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Acquisition and preparation of specimens of rock for large-scale testing (open access)

Acquisition and preparation of specimens of rock for large-scale testing

The techniques used for acquisition and preparation of large specimens of rock for laboratory testing depend upon the location of the specimen, the type of rock and the equipment available at the sampling site. Examples are presented to illustrate sampling and preparation techniques used for two large cylindrical samples of granitic material, one pervasively fractured and one containing a single fracture.
Date: February 1, 1981
Creator: Watkins, D.J.
System: The UNT Digital Library
AN APPLICATION OF FUZZY SET THEORY TO DATA DISPLAY (open access)

AN APPLICATION OF FUZZY SET THEORY TO DATA DISPLAY

Categorization supports decision making, letting an analyst look at data from different perspectives and different levels of detail. An approach to data analysis is described in which membership in subjectively defined categories is modeled by the fuzzy nature of color categories and presented via computer graphics for visual inspection by the analyst.
Date: February 1, 1981
Creator: Benson, William H.
System: The UNT Digital Library
Assessment of effectiveness of geologic isolation systems: the AEGIS geologic simulation model (open access)

Assessment of effectiveness of geologic isolation systems: the AEGIS geologic simulation model

Assessment of the post-closure performance of a nuclear waste repository has two basic components: the identification and analysis of potentially disruptive sequences and the pattern of geologic events and processes causing each sequence, and the identification and analysis of the environmental consequences of radionuclide transport and interactions subsequent to disruption of a repository. The AEGIS Scenario Analysis Task is charged with identifying and analyzing potenially disruptive sequences of geologic events and processes. The Geologic Simulation Model (GSM) was developed to evaluate the geologic/hydrologic system surrounding an underground repository, and describe the phenomena that alone, or in concert, could perturb the system and possibly cause a loss of repository integrity. The AEGIS approach is described in this report. It uses an integrated series of models for repository performance analysis; the GSM for a low-resolution, long-term, comprehensive evaluation of the geologic/hydrologic system, followed by more detailed hydrogeologic, radionuclide transport, and dose models to more accurately assess the consequences of disruptive sequences selected from the GSM analyses. This approach is felt to be more cost-effective than an integrated one because the GSM can be used to estimate the likelihoods of different potentially disruptive future evolutionary developments within the geologic/hydrologic system. The more costly …
Date: February 1, 1981
Creator: Foley, M. G. & Petrie, G. M.
System: The UNT Digital Library
Assessment of effectiveness of geologic isolation systems. WISAP Release Scenario Analysis Workshop, September 13-15, 1979 (open access)

Assessment of effectiveness of geologic isolation systems. WISAP Release Scenario Analysis Workshop, September 13-15, 1979

Individual papers were indexed for inclusion in the data base.
Date: February 1, 1981
Creator: unknown
System: The UNT Digital Library
Beam energy measurements at the Bevalac (open access)

Beam energy measurements at the Bevalac

In the Bevalac there are several problems that make it very difficult to determine a more precise value for magnetic field. The radial field shape enclosed within the B dot integrating loop on the poletips changes as a function of field strength. The effective magnetic quadrant length also changes as a function of field strength. This causes a major perturbation in the radial position of the equilibrium orbit as well as some uncertainty in the value of the magnetic field. In addition to the magnetic field value, there must be adequate information about the radial position of the closed orbit to determine a precise value for the kinetic energy. If there is sufficient information about the closed orbit, a known effective path length exists for the particle. The transit time of the particle on that path is a time-of-flight measurement. In a circular machine, this time measurement is a frequency measurement which is one of the most precise measurements that can be made. A Hewlett Packard 5360A frequency counter can read to 1 part in 10/sup 6/ for a 0.1 msec read time. This can be extended to 1 part in 10/sup 10/ for longer read time. With time measured …
Date: February 1, 1981
Creator: Crebbin, K. C.
System: The UNT Digital Library
Chemical modeling of irreversible reactions in nuclear waste-water-rock systems (open access)

