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Engineering, maintenance, and new initiatives to improve LAMPF beam availability and system reliability (open access)

Engineering, maintenance, and new initiatives to improve LAMPF beam availability and system reliability

Two different requirements are driving engineering studies and hardware development to improve LAMPF. The first is concerned with component and system improvements to increase beam availability during the LAMPF production cycle. Hardware changes in RF, power supplies, and magnets are being implemented to increase mean time between failure and reduce time to replace or repair failed units. A joint LAMPF-Industry project is on-going to improve reliability of RF components. A component test stand is being refurbished to include significant development capability. The second approach includes several changes that will increase the duty factor of the existing accelerator. Major changes are being evaluated for replacing the front end of the accelerator. Other changes improving high brightness capability could result in a new performance plateau for LAMPF.
Date: January 1, 1992
Creator: Harris, H. W.; DeHaven, R. A.; Hart, V. E.; Parsons, W. M. & Sturrock, J. C.
System: The UNT Digital Library
Understanding of carbonate fuel cell resistance issues for performance improvement (open access)

Understanding of carbonate fuel cell resistance issues for performance improvement

The overall objective of the current Task 6 under Contract AC21-90MC27168 is to develop understanding as well as quantification of cell ohmic resistance in carbonate fuel cell. The important resistance-contributing interfaces and elements are being investigated in high-temperature out-of-cell resistance experiments, using an AC-impedance technique. Ohmic resistance loss in a state-of-the-art carbonate fuel cell contributes about 65 mV loss at BOL (beginning-of-life). It may increase to about as much as 145 mV after 40,000 hours. Its reduction will offer further improvement in fuel cell power plant efficiency. The important resistance contributing elements/interfaces are illustrated in Figure 1. The majority of the ohmic loss attributed to electrolyte matrix (ionic) and cathode-side hardware (electronic). The ohmic loss due to anode-side hardware can generally be neglected because the anode-side hardware is surface protected resulting in very little surface oxide formation. The ohmic resistance of the electrodes is also negligible. The matrix ionic resistance is influenced by many factors: electrolyte conductivity, matrix porosity, tortuosity, electrolyte fill level and matrix thickness. At present, matrix contributes to > 300 m{Omega}cm{sup 2} (>70% of the total cell ohmic resistance) and is the major resistance contributor.
Date: January 1, 1992
Creator: Yuh, C. Y.; Farooque, M. & Johnsen, R.
System: The UNT Digital Library
ISOCELL trademark proof-of-concept for retrieval of wastes and contaminated soil (open access)

ISOCELL trademark proof-of-concept for retrieval of wastes and contaminated soil

ISOCELL{sup TM} cryogenic technology is designed to immobilize buried hazardous, radioactive, and mixed waste and contaminated soil by creating a block of frozen waste and soil that can be safely retrieved, stored, transported, and treated with a minimum of dust or aerosol production. A proof-of-concept'' test of the ISOCELL process was conducted in clean soil by RKK, Ltd., for the Idaho National Engineering Laboratory (INEL). Results indicate ISOCELL technology successfully froze moist soil into a solid block capable of being lifted and retrieved. Test conditions were compared to characteristics of possible buried waste sites in the INEL.
Date: January 1, 1992
Creator: Chatwin, T. D. (EG and G Idaho, Inc., Idaho Falls, ID (United States)) & Krieg, R. K. (RKK, Ltd., Bellevue WA (United States))
System: The UNT Digital Library
Evidence for alpha-particle chain configurations in sup 24 Mg (open access)

