NWMO-TMP-AD-0007-R004 – Technical Report

This confidence is built on our understanding of the following aspects: • the characteristics of the geological setting that provide containment and isolation; • the long-term stability of the geological setting; • the low risk of future human intrusion into the repository; • the site is amenable to characterization; • the robustness of the multiple barrier system; • the repository can be construc. [...] The mineralogy of the rock, and the geochemical composition of the groundwater and rock porewater at repository depth should not adversely impact the expected performance of the repository multiple-barrier system. [...] Importantly, the continuity of the sedimentary formations across southern Ontario in general, and in particular those of Ordovician age, provide a strong basis for the hypothesis that the favourable geoscientific properties of the sedimentary rocks beneath the area, including under the Bruce nuclear site, are transferable to the sedimentary formations underlying the South Bruce Site. [...] Figure 3.4: Location of the South Bruce potential repository site 17 3.4 Composition of Rock, Groundwater and Porewater The mineralogy of the rock, and the geochemical composition of the groundwater and porewater at repository depth should be such that they: • do not compromise the integrity of the multi-barrier system; and • promote the retardation of radionuclide movement. [...] Overall, the results to date indicate the favourable nature of the mineralogy of the rock, and the geochemical composition of the groundwater and porewater at repository depth, for the South Bruce Site.