× This site uses cookies. By continuing to browse the site, you are agreeing to our use of cookies. Read more from here
Home  /  RESPONSIBILITY  /  Environment and climate  /  Cooperation with the authorities


The operation of a nuclear power plant is subject to a licenses and permits, and it is governed by the authorities. The Radiation and Nuclear Safety Authority (STUK) supervises nuclear and radiation safety.

The competent environmental permit authority is the Southern Finland Regional State Administrative Agency, and the supervising authority is the Southwest Finland Centre for Economic Development, Transport and the Environment. Other authorities involved in the management of environmental issues include the environmental department of the municipality of Eurajoki and the Ministry of Economic Affairs and Employment, which acts as TVO’s liaison authority in EIA procedures.

Radiation monitoring samples taken from the Olkiluoto environment are submitted to STUK for analysis. TVO annually prepares a report on the waste and emissions caused by its operations and submits the report to several regional and national authorities. TVO annually reports its environmental investments and environmental protection activity costs to Statistics Finland. After verification, TVO reports the annual carbon dioxide emissions of the emergency diesel generators and reserve boilers to the Energy Authority. Finnish Safety and Chemicals Agency (Tukes) acts as the supervising authority for the industrial processing and storage of hazardous chemicals.

Seven special events in 2017

The events occurring at a nuclear power plant are rated on the international INES scale according to their degree of severity. The INES scale has seven categories of severity. Category 4–7 events are rated as accidents, category 1–3 events as incidents or anomalies with a negative effect on safety, and category 0 events as deviations with no significance for safety. In Finland, the most severe events at nuclear power plants have been INES category 2 events.

In 2017, seven events occurred at the Olkiluoto plant that were rated on the INES scale. All events were rated on the international INES scale to level 0 (of no significance to nuclear or radiation safety). The events did not endanger nuclear safety at the plant units. TVO publishes all significant events that are of interest to the public in the News section of its website. One event caused environmental impacts. In October 2017, damaged fuel element was removed from the reactor at the OL1 plant unit. The fuel damage did not result in any risks to radiation safety: radiation doses and emission amounts remained below the regulatory emission limits.

Technical and human factors have been identified by TVO as causes of the latest events. The changes considered necessary on the basis of the assessments made are implemented for further development of the procedures. All abnormal conditions and transients are also reported separately for each event to STUK, if necessary.

All operational events taking place at the Olkiluoto nuclear power plant are processed and events taking place at other nuclear power plants around the world are also continuously  monitored. Necessary changes will be implemented based on the assessments to further develop the operation.

Permits govern the activities

In addition to legislation pertaining to nuclear energy and radiation safety, the operation is also regulated by the requirements laid down in environmental laws. The permit referred to in the Environmental protection Act is required for the operation of the Olkiluoto nuclear power plant, and the permit referred to in the Water Act for the intake of cooling water. The Regional State Administrative Agency for Southern Finland issued on 16 December 2016 a decision on the adjustment of the permit regulations of the environmental permit and on the adjustment of the permit regulations of the water permit granted to the Olkiluoto nuclear power plant. The decisions are not yet valid.

The permit regulations lay down the amount of the power plant’s cooling water and the amount of heat contained in it, and they also specify the target value for the temperature of the sea area, taking into account the thermal load. According to the adjustment decisions, the maximum quantity of cooling water is increased to 140 m3/s and 4,415 million m3/a. The increase is needed due to the energy efficiency investments implemented at the OL1 and OL2 plant units. The limit value specified for heat emissions remained unchanged. The permit regulations also apply to matters such as wastewater treatment efficiency, processing of waste, operations in transient and abnormal conditions, as well as monitoring and reporting. The Olkiluoto nuclear power plant landfill has its own environmental permit. The licences referred to in the Chemicals Act have been granted for the handling and storage of hazardous chemicals.

The reserve boilers of the Olkiluoto nuclear power plant, as well as the emergency diesel generators of OL1, OL2, and OL3 (a total of 15 generators), are included within the scope of the emissions trading system. Pursuant to the Finnish Emissions Trading Act, TVO submits an annual verified emissions report and the verifier’s statement to the emissions trading authority.

Compliance with environmental legislation

TVO continuously monitors statutory regulations and other requirements pertaining to its operations. People in charge of different parts of the operations are in charge of ensuring that the organizations receive enough up-to-date information about statutory regulations and their impact on TVO’s operations. Compliance with the regulations and requirements is regularly assessed in internal and external audits as well as management reviews.