NAGRA Opalinus Clay (…002 - Version 1
FEP 9.3.2 Flow and advective transport through backfill and liner

Transport through the backfill and liner may be influenced by advection. Preferential flowpaths through the backfill may arise either (i), due to built-in heterogeneity (e.g. relatively permeable backfill between much less permeable waste containers), or (ii), due to uneven near-field degradation (e.g. cracking of backfill/liner). Preferential flowpaths through the liner may arise from cracking of this material. However, the low hydraulic conductivity of the host rock is expected to prevent significant advective flow.