Geochemical far-field processes in performance assessments for underground radioactive waste repositories

摘要

The release and transport of radionuclides from underground repositories into the biosphere is controlled by geological and technical barriers. As part of this barrier system geological formations play a decisive role with respect to the long-term safety of repositories. Various geochemical processes can cause a significant reduction of the contaminant concentration on its way through the geological formations in the far-field of a repository. This paper ties an overview of recent work concerning the modelling of nonlinear sorption processes and colloid facilitated contaminant transport and shows the influence of these geochemical processes in the performance assessment.