States

Texas Register, Volume 19, Number 49, Pages 5067-5128, July 1, 1994 (open access)

Texas Register, Volume 19, Number 49, Pages 5067-5128, July 1, 1994

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: July 1, 1994
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Development of stochastic indicator models of lithology, Yucca Mountain, Nevada (open access)

Development of stochastic indicator models of lithology, Yucca Mountain, Nevada

Indicator geostatistical techniques have been used to produce a number of fully three-dimensional stochastic simulations of large-scale lithologic categories at the Yucca Mountain site. Each realization reproduces the available drill hole data used to condition the simulation. Information is propagated away from each point of observation in accordance with a mathematical model of spatial continuity inferred through soft data taken from published geologic cross sections. Variations among the simulated models collectively represent uncertainty in the lithology at unsampled locations. These stochastic models succeed in capturing many major features of welded-nonwelded lithologic framework of Yucca Mountain. However, contacts between welded and nonwelded rock types for individual simulations appear more complex than suggested by field observation, and a number of probable numerical artifacts exist in these models. Many of the apparent discrepancies between the simulated models and the general geology of Yucca Mountain represent characterization uncertainty, and can be traced to the sparse site data used to condition the simulations. Several vertical stratigraphic columns have been extracted from the three-dimensional stochastic models for use in simplified total-system performance assessment exercises. Simple, manual adjustments are required to eliminate the more obvious simulation artifacts and to impose a secondary set of deterministic geologic features …
Date: July 1, 1994
Creator: Rautman, C.A. & Robey, T.H.
Object Type: Article
System: The UNT Digital Library
Integrated resource planning and the environment: A guide to the use of multi-criteria decision methods (open access)

Integrated resource planning and the environment: A guide to the use of multi-criteria decision methods

This report is intended as a guide to the use of multi-criteria decision-making methods (MCDM) for incorporating environmental factors in electric utility integrated resource planning (IRP). Application of MCDM is emerging as an alternative and complementary method to explicit economic valuation for weighting environmental effects. We provide a step-by-step guide to the elements that are common to all MCDM applications. The report discusses how environmental attributes should be selected and defined; how options should be selected (and how risk and uncertainty should be accounted for); how environmental impacts should be quantified (with particular attention to the problems of location); how screening should be conducted; the construction and analysis of trade-off curves; dominance analysis, which seeks to identify clearly superior options, and reject clearly inferior options; scaling of impacts, in which we translate social, economic and environmental impacts into value functions; the determination of weights, with particular emphasis on ensuring that the weights reflect the trade-offs that decision-makers are actually willing to make; the amalgamation of attributes into overall plan rankings; and the resolution of differences among methods, and between individuals. There are many MCDM methods available for accomplishing these steps. They can differ in their appropriateness, ease of use, validity, …
Date: July 1, 1994
Creator: Hobbs, B.F. & Meier, P.
Object Type: Report
System: The UNT Digital Library
Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada (open access)

Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada

The hydrologic system in the unsaturated tuff at Yucca Mountain, Nevada, is being evaluated for the US Department of Energy by the Yucca Mountain Project Branch of the US Geological Survey as a potential site for a high-level radioactive-waste repository. Part of this investigation includes a hydrochemical study that is being made to assess characteristics of the hydrologic system such as: traveltime, direction of flow, recharge and source relations, and types and magnitudes of chemical reactions in the unsaturated tuff. In addition, this hydrochemical information will be used in the study of the dispersive and corrosive effects of unsaturated-zone water on the radioactive-waste storage canisters. This report describes the design and validation of laboratory experimental procedures for extracting representative samples of uncontaminated pore water from welded and nonwelded, unsaturated tuffs from the Nevada Test Site.
Date: July 1, 1994
Creator: Mower, T. E.; Higgins, J. D.; Yang, In C. & Peters, C. A.
Object Type: Report
System: The UNT Digital Library
A large block heater test for high level nuclear waste management (open access)

