Download or read book Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal written by and published by . This book was released on 2010 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For example, the excavation-damaged zone (EDZ) near repository tunnels can modify local permeability (resulting from induced fractures), potentially leading to less confinement capability (Tsang et al., 2005). Because of clay's swelling and shrinkage behavior (depending on whether the clay is in imbibition or drainage processes), fracture properties in the EDZ are quite dynamic and evolve over time as hydromechanical conditions change. To understand and model the coupled processes and their impact on repository performance is critical for the defensible performance assessment of a clay repository. Within the Natural Barrier System (NBS) group of the Used Fuel Disposition (UFD) Campaign at DOE's Office of Nuclear Energy, LBNL's research activities have focused on understanding and modeling such coupled processes. LBNL provided a report in this April on literature survey of studies on coupled processes in clay repositories and identification of technical issues and knowledge gaps (Tsang et al., 2010). This report will document other LBNL research activities within the natural system work package, including the development of constitutive relationships for elastic deformation of clay rock (Section 2), a THM modeling study (Section 3) and a THC modeling study (Section 4). The purpose of the THM and THC modeling studies is to demonstrate the current modeling capabilities in dealing with coupled processes in a potential clay repository. In Section 5, we discuss potential future R & D work based on the identified knowledge gaps. The linkage between these activities and related FEPs is presented in Section 6.

Download or read book Coupled Processes Associated with Nuclear Waste Repositories written by Chin-Fu Tsang and published by Elsevier. This book was released on 2012-12-02 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coupled Processes Associated with Nuclear Waste Repositories covers the proceedings of the 1985 International Symposium on Coupled Processes Associated with Nuclear Waste Repositories. The study of the behavior of geologic waste repositories is based on the coupled thermal, hydrologic, chemical, and mechanical processes that may occur in these systems. The symposium is sponsored by the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy, in collaboration with the Nuclear Energy Authority in Paris and the Commission of the European Communities in Brussels. This book is organized into five parts encompassing 58 chapters. The introductory parts survey the concerns and interests from American and European agencies that have responsibilities in nuclear waste isolation research. These parts also provide overviews of coupled processes, with a particular emphasis on hydrology, geomechanics, and geochemistry. These topics are followed by summaries of major field projects on nuclear waste repositories in the U.S.A., France, Sweden, Canada, Belgium, and Switzerland. The fourth part covers considerable research results from topical studies of particular coupled processes. The concluding part provides the comments and discussion of various international researchers on the subject. This work will be of value to geology, hydrology, chemistry, thermodynamics, and rock mechanics students and researchers.

Download or read book Report on Modeling Coupled Processes in the Near Field of a Clay Repository written by and published by . This book was released on 2012 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world. Coupled thermal, hydrological, mechanical, and chemical (THMC) processes have a significant impact on the long-term safety of a clay repository. For example, the excavation damaged zone (EDZ) near repository tunnels can modify local permeability (resulting from induced fractures), potentially leading to less confinement capability. This report documents results from three R & D activities: (1) implementation and validation of constitutive relationships, (2) development of a discrete fracture network (DFN) model for investigating coupled processes in the EDZ, and (3) development of a THM model for the FE tests at Mont Terri, Switzerland, for the purpose of model validation. The overall objective of these activities is to provide an improved understanding of EDZ evolution in clay repositories and the associated coupled processes, and to develop advanced relevant modeling capabilities.

Download or read book Multiple Roles of Clays in Radioactive Waste Confinement written by S. Norris and published by Geological Society of London. This book was released on 2019-08-05 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Publication highlights the importance of clays and clayey material, and their multiple roles, in many national geological disposal facilities for higher activity radioactive wastes. Clays can be both the disposal facility host rock and part of its intrinsic engineered barriers, and may be present in the surrounding geological environment. Clays possess various characteristics that make them high-quality barriers to the migration of radionuclides and chemical contaminants, e.g. very little water movement, diffusive transport, retention capacity, self-sealing capacity, stability over millions of years, homogeneity and lateral continuity.

Download or read book Clays in Natural and Engineered Barriers for Radioactive Waste Confinement written by S. Norris and published by Geological Society of London. This book was released on 2014-10-24 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Publication contains 43 scientific studies presented at the 5th conference on ‘Clays in natural and engineered barriers for radioactive waste confinement’ held in Montpellier, France in 2012. The conference and this resulting volume cover all the aspects of clay characterization and behaviour considered at various temporal and spatial scales relevant to the confinement of radionuclides in clay, from basic phenomenological process descriptions to the global understanding of performance and safety at repository and geological scales. Special emphasis has been given to the modelling of processes occurring at the mineralogical level within the clay barriers. The papers in this Special Publication consider research into argillaceous media under the following topic areas: large-scale geological characterization; clay-based concept/large-scale experiments; hydrodynamical modelling; geochemistry; geomechanics; mass transfer/gas transfer; mass transfer mechanisms. The collection of different topics presented in this Special Publication demonstrates the diversity of geological repository research.