Chemical modeling of irreversible reactions in nuclear waste-water-rock systems

Chemical models of aqueous geochemical systems are usually built on the concept of thermodynamic equilibrium. Though many elementary reactions in a geochemical system may be close to equilibrium, others may not be. Chemical models of aqueous fluids should take into account that many aqueous redox reactions are among the latter. The behavior of redox reactions may critically affect migration of certain radionuclides, especially the actinides. In addition, the progress of reaction in geochemical systems requires thermodynamic driving forces associated with elementary reactions not at equilibrium, which are termed irreversible reactions. Both static chemical models of fluids and dynamic models of reacting systems have been applied to a wide spectrum of problems in water-rock interactions. Potential applications in nuclear waste disposal range from problems in geochemical aspects of site evaluation to those of waste-water-rock interactions. However, much further work in the laboratory and the field will be required to develop and verify such applications of chemical modeling.
Date: February 1, 1981
Creator: Wolery, T.J.
System: The UNT Digital Library
Computer simulation of longitudinal single-bunch effects in electron-positron storage rings (open access)

Computer simulation of longitudinal single-bunch effects in electron-positron storage rings

The computer code TRACK simulates longitudinal single-bunch effects in an electron-positron storage ring. The program tracks the turn-by-turn energy and phase deviations of N superparticles, where N is 100-1000. In addition to the usual RF and lattice parameters, an input to the program is the wake potential function for the ring vacuum chamber. The program has been applied to compute bunch lengthening in SPEAR as a function of charge per bunch. Although the computed results are in qualitative agreement with measurements, there are discrepancies in some details. Possible reasons for these discrepancies are discussed.
Date: February 1, 1981
Creator: Wilson, P.B.; Bane, K.L.F. & Satoh, K.
System: The UNT Digital Library
Conceptual design strategy for liquid-metal-wall inertial-fusion reactors (open access)

Conceptual design strategy for liquid-metal-wall inertial-fusion reactors

The liquid-metal-wall chamber has emerged as an attractive reactor concept for inertial fusion energy conversion. The principal feature of this concept is a thick, free-flowing blanket of liquid metal used to protect the structure of the reactor. The development and design of liquid-metal-wall chambers over the past decade provides a basis for formulating a conceptual design strategy for such chambers. Both the attractive and unattractive features of a LMW chamber are enumerated, and a design strategy is formulated which accommodates the engineering constraints while minimizing the liquid-metal flow rate.
Date: February 1, 1981
Creator: Monsler, M. J. & Meier, W. R.
System: The UNT Digital Library
Damage analysis and fundamental studies (open access)

Damage analysis and fundamental studies

As a planning activity, the objectives of the workshop were to list, prioritize and milestone the activities necessary to understand, interpret and control the mechanical behavior of candidate fusion reactor alloys. Emphasis was placed on flow and fracture processes which are unique to the fusion environment since the national fusion materials program must evaluate these effects without assistance from other reactor programs. The working group on flow processes and properties was concerned with the time-dependent and independent flow. This included radiation hardening and steady state and cyclic creep. The working group on the effect of flow on fracture was concerned with the relationships between the unique flow properties of irradiated materials, such as dislocation channeling, and the fracture properties of these materials. The working group on time-dependent fracture was concerned with high-temperature, time-dependent fracture, such as stress-rupture and fatigue fracture, while also being concerned with time-dependent environmental effects on fracture. The working group on radiation-induced or enhanced embrittlement was concerned primarily with time-independent fracture of materials for near-term fusion device applications.
Date: February 1, 1981
Creator: unknown
System: The UNT Digital Library
DOE's energy data base (EDB) versus other energy-related data bases: a comparative analysis (open access)

DOE's energy data base (EDB) versus other energy-related data bases: a comparative analysis

The release of the DOE Energy Data Base to commercial services in 1980 raised an immediate question in the minds of some searchers: how does this new data base fit into the spectrum of already-available data bases. Because the authors have been closely associated with the Department of Energy's RECON system and its data bases for several years, as trainers and as editor of the DOE/RECON Newsletter, the question was of great interest and we decided to investigate it.
Date: February 1, 1981
Creator: Robinson, J. & Hu, M.
System: The UNT Digital Library
Effect of couple-stress on the pure bending of a prismatic bar (open access)

