ABS plastic RPCs (open access)

ABS plastic RPCs

After investigating a number of materials, we discovered that an ABS plastic doped with a conducting polymer performs well as the resistive electrode in a narrow gap RPC (resistive plate chamber). Operating in the streamer mode, we find efficiencies of 90-96% with low noise and low strip multiplicities. We have also studied a variety of operating gases and found that a mixture containing SF{sub 6}, a non-ozone depleting gas, argon and isobutane gives good streamer mode performance, even with isobutane concentrations of 20% or less.
Date: February 1, 1996
Creator: Ables, E.; Bionta, R.; Olson, H.; Ott, L.; Parker, E.; Wright, D. et al.
Object Type: Article
System: The UNT Digital Library
Microstructural dependence of cavitation damage in polycrystalline materials. Final report, 1 November 1992--31 October 1994 (open access)

Microstructural dependence of cavitation damage in polycrystalline materials. Final report, 1 November 1992--31 October 1994

Microstructure of a sample of Inconel X-750 damaged by ISCC (intergranular stress corrosion cracking) was examined after fatigue precracking in a high-temperature environment of deaerated water. Orientation imaging microscopy was used to reveal the microstructure adjacent to the crack path. General high-angle boundaries were found to be most susceptible to cracking. An ordering of the susceptibilities to ISCC damage was proposed; all boundaries have been classified into one of 12 categories. A model is proposed to predict the crack path for ISCC based on ex situ record of damage probabilities. The cracking is modeled as a Markov chain on a regular hexagonal array of grain boundaries representing the connectivity of the network.
Date: February 5, 1996
Creator: Adams, B.L.
Object Type: Report
System: The UNT Digital Library
Technical findings from Sandia`s intrabuilding recabling project (open access)

Technical findings from Sandia`s intrabuilding recabling project

The US and other leading nations are at the forefront of a global trend to implement both national and international enterprise networks via information highways. New or upgraded cabling infrastructures are essential to support these activities. Professionals in the telecommunications industry are keenly aware of the challenges presented by such cabling upgrades. Desktop connectivity must be established before quantum leaps in information flow, as suggested by new technologies and global concepts. Some businesses with campus-type facilities have undertaken this formidable challenge. Universities and other higher-level learning institutions, corporate research facilities, independent and government-funded laboratories, financial institutions, medical facilities, and unique suburban housing test sites have risen to this challenge. Sandia National Laboratories is one such organization. This report presents the lessons learned from this project and gives 13 specific recommendations for manufacturers, buyers, and installers.
Date: February 1, 1996
Creator: Adams, R.L. & Eberhart, J.A.
Object Type: Report
System: The UNT Digital Library
Remote nuclear screening system for hostile environments (open access)

Remote nuclear screening system for hostile environments

A remote measurement system has been constructed for in situ gamma and beta isotopic characterization of highly radioactive nuclear material in hostile environments. A small collimated, planar CdZnTe detector is used for gamma-ray spectroscopy. Spectral resolution of 2% full width at half maximum at 662 kiloelectronvolts has been obtained remotely using rise time compensation and limited pulse shape discrimination, Isotopc measurement of high-energy beta emitters was accomplished with a ruggedized, deeply depleted, surface barrier silicon dictator. The primary function of the remote nuclear screening system is to provide fast qualitative and quantitative isotopic assessment of high-level radioactive material.
Date: February 27, 1996
Creator: Addleman, R. S.; Beck, M. A.; Blewett, G. R.; Selle, E. R.; McClellan, C. S.; Dodd, D. A. et al.
Object Type: Report
System: The UNT Digital Library
Ultrafine cement grout for sealing underground nuclear waste repositories (open access)

Ultrafine cement grout for sealing underground nuclear waste repositories

Sealing fractures in nuclear waste repositories concerns all programs investigating deep burial as a means of disposal. Because the most likely mechanism for contaminant migration is by dissolution and movement through groundwater, sealing programs are seeking low-viscosity sealants that are chemically, mineralogically, and physically compatible with their host. This paper presents the results of collaborative work between Whitesell Laboratories, operated by Atomic Energy of Canada, Ltd., and Sandia National Laboratories; the work was undertaken in support of the Waste Isolation Pilot Plant (WIPP). This effort addresses the technology associated with long-term isolation of nuclear waste in a natural salt medium. The work presented is part of the plugging and sealing program, specifically the development and optimization of Ultrafine cementitious grout that can be injected to adequately lower excessive, strain-induced permeability in the Distributed Rock Zone (DRZ) surrounding underground excavations. Innovative equipment and procedures employed in the laboratory produced a usable cement-based grout whose particles are 90% smaller than 8 microns and average 4 microns. The process involved simultaneous wet pulverization and mixing. The grout was used for a successful in situ test underground at the WIPP. Injection of grout sealed microfractures as small as 8 microns and lowered the gas …
Date: February 1, 1996
Creator: Ahrens, E. H. & Onofrei, M.
Object Type: Article
System: The UNT Digital Library
Investigation of syngas interaction in alcohol synthesis catalysts. Quartery technical progress report, July 1, 1995--September 31, 1995 (open access)

