Radiation safety

Limiting the doses and keeping the level of radioactive emissions as low as possible are already taken into account when designing the structures and functions. All employees must take radiation protection into account in their own work. Radiation protection operations are developed based on authority guidelines as well as international recommendations.

The radiation doses of everyone working in the controlled area of the nuclear power plant are monitored and measured using dosimeters. According to Section 13 of the Government Decree on Ionizing Radiation (Valtioneuvoston asetus ionisoivasta säteilystä, 1044/2018), the effective dose of a radiation worker must not exceed 20 millisieverts per year. TVO’s own targets regarding individual annual doses are keeping the dose obtained by all Olkiluoto employees from their work below 10 mSv per year and keeping doses caused by internal contamination below 0.5 mSv. These targets have been reached.

Environmental radiation exposure under extensive monitoring

Environmental radiation safety is at the Olkiluoto nuclear power plant monitored on a regular basis with many different methods and through the cooperation of several parties. TVO has set up four continuous radiation dose rate measurement points in the plant area and ten in the surrounding region. These automatically report their results as well as any alarms to both the Olkiluoto plant units and the Radiation and Nuclear Safety Authority (STUK). TVO has installed four air samplers and eleven dosimeters in the immediate vicinity of Olkiluoto. The sampler filters are analyzed for radioactivity every 1–4 weeks. The dosimeters are read four times a year. In addition to these, TVO carries out extensive measurements in the plant area twice a year, and uses portable measurement equipment to perform work-specific radiation monitoring when necessary.

The people living in the environment of the nuclear power plant are once a year measured in Olkiluoto in STUK's mobile full-body scanner unit. TVO reports the results of radiation safety monitoring carried out in the plant environment to environmental and radiation safety authorities.

In measurements conducted by STUK on the local residents, no radioactive nuclides originating from the plant were detected. The measurements of the internal exposure of the plant's radiation workers did not exceed the recording limit either.