Download or read book Evaluation of Used Fuel Disposition in Clay Bearing Rock written by and published by . This book was released on 2014 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive waste disposal in shale/argillite rock formations has been widely considered given its desirable isolation properties (low permeability), geochemically reduced conditions, anomalous groundwater pressures, and widespread geologic occurrence. Clay/shale rock formations are characterized by their high content of clay minerals such as smectites and illites where diffusive transport and chemisorption phenomena predominate. These, in addition to low permeability, are key attributes of shale to impede radionuclide mobility. Shale host-media has been comprehensively studied in international nuclear waste repository programs as part of underground research laboratories (URLs) programs in Switzerland, France, Belgium, and Japan. These investigations, in some cases a decade or more long, have produced a large but fundamental body of information spanning from site characterization data (geological, hydrogeological, geochemical, geomechanical) to controlled experiments on the engineered barrier system (EBS) (barrier clay and seals materials). Evaluation of nuclear waste disposal in shale formations in the USA was conducted in the late 70's and mid 80's. Most of these studies evaluated the potential for shale to host a nuclear waste repository but not at the programmatic level of URLs in international repository programs. This report covers various R & D work and capabilities relevant to disposal of heat-generating nuclear waste in shale/argillite media. Integration and cross-fertilization of these capabilities will be utilized in the development and implementation of the shale/argillite reference case planned for FY15. Disposal R & D activities under the UFDC in the past few years have produced state-of-the-art modeling capabilities for coupled Thermal-Hydrological-Mechanical-Chemical (THMC), used fuel degradation (source term), and thermodynamic modeling and database development to evaluate generic disposal concepts. The THMC models have been developed for shale repository leveraging in large part on the information garnered in URLs and laboratory data to test and demonstrate model prediction capability and to accurately represent behavior of the EBS and the natural (barrier) system (NS). In addition, experimental work to improve our understanding of clay barrier interactions and TM couplings at high temperatures are key to evaluate thermal effects as a result of relatively high heat loads from waste and the extent of sacrificial zones in the EBS. To assess the latter, experiments and modeling approaches have provided important information on the stability and fate of barrier materials under high heat loads. This information is central to the assessment of thermal limits and the implementation of the reference case when constraining EBS properties and the repository layout (e.g., waste package and drift spacing). This report is comprised of various parts, each one describing various R & D activities applicable to shale/argillite media. For example, progress made on modeling and experimental approaches to analyze physical and chemical interactions affecting clay in the EBS, NS, and used nuclear fuel (source term) in support of R & D objectives. It also describes the development of a reference case for shale/argillite media. The accomplishments of these activities are summarized as follows: Development of a reference case for shale/argillite; Investigation of Reactive Transport and Coupled THM Processes in EBS: FY14; Update on Experimental Activities on Buffer/Backfill Interactions at elevated Pressure and Temperature; and Thermodynamic Database Development: Evaluation Strategy, Modeling Tools, First-Principles Modeling of Clay, and Sorption Database Assessment;ANL Mixed Potential Model For Used Fuel Degradation: Application to Argillite and Crystalline Rock Environments.

Download or read book Modeling Radionuclide Transport in Clays written by and published by . This book was released on 2012 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated or plastic clays (Tsang and Hudson, 2010). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. During the lifespan of a clay repository, the repository performance is affected by complex thermal, hydrogeological, mechanical, chemical (THMC) processes, such as heat release due to radionuclide decay, multiphase flow, formation of damage zones, radionuclide transport, waste dissolution, and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) of the repository. These coupled processes may affect radionuclide transport by changing transport paths (e.g., formation and evolution of excavation damaged zone (EDZ)) and altering flow, mineral, and mechanical properties that are related to radionuclide transport. While radionuclide transport in clay formation has been studied using laboratory tests (e, g, Appelo et al. 2010, Garcia-Gutierrez et al., 2008, Maes et al., 2008), short-term field tests (e.g. Garcia-Gutierrez et al. 2006, Soler et al. 2008, van Loon et al. 2004, Wu et al. 2009) and numerical modeling (de Windt et al. 2003; 2006), the effects of THMC processes on radionuclide transport are not fully investigated. The objectives of the research activity documented in this report are to improve a modeling capability for coupled THMC processes and to use it to evaluate the THMC impacts on radionuclide transport. This research activity addresses several key Features, Events and Processes (FEPs), including FEP 2.2.08, Hydrologic Processes, FEP 2.2.07, Mechanical Processes and FEP 2.2.09, Chemical Process-- Transport, by studying near-field coupled THMC processes in clay/shale repositories and their impacts on radionuclide transport. This report documents the progress that has been made in FY12. Section 2 discusses the development of THMC modeling capability. Section 3 reports modeling results of THMC impacts on radionuclide transport. Planned work for the remaining months of FY12 and proposed work for FY13 are presented in Section 4.

