Modelling Bisulfide Transport through the Engineered Barrier System under Repository Conditions:

However, in the crystalline domain, the saturation times are insensitive to rock permeability since the rock permeability is higher than the bentonite permeability, making the bentonite the governing layer. [...] The heat evolved from the used fuel will dry the bentonite, and subsequent water infiltration from the host rock will saturate the bentonite once the temperature decreases (King et al. [...] The prediction for the duration of the oxic period is dependent on the processes that occur in the repository. [...] Unlike the crystalline domain, MIC rates in TC and THC models are different (Figure 20e) as saturation of the domain in the THC model delays the onset of bisulfide diffusion as it transports through the water filled fraction of the pore space; however, the peak MIC rates are similar (Figure 20e). [...] Therefore, the similarity in bisulfide evolution in the analytical and numerical models further confirms that the numerical approximation used in the DGR models is appropriate and the model is properly developed.