methods of analysis include gamma spectrometry and radiochemical analyses.

STUK publishes an annual report on the results of environmental monitoring of nuclear power plants. Some samples include small amounts of radioactive substances that originate from the power plants. However, the amounts are so minimal that they do not have an impact on the radiation exposure of the environment or humans.