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 2017-13



Studies on the Aquatic Environment at Olkiluoto and Reference Area: 6. Poosjoki River in 2014-2015


Haavisto, F., Toivola, M.



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This working report presents the results of a sampling campaign carried out in 2014-2015 at the reference river Poosjoki selected in the biosphere modelling to represent river systems expected to form at Olkiluoto Island in the future with the post-glacial crustal rebound (land uplift). The aim of the studies was to improve the knowledge of the river systems in the reference area and to produce input data for the safety case for the spent nuclear fuel repository at Olkiluoto.

The first main objective of the studies in Poosjoki River was to produce estimates on the areal biomass distribution, and on the dimensions of the characteristic river macrophytes and fauna. Another objective was to estimate the transfer of different elements from soil and water to river fauna and flora. Study concentrated on the key elements (C-14, Cl, I, Sr, Mo, Ag, Se, Nb, Cs, Ni, Pd, Pb and Sn) considered as analogues for their long-lived radioisotopes in the safety case modelling, and owing major importance for the safety case for spent nuclear fuel.

During the two-year research, samples were collected on surface water, soil and sediment, plankton, periphyton, terrestrial and aquatic macrophytes, fish and macrobenthic fauna for the biomass and dimension measurements, and for the analysis of element concentrations. To estimate transfer of the elements in the ecosystem, soil-to-biota and water-to-biota concentration ratios as well as element distribution coefficients (Kd) for the soil and sediment were calculated.

Among the studies on the aquatic environment, this sampling campaign in Poosjoki River in 2014-2015 is the first one carried out on the rivers of reference area, and the results presented comprise new information on the river ecosystems for the safety case for the nuclear fuel repository at Olkiluoto.


Water depth, water quality, plankton, surface sediments, macrophytes, fish, macrobenthos, biomass, dimensions, element concentration, concentration ratios, distribution coefficient (Kd)


WR 2017-13_web (pdf) (6.5 MB)


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