Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Effect Of Small Scale Fractures On Flow And Transport Processes At Yucca Mountain Nevada
Download Effect Of Small Scale Fractures On Flow And Transport Processes At Yucca Mountain Nevada full books in PDF, epub, and Kindle. Read online Effect Of Small Scale Fractures On Flow And Transport Processes At Yucca Mountain Nevada ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Effect of Small-scale Fractures on Flow and Transport Processes at Yucca Mountain, Nevada by :
Download or read book Effect of Small-scale Fractures on Flow and Transport Processes at Yucca Mountain, Nevada written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although many conceptual models for fracture-matrix interaction have been evaluated for Yucca Mountain site-characterization studies, the most widely used model is currently based on the dual-permeability concept. It was chosen for use in site-characterization partially because it has proved to be capable of matching many types of field observed data. Another consideration is that net infiltration rates at the site are estimated to be very low (on the order of millimeters/year), or close to saturated matrix hydraulic conductivity. Recent field studies and tests, in particular, fracture mapping data, collected along the walls of the underground tunnels reveal that there exists a significantly large variety in fracture sizes from centimeters to tens of meters. There is a considerable amount of small-scale fractures that have not been considered in the previous modeling studies. Although the majority of these small fractures may not contribute much to global flow and transport through the fracture-matrix system, they may provide large amounts of storage pore space and allow for additional connection areas for well-connected, large-scale fractures and surrounding matrix blocks, which ultimately affect fracture-matrix interactions. However, the currently used dual-permeability model is unable to include the potentially important effect of small fractures. To overcome the limitations of the dual-permeability approach, we have developed a triple-continuum conceptual model to investigate the impact of small-scale fractures on flow and transport processes in fractured rocks. This new conceptual model subdivides fractures into two types: large-scale and small-scale. Large-scale fractures are those responsible for global connections; small-scale fractures are those that provide large-fracture storage space and enhance the local connections to the matrix system without contributing to global flow or transport. Because the triple-continuum model is composed of the rock matrix and two types of fractures, it can be regarded as an extension of the traditional dual-permeability model. Using a generalized triple-continuum approach, the model formulation uses three parallel sets of conservation equations to describe flow and transport processes at each location of the system, for the two-fracture and one-matrix systems, respectively. The proposed triple-continuum model has been implemented using both analytical and numerical approaches and applied to field problems at Yucca Mountain. First we apply the new conceptual model to estimate model-related fracture-matrix parameters using field observation data and inverse modeling approach. Then we incorporate the estimated parameters to perform 3-D site-scale flow and transport simulations with the current hydrogeological model of Yucca Mountain. The 3-D modeling results with the triple-continuum model indicate that small fractures have significant impact on radionuclide transport in the UZ system, while their effects on flow and heat transfer are insignificant.
Book Synopsis Fracture Variability and Hydrologic Implications at Yucca Mountain, Nevada by :
Download or read book Fracture Variability and Hydrologic Implications at Yucca Mountain, Nevada written by and published by . This book was released on 2001 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: An understanding of the role of fractures at Yucca Mountain, Nevada, is needed to evaluate the suitability of the site to host a high-level nuclear waste repository. Current infiltration rates at Yucca Mountain require water to move through some fractures in the unsaturated welded units because the matrix porosity and permeability of these units are too small to accommodate the total flow. Though only about 20% of connected fractures are estimated to actively transmit water, flow and transport within fractures can greatly affect repository performance because fractures could be fast pathways for migration of radioactive particles. Under the current design, the potential repository would be located in a densely welded tuff sequence with highly variable fracture characteristics. This variability, resulting largely from the presence of lithophysal cavities, creates heterogeneous flow patterns through the unsaturated zone. Lithophysal cavities interrupt the continuity of fractures they intersect and may locally influence fracture propagation. In welded nonlithophysal zones, fractures tend to be longer and more widely spaced than in lithophysal zones, which generally display a greater number of closely spaced, short-length fractures. Seepage of water into potential waste-emplacement drifts will be affected by the fracture characteristics within the surrounding rock wall. Fractures with sufficient capillary suction, permeability, and lateral connectivity can enhance capillary barrier effects and lateral diversion around drift openings, thus reducing the potential for seepage. Lithophysal units, which have high secondary permeability owing to an abundance of well-connected small fractures capable of accommodating lateral flow, may be more favorable for repository performance (i. e., promote less seepage) than nonlithophysal units. Conceptual models for fracture flow based on mapped geometric and hydrologic fracture characteristics are presented, emphasizing the relevant subset of all fractures occurring within the unsaturated tuffs that may impact potential repository performance.
