Radionuclide Transport in Geologic Waste Repository

Radionuclide Transport in Geologic Waste Repository PDF Author: Daisuke Kawasaki
Publisher: VDM Publishing
ISBN: 9783836485128
Category : Technology & Engineering
Languages : en
Pages : 136

Book Description
Analyses of radionuclide transport in geologic radioactive waste repository are made for a water-saturated repository and an unsaturated repository. To deal with the transport problem at the repository scale with multiple nuclide sources, compartment models are developed. The models allow us to observe the effects of repository layout on the performance of waste disposal system, and thus can be applied for making comparisons among various designs of repository layout. Residence times of radionuclides in individual components are found to be the key parameters in the present analysis, and the peak concentration of the radionuclide in the groundwater is formulated in terms of the residence times. Compartment models are further developed in integration with stochastic processes in order to reflect two- and three-dimensional transport and to incorporate residence time distributions obtained from an analysis at a sub-compartment scale. The models and the analysis should be useful to researchers engaged in performance assessment of radioactive waste repository as well as environmental scientists modeling contaminant transport in groundwater.

Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste

Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste PDF Author: Michael J Apted
Publisher: Woodhead Publishing
ISBN: 0081006527
Category : Technology & Engineering
Languages : en
Pages : 804

Book Description
Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste, Second Edition, critically reviews state-of-the-art technologies and scientific methods relating to the implementation of the most effective approaches to the long-term, safe disposition of nuclear waste, also discussing regulatory developments and social engagement approaches as major themes. Chapters in Part One introduce the topic of geological disposal, providing an overview of near-surface, intermediate depth, and deep borehole disposal, spanning low-, medium- and high-level wastes. Part Two addresses the different types of repository systems – crystalline, clay, and salt, also discussing methods of site surveying and construction. The critical safety issue of engineered barrier systems is the focus of Part Three, with coverage ranging from nuclear waste canisters, to buffer and backfill materials. Lastly, Parts Four and Five focus on safety, security, and acceptability, concentrating on repository performance assessment, then radiation protection, environmental monitoring, and social engagement. Comprehensively revised, updated, and expanded with 25% new material on topics of current importance, this is the standard reference for all nuclear waste management and geological repository professionals and researchers. Contains 25% more material on topics of current importance in this new, comprehensive edition Fully updated coverage of both near-surface/intermediate depth, and deep borehole disposal in one convenient volume Goes beyond the scientific and technical aspects of disposal to include the political, regulatory, and societal issues involved, all from an international perspective

Geological Disposal of Radioactive Wastes and Natural Analogues

Geological Disposal of Radioactive Wastes and Natural Analogues PDF Author: W. Miller
Publisher: Elsevier
ISBN: 0080553052
Category : Technology & Engineering
Languages : en
Pages : 329

Book Description
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.

Confidence in Models of Radionuclide Transport for Site-specific Assessments

Confidence in Models of Radionuclide Transport for Site-specific Assessments PDF Author: NEA Project on Radionuclide Migration in Geologic, Heterogeneous Media
Publisher: OECD Publishing
ISBN:
Category : Science
Languages : en
Pages : 324

Book Description
ThIS fourth GEOTRAP workshop, Confidence in Models of Radionuclide Transport for Site-specific Performance Assessment held in June 1999, addressed the issue of technical confidence building and provided an overview of current developments in this field.

Disposition of High-Level Waste and Spent Nuclear Fuel

Disposition of High-Level Waste and Spent Nuclear Fuel PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309073170
Category : Science
Languages : en
Pages : 215

Book Description
Focused attention by world leaders is needed to address the substantial challenges posed by disposal of spent nuclear fuel from reactors and high-level radioactive waste from processing such fuel. The biggest challenges in achieving safe and secure storage and permanent waste disposal are societal, although technical challenges remain. Disposition of radioactive wastes in a deep geological repository is a sound approach as long as it progresses through a stepwise decision-making process that takes advantage of technical advances, public participation, and international cooperation. Written for concerned citizens as well as policymakers, this book was sponsored by the U.S. Department of Energy, U.S. Nuclear Regulatory Commission, and waste management organizations in eight other countries.

Radionuclide Retention in Geologic Media

Radionuclide Retention in Geologic Media PDF Author: Svensk kärnbränslehantering AB.
Publisher: Nuclear Energy Agency, Organisation for Economic Co-operation and Development
ISBN:
Category : Technology
Languages : en
Pages : 284

Book Description
GEOTRAP is the OECD/NEA Project on Radionuclide Migration in Geologic, Heterogeneous Media carried out in the context of site evaluation and safety assessment of deep repository systems for long-lived radioactive waste. Retention of radionuclides within the geosphere for prolonged periods is an important safety function of deep geologic disposal concepts for radioactive waste. The extent to which retention processes can be relied upon in repository performance assessment depends upon the existence of well-established theoretical bases for the processes. It also depends on support for the opera.