Evidence for alpha-particle chain configurations in sup 24 Mg

Many theoretical models have been employed to described the structure of the nucleus {sup 24}Mg. Among these are the Cranked Shell model (CSM), the Cranked Cluster Model (CCM), and calculations have also been performed using the Hartree-Fock formalism. One very striking prediction of these calculations is that in this nucleus there exist very unusual configurations, with structures reminiscent of linear chains of alpha particles. In the CSM, for instance, such a configuration is identified with a pronounced minimum in the potential energy energy at very large prolate deformation. In the CCM, several very different alpha-particle duster configurations are identified, many having rather large deformations. These cluster configurations can be associated with the different potential-energy minima obtained in the CSM results. In the case of the CCM, a 6{alpha} chain-like configuration is predicted to occur at excitation energies between 40 and 50 MeV, with predicted rotational spacing given by {Dirac h}{sup 2}/2I=22 keV. At this excitation energy, such a chain configuration would lie well above the threshold for the decay of {sup 24}Mg into 6 alpha particles, and its identification poses a difficult experimental challenge. This report discusses this challenge.
Date: January 1, 1992
Creator: Wuosmaa, A. H.; Back, B. B.; Betts, R. R.; Ferre, M.; Gehring, J.; Glagola, P. G. et al.
System: The UNT Digital Library
Three-terminal devices of high- Tc superconductors: A status report and future challenges (open access)

Three-terminal devices of high- Tc superconductors: A status report and future challenges

A study has been conducted on the recent progress of the three-terminal devices with transistor-like characteristics fabricated from the high-{Tc} superconducting materials. This study explored the operating principles and characteristics of these devices in relation to the relevant materials and techniques. A comparison of a variety of techniques for superconducting thin film deposition will be given. This study indirates that the feasibility of fabricating hybrid devices composed of semiconductors and superconductors appear to be the key issue to push forward the applications of high-{Tc} superconductors in microelectronics. The junction field-effect transistors with a semiconductor base controlled by the proximity effect are likely to be more manufacturable. The factors that influence the operating reliability of devices and the problems arising from integrating and packaging the devices will also be discussed.
Date: January 1, 1992
Creator: Kung, Pang-Jen (Los Alamos National Lab., NM (United States) Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering)
System: The UNT Digital Library
Geothermal energy and the utility market -- the opportunities and challenges for expanding geothermal energy in a competitive supply market: Proceedings (open access)

Geothermal energy and the utility market -- the opportunities and challenges for expanding geothermal energy in a competitive supply market: Proceedings

Each year the Geothermal Division of the US Department of Energy conducts an in-depth review of its entire geothermal R D program. The conference serves several purposes: a status report on current R D activities, an assessment of progress and problems, a review of management issues, and a technology transfer opportunity between DOE and the US geothermal city. This year's conference, Program Review X, was held in San Francisco on March 24--26, 1992. The theme of the review, Geothermal Energy and the Utility Market -- The Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market,'' focused on the needs of the electric utility sector. Geothermal energy, with its power capacity potential of 10 GWe by the year 2010, can provide reliable, enviromentally clean electricity which can help offset the projected increase in demand. Program Review X consisted of seven sessions including an opening session with presentations by Mr. Vikram Budhraja, Vice President of System Planning and Operations, Southern California Edison Company, and Mr. Richard Jaros, President and Chief Operating Officer, California Energy Company. The six technical sessions included presentations by the relevant field researchers covering DOE-sponsored R D in hydrothermal, hot dry rock, and geopressured energy. Individual …
Date: January 1, 1992
Creator: unknown
System: The UNT Digital Library
Considerations for the transition from fuel cell R D to manufacturing (open access)

Considerations for the transition from fuel cell R D to manufacturing

This paper has discussed some considerations important to making a successful transition from R D to manufacturing. It has described a product commercialization framework and discussed the importance of business analyses, especially product cost analysis, in determining the future potential of an emerging technology. Careful attention to the major elements discussed in this report should help both developers and venture sponsors to reduce the risks inherent in new business ventures.
Date: January 1, 1992
Creator: Cobb, M. S. & Meacham, G. B. K.
System: The UNT Digital Library
Chemical probes of metal cluster structure--Fe, Co, Ni, and Cu (open access)