Effect of couple-stress on the pure bending of a prismatic bar

An evaluation of the applicability of the couple-stress theory to the stress analysis of graphite structures is performed by solving a pure bending problem. The differences between solutions from the couple-stress theory and from the classical theory of elasticity are compared. It is found that the differences are sufficient to account for the inconsistencies which have often been observed between the classical elasticity theory and actual behavior of graphite under bend and tensile loadings. An experimental procedure to measure the material constants in the couple-stress theory is also suggested. The linear couple-stress theory, the origins of which go back to the turn of the last century, adds linear relations between couple-stresses and rotation gradients to the classical stress-strain law. By adopting the classical assumption that the plane cross section remains plane after deformation, the pure-bending problem is reduced to a plane couple-stress problem with traction-free boundary conditions. A general solution for an isotropic elastic prismatic bar under pure bending is then obtained using the Airy stress function and another stress function wich accounts for the couple-stresss. For a cylindrical bar, it reduces to a simple series solution. The moment-curvature and stress-curvature relations derived for a cylindrical bar from the general …
Date: February 1, 1981
Creator: Tzung, F.; Kao, B.; Ho, F. & Tang, P.
System: The UNT Digital Library
Effects of Anomalous Transport on Lower Hybrid Electron Heating (open access)

Effects of Anomalous Transport on Lower Hybrid Electron Heating

The transport of electron energy out of tokamaks is known to be far greater than that calculated using classical and neoclassical theory. However, low levels of non-axisymmetric magnetic field turbulence can couple the fast transport of electrons parallel to the magnetic field lines to radial transport, thus providing a plausible explanation for observed energy confinement. These models further predict that the electron loss rate is proportional to v/sub parallel bars/. This has subsequently been found to be consistent with data for runaway electrons in PLT, at energies up to 1 MeV. Recently it has been pointed out by Chan, Chiu and Ohkawa that anomalous transport processes should be taken into account in attempting to determine steady state electron distribution functions for cases involving RF electron tail heating, particularly in view of the v/sub parallel bars/ dependence of the loss rate. In this work these physical processes are modeled through a 2-D nonlinear program which describes the evolution of the electron distribution function in velocity magnitude; (v) and plasma radius (r), and which studies the efficiency of tail electron heating.
Date: February 1, 1981
Creator: McCoy, M. G. & Harvey, R. W.
System: The UNT Digital Library
Electrofibrous prefilters for use in nuclear ventilation systems (open access)

Electrofibrous prefilters for use in nuclear ventilation systems

We have established a comprehensive program for the US Department of Energy to develop electrofibrous prefilters to extend the life of High Efficiency Particulate Air (HEPA) filters that are used in the nuclear industry. We have selected the electrofibrous filter because, compared to the mechanical fibrous filter, it has a higher efficiency and longer lifetime. Two different electrofibrous filters have been developed for use in nuclear ventilation systems. One prototype is a stationary prefilter while the other is a rolling prefilter. Both prefilters use the same basic filtering technique in which a fibrous filter medium is sandwiched between a high voltage electrode and a ground electrode, both electrodes having a sufficient open area to offer minimum air resistance. The applied voltage on the electrodes generates an electric field that polarizes the filter fibers, which then attract suspended particles via electrostatic forces. The filter media and electrodes have been pleated to provide a sufficiently long particle residence time. The special requirement of protecting the HEPA filter from a high concentration of smoke aerosols during fire conditions led to the development of the rolling, electrofibrous prefilter. We established the feasibility of this concept in a series of tests using commercially available rolling …
Date: February 19, 1981
Creator: Bergman, W.; Kuhl, W. D.; Russell, W. L.; Taylor, R. D.; Hebard, H. D.; Biermann, A. H. et al.
System: The UNT Digital Library
Electroforming copper targets for RTNS-II (open access)

Electroforming copper targets for RTNS-II

Copper targets used in RTNS II, which is the world's most intense 14-MeV neutron source, contain water cooling channels for temperature control. There are two methods for fabricating these targets: (1) diffusion bonding a copper panel containing photoetched channels to another copper panel, and (2) an electroforming technique which involves filling the photoetched channels with wax, plating thick copper to seal over the channels and then removing the wax. Development of this latter process and results obtained with it are described.
Date: February 6, 1981
Creator: Kelley, W. K.; Dini, J. W. & Logan, C. M.
System: The UNT Digital Library
An Electron Microprobe Determination of Microscopic Elemental Homogeneity of Hot-Cross-Rolled and High-Energy-Rate Forged 21Cr-6Ni-9Mn Steel (open access)

