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Thermal conductivity and diffusivity of climax stock quartz monzonite at high pressure and temperature

Description: Measurements of thermal conductivity and thermal diffusivity have been made on two samples of Climax Stock quartz monzonite at pressures between 3 and 50 MPa and temperatures between 300 and 523{sup 0}K. Following those measurements the apparatus was calibrated with respect to the thermal conductivity measurement using a reference standard of fused silica. Corrected thermal conductivity of the rock indicates a value at room temperature of 2.60 +- 0.25 W/mK at 3 MPa increasing linearly to 2.75 +- 0.25 W/mK at 50 MPa. These values are unchanged (+- 0.07 W/mK) by heating under 50-MPa pressure to as high as 473{sup 0}K. The conductivity under 50-MPa confining pressure falls smoothly from 2.75 +- 0.25 W/mK at 313{sup 0}K to 2.15 +- 0.25 W/mK at 473{sup 0}K. Thermal diffusivity at 300{sup 0}K was found to be 1.2 +- 0.4 X 10{sup -6} m{sup 2}/s and shows approximately the same pressure and temperature dependencies as the thermal conductivity.
Date: November 1981
Creator: Durham, W. B. & Abey, A. E.
Partner: UNT Libraries Government Documents Department

Rock mechanics for hard rock nuclear waste repositories

Description: The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff (Nevada Test Site).
Date: September 1, 1981
Creator: Heuze, F.E.
Partner: UNT Libraries Government Documents Department

Techniques for in-service inspection of heat-transfer tubes in steam generators

Description: A multifaceted development program is in progress in the United States to study techniques for in-service inspection (ISI) of heat transfer tubes in breeder reactor steam generators. Several steam generator designs are involved. Although there are some similarities in the approaches, many of the details of techniques and capabilities are specific to the steam generator design. This paper describes the ultrasonic, eddy-current and penetrating radiation techniques being studied for the various steam generators, including the Large Leak Test Rig, the Clinch River Breeder Reactor design, and alternate steam generators being developed by Westinghouse and Babcock and Wilcox.
Date: January 1981
Creator: McClung, R. W.; Day, R. A.; Neely, H. H. & Powers, T.
Partner: UNT Libraries Government Documents Department

Sodium Depletion on Glass Surfaces During Auger Analysis

Description: The kinetics of the depletion of sodium on glass surfaces during Auger Electron Spectroscopic analysis is investigated. The decay process is mathematically represented as a sum of two single decaying exponential functions. This behavior may be described by a mechanism that accounts for the neutralization of sodium ions by the electron beam. Sodium ions and neutral sodium atoms are depleted by several known processes.
Date: April 22, 1981
Creator: Whitkop, P.G.
Partner: UNT Libraries Government Documents Department

Hydrogen Solubility in Austenitic Stainless Steels

Description: Hydrogen solubility was directly measured in specimens of Types 304L, 21-6-9, and modified A-286 austenitic stainless steels saturated with hydrogen at 69 MPa pressure at 470 K. Nitrogen in Type 21-6-9 stainless steel and precipitate morphology in the modified Type A-286 stainless steel altered the hydrogen solubility. Cold work and surface treatment had only minor effects on hydrogen solubility in the three stainless steels. This reports discusses this study.
Date: May 21, 1981
Creator: Caskey, G.R. Jr.
Partner: UNT Libraries Government Documents Department

Subcritical Limits for {sup 233}U Systems

Description: As a contribution to the required quinquennial review of American National Standard for Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors (ANSI N16.1-1975/ANS-8.1), limits for homogeneous 233U systems have been recalculated to confirm their sub-criticality or, where there were doubts, to propose more restrictive values. In addition, other limits were calculated to be proposed for inclusion, namely, limits for aqueous solutions of UO2(NO3)2 and limits for uranium oxides. The same three methods of calculation were used as in similar work done recently for plutonium and 235U systems. The validity of each was established by correlation with the results of pertinent critical experiments. This report discusses this study.
Date: October 21, 1981
Creator: Clark, H.K.
Partner: UNT Libraries Government Documents Department

