Application of results from the Pocos de Caldas project in the Kristallin-I HLW performance assessment

The Pocos de Caldas project was a major international natural analogue study carried out at 2 sites in Brazil - the Osamu Utsumi uranium mine and Morro do Ferro, an extremely rich deposit of thorium and rare earth elements. This project was a collaborative venture between Nagra (Switzerland), SKB (Sweden), US DOE, UK DOE and Uranio do Brasil. From the initial planning stages, emphasis was placed on testing the models and databases used for repository performance assessment. Since completion of this project, Nagra has initiated a comprehensive performance assessment of HLW disposal in the crystalline basement of Northern Switzerland (termed Kristallin-I as it represents the end of the phase I (regional) studies of this potential host rock). Verification and validation of assessment models are important issues in Kristallin-I; one approach planned here is to utilize data from the wide range of Swiss natural analogue studies carried out to date. This paper considers the contributions from the Pocos de Caldas project to this goal