A large block heater test for high level nuclear waste management

The radioactive decay heat from nuclear waste packages may, depending on the thermal load, create coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the near-field environment of a repository. A group of tests on a large block (LBT) are planned to provide a timely opportunity to test and calibrate some of the TMHC model concepts. The LBT is advantageous for testing and verifying model concepts because the boundary conditions are controlled, and the block can be characterized before and after the experiment. A block of Topopah Spring tuff of about 3 {times} 3 {times} 4.5 m will be sawed and isolated at Fran Ridge, Nevada Test Site. Small blocks of the rock adjacent to the large block will be collected for laboratory testing of some individual thermal-mechanical hydrological and chemical processes. A constant load of about 4 MPa will be applied to the top and sides of the large block. The sides will be sealed with moisture and thermal barriers. The large block will be heated by heaters within and guard heaters on the sides so that a dry-out zone and a condensate zone will exist simultaneously. Temperature, moisture content, pore pressure, chemical composition, stress, and displacement will be throughout the block during …
Date: July 1, 1994
Creator: Lin, W.; Wilder, D. G. & Blink, J. A.
Object Type: Article
System: The UNT Digital Library
McSKY: A hybrid Monte-Carlo lime-beam code for shielded gamma skyshine calculations (open access)

McSKY: A hybrid Monte-Carlo lime-beam code for shielded gamma skyshine calculations

McSKY evaluates skyshine dose from an isotropic, monoenergetic, point photon source collimated into either a vertical cone or a vertical structure with an N-sided polygon cross section. The code assumes an overhead shield of two materials, through the user can specify zero shield thickness for an unshielded calculation. The code uses a Monte-Carlo algorithm to evaluate transport through source shields and the integral line source to describe photon transport through the atmosphere. The source energy must be between 0.02 and 100 MeV. For heavily shielded sources with energies above 20 MeV, McSKY results must be used cautiously, especially at detector locations near the source.
Date: July 1, 1994
Creator: Shultis, J. K.; Faw, R. E.; Stedry, M. H. & Hall, W.
Object Type: Report
System: The UNT Digital Library
Development studies for a novel wet oxidation process. Phase 2 (open access)

Development studies for a novel wet oxidation process. Phase 2

DETOX{sup SM} is a catalyzed wet oxidation process which destroys organic materials in an acidic water solution of iron at 373 to 473 K. The solution can be used repeatedly to destroy great amounts of organic materials. Since the process is conducted in a contained vessel, air emissions from the process can be well controlled. The solution is also capable of dissolving and concentrating many heavy and radioactive metals for eventual stabilization and disposal. The Phase 2 effort for this project is site selection and engineering design for a DETOX demonstration unit. Site selection was made using a set of site selection criteria and evaluation factors. A survey of mixed wastes at DOE sites was conducted using the Interim Mixed Waste Inventory Report. Sites with likely suitable waste types were identified. Potential demonstration sites were ranked based on waste types, interest, regulatory needs, scheduling, ability to provide support, and available facilities. Engineering design for the demonstration unit is in progress and is being performed by Jacobs Applied Technology. The engineering design proceeded through preliminary process flow diagrams (PFDs), calculation of mass and energy balances for representative waste types, process and instrumentation diagrams (P and IDs), preparation of component specifications, and …
Date: July 1, 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
An updated fracture-flow model for total-system performance assessment of Yucca Mountain (open access)

An updated fracture-flow model for total-system performance assessment of Yucca Mountain

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ``weeps model`` now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive.
Date: July 1, 1994
Creator: Gauthier, J.H.
Object Type: Article
System: The UNT Digital Library
SKYDOSE: A code for gamma skyshine calculations using the integral line-beam method (open access)

SKYDOSE: A code for gamma skyshine calculations using the integral line-beam method

SKYDOS evaluates skyshine dose from an isotropic, monoenergetic, point photon source collimated by three simple geometries: (1) a source in a silo; (2) a source behind an infinitely long, vertical, black wall; and (3) a source in a rectangular building. In all three geometries, an optical overhead shield may be specified. The source energy must be between 0.02 and 100 MeV (10 MeV for sources with an overhead shield). This is a user`s manual. Other references give more detail on the integral line-beam method used by SKYDOSE.
Date: July 1, 1994
Creator: Shultis, J. K.; Faw, R. E.; Brockhoff, R. C. & Hall, W.
Object Type: Report
System: The UNT Digital Library
Great Basin paleoenvironmental studies project; Technical progress report: Fourth quarter, March--May, 1994 (open access)

