Geology of High-Level Nuclear Waste Disposal : An Introduction

An introduction to high-level nuclear waste and the concept of geological disposal 1.1 Classification of nuclear waste 1.2 Origin of class I and II wastes 1.3 Amounts of waste involved 1.4 The nature of HL Wand SURF 1.5 The need for containment 1.6 The concept of geological disposal of radioactive wastes 1.7 Criteria for a HL W geological repository 1.8 Non-geological methods of HL W disposal 1.9 Conclusions 2 The suitability of evaporites as HL W repositories 2.1 Introduction 2.2 Mineralogy and variability of evaporites 2.3 Physical properties of evaporites 2.4 Fluid inclusions in evaporites 2.5 Hydrogeology of evaporites 2.6 The rate of movement of salt diapirs 2.7 The effects of radiation on salt 2.8 Conclusions with respect to evaporites 1 1 2 9 30 3 The suitability of crystalline rocks as HL W repositories 3.1 Introduction 3.2 Mineralogy of granitic rocks 3.3 Physical and chemical properties of granites 3.4 The hydrogeology of granites 3.5 Effects of radiation on crystalline rock 3.6 Basalts 3.7 Tuffaceous rocks 3.8 Conclusions with respect to granitic and other crystalline rocks 4 The suitability of argillaceous rocks as HL W repositories 4.1 Introduction 4.2 Origin and composition of argillaceous rocks 71 75 vi Contents 4.3 The effect of heat on argillaceous rocks 84 4.4 The hydrogeology of clays 86 4.5 The ability of clays to retard the passage of 87 radionuclides 4.6 Conclusions with respect to argillaceous rocks 93 5 The containment of radionuclides within repositories 94 5.1 The major physicochemical processes involved in 94 radio nuclide retardation 5.2 The study of natural analogues 95 5.3 Stabilizing waste forms 98 5.4 The waste canister 100 5.5 Buffer and backfill materials 107 5.6 Conclusions 110 6 Repository options, design and construction 112 6.1 Introduction 112 6.2 Repository site selection guidelines 112 6.3 Thermal loading in repositories 114 6.4 Subsurface excavation 115 6.5 Geothermal gradients 124 6.6 Examples of repositories 124 6.7 Backfilling and sealing repositories 143 7 Seabed disposal of high-level radioactive waste Contents vii 8.4 Problems in defining the relevant hydrogeological parameters 8.5 Conclusions 9 Risk assessment and release scenarios for rock repositories 185 9.1 Introduction 9.2 Approaches to release scenarios and risk assessment 9.3 A time scale for predictions 9.4 Examples of generic and site-specific release scenarios 9.5 Conclusions regarding release scenarios and risk analysis References Glossary Index High-level nuclear waste and geological disposal Front Matter....Pages i-vii An introduction to high-level nuclear waste and the concept of geological disposal....Pages 1-39 The suitability of evaporites as HLW repositories....Pages 40-56 The suitability of crystalline rocks as HLW repositories....Pages 57-74 The suitability of argillaceous rocks as HLW repositories....Pages 75-93 The containment of radionuclides within repositories....Pages 94-111 Repository options, design and construction....Pages 112-144 Seabed disposal of high-level radioactive waste....Pages 145-172 Groundwater and its movement....Pages 173-184 Risk assessment and release scenarios for rock repositories....Pages 185-206 Back Matter....Pages 207-229