Distribution of uranium and radium in groundwater and rock in the Forsmark area
Understanding the interaction of U, metals and related radioactive tracers with mineral phases from bedrock fracture fillings in water-conducting fracture systems is crucial for safety analysis of low- and intermediate radioactive waste depositories. The distribution of U in groundwaters from the Forsmark area in east central Sweden has been the focus of much discussion. Possible sources for U, as well as other metals, include U mineralisation along the bedrock fractures. Understanding of U behaviour in itself is important, but can be used to constrain the behaviour of associated metals as well.
Through laboratory and field studies, the groundwater/mineral interactions in crystalline carbonate minerals, amorphous minerals, and colloidal particles will be studied to understand possible mechanisms and time scales for retention and transport of metals and U. U-series nuclides, including Ra, will be used to obtain age information of the U phases and determine transport rates that will be applied to metal transport in these aquifers. SKB will provide access to sites and provide background information.