Posiva publishes Working Reports and Posiva Reports. From the year 2006 nearly all the reports have been published on our webpage and they can be found in the databank. In the databank you can also find our Annual Reviews and some other publications as well. You can also find print-quality pictures and useful links in the databank.

Recent publications

Workreport 2018-45



Results of Monitoring at Olkiluoto in 2017 - Environment


Sojakka, T., Weckman, K., Lipping, T., Haavisto, F., Rinne, A.



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In 2003, Posiva Oy presented a programme for monitoring at Olkiluoto during construction and operation of ONKALO (Posiva 2003b). In 2012 the monitoring programme was updated to concern the years 2012–2018 (Posiva 2013a). In 2016 the monitoring programme was updated again to concern years 2017-2019 (POS-023624). The need to the update the programme came from the timing of the data-lock in safety case for operating license application. The surface environment monitoring programme has been producing initial data for the biosphere modelling. Because the data-lock for the biosphere modelling for safety case was set in the end of 2016, could the production of data needed in the biosphere modelling be ceased by the end of 2016. The current surface environment monitoring programme is focusing on the traditional environmental impacts of contruction and operation works of the final disposal project. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). This Working Report presents the main results of Posiva’s environmental monitoring programme on Olkiluoto Island in 2017. Results are presented under three topics: 1. Interaction between surface environment and groundwater in bedrock, 2. Environmental impact and 3. Baseline of monitoring of radioactive releases.

Interaction between surface environment and groundwater in bedrock included e.g. weather and surface water monitoring data. During 2017 the land use of Olkiluoto was monitored by taking aerial photographies of the area. From the aerial images the increase of industrial areas and growth of new forest on shore-area can be observed.  In the monitoring of surface runoff no events deviating from previous years were observed. The sulphate level in the ditch running south of ONKALO-site remains clearly higher than in other monitored ditches.

Environmental impact monitoring included e.g. monitoring of noise, effluent waters, nearby freshwater systems and private drilled wells. Noise monitoring in the vicinity of ONKALO showed that in the case of raised noise levels the main source is the traffic on the Olkiluodontie road. In the monitoring of the outlet waters of ONKALO the action limit set for pH (9.5) was not exceeded in 2017 and the action limit set for suspended solids (50 mg/l) in the rock piling area drainage waters was not exceeded either. During 2017 the nitrate levels in the outlet ditch remained higher compared to background levels. The origin of the nitrate is the explosives used in underground mining work. The sulphate levels of outlet waters remains in the same level than in previous year. High suspended solid value were observed occasionally in the sedimentation pool but not in the outlet waters. The water quality of the monitored private wells is poor or good depended on the well in case. Water quality is affected by the natural properties of the area. Water levels and water qualities of the drilled wells are not affected by the construction of ONKALO.

In 2017, Posiva’s environmental radioactivity baseline study had not yet been started, but the results of radiological monitoring of the environment of TVO’s nuclear facilities are presented in Chapter 5 as background information for Posiva's study.


Environmental monitoring, ecosystem, baseline condition, change


WR 2018-45_web (pdf) (14.4 MB)


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