Download or read book Shale Disposal of U S High level Radioactive Waste written by and published by . This book was released on 2010 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report evaluates the feasibility of high-level radioactive waste disposal in shale within the United States. The U.S. has many possible clay/shale/argillite basins with positive attributes for permanent disposal. Similar geologic formations have been extensively studied by international programs with largely positive results, over significant ranges of the most important material characteristics including permeability, rheology, and sorptive potential. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in shale media. We develop scoping performance analyses, based on the applicable features, events, and processes identified by international investigators, to support a generic conclusion regarding post-closure safety. Requisite assumptions for these analyses include waste characteristics, disposal concepts, and important properties of the geologic formation. We then apply lessons learned from Sandia experience on the Waste Isolation Pilot Project and the Yucca Mountain Project to develop a disposal strategy should a shale repository be considered as an alternative disposal pathway in the U.S. Disposal of high-level radioactive waste in suitable shale formations is attractive because the material is essentially impermeable and self-sealing, conditions are chemically reducing, and sorption tends to prevent radionuclide transport. Vertically and laterally extensive shale and clay formations exist in multiple locations in the contiguous 48 states. Thermal-hydrologic-mechanical calculations indicate that temperatures near emplaced waste packages can be maintained below boiling and will decay to within a few degrees of the ambient temperature within a few decades (or longer depending on the waste form). Construction effects, ventilation, and the thermal pulse will lead to clay dehydration and deformation, confined to an excavation disturbed zone within a few meters of the repository, that can be reasonably characterized. Within a few centuries after waste emplacement, overburden pressures will seal fractures, resaturate the dehydrated zones, and provide a repository setting that strongly limits radionuclide movement to diffusive transport. Coupled hydrogeochemical transport calculations indicate maximum extents of radionuclide transport on the order of tens to hundreds of meters, or less, in a million years. Under the conditions modeled, a shale repository could achieve total containment, with no releases to the environment in undisturbed scenarios. The performance analyses described here are based on the assumption that long-term standards for disposal in clay/shale would be identical in the key aspects, to those prescribed for existing repository programs such as Yucca Mountain. This generic repository evaluation for shale is the first developed in the United States. Previous repository considerations have emphasized salt formations and volcanic rock formations. Much of the experience gained from U.S. repository development, such as seal system design, coupled process simulation, and application of performance assessment methodology, is applied here to scoping analyses for a shale repository. A contemporary understanding of clay mineralogy and attendant chemical environments has allowed identification of the appropriate features, events, and processes to be incorporated into the analysis. Advanced multi-physics modeling provides key support for understanding the effects from coupled processes. The results of the assessment show that shale formations provide a technically advanced, scientifically sound disposal option for the U.S.

Download or read book Geological Disposal of Radioactive Waste in Deep Clay Formations written by X.L. Li and published by Geological Society of London Special Publications. This book was released on 2023-09-01 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of research into the geological disposal of radioactive waste in Belgium, the HADES underground research laboratory (URL) was constructed in a clay formation in the early 1980s. This was the world's first purpose-built URL in a deep clay formation. Over the past four decades, the HADES URL has played an important role in the research, development and demonstration (RD&D) of geological disposal. It enabled the in situ characterization of the clay host rock, it allowed experiments to be performed under realistic geological conditions and it demonstrated the feasibility of constructing, operating and closing underground repositories. This volume presents several key contributions of the HADES URL to both Belgian and international research into geological disposal. It not only compiles some important RD&D results, but also illustrates the essential role URLs such as the HADES URL have played in developing concepts for the geological disposal of radioactive waste.

Download or read book Waste Forms Technology and Performance written by National Research Council and published by National Academies Press. This book was released on 2011-09-05 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy's Office of Environmental Management (DOE-EM) is responsible for cleaning up radioactive waste and environmental contamination resulting from five decades of nuclear weapons production and testing. A major focus of this program involves the retrieval, processing, and immobilization of waste into stable, solid waste forms for disposal. Waste Forms Technology and Performance, a report requested by DOE-EM, examines requirements for waste form technology and performance in the cleanup program. The report provides information to DOE-EM to support improvements in methods for processing waste and selecting and fabricating waste forms. Waste Forms Technology and Performance places particular emphasis on processing technologies for high-level radioactive waste, DOE's most expensive and arguably most difficult cleanup challenge. The report's key messages are presented in ten findings and one recommendation.