Book Synopsis Conceptual Models of Flow and Transport in the Fractured Vadose Zone by : National Research Council
Download or read book Conceptual Models of Flow and Transport in the Fractured Vadose Zone written by National Research Council and published by National Academies Press. This book was released on 2001-06-21 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid flow and solute transport within the vadose zone, the unsaturated zone between the land surface and the water table, can be the cause of expanded plumes arising from localized contaminant sources. An understanding of vadose zone processes is, therefore, an essential prerequisite for cost-effective contaminant remediation efforts. In addition, because such features are potential avenues for rapid transport of chemicals from contamination sources to the water table, the presence of fractures and other channel-like openings in the vadose zone poses a particularly significant problem, Conceptual Models of Flow and Transport in the Fractured Vadose Zone is based on the work of a panel established under the auspices of the U.S. National Committee for Rock Mechanics. It emphasizes the importance of conceptual models and goes on to review the conceptual model development, testing, and refinement processes. The book examines fluid flow and transport mechanisms, noting the difficulty of modeling solute transport, and identifies geochemical and environmental tracer data as important components of the modeling process. Finally, the book recommends several areas for continued research.
Book Synopsis A Triple-continuum Approach for Modeling Flow and Transportprocesses in Fractured Rock by :
Download or read book A Triple-continuum Approach for Modeling Flow and Transportprocesses in Fractured Rock written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a triple-continuum conceptual model forsimulating flow and transport processes in fractured rock. Field datacollected from the unsaturated zone of Yucca Mountain, a repository siteof high-level nuclear waste, show a large number of small-scalefractures. The effect of these small fractures has not been considered inprevious modeling investigations within the context of a continuumapproach. A new triple-continuum model (consisting of matrix, small-fracture, and large-fracture continua) has been developed toinvestigate the effect of these small fractures. This paper derives themodel formulation and discusses the basic triple-continuum behavior offlow and transport processes under different conditions, using bothanalytical solutions and numerical approaches. The simulation resultsfrom the site-scale model of the unsaturated zone of Yucca Mountainindicate that these small fractures may have an important effect onradionuclide transport within the mountain.
Book Synopsis Yucca Mountain Site Characterization Project Bibliography, 1992-1993 by :
Download or read book Yucca Mountain Site Characterization Project Bibliography, 1992-1993 written by and published by . This book was released on 1994 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Yucca Mountain Site Characterization Project Bibliography, 1994-1995 by :
Download or read book Yucca Mountain Site Characterization Project Bibliography, 1994-1995 written by and published by . This book was released on 1996 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Flow and Transport Through Unsaturated Fractured Rock by : Daniel D. Evans
Download or read book Flow and Transport Through Unsaturated Fractured Rock written by Daniel D. Evans and published by American Geophysical Union. This book was released on 1987 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Rock Fractures and Fluid Flow by : National Research Council
Download or read book Rock Fractures and Fluid Flow written by National Research Council and published by National Academies Press. This book was released on 1996-08-27 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding of fluid flow in rock fracturesâ€"a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storageâ€"has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.
