Methods for Safety Assessment of Geological Disposal Facilities for Radioactive Waste : Outcomes of the NEA MeSA Initiative

Foreword......Page 5 Acknowledgements......Page 6 Table of contents......Page 7 Safety assessment and safety case flowcharts......Page 11 System description and scenarios......Page 12 Modelling strategy......Page 13 Treatment of uncertainties......Page 14 Regulatory issues......Page 15 1. Introduction......Page 19 2. Overall regulatory perspective......Page 21 3.1 Definitions......Page 23 3.2 The safety case as context for safety assessment......Page 24 3.3 Scope of safety assessment......Page 25 3.6 Evolution of the safety assessment and the safety case over time......Page 26 3.8 Safety assessment results and communication......Page 27 3.9 Regulatory perspective......Page 28 4.1 Development of assessment strategy flowcharts......Page 29 4.2 Generic assessment strategy flowchart......Page 30 4.3 Regulatory perspective......Page 34 5.2 System description: initial state and evolution......Page 35 5.3 Derivation of scenarios......Page 37 5.4 Structuring scientific knowledge and identifying safety-relevant phenomena and uncertainties......Page 38 5.5 Scenario probabilities......Page 39 5.6 Regulatory perspective......Page 41 6.2 Process-level models......Page 45 6.3 Integrated or system-level modelling......Page 46 6.5 Data gathering and management......Page 48 6.6 Model qualification......Page 49 6.7 Regulatory perspective......Page 50 7.2 Classification of indicators......Page 53 7.3 Safety indicators......Page 54 7.5 Safety function indicators......Page 55 7.6 Reference values......Page 56 7.8 Transferability......Page 57 7.9 Regulatory perspective......Page 58 8.1 Classification of uncertainty......Page 61 8.2 Strategies for treating uncertainty......Page 62 8.4 Regulatory perspectives......Page 63 9. Conclusions and recommendations......Page 65 10. References......Page 67 11.1 Introduction and definitions......Page 71 11.2 The safety case as context for safety assessment......Page 73 11.3 The scope and basis of safety assessment......Page 77 11.4 The safety assessment and safety case in repository development......Page 79 11.5 Interpretation and presentation of safety assessment results......Page 82 11.6 Conclusions......Page 83 11.7 References......Page 84 Abstract......Page 87 12.2 Methodology......Page 88 12.3 Conclusions......Page 103 12.4 References......Page 104 13.1 Introduction......Page 117 13.2 History and recent developments......Page 118 13.3 Place and purpose of system description and scenario development in the safety strategy and safety case......Page 122 13.4 System description: Initial state and evolution......Page 125 13.5 Derivation of scenarios......Page 131 13.6 The regulator’s perspective......Page 143 13.7 Conclusions......Page 145 13.8 References......Page 147 14.1 Introduction......Page 151 14.2 Methodology......Page 152 14.3 Types of models and modelling strategy......Page 153 14.4 Process-level modelling......Page 155 14.5 Integrated or system-level modelling......Page 156 14.6 Advances in tools......Page 158 14.7 Data selection......Page 160 14.8 Model qualification......Page 162 14.9 Conclusions......Page 164 14.10 References......Page 165 Abstract......Page 167 15.2 Methodology......Page 168 15.3 Conclusions......Page 187 15.4 References......Page 188 16.1 Introduction......Page 197 16.2 Sources and classification of uncertainties......Page 201 16.4 Description and quantification of uncertainties......Page 204 16.5 Impacts of uncertainties......Page 207 16.6 Mathematical techniques......Page 210 16.7 Conclusions......Page 212 16.8 References......Page 214 17.1 Introduction......Page 223 17.3 Safety concept......Page 225 17.4 Assessment strategy......Page 226 17.5 Indicators and criteria......Page 229 17.6 System description......Page 231 17.7 System evolution and scenarios......Page 232 17.8 Modelling strategy......Page 236 17.10 References......Page 238