Investigation of syngas interaction in alcohol synthesis catalysts. Quartery technical progress report, July 1, 1995--September 31, 1995

This report presents the work done on {open_quotes}Investigation of Syngas Interaction in Alcohol Synthesis Catalysts{close_quotes} during the last three months. In this report the results of the work done on the effect of CO adsorption on the magnetic character of cobalt in the Cu/Co/Cr catalysts is discussed.
Date: February 1, 1996
Creator: Akundi, M. A.
Object Type: Report
System: The UNT Digital Library
MACHO project 2nd year LMC microlensing results and dark matter implications (open access)

MACHO project 2nd year LMC microlensing results and dark matter implications

The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically monitored in an attempt to detect rare gravitational microlensing events caused by otherwise invisible Machos. Analysis of two years of photometry on 8.5 million stars in the LMC reveals 8 candidate microlensing events, far more than the one event expected from lensing by low-mass stars in known galactic populations. Five these eight events we estimate the optical depth towards the LMC from events with 2 < i < 200 days to be r2 280 about 2.9+1 4/-0.8 X 10-7. This exceeds the optical depth of 0.5 x 10-7 expected for known stars and is to be compared with an optical depth of 4.7 X 10-7 predicted for a `standard` halo composed entirely of Machos. The total mass in this lensing population is 2 +1.2/-0.7 x 10+11 Mo (within 50 kpc from the Galactic center). Event timescales yield a most probable Macho Mass of 0.5 +0.3/-0.2 Mo, although this value is quite model dependent. -0.2
Date: February 1996
Creator: Alcock, C.; Allsman, R. A. & Alves, D.
Object Type: Article
System: The UNT Digital Library
Government/industry partnership: A revolutionary approach in global leadership of advanced gas turbines (open access)

Government/industry partnership: A revolutionary approach in global leadership of advanced gas turbines

The U.S. Department of Energy (DOE) has established a government/industry partnership program to greatly improve the capabilities of U.S. gas turbine technology. A new and challenging program named the Advanced Turbine Systems Program (ATS) has been initiated by DOE. The technical and business objectives of this initiative are to challenge the bounds of high performance capabilities of gas turbines, meet stringent environmental requirements, and produce lower cost electric power and cogeneration steam. This program will also yield greater societal benefits through continued expansion of high skilled U.S. jobs and export of U.S. products world wide. A progress report on the ATS program pertaining to program status at DOE will be presented and reviewed in this paper. A preliminary design of an industrial advanced turbine system configuration will also be outlined in the paper. The technical challenges; advanced critical technologies incorporation, analytical and experimental solutions, and test results of an advanced gas turbine meeting the DOE goals will be described and discussed.
Date: February 1, 1996
Creator: Ali, S. A. & Zeh, C. M.
Object Type: Article
System: The UNT Digital Library
Solid phase epitaxial regrowth of (100)GaAs (open access)

Solid phase epitaxial regrowth of (100)GaAs

This thesis showed that low temperature (250 C) SPE of stoichiometrically balanced ion implanted GaAs layers can yield good epitaxial recovery for doses near the amorphization threshold. For 250 C anneals, most of the regrowth occurred in the first 10 min. HRTEM revealed much lower stacking fault density in the co-implanted sample than in the As-only and Ga-only samples with comparable doses. After low temp annealing, the nonstoichiometric samples had a large number of residual defects. For higher dose implants, very high temperatures (700 C) were needed to remove residual defects for all samples. The stoichiometrically balanced layer did not regrow better than the Ga-only and As-only samples. The co-implanted sample exhibited a thinner amorphous layer and a room temperature (RT) annealing effect. The amorphous layer regrew about 5 nm, suggesting that stoichiometrically balanced amorphous layers can regrow even at RT. Mechanisms for solid phase crystallization in (100)GasAs is discussed: nucleation and growth of randomly oriented crystallites and SPE. These two mechanisms compete in compound semiconductors at much lower temperatures than in Si. For the low dose As-only and Ga-only samples with low-temp anneals, both mechanisms are active. For this amorphization threshold dose, crystallites remain in the amorphous layer for …
Date: February 1, 1996
Creator: Almonte, M. I.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Using automatic differentiation with the quasi-procedural method for multidisciplinary design optimaization (open access)

