Engineered barrier systems (EBS) in the safety case : design confirmation and demonstration; workshop proceedings Tokyo, Japan, 12-15 september 2006

TABLE OF CONTENTS Executive Summary .............................................................................................................. 3 Introduction ........................................................................................................................... 9 The NEA EBS Project ......................................................................................................... 9 Background to the Workshop on Design Confirmation and Demonstration ....................... 10 Report Structure................................................................................................................... 10 Workshop Objectives and Structure ................................................................................... 11 National and International Achievements and Ongoing Work on Design Confirmation and Demonstration for Engineered Barrier Systems: Summary of Presentations and Technical Discussions .............................................................................................................................. 13 Approaches and Methods for Demonstration and Confirmation of the Geological Repository Design Concept in the Japanese Programme.............................................. 13 Planning, Assessment and Construction of a Drift Seal in a Salt Repository: Overview of Investigations in the German Programme................................................................. 15 Performance Assessments for Design Reviews – Lessons from the US Programme ... 17 Practical Lessons Learnt on the Role of the Engineered Barrier System in a Total System Performance Assessment.................................................................................. 19 Design Confirmation and Demonstration for EBS: Current Developments in Several European National Programmes as Part of the FP6 Euratom ESDRED Project........... 20 The KBS-3 EBS Workshops: An Example of Regulator-implementer Pre-licensing Interaction in the Swedish Programme ......................................................................... 22 The EBS Demonstration Programme at SKB: Some Examples ................................... 23 The French Methodology for EBS Confirmation and Demonstration .......................... 25 Working Group Findings...................................................................................................... 29 Working Group A: Decision Making and Design Factors in the EBS Design Process 29 Working Group B: Confirmation and Demonstration of the EBS in the Context of Confidence Building ................................................................................................. 32 Workshop Conclusions and Recommendations ............................................................ 35 Conclusions ................................................................................................................... 35 Recommendations for Future Work.............................................................................. 37 References .............................................................................................................................. 39 8 Appendix A – Workshop Agenda ........................................................................................... 41 Appendix B – Papers Presented to the Workshop................................................................... 47 Appendix C – Membership of Working Groups ..................................................................... 139 Appendix D – List of Participants ........................................................................................... 143