Significant quantities of gases may be generated after closure of a deep geological repository, primarily due to anoxic corrosion of metals and degradation of organic materials. Large quantities of steel in both the waste packages and engineered barriers mean that hydrogen is expected to constitute a major fraction of the total gas inventory. Its accumulation in a discrete gas phase could influence the hydraulic and mechanical evolution of the repository. This, in turn, may have implications for repository performance, e.g., the geochemical evolution of the emplaced waste and barriers, the mechanical integrity of the host rock, and the performance of seals with respect to gas and liquid transport. As such, understanding the production and fate of hydrogen under repository conditions is an essential aspect of repository performance assessments.
Brown et al. (Thu,) studied this question.