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Independent Safety Assessment of the TOPAZ-II space nuclear reactor power system (Revised)

Description: The Independent Safety Assessment described in this study report was performed to assess the safety of the design and launch plans anticipated by the U.S. Department of Defense (DOD) in 1993 for a Russian-built, U.S.-modified, TOPAZ-II space nuclear reactor power system. Its conclusions, and the bases for them, were intended to provide guidance for the U.S. Department of Energy (DOE) management in the event that the DOD requested authorization under section 91b. of the Atomic Energy Act of 1954, as amended, for possession and use (including ground testing and launch) of a nuclear-fueled, modified TOPAZ-II. The scientists and engineers who were engaged to perform this assessment are nationally-known nuclear safety experts in various disciplines. They met with participants in the TOPAZ-II program during the spring and summer of 1993 and produced a report based on their analysis of the proposed TOPAZ-II mission. Their conclusions were confined to the potential impact on public safety and did not include budgetary, reliability, or risk-benefit analyses.
Date: September 1, 1993
Partner: UNT Libraries Government Documents Department

Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada

Description: Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on three 214- to 260-m 2 pavements cleared of debris in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paint-brush Tuff. The pavements are two-dimensional sections through the three-dimensional network of strata-bound fractures. All fractures with trace lengths greater than 0.2 m were mapped and studied.
Date: December 31, 1993
Creator: Barton, C.C.; Larsen, E.; Page, W.R. & Howard, T.M.
Partner: UNT Libraries Government Documents Department

Diffusion in phase space

Description: In order to study diffusion in any region of phase space containing nested closed curves we choose action-angle variables, {gamma}, J. the action J labels each closed phase curve and is equal to its area divided by 2{pi}. We can introduce rectangular variables Q,P by the equations Q=(2J){sup 1/2}sin{gamma}, P=(2J){sup 1/2}cos{gamma}, where the angle variable {gamma} is measured clockwise from the P-axis. The phase curves are circles in the Q,P plane with radius (2J){sup 1/2}. We assume that the motion consists of a Hamiltonian motion along a curve of fixed J (in the original coordinate system and in the system Q,P) plus a diffusion and a damping which can change the value of J. Now consider a system of particles described by a density {rho}(J,t), so that the number of particles between the curves J and J+dJ is dN={rho}(J,t)dJ. These cN particles are distributed uniformly in the phase space between the curves J and J+dJ.
Date: April 5, 1993
Creator: Symon, K.
Partner: UNT Libraries Government Documents Department

Fabric composite radiators for space nuclear power applications. Final report, March 1993

Description: Nuclear power systems will be required to provide much greater power levels for both civilian and defense space activities in the future than an currently needed. Limitations on the amount of usable power from radioisotope thermal generators and the limited availability of radioisotope heat source materials lead directly to the conclusion that nuclear power reactors will be needed to enhance the exploration of the solar system as well as to provide for an adequate defense. Lunar bases and travel to the Martian surface will be greatly enhanced by the use of high levels of nuclear power. Space based radar systems requiring many kilowatts of electrical power can provide intercontinental airline traffic control and defense early warning systems. Since the, figure of merit used in defining any space power system is the specific power, the decrease in die mass of any reactor system component will yield a tremendous benefit to the overall system performance. Also, since the heat rejection system of any power system can make up a large portion of the total system mass, any reduction in the mass of the heat rejection radiators will significantly affect the performance of the power system. Composite materials which combine the high strength, flexibility, and low mass characteristics of Si% based fibers with the attractive compatibility and heat transfer features of metallic foils, have been proposed for use m a number of space radiator applications. Thus, the weave of the fabric and the high strength capability of the individual fibers are combined with the high conductivity and chemical stability of a metallic liner to provide a light weight, flexible alternative to heavy, rigid, metallic radiator structural containers. The primary focus of this investigation revolves around two applications of the fabric composite materials, notably a fabric heat pipe radiator design and the Bubble Membrane ...
Date: March 24, 1993
Creator: Klein, A.C.; Al-Baroudi, H.; Gulshan-Ara, Z.; Kiestler, W.C.; Snuggerud, R.D.; Abdul-Hamid, S.A. et al.
Partner: UNT Libraries Government Documents Department

