Selective extractions in uranium migration studies—findings from a natural analogue study at Palmottu, southern Finland

The usefulness of chemical extractions in the study of uranium migration through fractured rock is considered in the light of the results of a natural analogue study conducted at Palmottu in southern Finland. Chemical extractions provide a method for producing information of the mass transfer of U and its fixation in geochemical cycling. The present detailed study provides more specific information on the fixation of U on silicate material and its sorption in rock pores. The many observations made at the Palmottu study site show the potential of the method for filling the gap in interpretations between the natural partitioning of U as a results of water-rock interaction and the distribution of artificial tracers determined by the short-term laboratory experiments.