Great Basin paleoenvironmental studies project; Technical progress report: Fourth quarter, March--May, 1994

Examination of the paleoenvironmental and geomorphic records to determine the local and regional impact of past climates will advance the assessment of Yucca Mountain`s suitability as a high-level nuclear waste repository. Paleobotanical studies will reconstruct the response of vegetation to climate change at the community and the organismal levels in order to identify periods of mesic climate at Yucca Mountain and the adjacent region during the last 20,000 to 50,000 years. Constructing a history of Great Basin vertebrates, particularly mammals, will provide empirical evidence of past environmental and climatic conditions within the Great Basin. The objective of the geomorphology component of the program is to document the responses of surficial processes and landforms to the climatic changes documented by studies of packrat middens, pollens, and faunal distributions. The goal of the transportation component is to compare the results from three models (FESWMS-2DH, DAMBRK, and FLO-2D) that have been suggested as appropriate for evaluating flood flows on alluvial fans with the results obtained from the traditional one-dimensional, stochastic model used in previous research for the Yucca Mountain Project. Progress on all these tasks is described.
Date: July 1, 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The effect of frequency on Young`s modulus and seismic wave attenuation (open access)

The effect of frequency on Young`s modulus and seismic wave attenuation

Laboratory experiments were performed to measure the effect of frequency, water-saturation, and strain amplitude on Young`s modulus and seismic wave attenuation on rock cores recovered on or near the site of a potential nuclear waste repository at Yucca Mountain, Nevada. The purpose of this investigation is to perform the measurements using four techniques: cyclic loading, waveform inversion, resonant bar, and ultrasonic velocity. The measurements ranged in frequency between 10{sup {minus}2} and 10{sup 6} Hz. For the dry specimens Young`s modulus and attenuation were independent of frequency; that is, all four techniques yielded nearly the same values for modulus and attenuation. For saturated specimens, a frequency dependence for both Young`s modulus and attenuation was observed. In general, saturation reduced Young`s modulus and increased seismic wave attenuation. The effect of strain amplitude on Young`s modulus and attenuation was measured using the cyclic loading technique at a frequency of 10{sup {minus}1} Hz. The effect of strain amplitude in all cases was small. For some rocks, such as the potential repository horizon of the Topopah Spring Member tuff (TSw2), the effect of strain amplitude on both attenuation and modulus was minimal.
Date: July 1, 1994
Creator: Price, R. H.; Martin, R. J., III & Haupt, R. W.
Object Type: Report
System: The UNT Digital Library
Improvement of critical current density in thallium-based (Tl, Bi)Sr{sub 1.6}Ba{sub 0.4}Ca{sub 2}Cu{sub 3}O{sub 9-{delta}} superconductors (open access)

Improvement of critical current density in thallium-based (Tl, Bi)Sr{sub 1.6}Ba{sub 0.4}Ca{sub 2}Cu{sub 3}O{sub 9-{delta}} superconductors

Epitaxial (Tl,Bi)Sr{sub 1.6}Ba{sub 0.4}Ca{sub 2}Cu{sub 3}O{sub x} ((Tl, Bi)-1223) thin films on (100) single crystal LaAlO{sub 3} substrates were synthesized by a two-step procedure. Phase development, microstructure, and relationships between film and substrate were studied by x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Resistance versus temperature, zero-field-cooled and field-cooled magnetization, and transport critical current density (J{sub c}) were measured. The zero-resistance temperature was 105--111 K. J{sub c} at 77 K and zero field was >2 {times} 10{sup 6} A/cm{sup 2}. The films exhibited good flux pinning properties.
Date: July 1, 1994
Creator: Ren, Z.F.; Wang, C.A.; Wang, J.H.; Miller, D.J. & Goretta, K.C.
Object Type: Article
System: The UNT Digital Library
Iron oxide mineral-water interface reactions studied by AFM (open access)

