Summary record of the topical session of 13. Meeting of the IGSC

Aims of the topical session were to gain understanding of the strategies (e.g. in terms of R and D, feasibility, optimization) put in place in national programs to address the issues and in particular the irreducible uncertainties associated to gas. Therefore, information on work in national programs was gathered by addressing the following key questions: 1. What are the regulatory requirements and what are their impacts? 2. What is the relevance of the gases for the long-term safety? 3. How are gases and the related uncertainties considered in the latest SA? 4. What are the remaining process uncertainties? 5. What is the strategy that has been put in place to treat the remaining issues? 6. Where do the organizations see potential to lower conservatism in the description of the gas pathway? 7. What multiple lines of arguments do you use to address the issue of gases in the safety case? 8. What are the strategic choices for the future? Presentations from eight countries addressing the issue for the three main host formations clay, granite and rock salt as well as a presentation about the on-going EC project FORGE were given. The major discussion topics and conclusions of the session are summarized in the this document