Effect of Hydrogen on Work Hardening of Type 304L Austenitic Stainless Steel

Description: The grain size and strain dependence of work hardening in Type 304L stainless steel were analyzed between 200 and 250 K where hydrogen damage is greatest. Tensile data were obtained for specimens of several grain sizes, both with and without prior exposure to hydrogen gas at 69 MPa pressure. The analysis suggests that hydrogen has little influence on lattice friction stress but has a large effect on dislocation interaction and the back stress of dislocation pileups. This report discusses this study.
Date: May 21, 1981
Creator: Caskey, G. R., Jr.
Partner: UNT Libraries Government Documents Department

An Electron Microprobe Determination of Microscopic Elemental Homogeneity of Hot-Cross-Rolled and High-Energy-Rate Forged 21Cr-6Ni-9Mn Steel

Description: Electron microprobe analysis shows that iron, manganese, and nickel are inhomogeneously distributed in hot-cross-rolled plate and high-energy-rate forgings of 21Cr-6Ni-9Mn steel but that chromium is homogeneously distributed. Increases in iron content correlate with decreases in manganese and nickel. Rolling and forging flow lines occur in regions with high iron and low manganese and nickel. High-energy-rate forging increases inhomogeneity. Inhomogeneities are suspected to exist in the original ingot, where they are given directionality by rolling and are enhanced by high-energy-rate forging. This report discusses this study.
Date: February 17, 1981
Creator: Mosley, W.C.
Partner: UNT Libraries Government Documents Department

Nuclear waste repository characterization: a spatial estimation/identification approach

Description: This paper considers the application of spatial estimation techniques to a groundwater aquifer and geological borehole data. It investigates the adequacy of these techniques to reliably develop contour maps from various data sets. The practice of spatial estimation is discussed and the estimator is then applied to a groundwater aquifer system and a deep geological formation. It is shown that the various statistical models must first be identified from the data and evaluated before reasonable results can be expected.
Date: March 1, 1981
Creator: Candy, J.V. & Mao, N.
Partner: UNT Libraries Government Documents Department

Geomechanics of the Climax mine-by, Nevada Test Site

Description: A generic test of retrievable geologic storage of spent fuel assemblies in an underground chamber is being conducted at the Nevada Test Site. The horizontal shrinkage of the pillars is not explainable, but the vertical pillar stresses are easily understood. A two-phase project was initiated to estimate the in-situ deformability of the Climax granite and to refine the in-situ stress field data, and to model the mine-by. (DLC)
Date: March 1, 1981
Creator: Heuze, F.E.
Partner: UNT Libraries Government Documents Department

Definition of a facility for experimental studies of two-phase flows and heat transfer in porous materials

Description: A facility-development effort is currently underway at Sandia National Laboratories in order to create an experimental capability for the study of two-phase, steam/water flows through a variety of porous media. The facility definition phase of this project is described. Equations are derived for the steady, adiabatic, macroscopically-linear two-phase flow of a single-component fluid through a porous medium, including energy transfer both by convection and conduction. These equations are then solved to give relative permeabilities for the steam and water phases as functions of known and/or measurable quantities. A viable experimental approach was thereby formulated, leading to the definition of facility components and instrumentation requirements, including the application of gamma-beam densitometry for the measurement of liquid-saturation distributions in porous media. Finally, a state-of-the-art computer code was utilized to numerically simulate the proposed experiments, providing an estimate of the facility operating envelope.
Date: December 31, 1981
Creator: Reda, D.C. & Eaton, R.R.
Partner: UNT Libraries Government Documents Department