Iron oxide mineral-water interface reactions studied by AFM

Natural iron mineral surfaces have been examined in air by atomic force (AFM) and scanning tunneling (STM) microscopies. A number of different surface features were found to be characteristic of the native surface. Even surfaces freshly exposed by crushing larger crystals were found to have a pebbly surface texture caused by the presence of thin coatings of what might be surface precipitates. This finding is interpreted as evidence for previous exposure to water, probably through an extensive network of microfractures. Surface reactions on the goethite crystals were studied by AFM at size resolutions ranging from microns to atomic resolution before, during, and after reaction with distilled water and 0.lN HCl. Immediate and extensive surface reconfiguration occurred on contact with water. In one case, after equilibration with water for 3 days, surface reprecipitation, etching and pitting were observed. Atomic resolution images taken under water were found to be disordered. The result of surface reaction was generally to increase the surface area substantially through the extension of surface platelet arrays, present prior to reaction. This work is being done in support of the site characterization project at Yucca Mountain.
Date: July 1, 1994
Creator: Hawley, M. E. & Rogers, P. S. Z.
Object Type: Article
System: The UNT Digital Library
Efficiency and stray light measurements and calculations of diffraction gratings for the ALS (open access)

Efficiency and stray light measurements and calculations of diffraction gratings for the ALS

Water cooled gratings manufactured for spherical grating monochromators of the Advanced Light Source beamlines 7.0, 8.0 and 9.0 were measured with the laser plasma source and reflectometer in the Center for X-ray Optics at LBL. The square-wave gratings are ion-milled into the polished electroless nickel surface after patterning by holographic photolithography. Absolute efficiency data are compared with exact electromagnetic theory calculation. Inter-order stray light and groove depths can be estimated from the measurements.
Date: July 1, 1994
Creator: McKinney, W.R.; Mossessian, D.; Gullikson, E. & Heimann, P.
Object Type: Article
System: The UNT Digital Library
Scaling behavior of gas permeability measurements in volcanic tuffs (open access)

Scaling behavior of gas permeability measurements in volcanic tuffs

One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property scaling is addressed. Property scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property scaling with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. The approach is to systematically isolate those factors believed to influence property scaling and investigate their relative contributions to overall scaling behavior. Two blocks of tuff, each exhibiting differing heterogeneity structure, have recently been examined. Results of the investigation show very different scaling behavior, as exhibited by changes in the distribution functions and variograms, for the two tuff samples. Even for the relatively narrow range of measurement scales employed significant changes in the distribution functions, variograms, and summary statistics occurred. Because such data descriptors will likely play an important role in calculating effective media properties, these results demonstrate both the need to understand and …
Date: July 1, 1994
Creator: Tidwell, V. C.
Object Type: Article
System: The UNT Digital Library
Modelling renewable electric resources: A case study of wind (open access)

Modelling renewable electric resources: A case study of wind

The central issue facing renewables in the integrated resource planning process is the appropriate assessment of the value of renewables to utility systems. This includes their impact on both energy and capacity costs (avoided costs), and on emissions and environmental impacts, taking account of the reliability, system characteristics, interactions (in dispatch), seasonality, and other characteristics and costs of the technologies. These are system-specific considerations whose relationships may have some generic implications. In this report, we focus on the reliability contribution of wind electric generating systems, measured as the amount of fossil capacity they can displace while meeting the system reliability criterion. We examine this issue for a case study system at different wind characteristics and penetration, for different years, with different system characteristics, and with different modelling techniques. In an accompanying analysis we also examine the economics of wind electric generation, as well as its emissions and social costs, for the case study system. This report was undertaken for the {open_quotes}Innovative IRP{close_quotes} program of the U.S. Department of Energy, and is based on work by both Union of Concerned Scientists (UCS) and Tellus Institute, including America`s Energy Choices and the UCS Midwest Renewables Project.
Date: July 1, 1994
Creator: Bernow, S.; Biewald, B.; Hall, J. & Singh, D.
Object Type: Report
System: The UNT Digital Library
RCRA corrective action: Statement of basis and response to comments decision documents (open access)

RCRA corrective action: Statement of basis and response to comments decision documents