Chemical probes of metal cluster structure--Fe, Co, Ni, and Cu

Chemical reactivity is one of the few methods currently available for investigating the geometrical structure of isolated transition metal clusters. In this paper we summarize what is currently known about the structures of clusters of four transition metals, Fe, Co, Ni, and Cu, in the size range from 13 to 180 atoms. Chemical probes used to determine structural information include reactions with H{sub 2}(D{sub 2}), H{sub 2}0, NH{sub 3} and N{sub 2}. Measurements at both low coverage and at saturation are discussed.
Date: January 1, 1992
Creator: Parks, E. K.; Zhu, L.; Ho, J. & Riley, S. J.
System: The UNT Digital Library
Kinetic studies of reactions of cobalt clusters with deuterium (open access)

Kinetic studies of reactions of cobalt clusters with deuterium

The kinetics of chemical reactions of cobalt clusters Co{sub n} with deuterium are described. Absolute rate constants have been measured in the cluster range n = 7--68 at 293 K. The rate constants are found to be a strong function of cluster size, varying by up to three orders of magnitude. This size , dependence is most prominent in the n = 7--25 size range: CO{sub 15} is the most reactive cluster, and CO{sub 7-9} and CO{sub 19--20} are particularly unreactive. Abrupt changes in the rate constants from one cluster size to the next are observed. For the clusters above n = 25, the rate constants show several less prominent maxima and minima superimposed on a slow, nearly monotonic increase with cluster size.
Date: January 1, 1992
Creator: Ho, J.; Zhu, L.; Parks, E. K. & Riley, S. J.
System: The UNT Digital Library
Perovskite solid electrolytes for SOFC (open access)

Perovskite solid electrolytes for SOFC

Selected perovskite solid electrolytes incorporated into research size fuel cells have shown stability for > 4000 hours at 600{degrees}C. Perovskite lattice requirements which favor low E{sub a} for ionic conduction include (i) that the perovskite lattice possess a moderate enthalpy of formation, (ii) perovskite lattice possess large free volumes, (iii) that the lattice minimally polarizes the mobile ion and (iv) that the crystallographic saddle point r{sub c} for ionic conduction is {approx equal} 1.
Date: January 1, 1992
Creator: Sammells, A. F.
System: The UNT Digital Library
Memory access in shared virtual memory (open access)

Memory access in shared virtual memory

Shared virtual memory (SVM) is a virtual memory layer with a single address space on top of a distributed real memory on parallel computers. We examine the behavior and performance of SVM running a parallel program with medium-grained, loop-level parallelism on top of it. A simulator for the underlying parallel architecture can be used to examine the behavior of SVM more deeply. The influence of several parameters, such as the number of processors, page size, cold or warm start, and restricted page replication, is studied.
Date: January 1, 1992
Creator: Berrendorf, R. (Zentralinstitut fuer Angewandte Mathematik Forschungszentrum Juelich, KFA (FRG))
System: The UNT Digital Library
Results of Field Testing of Radioactive Waste Forms Using Lysimeters (open access)

Results of Field Testing of Radioactive Waste Forms Using Lysimeters

The Field Lysimeter Investigation: Low-Level Waste Data Base Development Program is obtaining informaiton on the performance of radioactive waste in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-II prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. In this paper, radionuclide releases from waste forms in the first six years of sampling are presented and discussed. Application of lysimeter data to use in performance assessment models is presented. Initial results from use of data in a performance assessment model are discussed.
Date: January 1, 1992
Creator: McConnell, J. W., Jr.; Rogers, R. D.; Jastrow, J. D. & Wickliff, D. S.
System: The UNT Digital Library
Interdisciplinary hydrogeologic site characterization at the Nevada Test Site (open access)