Maximum likelihood borehole corrections for dual-detector density logs

Description: This report discusses Dual-detector density logs which have been used in the petroleum industry for years. The tool was designed with a second detector to allow compensation for the effect of a layer of mudcake between the tool and the formation being measured. The compensation algorithm commonly used calculates the correction to apply to the density measured by the long-spaced detector as proportional to the difference in the densities measured by the two detectors. The coefficient of proportionality is determined from experimental data taken with the tool in a fluid-filled hole of 15 to 40 cm diameter, with uniform thickness sheets of various materials simulating the mudcake. In applying this technology for the Containment program at the Department of Energy Nevada Test Site (NTS) we have discovered two problems. First, we frequently log in air-filled holes much larger than 40 cm. Second, the gap, or layer, is rarely uniform with depth or vertical position on the face of the tool. We have developed a method to determine the proper amount of correction dynamically. No experimental data on the gap effect are needed as long as the two detectors are calibrated to read the proper density when the gap is zero. The method assumes that the form of the equation used in the standard algorithm is correct, but uses the variation of the two density signals with depth to determine the appropriate value of the coefficient, assuming true density varies more slowly than the gap effects. This new, maximum likelihood, method appears to work better than the standard method in both fluid and air-filled holes where the borehole wall is rough and no mudcake is present. It cannot, however, correct for a uniform mudcake or air gap, and so complements but does not replace the standard method.
Date: October 1, 1993
Creator: Carlson, R.C.
Partner: UNT Libraries Government Documents Department

Proposed particle-beam characterizations for the APS undulator test line

Description: A research and development effort is underway at the Advanced Photon Source (APS) to use an rf gun as a low-emittance electron source for injection into the 100- to 650-MeV linac subsystem and subsequently to an undulator test area. This configuration would combine the acceleration capability of the 200-MeV S-band electron linac and the in-line 450-MeV positron linac that normally provide positrons to the positron accumulator ring (PAR). A transport line that bypasses the PAR will bring the electrons to the undulator test area. Characterization techniques will be discussed for the electron beam with a normalized, rms emittance of <10 {pi} mm mrad (1{sigma}) at micropulse charges of up to 350 pC and micropulse durations of {approximately}5 ps (FWHM). Tests proposed include measurement of particle beam transport effects (at one-tenth the storage ring beam rigidity) caused by small undulator field errors as well as operations intended to produce coherent, short wavelength radiation (<200 nm).
Date: September 1, 1993
Creator: Lumpkin, A.H.; Borland, M. & Milton, S.
Partner: UNT Libraries Government Documents Department

Preliminary Hazards Analysis Plasma Hearth Process

Description: This Preliminary Hazards Analysis (PHA) for the Plasma Hearth Process (PHP) follows the requirements of United States Department of Energy (DOE) Order 5480.23 (DOE, 1992a), DOE Order 5480.21 (DOE, 1991d), DOE Order 5480.22 (DOE, 1992c), DOE Order 5481.1B (DOE, 1986), and the guidance provided in DOE Standards DOE-STD-1027-92 (DOE, 1992b). Consideration is given to ft proposed regulations published as 10 CFR 830 (DOE, 1993) and DOE Safety Guide SG 830.110 (DOE, 1992b). The purpose of performing a PRA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PRA then is followed by a Preliminary Safety Analysis Report (PSAR) performed during Title I and II design. This PSAR then leads to performance of the Final Safety Analysis Report performed during construction, testing, and acceptance and completed before routine operation. Radiological assessments indicate that a PHP facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous material assessments indicate that a PHP facility will be a Low Hazard facility having no significant impacts either onsite or offsite to personnel and the environment.
Date: November 1, 1993
Creator: Aycock, M.; Coordes, D.; Russell, J.; TenBrook, W. & Yimbo, P.
Partner: UNT Libraries Government Documents Department