Using automatic differentiation with the quasi-procedural method for multidisciplinary design optimaization

As computers have become increasingly powerful, the field of design optimization has moved toward higher fidelity models (involving many more variables) in the early stages of design. One way in which this movement has manifested itself is in the increasing popularity of multidisciplinary design optimization (MDO). Because the models used in MDO are large and very complicated, a modular design is desirable. Because there are many- design parameters to optimize, derivatives must be computed accurately and efficiently. This paper describes how the quasi-procedural program architecture developed by Takai and Kroo [9] and the technique of automatic differentiation [6] can be combined to effectively address these needs. The two techniques are explained, the manner in which they were integrated into a single framework is described, and the result of using this framework for an optimization problem in airplane design is presented.
Date: February 1, 1996
Creator: Altus, S.; Kroo, I.; Bischof, C. & Hovland, P.
Object Type: Article
System: The UNT Digital Library
Westinghouse GOCO conduct of casualty drills (open access)

Westinghouse GOCO conduct of casualty drills

Purpose of this document is to provide Westinghouse Government Owned Contractor Operated (GOCO) Facilities with information that can be used to implement or improve drill programs. Elements of this guide are highly recommended for use when implementing a new drill program or when assessing an existing program. Casualty drills focus on response to abnormal conditions presenting a hazard to personnel, environment, or equipment; they are distinct from Emergency Response Exercises in which the training emphasis is on site, field office, and emergency management team interaction. The DOE documents which require team training and conducting drills in nuclear facilities and should be used as guidance in non-nuclear facilities are: DOE 5480.19 (Chapter 1 of Attachment I) and DOE 5480.20 (Chapter 1, paragraphs 7 a. and d. of continuing training). Casualty drills should be an integral part of the qualification and training program at every DOE facility.
Date: February 1, 1996
Creator: Ames, C.P.
Object Type: Report
System: The UNT Digital Library
Quantification of seismic liquefaction risk (open access)

Quantification of seismic liquefaction risk

Explicit goals of acceptable risk for natural phenomena hazards (earthquake, extreme wind, and flood) have been established by the Department of Energy (DOE) 1994. Closely associated to the earthquake risk is the issue of seismically-induced liquefaction. Because deterministic methods currently available to answer the question to whether a site is liquefiable or not are incapable of providing a clue as to the likelihood or risk of liquefaction, the application of the criteria to a given facility requires that alternative evaluation techniques be formulated. This paper describes the application to a nuclear facility of a newly developed probabilistic methodology which rigorously accounts for geotechnical and seismologic uncertainties. The results of the analyses are compared with the acceptable levels of risk presented by DOE. This comparison is used to emphasize the power of the methodology as a tool in the decision-making processes.
Date: February 29, 1996
Creator: Arango, I.; Ostadan, F.; Lewis, M. R. & Gutierrez, B. J.
Object Type: Article
System: The UNT Digital Library
Disposition of excess plutonium using ``off-spec`` MOX pellets as a sintered ceramic waste form (open access)

Disposition of excess plutonium using ``off-spec`` MOX pellets as a sintered ceramic waste form

The authors describe a potential strategy for the disposition of excess weapons plutonium in a way that minimizes (1) technological risks, (2) implementation costs and completion schedules, and (3) requirements for constructing and operating new or duplicative Pu disposition facilities. This is accomplished by an optimized combination of (1) using existing nuclear power reactors to ``burn`` relatively pure excess Pu inventories as mixed oxide (MOX) fuel and (2) using the same MOX fuel fabrication facilities to fabricate contaminated or impure excess Pu inventories into an ``off-spec`` MOX solid ceramic waste form for geologic disposition. Diversion protection for the SCWF to meet the ``spent fuel standard`` introduced by the National Academy of Sciences can be achieved in at least three ways. (1) One can utilize the radiation field from defense high-level nuclear waste by first packaging the SCWF pellets in 2- to 4-L cans that are subsequently encapsulated in radioactive glass in the Defense Waste Processing Facility (DWPF) glass canisters (a ``can-in-canister`` approach). (2) One can add {sup 137}Cs (recovered from defense wastes at Hanford and currently stored as CsCl in capsules) to an encapsulating matrix such as cement for the SCWF pellets in a small hot-cell facility and thus fabricate …
Date: February 1, 1996
Creator: Armantrout, G. A. & Jardine, L. J.
Object Type: Article
System: The UNT Digital Library
Long range position and Orientation Tracking System (open access)