Book Synopsis Estimating the Consequences of Significant Fracture Flow at Yucca Mountain by :
Download or read book Estimating the Consequences of Significant Fracture Flow at Yucca Mountain written by and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple model is proposed for investigating the possibility of significant fracture flow at Yucca Mountain, Nevada. The model allows an estimate of the number of flowing fractures at Yucca Mountain based on the size of the fractures and the yearly volume of infiltrating water. Given the number of flowing fractures, the number of waste containers they contact is estimated by a geometric argument. Preliminary results indicate that the larger the flowing fractures, the lower the releases of radionuclides. Also, even with significant fracture flow, releases could be well below the limits set by the Environmental Protection Agency.
Book Synopsis Hydrology and Geochemistry of Yucca Mountain and Vicinity, Southern Nevada and California by : John S. Stuckless
Download or read book Hydrology and Geochemistry of Yucca Mountain and Vicinity, Southern Nevada and California written by John S. Stuckless and published by Geological Society of America. This book was released on 2012 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Physical and Hydrologic Flow Properties of Fractures by : Christopher C. Barton
Download or read book Physical and Hydrologic Flow Properties of Fractures written by Christopher C. Barton and published by American Geophysical Union. This book was released on 1991-01-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 385. Fractures are one of the most abundant structures in geology and are found in almost all rocks and soils at or near the Earth's surface. They are found over a wide range of length scales, from micro-fractures within mineral grams (micro-meters) to oceanic-intraplate fractures as much as 5000 km in length. The important role of fractures in fluid transport in the crust has long been recognized by geologists who have studied dikes (fracture conduits for flow of igneous rocks) and mineral veins fracture conduits for precipitation from aqueous Fluids). In studying these paleo-flow systems, little attention has been given to quantification of the flow properties of the system. Until two decades ago, hydrologists (Long, 1983) and petroleum-reservoir engineers (Nelson, 1985) studying fluid flow in rock had recognized the role of fractures only qualitatively. Quantitatively, the mathematics of fracture flow had been considered intractable while the mathematics of porous-media flow through the rock matrix had been developed and refined for almost one hundred ears. Direct observation of the flow properties of rock at field scales demonstrated the inadequacy of the porous media models beyond the scale of laboratory samples. The hydraulic conductivity of fractured bulk rock has been measured to be as much as 8 orders of magnitude greater than matrix hydraulic conductivity measured in laboratory samples of the same intact rock. Clearly, fractures are primary conduits for fluid flow in rock at time scales of economic and practical interest. Quantitative understanding of the physics of flow in individual fractures and fracture networks has become an important research topic with direct applications to contemporary and paleo flow systems.
Book Synopsis Update Report on Fracture Flow in Saturated Tuff by : David R. Janecky
Download or read book Update Report on Fracture Flow in Saturated Tuff written by David R. Janecky and published by . This book was released on 1990 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Preliminary Three-dimensional Discrete Fracture Model, Tiva Canyon Tuff, Yucca Mountain Area, Nye County, Nevada by :
Download or read book Preliminary Three-dimensional Discrete Fracture Model, Tiva Canyon Tuff, Yucca Mountain Area, Nye County, Nevada written by and published by . This book was released on 1998 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-dimensional discrete fracture model was completed to investigate the potential effects of fractures on the flow of water at Yucca Mountain, Nye County, Nevada. A fracture network of the Exploratory Studies Facility starter tunnel area was simulated and calibrated with field data. Two modeled volumes were used to simulate three-dimensional fracture networks of the Tiva Canyon tuff. One volume had a width and length of 150 meters, and the other had a width and length of 200 meters; both volumes were 60 meters thick. The analysis shows that the fracture system in the Exploratory Studies Facility starter tunnel area has numerous connected fractures that have relatively large permeabilities. However, pathway analysis between three radial boreholes indicated there were few pathways and little connection, which is consistent with results of cross-boreholes pressure testing. Pathway analysis also showed that at the scales used there was only one pathway connecting one end of the flow box to the opposite end. The usual vertical pathway was along one large fracture, whereas in four horizontal directions the pathway was from multiple fracture connections. As a result, the fracture network can be considered sparse. The fracture network was refined by eliminating nonconductive fractures determined from field-derived permeabilities. Small fractures were truncated from the simulated network without any effect on the overall connectivity. Fractures as long as 1.25 meters were eliminated (a large percentage of the total number of fractures) from the network without altering the number of pathways. Five directional permeabilities were computed for the 150- and 200-meter-scale flow box areas. Permeabilities for the 150-meter scale vary by almost two orders of magnitude, with the principal permeability direction being easterly. At the 200-meter scale, however, the flow box permeabilities only vary by a factor of four, with the principal permeability direction being vertical.