Studies of non-isothermal flow in saturated and partially saturated porous media

Description: Physical and numerical experiments have been performed to investigate the behavior of nonisothermal flow in two-dimensional saturated and partially saturated porous media. The physical experiments were performed to identify non-isothermal flow fields and temperature distributions in fully saturated, half-saturated, and residually saturated two-dimensional porous media with bottom heating and top cooling. Two counter-rotating liquid-phase convective cells were observed to develop in the saturated regions of all three cases. Gas-phase convection was also evidenced in the unsaturated regions of the partially saturated experiments. TOUGH2 numerical simulations of the saturated case were found to be strongly dependent on the assumed boundary conditions of the physical system. Models including heat losses through the boundaries of the test cell produced temperature and flow fields that were in better agreement with the observed temperature and flow fields than models that assumed insulated boundary conditions. A sensitivity analysis also showed that a reduction of the bulk permeability of the porous media in the numerical simulations depressed the effects of convection, flattening the temperature profiles across the test cell.
Date: December 31, 1993
Creator: Ho, C.K.; Maki, K.S. & Glass, R.J.
Partner: UNT Libraries Government Documents Department

Water levels in continuously monitored wells in the Yucca Mountain area, Nevada, 1985--88

Description: Water levels have been monitored hourly in 15 wells completed in 23 depth intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water- level measurements. The amount of transducer output that was converted to water levels ranged from zero for several intervals to about 98 percent for one interval. Fourteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed.
Date: July 1, 1993
Creator: Luckey, R.R.; Lobmeyer, D.H. & Burkhardt, D.J.
Partner: UNT Libraries Government Documents Department

Effects of radionuclide decay on waste glass behavior: A critical review

Description: This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact.
Date: December 1, 1993
Creator: Wronkiewicz, D.J.
Partner: UNT Libraries Government Documents Department

Role of magma-water interaction in very large explosive eruptions

Description: An important class of explosive eruptions, involving large-scale magma-water interaction during the discharge of hundreds to thousands of cubic kilometers of magma, is discussed. Geologic evidence for such eruptions is summarized. Case studies from New Zealand, Australia, England, and the western United States are described, focusing on inferred eruption dynamics. Several critical problems that need theoretical and experimental research are identified. These include rates at which water can flow into a volcanic vent or plumbing system, entrainment of water by explosive eruptions through lakes and seas, effects of magma properties and gas bubbles on magma-water interaction, and hazards associated with the eruptions.
Date: November 1, 1993
Creator: Valentine, G.A.
Partner: UNT Libraries Government Documents Department

Technical evaluation of available state of Nevada survey instruments

Description: Argonne National Laboratory (ANL) is reviewing the survey research studies completed by Mountain West Research (1987-1989) for the state of Nevada`s Nuclear Waste Project Office. In this research, 14 survey instruments were used to seek data on whether perceptions of risk could be associated with the possible siting of a high-level radioactive waste repository in Nevada and could be a dominant source of potential, significant, adverse economic impacts. This report presents results from phase 1 of the review, in which ANL contracted with the National Opinion Research Center (NORC) at the University of Chicago to evaluate the technical merits of the nine survey instruments that ANL had been able to acquire. The scope of NORC`s work was limited to rating the questions and stating their strengths and weaknesses. NORC concluded that the surveys could provide valuable data about risk perceptions and potential behavioral responses. NORC identified a few minor problems with a number of questions and the calculated response rates but claimed these problems would probably not have any major biasing effect. The NORC evaluation would have been more complete if the terms used in the questionnaires had been defined, all survey instruments had been acquired, and all data had been made available to the public.
Date: February 1993
Partner: UNT Libraries Government Documents Department

Particle interations in concentrated suspensions

Description: An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. We describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. We suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. We also describe data from experiments in which the detailed fluctuations of a falling ball`s velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, we briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions.
Date: June 1, 1993
Creator: Mondy, L.A.; Graham, A.L.; Abbott, J.R. & Brenner, H.
Partner: UNT Libraries Government Documents Department

Large-scale in situ heater tests for hydrothermal characterization at Yucca Mountain