Scientific and Technical Basis for the Geological Disposal of Radioactive Wastes

Scientific and Technical Basis for the Geological Disposal of Radioactive Wastes PDF Author:
Publisher: Technical Reports Series
ISBN:
Category : Business & Economics
Languages : en
Pages : 98

Book Description
This report focuses on the different functions of a repository within its life cycle and describes the processes relevant to the containment of long lived radioactive waste and other criteria influencing the long term integrity of the repository. It emphasizes the central role of safety and the importance of safety/performance assessments in the decision making process during repository development.

Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste

Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste PDF Author: Michael J Apted
Publisher: Elsevier
ISBN: 1845699785
Category : Technology & Engineering
Languages : en
Pages : 789

Book Description
Geological disposal has been internationally adopted as the most effective approach to assure the long-term, safe disposition of the used nuclear fuels and radioactive waste materials produced from nuclear power generation, nuclear weapons programs, medical, treatments, and industrial applications. Geological repository systems take advantage of natural geological barriers augmented with engineered barrier systems to isolate these radioactive materials from the environment and from future populations. Geological repository systems for safe disposal of spent nuclear fuels and radioactive waste critically reviews the state-of-the-art technologies, scientific methods, regulatory developments, and social engagement approaches directly related to the implementation of geological repository systems. Part one introduces geological disposal, including multiple-barrier geological repositories, as well as reviewing the impact of nuclear fuel recycling practices and underground research laboratory activities on the development of disposal concepts. Part two reviews geological repository siting in different host rocks, including long-term stability analysis and radionuclide transport modelling. Reviews of the range of engineered barrier systems, including waste immobilisation technologies, container materials, low pH concretes, clay-based buffer and backfill materials, and barrier performance are presented in Part three. Part four examines total system performance assessment and safety analyses for deep geological and near-surface disposal, with coverage of uncertainty analysis, use of expert judgement for decision making, and development and use of knowledge management systems. Finally, Part five covers regulatory and social approaches for the establishment of geological disposal programs, from the development of radiation standards and risk-informed, performance-based regulations, to environmental monitoring and social engagement in the siting and operation of repositories. With its distinguished international team of contributors, Geological repository systems for safe disposal of spent nuclear fuels and radioactive waste is a standard reference for all nuclear waste management and geological repository professionals and researchers. Critically reviews the state-of-the-art technologies, scientific methods, regulatory developments, and social engagement approaches related to the implementation of geological repository systems Chapters introduce geological disposal and review the development of disposal concepts Examines long-term stability analysis, the range of engineered barrier systems and barrier performance

Natural Analogue Studies in the Geological Disposal of Radioactive Wastes

Natural Analogue Studies in the Geological Disposal of Radioactive Wastes PDF Author: W.M. Miller
Publisher: Elsevier
ISBN: 0080875165
Category : Science
Languages : en
Pages : 413

Book Description
The first purpose of this book is to provide a comprehensive review of the state of development of natural analogue studies with emphasis on those studies which are relevant to the following repository designs: Nagra (Switzerland) disposal concepts for high-level waste/low and intermediate-level waste; SKB (Sweden) disposal concepts for spent fuel/low and intermediate-level waste; and Nirex (UK) disposal concept for low and intermediate-level waste. The book's second aim is to discuss the expanding application of natural analogues for non-performance assessment purposes, especially their potential for presenting the concept of geological disposal to various interested audiences in a coherent, understandable and scientifically legitimate manner. Much of the discussion of the book is relevant to concepts for geological disposal of radioactive wastes by other countries, and is concerned only with those physico-chemical processes which control the release of radionuclides from the near-field, and their subsequent retardation and transport in the geosphere.

Calculated Radionuclide Migration from a Geologic High Level Waste Repository

Calculated Radionuclide Migration from a Geologic High Level Waste Repository PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Book Description
Transport by groundwater is the most likely means of escape for radioactive waste contained in a geologic repository. The rock formations through which the groundwater flows are characterized by inhomogeneities on all distance scales. Large scale inhomogeneities cause pulses of dissolved pollutants to spread both in the direction of motion and transverse to it. This phenomenon is known as macroscopic dispersion. Similarly, inhomogeneities in the chemical properties of the rock will cause this spreading to be greater for species whose movement through the rock is retarded by waste rock chemical interactions. Previous risk analyses of nuclear waste disposal which have ignored macroscopic dispersion found that predicted radiation doses to individuals are very sensitive to the waste dissolution time. When macroscopic dispersion is incorporated into the analysis, however, the sensitivity of risk to dissolution time is greatly reduced. 6 figures, 2 tables.