Book Synopsis Scaling Methods in Soil Physics by : Yakov Pachepsky
Download or read book Scaling Methods in Soil Physics written by Yakov Pachepsky and published by CRC Press. This book was released on 2003-03-26 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scaling issue remains one of the largest problems in soil science and hydrology. This book is a unique compendium of ideas, conceptual approaches, techniques, and methodologies for scaling soil physical properties. Scaling Methods in Soil Physics covers many methods of scaling that will be useful in helping scientists across a range of soil-rel
Book Synopsis Flow and Transport Through Unsaturated Fractured Rock by : Daniel D. Evans
Download or read book Flow and Transport Through Unsaturated Fractured Rock written by Daniel D. Evans and published by American Geophysical Union. This book was released on 2001-01-09 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 42. This monograph is an update and revision of the first edition, Geophysical Monograph 42, on ground-water flow and transport through unsaturated, fractured rock, published by AGU in 1987. The first edition evolved from a special symposium held during the American Geophysical Union fall meetings in San Francisco in December 1986. Invited and contributed papers at that AGU session, as well as panel presentations, focused on conceptualizing, measuring and modeling flow and transport through unsaturated fractured rock. As noted in the preface to the first edition, "the expanded interest in the topic (water flow and contaminant transport through unsaturated fractured rock) was initiated when the U.S. Geological Survey proposed that deep unsaturated zones in arid regions be considered in the site selection for the first high-level, commercially generated radioactive waste repository." Much of the research reported in that first edition was motivated by the U.S. Department of Energy's program to investigate Yucca Mountain at the Nevada Test Site as a possible geologic repository for commercially generated, high-level radioactive waste. As noted in the overview paper of the first edition, "characterization methods and modeling are in their developmental stage with the greatest lack of knowledge being the interaction between fracture and matrix flow and transport properties." Although the first edition of this monograph reflected the state-of-the science, laboratory and field experimental programs were novel and limited and, in general, followed from the principles and methods developed in the soil science community.
Book Synopsis Site Characterization Progress Report by :
Download or read book Site Characterization Progress Report written by and published by . This book was released on 1996 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analyzing Flow Patterns in Unsaturated Fractured Rock of YuccaMountain Using an Integrated Modeling Approach by :
Download or read book Analyzing Flow Patterns in Unsaturated Fractured Rock of YuccaMountain Using an Integrated Modeling Approach written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a series of modeling investigations to characterize percolation patterns in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository site for storing high-level radioactive waste. The investigations are conducted using a modeling approach that integrates a wide variety of moisture, pneumatic, thermal, and isotopic geochemical field data into a comprehensive three-dimensional numerical model through model calibration. This integrated modeling approach, based on a dual-continuum formulation, takes into account the coupled processes of fluid and heat flow and chemical isotopic transport in Yucca Mountain's highly heterogeneous, unsaturated fractured tuffs. In particular, the model results are examined against different types of field-measured data and used to evaluate different hydrogeological conceptual models and their effects on flow patterns in the unsaturated zone. The objective of this work to provide understanding of percolation patterns and flow behavior through the unsaturated zone, which is a crucial issue in assessing repository performance.