Description: To safely and permanently store high-level nuclear waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact a waste package, accelerate its failure rate, and eventually transport radionuclides to the water table. Our analyses indicate that the ambient hydrological system will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years. In situ heater tests are required to provide an understanding of coupled geomechanical-hydrothermal-geochemical behavior in the engineered and natural barriers under repository thermal loading conditions. In situ heater tests have been included in the Site Characterization Plan in response to regulatory requirements for site characterization and to support the validation of process models required to assess the total systems performance at the site. Because of limited time, some of the in situ tests will have to be accelerated relative to actual thermal loading conditions. We examine the trade-offs between the limited test duration and generating hydrothermal conditions applicable to repository performance during the entire thermal loading cycle, including heating (boiling and dry-out) and cooldown (re-wetting). For in situ heater tests to be applicable to actual repository conditions, a minimum heater test duration of 6-7 yr (including 4 yr of full-power heating) is required.
Date: January 1, 1993
Creator: Buscheck, T.A.; Wilder, D.G. & Nitao, J.J.
Partner: UNT Libraries Government Documents Department

Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site characterization study; Progress report, April 1, 1993--June 30, 1993

Description: This report is in two parts one for the fluorinated benzoic acids and one for the fluorinated aliphatic acids. The assumptions made in the report regarding the amount of tracer that will be used, dilution of the tracer during the test and the length of exposure (if any) to individuals drinking the water were made by the authors. These assumptions must really come from the USGS hydrologists in charge of the c-well tracer testing program. Accurate estimates of dilution of the tracer during the test are also important because of solubility limitations of some of the tracers. Three of the difluorobenzoic acids have relatively low solubilities and may not be usable if the dilution estimates are large. The toxicologist that reviewed the document agreed with our conclusion that the fluorinated benzoic and toluic acids do not represent a health hazard if used under the conditions as outlined in the report. We are currently testing 15 of these compounds, and if even if three difluorobenzoic acids cannot be used because of solubility limitations we will still have 12 tracers. The toxicologist felt that the aliphatic fluorinated acids potentially present more of a health risk than the aromatic. This assessment was based on the fact of a known allergic response to halothane anesthetic. This risk, although minimal, is known and he felt that was enough reason to recommend against their use. The authors feel that the toxicologists interpretation of this risk was overly conservative, however, we will not go against his recommendation at this time for the following reasons. First, without the aliphatic compounds we still have 12 to 15 fluorinated aromatic acids which, should be enough for the c-well tests. Second, to get a permit to use aliphatic compounds would undoubtedly require a hearing which could be quite lengthy.
Date: August 1, 1993
Creator: Dombrowski, T. & Stetzenbach, K.
Partner: UNT Libraries Government Documents Department

The role of multiple barriers in assuring waste package reliability; Yucca Mountain Project

Description: Yucca Mountain in southwestern Nevada is being studied as a potential repository site for the permanent storage of high-level nuclear waste. Regulators have set performance standards that the potential repository must meet in order to obtain regulatory approval. Nuclear Regulatory Commission (NRC) regulations state that containment of radioactivity must be ``substantially complete`` for the first 1000 years after closure of the facility. Thereafter, the acceptable annual limit on releases is 1/100,000 of each radionuclide remaining in the inventory after 1000 years. To demonstrate that the potential facility is in compliance with the regulations, it is necessary to obtain some understanding of the probability distribution of the cumulative quantity of releases by certain time points. This paper will discuss the probability distribution of waste container lifetimes and how the understanding of this distribution will play a role in finding the distribution of the release quantities over time. It will be shown that, for reasonable assumptions about the process of barrier failure, the reliability of a multiple-barrier container can be achieved and demonstrated much more readily than a container consisting of a single barrier. The discussion will focus primarily on the requirement of substantially complete containment for the first 1000 years.
Date: August 1, 1993
Creator: Bradford, R.M.
Partner: UNT Libraries Government Documents Department

Dependence of radionuclide sorption on sample grinding, surface area, and water composition