Long range position and Orientation Tracking System

The long range Position and Orientation Tracking System is an active triangulation-based system that is being developed to track a target to a resolution of 6.35 mm (0.25 in.) and 0.009{degrees}(32.4 arcseconds) over a range of 13.72 m (45 ft.). The system update rate is currently set at 20 Hz but can be increased to 100 Hz or more. The tracking is accomplished by sweeping two pairs of orthogonal line lasers over infrared (IR) sensors spaced with known geometry with respect to one another on the target (the target being a rigid body attached to either a remote vehicle or a remote manipulator arm). The synchronization and data acquisition electronics correlates the time that an IR sensor has been hit by one of the four lasers and the angle of the respective mirror at the time of the hit. This information is combined with the known geometry of the IR sensors on the target to determine position and orientation of the target. This method has the advantage of allowing the target to be momentarily lost due to occlusions and then reacquired without having to return the target to a known reference point. The system also contains a camera with operator …
Date: February 1, 1996
Creator: Armstrong, G. A.; Jansen, J. F.; Burks, B. L.; White, Peter D. & Nypaver, Delphy J.
Object Type: Article
System: The UNT Digital Library
Amorphous silicon research. Annual subcontract report, October 1, 1994--September 30, 1995 (open access)

Amorphous silicon research. Annual subcontract report, October 1, 1994--September 30, 1995

The major effort in this program is to develop cost-effective processes which satisfy efficiency, yield, and material usage criteria for mass production of amorphous silicon-based multijunction modules. New and improved processes were developed for the component cells and a more robust rear contact was developed for better long term stability.
Date: February 1, 1996
Creator: Arya, R.R.; Bennett, M. & Bradley, D.
Object Type: Report
System: The UNT Digital Library
Safety assessment of a robotic system handling nuclear material (open access)

Safety assessment of a robotic system handling nuclear material

This paper outlines the use of a Failure Modes and Effects Analysis for the safety assessment of a robotic system being developed at Sandia National Laboratories. The robotic system, The Weigh and Leak Check System, is to replace a manual process at the Department of Energy facility at Pantex by which nuclear material is inspected for weight and leakage. Failure Modes and Effects Analyses were completed for the robotics process to ensure that safety goals for the system had been meet. These analyses showed that the risks to people and the internal and external environment were acceptable.
Date: February 1, 1996
Creator: Atcitty, C.B. & Robinson, D.G.
Object Type: Article
System: The UNT Digital Library
Productivity and injectivity of horizontal wells. Quarterly technical progress report, October 1, 1995--December 31, 1995 (open access)

Productivity and injectivity of horizontal wells. Quarterly technical progress report, October 1, 1995--December 31, 1995

As the length of a horizontal well is increased, its contact with the reservoir increases. But at the same time, the resistance to the flow in the well also increases which has a direct negative effect on the productivity of the well. The overall performance of horizontal wells depends on the balance of these two opposing factors. No reliable tools are currently available that account for both these factors in the evaluation of horizontal well performance. An analytical well-model is developed which can quantify the effects of pressure loss in the well on the overall well performance. A sensitivity study is conducted on the effect of various reservoir, fluid and well parameters on well performance.
Date: February 1, 1996
Creator: Aziz, K.
Object Type: Report
System: The UNT Digital Library
Parametric thermal evaluations of waste package emplacement (open access)

Parametric thermal evaluations of waste package emplacement

Parametric thermal evaluations of spent nuclear fuel (SNF) waste packages (WPs) emplaced in the potential repository were performed to determine the impact of thermal loading, WP spacing, drift diameter, SNF aging, backfill, and relocation on the design of the Engineered Barrier System. Temperatures in the WP and near-field host rock are key to radionuclide containment, as they directly affect oxidation rates of the metal barriers and the ability of the rock to impede particle movement which must be demonstrated for a safe and licensable repository. Maximum allowable temperatures are based on material performance criteria and are specified as the following design goals for the WP/EBS design: SNF cladding 350{degrees}C, drift wall 200{degrees}C, and TSw3 rock 115{degrees}C.
Date: February 1, 1996
Creator: Bahney, R. H., III & Doering, T. W.
Object Type: Article
System: The UNT Digital Library
Mutual reciprocal inspections: Issues regarding next steps (open access)