Disruption scenarios for a nuclear-waste repository on the Nevada Test Site

Description: Scenarios are being constructed for the release of radioactive maerial from hypothetical repositories in different types of rock at NTS. Deductive event trees are constructed; each path through an event tree is a scenario. The complete set of NTS event trees comprises about 340 scenarios, not counting the multiple paths through the subtrees made by expanding complex events. Each of these scenarios is being analyzed for 10 different types of rocks. (DLC)
Date: December 31, 1981
Creator: Link, R.L.; Bingham, F.W. & Barr, G.E.
Partner: UNT Libraries Government Documents Department

Near-field heat transfer at the spent fuel test-climax: a comparison of measurements and calculations

Description: The Spent Fuel Test in the Climax granitic stock at the DOE Nevada Test Site is a test of the feasibility of storage and retrieval of spent nuclear reactor fuel in a deep geologic environment. Eleven spent fuel elements, together with six thermally identical electrical resistance heaters and 20 peripheral guard heaters, are emplaced 420 m below surface in a three-drift test array. This array was designed to simulate the near-field effects of thousands of canisters of nuclear waste and to evaluate the effects of heat alone, and heat plus ionizing radiation on the rock. Thermal calculations and measurements are conducted to determine thermal transport from the spent fuel and electrical resistance heaters. Calculations associated with the as-built Spent Fuel Test geometry and thermal source histories are presented and compared with thermocouple measurements made throughout the test array. Comparisons in space begin at the spent fuel canister and include the first few metres outside the test array. Comparisons in time begin at emplacement and progress through the first year of thermal loading in this multi-year test.
Date: August 21, 1981
Creator: Patrick, W.C.; Montan, D.N. & Ballou, L.B.
Partner: UNT Libraries Government Documents Department

K-shell ionization by low-velocity ions

Description: Article discussing K-shell ionization by low-velocity ions. K-shell x-ray-production measurements are reported for protons, deuterons, and alpha particles incident on thin foils of copper, niobium, silver, and antimony.
Date: August 1981
Creator: Rice, R.; McDaniel, Floyd Del. (Floyd Delbert), 1942-; Basbas, George & Duggan, Jerome L.
Partner: UNT College of Arts and Sciences

High power densities from high-temperature material interactions

Description: Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs) offer important and unique advantages in terrestrial and space energy processing. And they are well suited to serve together synergistically. TEC and MFHPs operate through working-fluid vaporization, condensation cycles that accept great thermal power densities at high temperatures. TEC and MFHPs have apparently simple, isolated performance mechanisms that are somewhat similar. And they also have obviously difficult, complected material problems that again are somewhat similar. Intensive investigation reveals that aspects of their operating cycles and material problems tend to merge: high-temperature material effects determine the level and lifetime of performance. Simplified equations verify the preceding statement for TEC and MFHPs. Material properties and interactions exert primary influences on operational effectiveness. And thermophysicochemical stabilities dictate operating temperatures which regulate the thermoemissive currents of TEC and the vaporization flow rates of MFHPs. Major high-temperature material problems of TEC and MFHPs have been solved. These solutions lead to productive, cost-effective applications of current TEC and MFHPs - and point to significant improvements with anticipated technological gains.
Date: January 1, 1981
Creator: Morris, J.F.
Partner: UNT Libraries Government Documents Department

GaP Schottky diodes for high temperature applications

Description: A need for high temperature electronic components has been established. In an effort to meet part of this need four metals have been evaluated for use in fabricating a Schottky barrier diode. Schottky diodes made from Pt, Cr, Al and Ni were aged for 1000 hours at 275/sup 0/C. These devices were evaluated considering the barrier height, phi/sub bn/, and leakage current density, J/sub l/ as a function of aging time. Results indicate that the devices are dominated by a large surface state density which is partially compensated by prolonged aging. Nickel Schottky diodes emerge as the most stable devices.
Date: January 1, 1981
Creator: Weichold, M.H.; Eknoyan, O. & Coquat, J.A.
Partner: UNT Libraries Government Documents Department