Under the Resource Conservation and Recovery Act (RCRA), Statement of Basis (SB) and Response to Comments (RTC) decision documents are prepared when a corrective action is implemented through either a permit or enforcement order [RCRA {section} 3008(h)]. EPA`s Guidance on RCRA Corrective Action Decision Documents presents a standard format for documenting RCRA corrective action decisions. The guidance clarifies the roles and responsibilities of regulatory agencies in developing and issuing decision documents. DOE, for some corrective actions, may be directed to prepare materials for the Statement of Basis. EPA`s guidance is intended to provide consistency in the organization and content of decision documents as well as promote clear and logical presentations of rationales for remedy selection decisions based on facility-specific information and supporting analysis. This Information Brief summarizes EPA`s guidance on SB and RTC decision documents.
Date: July 1, 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Text for Mechanical and bulk properties in support of ESF design issues (open access)

Text for Mechanical and bulk properties in support of ESF design issues

An intensive laboratory investigation is being performed to determine the mechanical properties of tuffs for the Yucca Mountain Site Characterization Project (YMP). Most recently, experiments are being performed on tuff samples from a series of drill holes along the proposed alignment of the Exploratory Study Facilities (ESF) north ramp. Unconfined compression and indirect tension experiments are being performed and the results are being analyzed with the help of bulk property information. The results on samples from five of the drill holes are presented here. In general, the properties vary widely, but are highly dependent on the sample porosity.
Date: July 1, 1994
Creator: Price, R. H.; Martin, R. J.; Boyd, P. J. & Noel, J. S.
Object Type: Article
System: The UNT Digital Library
Mitigating crosslinking reactions through preconversion strategies. Final report (open access)

Mitigating crosslinking reactions through preconversion strategies. Final report

The primary objective of this project was to determine the effect of reductive pretreatments of low-rank coals through the use of electron-transfer agents. This potential was explored in laboratory studies through determination of the impact on the evolution of oxygen functions, crosslinking, and conversion. The pretreatments explored include treatment with CO/water/base and hydroquinones or other electron-transfer agents in various combinations. The effects of these pretreatments on functional group distribution, macromolecular structure, and liquefaction were compared with those of pretreatments that have in the past shown promise for improved conversions, such as simple hydrothermal pretreatment, mild hydrogenation with dispersed catalysts, and demineralization. Additional objectives were to improve test procedures for assessing the effect of the pretreatment on subsequent liquefaction and to achieve some understanding of the chemical origins of the effects observed. These tests are: (1) proton magnetic resonance thermal analysis, (PMRTA) for determining the effect of pretreatment on fluidity as liquefaction conditions (temperature, pressure) are approached and (2) a thermogravimetric assay (TGA)-based simulated distillation for convenient measurement of product volatility following small-scale batch-liquefaction experiments. The purpose of the PMRTA test is to gain additional insight into whether beneficial pretreatments primarily affect pre-existing crosslinks in the coals or primarily limit additional …
Date: July 1, 1994
Creator: McMillen, D.F. & Malhotra, R.
Object Type: Report
System: The UNT Digital Library
Comparative approaches to siting low-level radioactive waste disposal facilities (open access)

Comparative approaches to siting low-level radioactive waste disposal facilities

This report describes activities in nine States to select site locations for new disposal facilities for low-level radioactive waste. These nine States have completed processes leading to identification of specific site locations for onsite investigations. For each State, the status, legal and regulatory framework, site criteria, and site selection process are described. In most cases, States and compact regions decided to assign responsibility for site selection to agencies of government and to use top-down mapping methods for site selection. The report discusses quantitative and qualitative techniques used in applying top-down screenings, various approaches for delineating units of land for comparison, issues involved in excluding land from further consideration, and different positions taken by the siting organizations in considering public acceptance, land use, and land availability as factors in site selection.
Date: July 1, 1994
Creator: Newberry, W.F.
Object Type: Report
System: The UNT Digital Library
RCRA facility assessments (open access)