Description: In its 1987 technical position paper, ``Determination of Radionuclide Sorption for High-Level Nuclear Waste Repositories``, the Nuclear Regulatory Commission (NRC) review panel delineated several studies needed to show that experimental sorption coefficients could accurately model radionuclide sorption behavior along release pathways. In particular, they focused on the potential problems involved with the use of crushed rock samples, stating ``If crushed solids are used, it is essential to show that laboratory experiments involving sorption on crushed solids are relevant to the repository site. The surfaces of crushed material may be significantly different from the surfaces of intact material, both porous and fractured. Grinding may expose the surfaces of solid phases different from those which groundwater would contact in a repository and/or may change the reactivity of the same mineral surfaces with dissolved radionuclides. The surface of crushed minerals can be enriched in certain elements by factors of two and three relative to the bulk composition. The experiments reported here were performed in direct response to the NRC technical position paper.
Date: February 1993
Creator: Rogers, P. S. Z. & Meijer, A.
Partner: UNT Libraries Government Documents Department

Evaluation of uranium transitions for isotopically-selective laser induced fluorescence with diode lasers (Technical Report for ST064)

Description: Isotopically-selective excitation of uranium atoms by diode lasers can be the basis for a portable instrument to perform uranium isotopic assays in the field. Such an instrument would improve the ability of on-site inspections to detect and deter nuclear proliferation. Published and unpublished spectroscopic data on atomic uranium were examined to identify candidate transitions for isotopically-selective laser excitation with diode lasers. Eleven candidate transitions were identified and evaluated for their potential usefulness for a portable uranium assay instrument. Eight of these transitions are suitable for laser induced fluorescence using different excitation and detection wavelengths, which will improve sensitivity and elemental selectivity. Data sheets on the 25 uranium transitions in the wavelength range 629 nm to 1,000 nm that originate in the ground or first excited states of neutral atomic uranium are included. Each data sheet provides the wavelength, upper and lower energy levels, angular momentum quantum numbers, {sup 235}U isotope shift (relative to {sup 238}U), and high-resolution spectra of weapons-grade uranium (93% {sup 235}U and 7% {sup 238}U).
Date: October 1, 1993
Creator: Cannon, B.D.
Partner: UNT Libraries Government Documents Department

Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

Description: This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p {number_sign}1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p {number_sign}1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells.
Date: July 1, 1993
Creator: O`Brien, G.M.
Partner: UNT Libraries Government Documents Department

An experimental study of NO{sub x} recycle in the NOXSO flue gas cleanup process. Final report

Description: NO{sub x} recycle represents one part of the NOXSO process. This process can remove 90% of NO{sub x} and SO{sub 2} simultaneously from flue gas by using a fluidized bed of sorbent. Spent sorbent is regenerated by treatment at high temperatures with a reducing gas. Adsorbed NO{sub x} is evolved on heating the sorbent to a regeneration temperature. The concentrated stream of NO{sub x} produced is returned to the boiler with the combustion air and reduced in the flame, which is called NO{sub x} recycle. The concept of NO{sub x} recycle has been experimentally evaluated at the US Department of Energy`s Pittsburgh Energy Technology Center (PETC). NO{sub x} destruction has been demonstrated on a 500 lb/hr pulverized coal combustor and a 1.7 MMBtu/hr tunnel furnace combustor firing both natural gas and coal-water slurry. The NO{sub x} recycle experimental study discussed in this report and performed on Babcock & Wilcox (B&W)`s six MMBtu/hr Small Boiler Simulator (SBS) is a pilot-scale test. The objective is to provide further fundamental understanding and necessary information for the NOXSO full-scale demonstration at Ohio Edison`s Niles Power Plant which uses the same type of cyclone burners. The experimental testing included injection of NO, NO{sub x} and different combinations of NO/NO{sub 2} with tile primary air (PA) and secondary air (SA) to the combustor. Results are consistent with earlier test data obtained on PETC`s facility and will be used for the design of the NOXSO commercial demonstration plant at Niles.
Date: March 1993
Creator: Zhou, Q.; Haslbeck, J. L. & Neal, L. G.
Partner: UNT Libraries Government Documents Department

Groundwater chemistry at the Nevada Test Site: Data and preliminary interpretations

