Environmental impacts during construction

Our objective is that the construction of the nuclear power plant would interfere as little as possible with the nature around the construction site area.

The construction period, which is approximately ten years, will have a significant impact on the environment. The site area in the Hanhikivi headland is a greenfield site – a natural state area, which has become an industrial site.

Landscape and land use

The power plant will be placed in a visible area at the tip of a headland reaching out into the open sea, and it changes the landscape significantly.

The beginning of the groundwork has already changed the land use in the area of the Hanhikivi headland. The plant site area has been fenced, and the access routes in the area have changed. A decree on restrictions of movement and presence on the Hanhikivi 1 plant site entered into force in November 2015.

Instead, land use on the north and north-east coasts that are significant ecologically remains largely unchanged. Access to a protected Hanhikivi boundary stone is not possible at the moment.

The most significant impacts of the project on the recreation use are connected with fishing and hunting.

Hanhikivi 1 construction site.

Water system and fishing

The construction of the nuclear power plant has local impacts on the water systems and fishery in the area. The coastline around the Hanhikivi headland is open and there are not many species of aquatic vegetation. The fish species typically found in the area are those typically found in the whole of the Bay of Bothnia.

Water construction work started with dredging work in November 2015 and continued in September 2016. The construction activities in the sea area cause temporary turbidity of the seawater in a small area, but it doesn't have a significant impact on the water quality. The impacts of turbidity are controlled with continuous measuring. The turbidity of the seawater off the coast of the Hanhikivi headland also naturally increases during storms or periods of heavy rainfall.

Fishing in the immediate vicinity of the water construction area and in the immediate vicinity is not possible during the water construction work. The construction activities in the sea area can also drive away fish from a larger area and temporarily influence the migration routes of fish. Excavation, in particular, causes underwater noise that may drive away fish from the area. The construction activities in the sea area destroy some whitefish and herring spawning areas in the dredging areas. The sea in front of Hanhikivi headland is significant both in terms of the fish stock and in terms of fishery, and there are professional fishermen whose livelihood the project will affect negatively.

In 2016, fishery and fishing industry monitoring were conducted as required in the water permits. The purpose of the monitoring is to assess the impacts that the water construction works cause to fishery. The monitoring included a survey of professional fishermen, fry production surveys of whitefish, vendace and herring, and experimental net fishing.

Fish monitoring. 

Sea water quality monitoring

Fennovoima continued sea water quality monitoring at the sea area. The water samples are taken five times in a year at six monitoring points located around the Hanhikivi headland.

Based on obligations in water permits, turbidity monitoring began again on August 10, 2016 before the dredging work was commenced. Turbidity monitoring continued until November 16, 2016. Turbidity was monitored at six monitoring points, of which two were located in the marine spoil area approximately 10 km from the Hanhikivi headland and four were near the Hanhikivi headland.

In connection with the dredging work conducted by a sub-supplier, there were four oil spills at the coast of the Hanhikivi Headland in September and October 2016.

  • September 6 - gear oil spilled after a propulsion unit hit an underwater obstacle (300 liters)
  • September 16 - hydraulic oil spilled after a mechanical failure in a barge hopper’s hydraulic system (50 liters)
  • September 22 - gear oil spilled from the propulsion unit after the vessel grounded (30 litres)
  • October 6 - gear oil spilled after propulsion unit hit an underwater obstacle (105 liters)

Based on the dilution and harmfulness of the substance in question, the oil spills did not cause any permanent damage to the environment. No oil was found on the shoreline of the Hanhikivi headland, which indicates that no harm was caused to the nearby flora and fauna. Fennovoima suspended the dredging work until a detailed report about the accident was received, and the required corrective measures and practices were taken.

Prior to the commencement of the dredging work in spring 2017, more emphasis is placed on the proactive prevention measures of all environmental accidents. Fennovoima, the plant supplier RAOS Project Oy, the main contractor Titan-2 and the dredging company have established a steering group for the dredging work. The thorough analysis of the accidents has resulted in improved prevention of environmental accidents and preparedness to act in similar situations. The oil spill response plan for the construction site was prepared together with the plant supplier, and it has been communicated to the authorities. All contractors at the plant site are obliged to follow the oil spill response plan.

Dredging work at the sea area in front of Hanhikivi headland in fall 2016.

Flora, fauna and protected areas

The direct impacts of the project during the construction phase affect the area in which the buildings and structures of the nuclear power plant and various related functions are built. The main part of the construction efforts will take place in an area of about 1 km2 in the central part of the Hanhikivi headland.

As a result of the construction, the forest and coastal areas will change partially into built environment, and the species and habitat types found in the immediate environment of the built areas may change over the short or the long term. Construction work has also resulted in the fragmentation of continuous shore and forest areas. During the construction phase, the indirect impact of the noise and dust from the construction site and the related traffic, and the vibration from blasts and excavation, will affect the surrounding nature.

The Hanhikivi headland’s nature conservation areas and areas defined as habitat types protected under the Nature Conservation Act remain outside the constructed areas, and construction work will not have any significant adverse impacts on these areas.

Construction workers are instructed and trained to avoid moving in the areas outside the site fence.

More information about protected areas can be found in the Nature conservation section.

Yellow iris (Iris pseudacorus).

Air quality

Dust and emissions from traffic affect the air quality. The impacts are, however, local and are estimated to have no major impacts on the protected areas in the Hanhikivi headland.

The earthwork, traffic at the site, and certain operations, such as rock crushing, will generate dust during the construction of the nuclear power plant. Most dust sources will be located at low elevation levels, so the dust cannot spread far and its impact on air quality will mainly be limited to the construction site.

The impacts of traffic emissions are very local, and their impacts on the air quality will depend, in addition to the emission volumes, on the traffic routes used.

The residential areas by these roads are mostly located at distances from the road where the increase in the contaminant concentrations will have no significance. The residential building closest to the new road in the Hanhikivi headland is located approximately 300 meters from the road, while the rest of the residential buildings are located at the distance of some 0.5–1 kilometers.

To decrease emissions from traffic, Fennovoima has paved the access road that connects the plant site to highway 8 with asphalt and set a speed limit of 30 km/h for the construction area and 40 km/h for the road that leads to Fennovoima’s plant site office. Generation of road dust at the plant site is also decreased by irrigation.


Dust monitoring was started in 2015 and continued in 2016. Fennovoima has conducted dust monitoring especially near the nature conservation areas. No increase in the dust levels have been detected since the beginning of the monitoring.

No increase in the dust levels


According to noise modelling, the noise caused by the project will remain below the guideline values set for residential areas and areas including holiday residences, both during construction and the operation of the plant. The noise levels may vary greatly depending on the on-going construction phase. The area influenced by noise during construction and operation will be less than one kilometer from the power plant site.

During the heaviest construction phase, the traffic noise from the road leading to the Hanhikivi headland will spread to fairly narrow zones, and there are no residences within the areas affected. The impact of noise on nesting or bird populations is not likely to be significant.


Average noise levels at different measuring points have been 30-65 dB during 2016 (same level as 2015). The noise level has varied according to the location of the measuring point and the time of day (day versus night time). The individual peaks in the noise level are usually explained by the weather conditions such as strong wind or heavy rain.

Average noise levels at different measuring points between 30-65 dB 

More information on the assessment on environmental impacts during the construction can be found in Fennovoima's Environmental Impact Assessments that are available on our website:  www.fennovoima.fi/en/publications