Download or read book Application of Geochemical Models to High Level Nuclear Waste Repository Assessment written by Office of Nuclear Material Safety and Safeguards and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Geochemical Models to High level Nuclear Waste Repository Assessment Proceedings of a Conference On written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conference on the application of geochemical models to high level nuclear waste repository assessment proceedings written by G. K. Jacobs and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Conference on the Application of Geochemical Models to High level Nuclear Waste Repository Assessment written by Gary K. Jacobs and published by . This book was released on 1985 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OVERVIEW OF MODELING APPROACHES FOR ASSESSING NATURAL SYSTEM PERFORMANCE OF THE HIGH LEVEL RADIOACTIVE WASTE REPOSITORY AT YUCCA MOUNTAIN NEVADA written by M. Zhu and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For two decades, extensive hydrologic investigations have been conducted for geologic disposal of high-level radioactive waste in fractured volcanic tuffs at Yucca Mountain, Nevada. Extensive field and laboratory geologic, hydrologic, and geochemical testing has provided a large amount of data for developing the conceptual understanding of these processes and parameters for quantifying these processes. A suite of sophisticated numerical models has been developed to assess the long-term performance of the natural barrier of unsaturated zone (UZ) and saturated zone (SZ) to flow of groundwater and transport of radionuclides released from the repository. This work focuses on characterizing surface and subsurface processes of climate change, infiltration, percolation in the UZ and groundwater flow in the SZ, as well as on predicting hydrologic responses of the natural system to the emplacement of waste packages in drifts, including seepage of water into emplacement drifts and radionuclide transport in the UZ and SZ. These models are then abstracted into a total system performance assessment (TSPA) model. The TSPA integrates these natural attributes with features of engineered systems, and through systematic stochastic analyses involving Monte Carlo simulations, predicts the dose consequences and groundwater concentrations for at least 10,000 years for various future climate conditions, waste types, release scenarios, and transport pathways. The TSPA predictions demonstrate compliance with postclosure individual and groundwater protection standards in the license application for the repository. This presentation provides an overview of the development and use of these natural-system models, including the infiltration model, the site-scale UZ flow model, the seepage calibration and abstraction models, the UZ radionuclide transport and abstraction models, and the site-scale SZ flow and transport models. It describes the approaches used in the design and construct of these models, summarizes the tests and experiments conducted to obtain key input data, and discusses lessons learned in the efforts to validate the models and the treatment of uncertainties in the TSPA.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993-02 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing the Geochemical Fate of Deep well injected Hazardous Wastes written by and published by . This book was released on 1990 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geochemical Models Suitable for Performance Assessment of Nuclear Waste Storage written by Intera Environmental Consultants and published by . This book was released on 1983 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ground Water Geochemical Modeling and Simulation of a Breached High level Radioactive Waste Repository in the Northern Tulsarosa Basin New Mexico written by Richard W. Chappell and published by . This book was released on 1989 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Repository Systems for Safe Disposal of Spent Nuclear Fuels and Radioactive Waste written by Michael J Apted and published by Woodhead Publishing. This book was released on 2017-05-25 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Performance Prediction for Large Scale Nuclear Waste Repositories written by and published by . This book was released on 2001 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project was development of a software package capable of utilizing terascale computational platforms for solving subsurface flow and transport problems important for disposal of high level nuclear waste materials, as well as for DOE-complex clean-up and stewardship efforts. We sought to develop a tool that would diminish reliance on abstracted models, and realistically represent the coupling between subsurface fluid flow, thermal effects and chemical reactions that both modify the physical framework of the rock materials and which change the rock mineralogy and chemistry of the migrating fluid. Providing such a capability would enhance realism in models and increase confidence in long-term predictions of performance. Achieving this goal also allows more cost-effective design and execution of monitoring programs needed to evaluate model results. This goal was successfully accomplished through the development of a new simulation tool (NUFT-C). This capability allows high resolution modeling of complex coupled thermal-hydrological-geochemical processes in the saturated and unsaturated zones of the Earth's crust. The code allows consideration of virtually an unlimited number of chemical species and minerals in a multi-phase, non-isothermal environment. Because the code is constructed to utilize the computational power of the tera-scale IBM ASCI computers, simulations that encompass large rock volumes and complex chemical systems can now be done without sacrificing spatial or temporal resolution. The code is capable of doing one-, two-, and three-dimensional simulations, allowing unprecedented evaluation of the evolution of rock properties and mineralogical and chemical change as a function of time. The code has been validated by comparing results of simulations to laboratory-scale experiments, other benchmark codes, field scale experiments, and observations in natural systems. The results of these exercises demonstrate that the physics and chemistry embodied in the code accurately represents the state-of-the-art in modeling these processes, and that the conceptualization of the models used in the simulations honors the primary processes that are controlling these systems. Application of the code to a wide range of important and strategic problems has been undertaken. Particularly significant are results obtained concerning the evolution of a potential high level nuclear waste repository at Yucca Mountain, Nevada. In these simulations, the results suggest that fluid movement and chemical changes will be such as to encourage solute transport around the sides of the waste emplacement tunnels, thus minimizing the potential for seepage of water and dissolved salts into the tunnels. The results also indicate that the short term response of the geological system to waste emplacement will be complex and rapid, and will be most readily detected below waste emplacement tunnels. A successful monitoring program of repository performance during the early stages of the operational period would thus benefit by coordinating design and execution of sampling strategies with a simulation tool such as NUFT-C. Such an approach would allow efficient and cost-effective sampling strategies, and would facilitate interpretation of what will surely be complex and massive data sets.
