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Radiochemical analyses of samples from beneath a solid radioactive waste disposal pit at Los Alamos, New Mexico

Description: Solid radioactive wastes are disposed of by burial in pits excavated in rhyolite tuff at the Los Alamos Scientific Laboratory (LASL). Contaminants in the waste include fission products, uranium, and transuranic elements. In 1976, horizontal core holes were drilled beneath a waste disposal pit that was used from 1963 to 1966. Samples of the core were analyzed for gross alpha, gross beta, total uranium, /sup 90/Sr, /sup 137/Cs, /sup 238/Pu, /sup 239/ /sup 240/Pu, and /sup 241/Am. The measured gro… more
Date: June 1, 1980
Creator: Purtymun, W. D.; Rogers, M. A. & Wheeler, M. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High-energy gas fracturing in cased and perforated wellbores

Description: A propellant-based technology, High-Energy Gas Fracturing (HEGF), has been applied to fracturing through perforations in cased boreholes. HEGF is a tailored-pulse fracturing technique originally developed by Sandia National Laboratories for application in uncased, liquid-free gas wells in Appalachian Devonian shales. Because most oil and gas wells are liquid filled as well as cased and perforated, the potential impact of present research is significantly broader. A number of commercial tailored… more
Date: June 1, 1986
Creator: Cuderman, J.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of Thermally Induced Changes in Fractured Rock Permeability during Eight Years of Heating and Cooling at the Yucca Mountain Drift Scale Test

Description: We analyzed a data set of thermally induced changes in fractured rock permeability during a four-year heating (up to 200 C) and subsequent four-year cooling of a large volume, partially saturated and highly fractured volcanic tuff at the Yucca Mountain Drift Scale Test, in Nevada, USA. Permeability estimates were derived from about 700 pneumatic (air-injection) tests, taken periodically at 44 packed-off borehole intervals during the heating and cooling cycle from November 1997 through November … more
Date: June 1, 2008
Creator: Rutqvist, J.; Freifeld, B.; Min, K.-B.; Elsworth, D. & Tsang, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparative yield estimation via shock hydrodynamic methods

Description: Shock TOA (CORRTEX) from recent underground nuclear explosions in saturated tuff were used to estimate yield via the simulated explosion-scaling method. The sensitivity of the derived yield to uncertainties in the measured shock Hugoniot, release adiabats, and gas porosity is the main focus of this paper. In this method for determining yield, we assume a point-source explosion in an infinite homogeneous material. The rock is formulated using laboratory experiments on core samples, taken prior t… more
Date: June 1, 1991
Creator: Attia, A. V.; Moran, B. & Glenn, L. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Infiltration and Seepage Through Fractured Welded Tuff

Description: The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled … more
Date: June 20, 2006
Creator: Ghezzehei, T. A.; Dobson, P. F.; Rodriguez, J. A. & Cook, P. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of Permeability Change Due to Coupled Thermal-Hydrological-Mechanical Effects

Description: The purpose of this calculation is to provide a bounding estimate of how thermal-hydrological-mechanical (THM) behavior of rock in the region surrounding an emplacement drift in a Monitored Geologic Repository subsurface facility may affect the permeability of fractures in the rock mass forming the region. The bounding estimate will provide essential input to performance assessment analysis of the potential repository system. This calculation also supports the Near Field Environment Process Mod… more
Date: June 28, 2000
Creator: Blair, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Geochemistry of Natural Components in the Near-Field Environment, Yucca Mountain, Nevada

Description: The natural near-field environment in and around the emplacement drifts of the proposed nuclear waste repository at Yucca Mountain, Nevada, includes the host rock, dust, seepage water, and pore water. The chemical compositions of these components have been analyzed to provide a basis for assessing possible chemical and mineralogical reactions that may occur in and around the emplacement drifts during the heating and cooling cycle. The crystal-poor rhyolite of the Topopah Spring Tuff of Miocene … more
Date: June 19, 2006
Creator: Peterman, Z. E. & Oliver, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Influence of Lithophysal Geometry on the Uniaxial Compression of Tuff-Like Rock

