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 Total System Performance Predictions TSPA 1995 for the Potential High level Waste Repository at Yucca Mountain written by and published by . This book was released on 1996 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The management and operating contractor for the potential high-level nuclear waste repository at Yucca Mountain, Nevada, has been recently completed a new performance assessment of the ability of the repository to isolate and contain nuclear waste for long time periods (up to 1,000,000 years). Sensitivity analyses determine the most important physical parameters and processes, using the most current information and models.
Download or read book One Step at a Time written by Committee on Principles and Operational Strategies for Staged Repository Systems and published by . This book was released on 2003-02-06 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared to other large engineering projects, geologic repositories for high-level waste present distinctive challenges because: 1) they are first-of-a-kind, complex, and long-term projects that must actively manage hazardous materials for many decades: 2) they are expected to hold these hazardous materials passively safe for many millennia after repository closure; and 3) they are widely perceived to pose serious risks. As is the case for other complex projects, repository programs should proceed in stages. One Step at a Time focuses on a management approach called "adaptive staging" as a promising means to develop geologic repositories for high-level radioactive waste such as the proposed repository at Yucca Mountain, Nevada. Adaptive staging is a learn-as-you-go process that enables project managers to continuously reevaluate and adjust the program in response to new knowledge and stakeholder input. Advice is given on how to implement staging during the construction, operation, closure, and post-closure phases of a repository program.
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 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 Scale up Considerations Relevant to Experimental Studies of Nuclear Waste package Behavior written by D. G. Coles and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Disposition of High Level Waste and Spent Nuclear Fuel written by National Research Council and published by National Academies Press. This book was released on 2001-07-05 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Review of Scenario Selection Approaches for Performance Assessment of High level Waste Repositories and Related Issues written by E. J. Bonano and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing the Performance of Geologic Repositories for Nuclear Waste written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Predictions of the rate of release of radionuclides from waste packages, their rates of dissolution in groundwater, their hydrogeologic transport to the environment, and their ultimate uptake by people are summarized. Both the details of performance assessment and conclusions on performance are affected by what performance criteria are adopted. 9 references, 1 figure, 1 table.
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1987 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 107 1 Hearings Energy And Water Development Appropriations For 2002 Part 6 May 3 2001 written by and published by . This book was released on 2001 with total page 1326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Closed system Postulates for Predicting Waste package Performance in a Geological Repository written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In a recent paper we reviewed the need for reliable theory and experiment in making long-term predictions of waste performance in a geologic repository. We discussed uncertainties in postulated techniques of applying closed-system laboratory leach data to predicting the dissolution of waste solids in a geologic repository, and we discussed the use of mass-transfer analysis to unify theory and experiment and to provide a clear theoretical basis for long-term prediction. Comments on our recent paper by Drs. P.B. Macedo and C.J. Montrose provide a welcome opportunity to clarify several issues related to predicting waste performance. Their comments help illustrate the need for reliable and sound theories for predicting waste performance in the long-term future, and they help focus the fundamental differences between waste dissolution in laboratory leach experiments and dissolution in a repository. To aid better understanding and resolution of the differences between mass transfer in the closed systems considered by Macedo et al. and others and mass transfer in the open systems of waste repositories considered in our mass transfer analysis, we comment here in some detail.
Download or read book Scientific and Technical Basis for the Geological Disposal of Radioactive Wastes written by and published by Technical Reports Series. This book was released on 2003 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Energy and Water Development Appropriations for 2002 Department of Energy Atomic Energy Defense activities written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2001 with total page 1260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uncertainties Associated with Performance Assessment of High level Radioactive Waste Repositories written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Risk informing Decisions about High level Nuclear Waste Repositories written by Suchandra Tina Ghosh and published by . This book was released on 2004 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance assessments (PAs) are important sources of information for societal decisions in high-level radioactive waste (HLW) management, particularly in evaluating safety cases for proposed HLW repository development. Assessing risk from geologic repositories for HLW poses a significant challenge due to the uncertainties in modeling complex systems of such large temporal and spatial scales. Because of the extensive uncertainties, a typical safety case for a proposed HLW repository is comprised of PA results coupled with various defense-in-depth elements, such as the multi-barrier requirement for repository design, and insights from supplementary analyses. This thesis proposes an additional supplementary analysis, the Strategic Partitioning of Assumption Ranges and Consequences (SPARC), that could be used: (1) in a safety case to help build confidence in a repository system, (2) to provide risk information for decisions on how to allocate resources for future research, and (3) to provide risk information for stakeholder deliberation.