Download or read book Gas Generation and Migration in Deep Geological Radioactive Waste Repositories written by R.P. Shaw and published by Geological Society of London. This book was released on 2015-06-11 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the behaviour of gases in the context of radioactive waste disposal is a fundamental requirement in developing a safety case for the disposal of radioactive waste. Of particular importance are the long-term performance of bentonite buffers and cement-based backfill materials that may be used to encapsulate and surround the waste in a repository, and the behaviour of plastic clays, indurated mudrocks and crystalline formations that may be the host rocks for a repository. The EC Euratom programme funded project, FORGE, has provided new insights into the processes and mechanisms governing gas generation and migration with the aim of reducing uncertainty. This volume brings together papers on aspects of this topic arising from both the FORGE project and work undertaken elsewhere. This has been achieved by the acquisition of new experimental data coupled with modelling, through a series of laboratory and field-scale experiments performed at a number of underground research laboratories throughout Europe.

Download or read book Subsurface Environmental Modelling Between Science and Policy written by Dirk Scheer and published by Springer Nature. This book was released on 2020-07-25 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a broad overview of essential features of subsurface environmental modelling at the science-policy interface, offering insights into the potential challenges in the field of subsurface flow and transport, as well as the corresponding computational modelling and its impact on the area of policy- and decision-making. The book is divided into two parts: Part I presents models, methods and software at the science-policy interface. Building on this, Part II illustrates the specifications using detailed case studies of subsurface environmental modelling. It also includes a systematic research overview and discusses the anthropogenic use of the subsurface, with a particular focus on energy-related technologies, such as carbon sequestration, geothermal technologies, fluid and energy storage, nuclear waste disposal, and unconventional oil and gas recovery.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tracers and Modelling in Hydrogeology written by Alain Dassargues and published by IAHS Press. This book was released on 2000 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Natural and Engineered Clay Barriers written by and published by Elsevier. This book was released on 2015-05-14 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clays are used as barriers for the isolation of landfills and contaminated sites. They are envisioned as long-term storage media for hazardous materials and radioactive wastes, and as seals in the case of geological CO2 sequestration or energy storage. Clay properties greatly influence the integrity, efficiency, and safety of these applications. Natural and Engineered Clay Barriers provides a clear view of the fundamental properties of clay materials and how these properties affect their engineering applications. This volume focuses on how the mass transfer properties (hydraulic permeability, gas fluxes, molecular diffusion, semi-permeable membrane properties), geochemical reactivity (adsorption, dissolution) and mechanical properties of clay barriers at the macroscale are influenced by phenomena that occur at clay mineral - water interfaces. Examines clay properties from the molecular to the macroscopic scale Addresses experimental and modeling issues Authored by experts in the properties of clay barriers

Download or read book Reactive Transport Modeling written by Yitian Xiao and published by John Wiley & Sons. This book was released on 2018-03-12 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Teaches the application of Reactive Transport Modeling (RTM) for subsurface systems in order to expedite the understanding of the behavior of complex geological systems This book lays out the basic principles and approaches of Reactive Transport Modeling (RTM) for surface and subsurface environments, presenting specific workflows and applications. The techniques discussed are being increasingly commonly used in a wide range of research fields, and the information provided covers fundamental theory, practical issues in running reactive transport models, and how to apply techniques in specific areas. The need for RTM in engineered facilities, such as nuclear waste repositories or CO2 storage sites, is ever increasing, because the prediction of the future evolution of these systems has become a legal obligation. With increasing recognition of the power of these approaches, and their widening adoption, comes responsibility to ensure appropriate application of available tools. This book aims to provide the requisite understanding of key aspects of RTM, and in doing so help identify and thus avoid potential pitfalls. Reactive Transport Modeling covers: the application of RTM for CO2 sequestration and geothermal energy development; reservoir quality prediction; modeling diagenesis; modeling geochemical processes in oil & gas production; modeling gas hydrate production; reactive transport in fractured and porous media; reactive transport studies for nuclear waste disposal; reactive flow modeling in hydrothermal systems; and modeling biogeochemical processes. Key features include: A comprehensive reference for scientists and practitioners entering the area of reactive transport modeling (RTM) Presented by internationally known experts in the field Covers fundamental theory, practical issues in running reactive transport models, and hands-on examples for applying techniques in specific areas Teaches readers to appreciate the power of RTM and to stimulate usage and application Reactive Transport Modeling is written for graduate students and researchers in academia, government laboratories, and industry who are interested in applying reactive transport modeling to the topic of their research. The book will also appeal to geochemists, hydrogeologists, geophysicists, earth scientists, environmental engineers, and environmental chemists.