Description: A large portion of the rock of the high-level nuclear waste repository at Yucca Mountain contains lithophysae or voids. These voids have a significant detrimental effect on the engineering properties of the rock mass and its performance. The lithophysae were formed at the time of volcanic deposition by pockets of gas trapped within the compressing and cooling pyroclastic flow material. Lithophysae vary by size, shape, and spatial frequency of occurrence. Due to the difficulties of testing actua… more
Date: June 13, 2007
Creator: Rigby, Douglas B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preliminary Estimates of Specific Discharge and TransportVelocities near Borehole NC-EWDP-24PB

Description: This report summarizes fluid electrical conductivity (FEC)and thermal logging data collected in Borehole NC-EWDP-24PB, locatedapproximately 15 km south of the proposed repository at Yucca Mountain.Preliminary analyses of a small fraction of the FEC and temperature dataindicate that relatively large, localized fluid fluxes are likely toexist at this location. The implication that considerable flow is inducedby small gradients, and that flow is highly localized, is significant forthe estimation o… more
Date: June 21, 2006
Creator: Freifeld, Barry; Doughty, Christine & Finsterle, Stefan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Creep in Topopah Spring Member welded tuff. Yucca Mountain Site Characterization Project

Description: A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 {times} 10{sup 5} secon… more
Date: June 1, 1995
Creator: Martin, R. J., III; Boyd, P. J.; Noel, J. S. & Price, R. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High-Resolution Aeromagnetic Survey Map of Part of the Southwest Nevada Volcanic Field

Description: A high-resolution aeromagnetic survey was recently flown to collect data for geologic investigations in the Southwest Nevada Volcanic Field. This survey represents a marked improvement over previous (1999) surveys. The survey includes over 860 km{sup 2} covered by nearly 16,000 km of flightline with 60-m spacing and an instrument altitude of 30 m above the ground surface. Features of interest visible in the dataset include magnetic banding in the volcanic tuffs that form the faulted terrain and… more
Date: June 21, 2004
Creator: Keating, G.; Prueitt, R. & Cogbill, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Physical, Chemical and Structural Evolution of Zeolite-Containing Waste Forms Produced from Metakaolinite and Calcined Sodium Bearing Waste (HLW and/or LLW)

Description: Zeolites are extremely versatile. They can adsorb liquids and gases and serve as cation exchange media. They occur in nature as well cemented deposits. The ancient Romans used blocks of zeolitized tuff as a building material. Using zeolites for the management of radioactive waste is not a new idea, but a process by which the zeolites can be made to act as a cementing agent is. Zeolitic materials are relatively easy to synthesize from a wide range of both natural and man-made substances. The pro… more
Date: June 27, 2005
Creator: Grutzeck, Michael W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Assessing Groundwater Model Uncertainty for the Central Nevada Test Area

Description: The purpose of this study is to quantify the flow and transport model uncertainty for the Central Nevada Test Area (CNTA). Six parameters were identified as uncertain, including the specified head boundary conditions used in the flow model, the spatial distribution of the underlying welded tuff unit, effective porosity, sorption coefficients, matrix diffusion coefficient, and the geochemical release function which describes nuclear glass dissolution. The parameter uncertainty was described by a… more
Date: June 14, 2002
Creator: Pohll, Greg; Pohlmann, Karl; Hassan, Ahmed; Chapman, Jenny & Mihevc, Todd
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Transport of Radon Gas into a Tunnel at Yucca Mountain-Estimating Large-Scale Fractured Tuff Hydraulic Properties and Implications for the Operation of the Ventilation System

Description: Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentration… more
Date: June 6, 2003
Creator: Unger, A.; Finsterle, S. & Bodvarsson, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Anisotropy of mechanical properties of tuff at Yucca Mountain

Description: The purpose of this study is to investigate anisotropy of mechanical properties, namely, compressive strength and modulus, for Tiva Canyon welded tuff from the starter tunnel at Yucca Mountain. Mechanical properties of Tiva Canyon Tuff are needed for the design of the ramps and drifts within the Tiva Canyon horizon. Approximately one cubic foot block samples, all of which were from the thermo -- mechanical unit TCw, were obtained from a muck pile containing excavated rock from the starter tunne… more
Date: June 1, 1995
Creator: Karakouzian, M. & Hudyma, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Summary evaluation of Yucca Mountain surface transects with implications for downhole sampling. Yucca Mountain Site Characterization Project