Description: The interpretation of chemical analyses of groundwater collected at and near the Nevada Test Site (NTS) has been vital in developing conceptual models of groundwater flow in the area. These conceptual models are tested using recent chemical data generated by the Desert Research Institute, as well as historic analyses from the US Geological Survey. A total of 81 wells are represented by analyses from 1957 to 1990, with generally excellent agreement between repeat samples from the same location. As identified by previous workers, three hydrochemical facies are represented by the samples: Ca-Mg-HCO{sub 3} water in carbonate rocks or alluvium derived from carbonates, Na-K-HCO{sub 3} water in volcanic rocks and alluvium derived from volcanic rocks, and a mixed fades found in many carbonate and alluvium water samples, and some volcanic waters. There is a general lack of lateral continuity in chemical characteristics along presumed flowpaths within each hydrologic unit (alluvium, carbonate, and volcanic). Though a lack of continuity between basins on the east side of the NTS was expected for water in alluvial and volcanic units due to the absence of interbasin flow, chemical differences observed within individual basins suggest a dominance of vertical over lateral flow. Groundwater in volcanic materials on the east side of Yucca and Frenchman Flats and on the west side of Pahute Mesa and Yucca Mountain has a nearly pure Na-K-HCO{sub 3} signature that reflects contact with primarily volcanic material. Groundwater in volcanic units in the middle of the NTS and on the east side of Pahute Mesa contains a higher proportion of Ca, Mg, Cl, and SO{sub 4} than the other volcanic waters and indicates the contribution of water from the upper carbonate aquifer and/or hydrothermally altered regions.
Date: March 1, 1993
Creator: Chapman, J.B. & Lyles, B.F.
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes, Volume III

Description: A generalized one-dimensional, heterogeneous, steady-state, fixed-bed model for coal gasification and combustion is presented. The model, FBED-1, is a design and analysis tool that can be used to simulate a variety of gasification, devolatilization, and combustion processes. The model considers separate gas and solid temperatures, axially variable solid and gas flow rates, variable bed void fraction, coal drying, devolatilization based on chemical functional group composition, depolymerization, vaporization and crosslinking, oxidation, and gasification of char, and partial equilibrium in the gas phase.
Date: August 1, 1993
Creator: Ghani, M.U.; Hobbs, M.L. & Hamblen, D.G.
Partner: UNT Libraries Government Documents Department

K/AR dating of clinoptilolite, mordenite, and associated clays from Yucca Mountains, Nevada

Description: Zeolites are abundant in the geologic record in both continental and marine environments. The purpose of the present study is to evaluate the utility of K-bearing zeolites for dating by the K/Ar method to determine the time of zeolite diagenesis at Yucca Mountain, Nevada (Fig. 1). At Yucca Mountain, K-rich clinoptilolite and possibly mordenite are the only potentially K/Ar dateable secondary minerals present in the zeolite-rich tuffs except for some illite/smectites ({ge}10% illite layers) associated with these minerals. Direct dating of K-rich clinoptilolite, the most abundant zeolite in the altered tuffs, is important to delineate zeolite chronology as part of the site characterization of Yucca Mountain.
Date: July 1, 1993
Creator: WoldeGabriel, G.
Partner: UNT Libraries Government Documents Department

LAPACK++: A design overview of object-oriented extensions for high performance linear algebra

Description: LAPACK++ is an object-oriented C++ extension of the LAPACK (Linear Algebra PACKage) library for solving the common problems of numerical linear algebra: linear systems, linear least squares, and eigenvalue problems on high-performance computer architectures. The advantages of an object-oriented approach include the ability to encapsule various matrix representations, hide their implementation details, reduce the number of subroutines, simplify their calling sequences, and provide an extendible software framework that can incorporate future extensions of LAPACK such as ScaLAPACK++ for distributed memory architectures. The authors present an overview of the object-oriented design of the matrix and decomposition classes in C++ and discuss its impact on elegance, generality, and performance.
Date: December 31, 1993
Creator: Dongarra, J.J.; Pozo, R. & Walker, D.W.
Partner: UNT Libraries Government Documents Department