Real system analyses/natural analogues

This paper gives an overview of the behaviour of U in two natural systems, the Forsmark site (a granitic system) in Sweden and the Ruprechtov site (a Tertiary sedimentary system) in the Czech Republic, which have been investigated in the frame of the FUNMIG project. It is not a full review paper on U geochemistry. It shows how different approaches and methods have been used to derive information on U solubility and speciation, on characteristics of key processes as well as on timescales of these processes and accordingly information on the long-term stability of U phases in the natural systems. The results are set in a wider context by relation to selected results from other sites.