Mutual reciprocal inspections: Issues regarding next steps

Pressures are mounting for a regime to verify the dismantlement of US and Russian warheads, as well as a system of international control over the weapons` fissile materials to assure irreversibility. There are at least four motivating factors for these measures: (1) as the United States and Russia lower their numbers of nuclear weapons, each side seeks assurance that the warheads are actually being dismantled; (2) by accounting for the fissile materials and placing them under effective controls, the potential for smuggling and theft is reduced; (3) a fissile materials cutoff is being discussed at the Conference on Disarmament in Geneva; verification of a US-Russian cutoff, as well as substantial reductions in fissile materials stockpiles, are seen as integral to the cutoff; (4) calls for total nuclear disarmament have greatly increased; dismantlement verification and international control of fissile materials are widely viewed as requisite steps toward this goal. There are many questions to be answered before the United States can agree to a warhead verification regime and international control over excess fissile materials, let alone total nuclear disarmament. Two of the most important are: What are the prospects for effective verification? and How much fissile material can be declared as …
Date: February 27, 1996
Creator: Bailey, K. C.
Object Type: Article
System: The UNT Digital Library
System design description for sampling fuel in K basins (open access)

System design description for sampling fuel in K basins

This System Design Description provides: (1) statements of the Spent Nuclear Fuel Projects (SNFP) needs requiring sampling of fuel in the K East and K West Basins, (2) the sampling equipment functions and requirements, (3) a general work plan and the design logic being followed to develop the equipment, and (4) a summary description of the design for the sampling equipment. The report summarizes the integrated application of both the subject equipment and the canister sludge sampler in near-term characterization campaigns at K Basins.
Date: February 9, 1996
Creator: Baker, R.B.
Object Type: Report
System: The UNT Digital Library
System design description for sampling sludge in K basins fuel storage canisters (open access)

System design description for sampling sludge in K basins fuel storage canisters

This System Design Description provides: (1) statements of the Spent Nuclear Fuel Projects (SNFP) needs requiring sampling of canister sludge in the K East and K West Basins, (2) the sampling equipment system functions and requirements, (3) a general work plan and the design logic being followed to develop the equipment, and (4) a summary description of the design for the sampling equipment.
Date: February 6, 1996
Creator: Baker, R.B.
Object Type: Report
System: The UNT Digital Library
Revised 60-day safety screening and ferrocyanide results for tank 241-BY-108, rotary samples core 98 and core 104 (open access)

Revised 60-day safety screening and ferrocyanide results for tank 241-BY-108, rotary samples core 98 and core 104

Revised Report for 60-Day Safety Screening Results, Rotary Samples Core 98 and Core 104, Safety Screening and Ferrocyanide Results.
Date: February 1, 1996
Creator: Baldwin, J.H.
Object Type: Report
System: The UNT Digital Library
Tank characterization report for single-shell tank 241-BY-108 (open access)

Tank characterization report for single-shell tank 241-BY-108

This report summarizes information on the historical uses, current status, and sampling and analysis results of waste stored in single-shell underground tank 241-BY-108.
Date: February 9, 1996
Creator: Baldwin, J.H.
Object Type: Report
System: The UNT Digital Library
Observation of a narrow structure in the pp elastic scattering at T{sub kin} = 2.11 GeV (open access)

Observation of a narrow structure in the pp elastic scattering at T{sub kin} = 2.11 GeV

The angular dependences of the pp elastic scattering analyzing power, spin correlation, depolarization transfer were measured in the angular range from 60{degrees} to 97{degrees} CM at 14 energies between 1.96 and 2 .23 GeV. At fixed angles two maxima were observed in the analyzing Power energy dependence, both below and above 2.11 GeV. Furthermore a rapid decrease Of the spin correlation Parameter at 90{degrees} CM occurs around this energy. The observables allow determination of the absolute values of three nonvanishing pp amplitudes at 90{degrees}. The energy dependence of the spin-single amplitude shows a shoulder centered at 2.11 GeV, while the spin-triplet amplitudes are decreasing functions of energy snowing no evidence of structure. All experimental data are listed in tables and their energy dependences are shown in figures.
Date: February 1, 1996
Creator: Ball, J.; Chamouard, P.A. & Combet, M.
Object Type: Report
System: The UNT Digital Library