Results of Monitoring at Olkiluoto in 2006 - Environment (pdf) - Posiva

12Roivainen (2006) studied the distribution of some radionuclides (K-40, Cs-137, Cs-134and Be-7) and stable elements (K, P, Ca and Cu) in three shoreline alder forests ofOlkiluoto. Samples were collected from vegetation and small mammals. Be-7 wasfound in litter and understorey samples only. It was found that the behaviour of theelements did not differ from what is generally known from their behaviour in forests.Clear differences were found between the monitoring plots in the distribution of theelements on the basis of concentration ratios.3.2.2 Terrestrial SystemsSoil Inventory by FEH PlotsThe FEH plots (Fig. 6), which were inventoried for their vegetation types and coveragesin 2005 (Huhta & Korpela 2006), were also inventoried for their humus, mineralsoil (0–60 cm) and peat (0–30 cm) properties. Samples were taken for further analysesand the results reported by Tamminen et al. (2007). According to the survey, the mostcommon soil types at Olkiluoto are weakly developed (often podzolised) coarse to medium-coarseArenosols or fine-textured Regosols, shallow Leptosols and Gleysols characterisedby shallow groundwater. In general, the groundwater in FEH plots lay withinthe depth of 0 to 40 cm on 15 plots, and 24 sample pits out of the 85 mineral soil oneswere under 50 cm deep due to bedrock, big boulders or groundwater. Organic layer wasclassified in most cases as mor, peat or mull-like peat. The thickness of the organiclayer varied from 2.3 to 21.1 cm and in the peatland from 6 to 115 cm. The mediumparticle size class in mineral soils was very fine sand.Figure 6. Original FEH sample plots (Huhta & Korpela 2006) and land-use situationin summer 2006.