Fig. 5

The possible evolution of a potential high-level waste repository in the Opalinus Clay based on the Swiss disposal concept. Indicated in green are the human engineering activities starting with the construction of a repository until its sealing at the end (the time periods are best estimates and may differ considerably, depending on future decisions by the implementer, safety organisation, and authorities). The expected processes during the lifespan of a repository are given in orange (disequilibrium) grading to yellow (equilibrium), starting with the formation of the excavation damaged zone (EDZ) and ending with the release of radionuclides from breached canisters. Thermo-hydraulic-mechanical and chemical equilibrium is assumed to occur after 10,000 years (see red line)