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

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.
System: The UNT Digital Library
Environmental decontamination (open access)

Environmental decontamination

The record of the proceedings of the workshop on environmental decontamination contains twenty-seven presentations. Emphasis is placed upon soil and surface decontamination, the decommissioning of nuclear facilities, and assessments of instrumentation and equipment used in decontamination. (DLS)
Date: February 1, 1981
Creator: Cristy, George A. & Jernigan, Helen C.
System: The UNT Digital Library
Estimate of coherent tune shifts for PEP (open access)

Estimate of coherent tune shifts for PEP

Transverse and longitudinal instabilities for a bunched PEP beam with a Gaussian distribution are treated using the standard technique in which instability problems are solved by looking for eigenvalues of the linearized Vlasov equation. The eigen solutions are conveniently expanded in terms of the Laquerre polynomials, and the eigenvalues are given by a symmetric matrix whose elements can be expressed in infinite series. The well-known formalism is used to obtain the matrix formula, and then applied numerically to the PEP ring to estimate the transverse coherent tune shifts. The impedance used is that estimated for the PEP RF cavities. The agreement with experimental data seems reasonable.
Date: February 1, 1981
Creator: Yao, C.Y. & Chao, A.W.
System: The UNT Digital Library
Evaluation of the seismic integrity of a plutonium-handling facility (open access)

Evaluation of the seismic integrity of a plutonium-handling facility

Many studies have been made by and for the Lawrence Livermore National Laboratory (LLNL) to ensure the seismic safety of its Plutonium Facility (Building 332). These studies have included seismological and geologic field investigations to define the actual seismic hazard existing at the Laboratory site as well as structural studies of the Facility itself. Because the basic seismic design criteria has undergone changes over the years, numerous structural studies and upgrades have been completed. The seismic criteria in use at the LLNL site is reviewed on a continuing basis as new information on the seismicity and geology of the Livermore Valley is obtained. At present, the Laboratory's Earth Sciences Division is conducting a multi-million dollar program to identify and characterize the geologic hazards at the Livermore site, with the primary emphasis on earthquake hazards in the Livermore Valley. This effort is undergoing an independent review by Woodward-Clyde Associates. Additionally, because of increased concerns over the seismic safety of Building 332, the Laboratory has initiated an independent structural review. This review effort will be monitored by the California Seismic Safety Commission to ensure its independence. Both of these studiies are in their early stages and results are not yet available.
Date: February 4, 1981
Creator: Coats, D.W.
System: The UNT Digital Library
FERMI: a code for modeling field-reversed magnetic-mirror fusion devices (open access)

FERMI: a code for modeling field-reversed magnetic-mirror fusion devices

We present the design and implementation for the array processor of FERMI, a code for modeling the physics of field-reversed magnetic-mirror fusion machines. The physical model is described briefly, along with a discussion of important physical effects that this code can model. We show that the code results are in agreement with theoretical predictions.
Date: February 1, 1981
Creator: Brengle, T.A. & Cohen, B.I.
System: The UNT Digital Library
Fluid and structural dynamic design considerations of the HYLIFE nozzle plate (open access)

Fluid and structural dynamic design considerations of the HYLIFE nozzle plate

The basic concept of the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber involves a falling liquid-metal (lithium) jet array that absorbs 90% of the energy released from inertial confinement fusion reactions. The key element of the chamber that produces the jet array is the nozzle plate. This paper describes the design and analysis of a nozzle plate which can withstand the structural loads and permit the fluid jet array to be reestablished for a 1-Hz fusion reaction frequency. The shape of the nozzle plate and jet array is dictated by considerations of fluid dynamics and neutron-shielding. A vertical jet array, rather than a single annulus, is used because this design enhances fluid momentum interchange and dissipation of the kinetic energy that occurs when the jets disassemble. Less net outward-directed momentum results than with a single liquid annular flow configuration, thus producing lower stresses in the structural components.
Date: February 1, 1981
Creator: Pitts, J.H. & Ojalvo, I.U.
System: The UNT Digital Library
HIGH CURRENT D- PRODUCTION BY CHARGE EXCHANGE IN SODIUM (open access)

