Modelling large-scale laboratory HTO and strontium diffusion experiments in Mont Terri and Bure clay rocks

摘要: Abstract Clay formations are adequate host rocks for high-level radioactive waste repositories. Since in clay materials diffusion is the main radionuclide transport mechanism, determination of coefficients under conditions as realistic possible fundamental performance assessment deep geological Recently, design large-scale laboratory experiments large cylindrical blocks that allows determining experimental profiles 3D was developed [Garcia-Gutierrez, M., Cormenzana, J.L., Missana, T., Mingarro, Martin, P.L., 2006. Large-scale rocks. Physics and Chemistry Earth 31, 523–530]. In present work, we will focus on modelling several new carried out with this novel set-up. These were performed Opalinus (OPA) samples from Mont Terri (Switzerland) Callovo-Oxfordian (COx) Bure (France), using both neutral (HTO) weakly sorbing cationic (85Sr) tracers. these experiments, bedding roughly parallel to cylinder bases, allowed following a approach, which represented significant improvement respect previous experiments. After period, 24 small cylinders drilled each sample at different distances axis. Then they sliced tracer activity slice measured obtain vertical concentration profiles. compared those calculated values sensitivity studies out. Both numerical graphical comparisons done order establish range better adjusted results. Estimations Dp perpendicular planes obtained HTO OPA COx clays. Only Da could be estimated 85Sr It interesting noticing quite similar.