RCRA facility assessments

The Hazardous and Solid Waste Amendments of 1984 (HSWA) broadened the authorities of the Resource Conservation and Recovery Act (RCRA) by requiring corrective action for releases of hazardous wastes and hazardous constituents at treatment, storage, and disposal (TSD) facilities. The goal of the corrective action process is to ensure the remediation of hazardous waste and hazardous constituent releases associated with TSD facilities. Under Section 3004(u) of RCRA, operating permits issued to TSD facilities must address corrective actions for all releases of hazardous waste and hazardous constituents from any solid waste management unit (SWMU) regardless of when the waste was placed in such unit. Under RCRA Section 3008(h), the Environmental Protection Agency (EPA) may issue administrative orders to compel corrective action at facilities authorized to operate under RCRA Section 3005(e) (i.e., interim status facilities). The process of implementing the Corrective Action program involves the following, in order of implementation; (1) RCRA Facility Assessment (RFA); (2) RCRA Facility Investigation (RFI); (3) the Corrective Measures Study (CMS); and (4) Corrective Measures Implementation (CMI). The RFA serves to identify and evaluate SWMUs with respect to releases of hazardous wastes and hazardous constituents, and to eliminate from further consideration SWMUs that do not pose a …
Date: July 1, 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Full-scale demonstration of low-NO{sub x} cell{trademark} burner retrofit. Final report (open access)

Full-scale demonstration of low-NO{sub x} cell{trademark} burner retrofit. Final report

The objective of the Low-NO{sub x} Cell{trademark}Burner (LNCB{trademark}) demonstration is to evaluate the applicability of this technology for reducing NO{sub x} emissions in full-scale, cell burner-equipped boilers. More precisely, the program objectives are to: (1) Achieve at least a 50% reduction in NO{sub x} emissions. (2) Reduce NO{sub x} with no degradation to boiler performance or life of the unit. (3) Demonstrate a technically and economically feasible retrofit technology. Cell burner equipped boilers comprise 13% of the Pre-New Source Performance Standards (NSPS) coal-fired generating capacity. This relates to 34 operating units generating 23,639 MWe, 29 of which are opposed wall fired with two rows of two-nozzle cell burners on each wall. The host site was one of these 29. Dayton Power & Light offered use of J.M. Stuart Station`s Unit No. 4 as the host site. It was equipped with 24, two-nozzle cell burners arranged in an opposed wall configuration. To reduce NO{sub x} emissions, the LNCB{trademark} has been designed to delay the mixing of the fuel and combustion air. The delayed mixing, or staged combustion, reduces the high temperatures normally generated in the flame of a standard cell burner. A key design criterion for the burner was accomplishing delayed …
Date: July 1, 1994
Creator: Eckhart, C.F.; Kitto, J.B. & Kleisley, R.J.
Object Type: Report
System: The UNT Digital Library
Effect of fractures on repository dryout (open access)

Effect of fractures on repository dryout

Calculations of water flow through Yucca Mountain show significant dryout and water perching in the vicinity of the proposed nuclear waste repository. These calculations also show that the extent of the dryout and perched water zones is a strong function of the material characteristics which are used to represent the fracture zones. The results show that for 100 {mu}m fracture case appreciable dryout and perched regions exist. When 1 {mu}m fractures are used no dryout or perched regions are calculated.
Date: July 1, 1994
Creator: Eaton, R. R.
Object Type: Report
System: The UNT Digital Library
Relation between static and dynamic rock properties in welded and nonwelded tuff (open access)

Relation between static and dynamic rock properties in welded and nonwelded tuff

An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada involves accurate prediction of the in situ rheology for design and construction of the facility and emplacement of the canisters containing radioactive waste. The data required as input to successful thermal and mechanical models of the behavior of the repository and surrounding lithologies include bulk density, grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensile strengths. In this study a suite of experiments was performed on cores recovered from the USW-NRG-6 borehole drilled to support the Exploratory Studies Facility (ESF) at Yucca Mountain. USW-NRG-6 was drilled to a depth of 1100 feet through four thermal/mechanical units of Paintbrush tuff. A large data set has been collected on specimens recovered from borehole USW-NRG-6. Analysis of the results of these experiments showed that there is a correlation between fracture strength, Young`s modulus, compressional wave velocity and porosity. Additional scaling laws relating; static Young`s modulus and compressional wave velocity; and fracture strength and compressional wave velocity are promising. Since there are no other distinct differences in material properties, the scatter that is present at each fixed porosity suggests that the differences …
Date: July 1, 1994
Creator: Price, R. H.; Boyd, P. J.; Noel, J. S. & Martin, R. J., III
Object Type: Report
System: The UNT Digital Library