Download or read book Analysis of Fracture in Cores from the Tuff Confining Unit Beneath Yucca Flat Nevada Test Site written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.

Download or read book Geohydrology of Volcanic Tuff Penetrated by Test Well UE 25b 1 Yucca Mountain Nye County Nevada written by R. G. Lahoud and published by . This book was released on 1984 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Evaluation of Hydrologic Properties of Cores of Unsaturated Tuff Test Well USW H 1 Yucca Mountain Nevada written by Edwin P. Weeks and published by . This book was released on 1984 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thickness of Surficial Deposits and Tuff in Yucca Flat Nevada Test Site written by Arthur Thomas Fernald and published by . This book was released on 1970 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification And Characterization of Hydrologic Properties of Fractured Tuff Using Hydraulic and Tracer Tests written by and published by . This book was released on 1985 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Characterization of Hydrologic Properties of Fractured Tuff Using Hydraulic and Tracer Tests test Well USW H 4 Yucca Mountain Nye County Nevada written by J. R. Erickson and published by . This book was released on 1985 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frictional Sliding and Fracture Behavior of Some Nevada Test Site Tuffs written by and published by . This book was released on 1984 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deformation studies were performed on tuffaceous rocks from Yucca Mountain, Nevada Test Site to determine the strengths and coefficients of friction under confining pressures from 10 to 50 MPa at room temperature. Frictional strengths of 30° sawcut samples increased with pressure and reached values of around 150 MPa at the higher confining pressures. However, the failure strengths of the intact samples were quite unpredictable. The coefficients of friction ranged between 0.7 and 0.9 for all specimens. These data can be used in conjunction with in situ stress measurements at Yucca Mountain, to evaluate the potential for earthquake activity in the region. 1 ref., 7 figs.

Download or read book Hydraulic Characterization of Overpressured Tuffs in Central Yucca Flat Nevada Test Site Nye County Nevada written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

Download or read book Analysis of the Rock Mechanics Properties of Volcanic Tuff Units from Yucca Mountain Nevada Test Site written by Ronald Harlow Price and published by . This book was released on 1983 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydraulic Characterization of Overpressured Tuffs in Central Yucca Flat Nevada Test Site Nye County Nevada written by Keith J. Halford and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fractured Core Analysis written by Byron R. Kulander and published by . This book was released on 1990 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Characterization of the Large block Test Fran Ridge Yucca Mountain Nevada written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The US Department of Energy (DOE) is investigating the suitability of Yucca Mountain as a potential site for the nation's first high-level nuclear waste repository. The site is located about 120 km northwest of Las Vegas, Nevada, at the Nevada Test Site. Favorable aspects of Yucca Mountain as a potential repository site include its arid nature and the sorptive properties of the rock materials. The arid environment results in unsaturated conditions at the potential emplacement horizon, which is the Topopah Spring tuff of the Paintbrush Group. The Large Block Test (LBT) was designed to be one of a series of tests at different scales and conditions that assist in defining the physical processes that need to be considered in models of a potential repository in Yucca Mountain. The LBT is a critical test because it is of sufficient size to incorporate a fracture system that is representative of the distribution of fracture dimensions and characteristics--with the exception of major structures, such as faults--that would likely be present in a repository. The LBT location was chosen to include large, through-going fractures as well as small, healed fractures that are of limited extent. The LBT location also includes a variety of fracture sizes, connectivities, and characteristics that fall between the bounds of the large and very small fractures. The LBT allows for boundary controls and monitoring that are somewhat similar to those typical of laboratory studies, and it allows for three-dimensional (3-D) characterization and monitoring. The unique combination of size with boundary controls of the LBT allows processes to be evaluated and models to be tested more completely than in tests of any other scale (Wilder et al. 1997, Section 1).

Download or read book Summary of Micrographic Analysis of Fracture Coating Phases on Drill Cores from Pahute Mesa Nevada Test Site Revision 1 written by and published by . This book was released on 1998 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow path between Pahute Mesa and the groundwater discharge area in Oasis Valley (approximately 18 miles to the southwest) is of concern due to the relatively short travel distance between a recharge area where underground nuclear testing has been conducted and the off-site water users. Groundwater flow and transport modeling by IT Corporation (IT) has shown rapid tritium transport in the volcanic rock aquifers along this flow path. The resultant estimates of rapid transport were based on water level data, limited hydraulic conductivity data, estimates of groundwater discharge rates in Oasis Valley, assumed porosities, and estimated retardation rates. Many of these parameters are poorly constrained and may vary considerably. Sampling and analytical techniques are being applied as an independent means to determine transport rates by providing an understanding of the geochemical processes that control solute movement along the flow path. As part of these geochemical investigations, this report summarizes the analysis of fracture coating mineral phases from drill core samples from the Pahute mesa area of the Nevada Test Site (NTS). Archived samples were collected based on the presence of natural fractures and on the types and abundance of secondary mineral phases present on those fracture surfaces. Mineral phases present along fracture surfaces are significant because, through the process of water-rock interaction, they can either contribute (as a result of dissolution) or remove (as a result of precipitation or adsorption) constituents from solution. Particular attention was paid to secondary calcite occurrences because they represent a potential source of exchangeable carbon and can interact with groundwater resulting in a modified isotopic signature and apparent water age.

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:

Download or read book Creep in Topopah Spring Member Welded Tuff written by R. J. Martin and published by . This book was released on 1995 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fractured Core Analysis written by Byron R. Kulander and published by . This book was released on 1990-01-01 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Flow and Transport in Partially Saturated Fractured Tuff written by and published by . This book was released on 1983 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unsaturated, fractured tuff of Yucca Mountain in the Nevada Test Site is one of the target sites for geologic storage of high-level radioactive waste. A modeling study of flow and transport in this geologically complex site is presented. Numerical models of mass and heat flow in conjunction with analytical solutions are being used for sensitivity and pathway analysis studies and to aid in design and interpretation of laboratory and field flow and transport tests in tuff. 11 references, 9 figures, 1 table.