Air Injection Laboratory Experiments on Opalinus Clay. Experimental techniques, Results and Analyses

Understanding gas transport processes is one of the key issues in the assessment of radioactive waste repository performance and is the focus of this research. If the gas production rate (generated by the anaerobic corrosion of the ferrous metal and microbial degradation of organic material) exceeds the rate of diffusion of gas in the host rock pore-water, a free gas phase will develop, pressure will increase and gas will migrate through the engineered barrier system (EBS) and into the surrounding host rock. The actual gas migration mechanisms may entail standard two-phase flow or more complex mechanisms involving coupled two-phase geomechanical and possibly geochemical phenomena.