Geological Disposal of Radioactive Wastes and Natural Analogues

by Miller, William; Alexander, Russell; Chapman, Neil; McKinley, Ian; Smellie, John

• ISBN13: 9780080438528
• ISBN10: 0080438520
• Format: Hardcover
• Copyright: 2000-09-01
• Publisher: Elsevier Science Ltd

Summary

Many countries are currently exploring the option to dispose of highly radioactive solid wastes deep underground in purpose built, engineered repositories. A number of surface and shallow repositories for less radioactive wastes are already in operation. One of the challenges facing the nuclear industry is to demonstrate confidently that a repository will contain wastes for so long that any releases that might take place in the future will pose no significant health or environmental risk. One method for building confidence in the long-term future safety of a repository is to look at the physical and chemical processes which operate in natural and archaeological systems, and to draw appropriate parallels with the repository. For example, to understand why some uranium orebodies have remained isolated underground for billions of years. Such studies are called 'natural analogues'. This book investigates the concept of geological disposal and examines the wide range of natural analogues which have been studied. Lessons learnt from studies of archaeological and natural systems can be used to improve our capabilities for assessing the future safety of a radioactive waste repository.

Table of Contents

The issue of radioactive waste disposal	1	(28)
The nature of radioactive wastes	3	(1)
The concept of geological disposal	4	(3)
Evaluating repository safety	7	(9)
Key uncertainties in safety calculations	11	(4)
Requirements for supporting natural data	15	(1)
Natural analogue studies	16	(5)
Other field-based studies of natural systems	21	(5)
Site characterisation	21	(2)
Palaeohydrogeology	23	(1)
Natural safety indicators	24	(1)
Biosphere studies	25	(1)
Toxic waste disposal	26	(3)
Radioactive waste types and repository designs	29	(24)
The nuclear fuel cycle and radioactive wastes	29	(3)
Used fuel and reprocessing wastes	30	(1)
Operational wastes	31	(1)
Decommissioning wastes	31	(1)
Other wastes	31	(1)
Classification of radioactive wastes	32	(1)
Repository designs	33	(14)
Deep repository designs for HLW	35	(7)
Deep repository designs for ILW	42	(4)
Near-surface repository designs for LLW	46	(1)
Geological disposal environments	47	(6)
Varieties of analogue studies	53	(12)
Chemical analogues	54	(2)
Natural geological and geochemical systems	56	(5)
Uranium orebodies	56	(2)
Geochemical discontinuities in clays	58	(1)
Hyperalkaline environments	59	(1)
Hydrothermal systems	59	(1)
Natural occurrences of repository materials	60	(1)
Archaeological analogues	61	(1)
Sites of anthropogenic contamination	62	(3)
Analogues of repository materials	65	(88)
Silicate glass	66	(11)
Spent fuel	77	(17)
Mineral and ceramic wasteforms	94	(3)
Metals	97	(16)
Bentonite	113	(13)
Concretes and cement	126	(16)
Bitumen	142	(6)
Organic materials	148	(5)
Analogues of transport and retardation	153	(90)
Elemental solubility and speciation	153	(19)
Elemental retardation processes	172	(17)
Matrix diffusion	189	(20)
Radiolysis	209	(7)
Redox fronts	216	(6)
Colloids	222	(12)
Microbiological activity	234	(4)
Gas generation and migration	238	(5)
The application of analogue information	243	(14)
Natural analogues in the support of performance assessment	243	(9)
The reality of analogue application to performance assessment	248	(4)
Natural analogues in non-technical demonstrations of safety	252	(2)
Natural analogues applied to other environmental issues	254	(3)
Summary, conclusions and recommendations	257	(8)
Summary of analogue results	257	(5)
Analogues of repository materials	257	(3)
Analogues of transport and retardation	260	(2)
Conclusions	262	(3)
Suggested areas for future analogue investigation	263	(2)
References	265	(46)
Index	311