HIGH CURRENT D- PRODUCTION BY CHARGE EXCHANGE IN SODIUM

A beam of D{sup -} ions has been produced at 7-13 keV, with currents up to 2.2 {angstrom}, using charge exchange in sodium vapor. The beam profile is bi-Gaussian with angular divergence 0.7{sup o} x 2.8{sup o} and peak current density 15 mA/cm{sup 2}. The characteristics of the beam are in excellent agreement with predictions based on atomic cross sections. The sodium vapor target is formed by a jet directed across the beam. The sodium density drops rapidly in the beamline downstream from the charge exchange region, decreasing three orders of magnitude in 15 cm. Measurement and analysis of the plasma accompanying the beam demonstrate that plasma densities nearly equal to the beam density are obtained 1 m from the charge exchange medium. The plasma produced in the sodium is thus well confined to the charge exchange region and does not propagate along the beam.
Date: February 1, 1981
Creator: Hooper, E.B.; Poulsen, P. & Pincosy, P.A.
System: The UNT Digital Library
High-current, short-pulse, RF-synchronized electron gun for the Stanford Linear Accelerator (open access)

High-current, short-pulse, RF-synchronized electron gun for the Stanford Linear Accelerator

For the generation of intense single and multiple bunches of electrons (> 8 nc per bunch) for accelerator studies at SLAC, a high peak current photoemission electron gun has been developed. A gallium arsenide photocathode is illuminated by the optical beam from a frequency doubled, actively mode-locked and Q-switched Nd:YAG laser. The mode-locked optical pulses are of variable, sub-nanosecond width and occur with a spacing of 8.4 nsec, synchronized with the 2856 MHz accelerator rf. The gun is designed to be space charge limited at 15 A and 200 kV, although emission of 60 A was obtained with a 57 kV test structure, corresponding to a current density of 180 A/cm/sup 2/. With the proper choice of laser wavelength, the electron beam may be 40% longitudinally polarized.
Date: February 1, 1981
Creator: Sinclair, Charles K. & Miller, Roger H.
System: The UNT Digital Library
High Resolution Scanning Auger Microscopic Investigation of Intergranular Fracture in as-Quenched Fe-12Mn (open access)

High Resolution Scanning Auger Microscopic Investigation of Intergranular Fracture in as-Quenched Fe-12Mn

Previous research in this laboratory led to the conclusion that the low temperature intergranular fracture mode in Fe-Mn alloys is microstructurally determined, and does not require metalloid segregation or other chemical contamination. That conclusion was tested in the present investigation, which used high resolution scanning Auger microscopy to study the intergranular fracture surfaces. The fracture mode at liquid nitrogen temperature was found to be intergranular fracture whenever the alloy was quenched from the austenite field, irrespective of the austenization time or temperature. High resolution chemical analyses of the intergranular fracture surfaces failed to reveal any consistent segregation of P, S, 0, or N. The occasional appearance of sulfur or oxygen on the fracture surface was found to be due to a low density precipitation of MnS and MnO{sub 2} along the prior austenite grain boundaries. Excepting these dispersed precipitates, there was no evidence of manganese enrichment of the prior austenite grain boundaries. A slight segregation of carbon was found along the grain boundaries, but does not appear to be implicated in the tendency toward intergranular fracture. The present results hence reinforce the conclusion that the low temperature intergranular fracture of Fe-12Mn is microstructurally determined.
Date: February 1, 1981
Creator: Lee, H. J. & Morris, J. W., Jr.
System: The UNT Digital Library
Hydrogen and deuterium trapping in iron (open access)

Hydrogen and deuterium trapping in iron

The research described is directed at present almost exclusively to hydrogen transport, including both chemical and physical trapping, in iron and iron-base alloys. Some attention is directed to isotope effects. Efforts are made to clarify and understand hydrogen-related phenomena which are believed to be of direct importance to practical performance.
Date: February 1, 1981
Creator: Johnson, Herbert H. & Lin, R. W.
System: The UNT Digital Library