Download or read book Site Investigations for Repositories for Solid Radioactive Wastes in Deep Continental Geological Formations written by International Atomic Energy Agency and published by Bernan Press(PA). This book was released on 1982 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ground Water Geochemical Modeling and Simulation of a Breached High level Radioactive Waste Repository in the Northern Tularosa Basin New Mexico written by Richard William Chappell and published by . This book was released on 1989 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1985 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Download or read book Progress in Evaluation of Radionuclide Geochemical Information Developed by DOE High level Nuclear Waste Repository Site Projects written by and published by . This book was released on 1985 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geotechnical Assessment and Instrumentation Needs for Nuclear Waste Isolation in Crystalline and Argillaceous Rocks written by and published by . This book was released on 1978 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Geochemistry of Radioactive Contamination written by Charles R. Bryan and published by . This book was released on 2003 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report attempts to describe the geochemical foundations of the behavior of radionuclides in the environment. The information is obtained and applied in three interacting spheres of inquiry and analysis: (1) experimental studies and theoretical calculations, (2) field studies of contaminated and natural analog sites and (3) model predictions of radionuclide behavior in remediation and waste disposal. Analyses of the risks from radioactive contamination require estimation of the rates of release and dispersion of the radionuclides through potential exposure pathways. These processes are controlled by solubility, speciation, sorption, and colloidal transport, which are strong functions of the compositions of the groundwater and geomedia as well as the atomic structure of the radionuclides. The chemistry of the fission products is relatively simple compared to the actinides. Because of their relatively short half-lives, fission products account for a large fraction of the radioactivity in nuclear waste for the first several hundred years but do not represent a long-term hazard in the environment. The chemistry of the longer-lived actinides is complex; however, some trends in their behavior can be described. Actinide elements of a given oxidation state have either similar or systematically varying chemical properties due to similarities in ionic size, coordination number, valence, and electron structure. In dilute aqueous systems at neutral to basic pH, the dominant actinide species are hydroxy- and carbonato-complexes, and the solubility-limiting solid phases are commonly oxides, hydroxides or carbonates. In general, actinide sorption will decrease in the presence of ligands that complex with the radionuclide; sorption of the (IV) species of actinides (Np, Pu, U) is generally greater than of the (V) species. The geochemistry of key radionuclides in three different environments is described in this report. These include: (1) low ionic strength reducing waters from crystalline rocks at nuclear waste research sites in Sweden; (2) oxic water from the J-13 well at Yucca Mountain, Nevada, the site of a proposed repository for high level nuclear waste (HLW) in tuffaceous rocks; and (3) reference brines associated with the Waste Isolation Pilot Plant (WIPP). The transport behaviors of radionuclides associated with the Chernobyl reactor accident and the Oklo Natural Reactor are described. These examples span wide temporal and spatial scales and include the rapid geochemical and physical processes important to nuclear reactor accidents or industrial discharges as well as the slower processes important to the geologic disposal of nuclear waste. Application of geochemical information to remediating or assessing the risk posed by radioactive contamination is the final subject of this report. After radioactive source terms have been removed, large volumes of soil and water with low but potentially hazardous levels of contamination may remain. For poorly-sorbing radionuclides, capture of contaminated water and removal of radionuclides may be possible using permeable reactive barriers and bioremediation. For strongly sorbing radionuclides, contaminant plumes will move very slowly. Through a combination of monitoring, regulations and modeling, it may be possible to have confidence that they will not be a hazard to current or future populations. Abstraction of the hydrogeochemical properties of real systems into simple models is required for probabilistic risk assessment. Simplifications in solubility and sorption models used in performance assessment calculations for the WIPP and the proposed HLW repository at Yucca Mountain are briefly described.