Description: The results of previously completed vertical outcrop sampling transacts are summarized with respect to planning downhole sampling. The summary includes statistical descriptions and descriptions of the spatial variability of the sampled parameters. Descriptions are made on each individual transect, each thermal/mechanical unit and each previously defined geohydrologic unit. Correlations between parameters indicate that saturated hydraulic conductivity is not globally correlated to porosity. The … more
Date: June 1, 1995
Creator: McKenna, S. A. & Rautman, C. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Review of Degradation Behavior of Container Materials for Disposal of High-Level Nuclear Waste in Tuff and Alternative Repository Environments

Description: Corrosion resistance of materials in aqueous systems is reviewed from the perspective of their suitability as container materials for nuclear waste. A discussion of the chemistry and characterization of repository environments, namely, tuff and alternative environments (shale, limestone, and carbonate), is followed by a description of corrosion mechanisms. In this review, emphasis is placed on localized corrosion (e.g., stress corrosion cracking, crevice corrosion, and pitting) because localize… more
Date: June 1989
Creator: Maiya, P. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Evaluation and compilation of DOE waste package test data; Volume 8: Biannual report, August 1989--January 1990

Description: This report summarizes evaluations by the National Institute of Standards and Technology (NIST) of some of the Department of Energy (DOE) activities on waste packages designed for containment of radioactive high-level nuclear waste (HLW) for the six-month period, August 1989--January 1990. This includes reviews of related materials research and plans, information on the Yucca Mountain, Nevada disposal site activities, and other information regarding supporting research and special assistance. S… more
Date: June 1, 1993
Creator: Interrante, C. G.; Fraker, A. C. & Escalante, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Mechanical Characterization of Densely Welded Apache Leap Tuff

Description: An empirical criterion is formulated to describe the compressive strength of the densely welded Apache Leap tuff. The criterion incorporates the effects of size, L/D ratio, loading rate and density variations. The criterion improves the correlation between the test results and the failure envelope. Uniaxial and triaxial compressive strengths, Brazilian tensile strength and elastic properties of the densely welded brown unit of the Apache Leap tuff have been determined using the ASTM standard te… more
Date: June 1, 1991
Creator: Fuenkajorn, K. & Daemen, J. J. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Critical assessment of seismic and geomechanics literature related to a high-level nuclear waste underground repository

Description: A comprehensive literature assessment has been conducted to determine the nature and scope of technical information available to characterize the seismic performance of an underground repository and associated facilities. Significant deficiencies were identified in current practices for prediction of seismic response of underground excavations in jointed rock. Conventional analytical methods are based on a continuum representation of the host rock mass. Field observations and laboratory experim… more
Date: June 1991
Creator: Kana, D. D.; Vanzant, B. W.; Nair, P. K. & Brady, B. H. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Estimation of hydraulic conductivities of Yucca Mountain tuffs from sorptivity and water retention measurements

Description: The hydraulic conductivity functions of the matrix rocks at Yucca Mountain, Nevada, are among the most important data needed as input for the site-scale hydrological model of the unsaturated zone. The difficult and time-consuming nature of hydraulic conductivity measurements renders it infeasible to directly measure this property on large numbers of cores. Water retention and sorptivity measurements, however, can be made relatively rapidly. The sorptivity is, in principle, a unique functional o… more
Date: June 1, 1995
Creator: Zimmerman, R.W. & Bodvarsson, G.S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Radioelements and their occurrence with secondary minerals in heated and unheated tuff at the Nevada Test Site

Description: Samples of devitrified welded tuff near and away from the site of a heater test in Rainier Mesa were examined with regard to whole-rock radioelement abundances, microscopic distribution of U, and oxygen isotope ratios. Wholerock U averages between 4 and 5 ppM, and U is concentrated at higher levels secondary opaque minerals as well as in accessory grains. U in primary and secondary sites is most commonly associated with Mn phases, which average {approximately}30 ppM U in more uraniferous occurr… more
Date: June 1, 1992
Creator: Flexser, S. & Wollenberg, H.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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On the movement of a liquid front in an unsaturated, fractured porous medium, Part 1

Description: The primary aim of this paper is to present approximate analytical solutions of the fracture flow which gives the position of the liquid fracture front as a function of time. These solutions demonstrate that the liquid movement in the fracture can be classified into distinctive time periods, or flow regimes. It is also shown that when plotted versus time using a log-log scale, the liquid fracture front position asymptotically approaches a series of line segments. Two-dimensional numerical simul… more
Date: June 1, 1989
Creator: Nitao, J. J. & Buscheck, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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