Computer modeling of cracks

Description: The theoretical techniques used in modeling cracks in crystalline lattices are reviewed. It is shown that there is generally a trade-off between sample size and realistic interatomic potentials. The results of a recent molecular dynamic study of a two-dimensional triangular Lennard-Jones system of about 10,000 atoms are described. Static calculations on this system show very little lattice trapping in contrast to the often quoted results of lattice statics models. Using molecular dynamics, the properties of the system, with and without a crack, are understood sufficiently quantitatively to allow extrapolation to infinite size. At 10,000 atoms size effects are small enough to render the simulation highly reliable. It is also shown that when lattice statics and hybrid lattice statics calculations are performed using realistic, long-range potentials, lattice trapping is small. Dynamic simulations at constant applied stress show an intricate interplay between brittle crack propagation and the tendency to form dislocations. At low stresses the behavior is brittle while dislocation generation and crack blunting is observed at elevated stresses. The velocity of crack propagation has also been studied using a constant applied strain. A constant velocity is attained relatively soon after the crack has begun to propagate at both constant applied stress or strain. The credibility of the various models is discussed.
Date: January 1, 1981
Creator: Dienes, G J & Paskin, A
Partner: UNT Libraries Government Documents Department

Consideration of age-dependent radium retention in people on the basis of the beagle model

Description: This paper examines in humans the proposition emanating from studies in beagles that long-term retention of radium varies in proportion to the calcium addition rate at the time of intake. Because data on the calcium addition rate in younger humans were fragmentary, human calcium-addition rates were scaled from those in beagles, the relative calcium accretion rates in the two species at equivalent stages of skeletal growth providing the scaling factor. The variation of radium retention with age was determined by fitting a modified power function to data on the retention of radium from about 30 to 15,000 days following a series of therapeutic injections of /sup 226/Ra in humans ranging in age from 18 to 63 yr. The fractional retention R at t days following a single injection of /sup 226/Ra was described by R = (1 + t/d)/sup -0/ /sup 44/. The age-dependent time constant d in the retention function was found to be proportional to the calcium addition rate at the time of injection in subjects receiving < 200 ..mu..g /sup 226/Ra.
Date: January 1, 1981
Creator: Parks, N.J. & Keane, A.T.
Partner: UNT Libraries Government Documents Department

Energy losses in conductors carrying very high currents

Description: Conductors carrying very high currents show losses of an electromagnetic and a shock compression nature. Electromagnetic losses (joule heating in the skin layer, magnetic flux diffusion) scale as H/sup 3/ or (I/a)/sup 3/, where H is the self magnetic field of the current and I/a is the current divided by conductor - periphery; shock losses scale as H/sup 4/ or H/sup 3/ ((I/a)/sup 4/ or (I/a)/sup 3/) depending on the magnitude of I. In experiments where electrical energy must be converged from a large pulsed power supply to a small load, these losses can account for half the orignal energy and limit the magnitude of the energy per unit volume in the load. These considerations may be important for the study of material properties at high energy density.
Date: January 1, 1981
Creator: Singer, S. & Hunter, R.O.
Partner: UNT Libraries Government Documents Department

Effects of internal gain assumptions in building energy calculations

Description: The utilization of direct solar gains in buildings can be affected by operating profiles, such as schedules for internal gains, thermostat controls, and ventilation rates. Building energy analysis methods use various assumptions about these profiles. The effects of typical internal gain assumptions in energy calculations are described. Heating and cooling loads from simulations using the DOE 2.1 computer code are compared for various internal-gain inputs: typical hourly profiles, constant average profiles, and zero gain profiles. Prototype single-family-detached and multi-family-attached residential units are studied with various levels of insulation and infiltration. Small detached commercial buildings and attached zones in large commercial buildings are studied with various levels of internal gains. The results of this study indicate that calculations of annual heating and cooling loads are sensitive to internal gains, but in most cases are relatively insensitive to hourly variations in internal gains.
Date: January 1, 1981
Creator: Christensen, C. & Perkins, R.
Partner: UNT Libraries Government Documents Department