Interdisciplinary hydrogeologic site characterization at the Nevada Test Site

The Nevada Test Site was established in 1950 as a continental area for testing nuclear devices. Hydrogeologic investigations began in earnest with the US Geological Survey mapping much of the area from 1960 to 1965. Since 1963, all nuclear detonations have been underground. Most tests are conducted in vertical shafts, but a small percentage are conducted in tunnels. The majority of detonation points are above the water table, primarily in volcanic rocks, but sometimes in alluvium. Hydrogeologic investigations began in earnest with the US Geological Survey's mapping of much of the NTS region from 1960 to 1965. Following the BANEBERRY test in December 1970, which produced an accidental release of radioactivity to the atmosphere, the US Department of Energy (then the Atomic Energy Commission) established the Containment Evaluation Panel (CEP). Results of interdisciplinary hydrogeologic investigations for each test location are included in a Containment Prospectus which is thoroughly reviewed by the CEP.
Date: January 1, 1992
Creator: Hawkins, W. L. (Los Alamos National Lab., NM (United States)); Wagoner, J. L. (Lawrence Livermore National Lab., CA (United States)) & Drellack, S. L. (Raytheon Services Nevada, Mercury, NV (United States))
System: The UNT Digital Library
Particle-fluid two-phase flow modeling (open access)

Particle-fluid two-phase flow modeling

This paper describes a numerical scheme and computer program, DISCON, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between-thermal instantaneous and the averaged two-fluid model. It solves the Eulerian continuity, momentum, and energy equations for each liquid control volume, and the Lagrangian mass, momentum, energy, and position equations for each bubble. The bubbles are modeled individually using a large representative number of bubbles thus avoiding the numerical diffusion associated with Eulerian models. DISCON has been used to calculate the bubbling of air through a column of water and the subcooled boiling of water in a flow channel. The results of these calculations are presented.
Date: January 1, 1992
Creator: Mortensen, G. A. & Trapp, J. A.
System: The UNT Digital Library
Dynamic vacuum analysis for APS high heat flux beamline front ends using optical ray-tracing simulation methods (open access)

Dynamic vacuum analysis for APS high heat flux beamline front ends using optical ray-tracing simulation methods

The high-power and high-flux x-ray beams produced by third generation synchrotron radiation sources such as the Advanced Photon Source (APS) can cause significantly high gas desorption rates on beamline front-end components if beam missteering occurs. The effect of this gas desorption needs to be understood for dynamic vacuum analysis. To simulate beam missteering conditions, optical ray-tracing methods have been employed. The results of the ray-tracing analysis have been entered into a system-oriented vacuum program to provide dynamic vacuum calculations for determination of pumping requirements for the beamline front-ends. The APS will provide several types of synchrotron radiation sources, for example, undulators, wigglers, and bending magnets. For the purpose of this study, the wiggler source was chosen as a worst case'' scenario due to its high photon flux, high beam power, and relatively large beam cross section.
Date: January 1, 1992
Creator: Xu, S. & Nielsen, R. W.
System: The UNT Digital Library
A multi-disciplinary assessment of operator action time for mitigating a postulated accident (open access)

A multi-disciplinary assessment of operator action time for mitigating a postulated accident

This report discusses mitigation of the postulated Loss of Heat Sink Accident for the Savannah River Site K Reactor which requires operator action to place the plant in a water conservation configuration. In August 1991, concerns were raised about the allowances in the safety analyses for operator action times in an unpowered scenario, where several valves would be manually closed. WSRC management conservatively decided to include explicit consideration of a seismic initiator for this scenario, which introduced the additional concern that operator actions could be hindered by tritium from flange leakage. The revised analyses concluded that the powered case documented in the Safety Analysis Report is limiting and that all acceptance criteria are met.
Date: January 1, 1992
Creator: Morgan, C. D.; Fields, C. C.; Hightower, N. T. III (Westinghouse Savannah River Co., Aiken, SC (United States)); Buczek, J. A. (ABB Government Services, Inc. (United States)); Jenkins, T. B. & Swanson, P. J. (Concord Associates, Inc., Knoxville, TN (United States))
System: The UNT Digital Library
Sulfided heterogeneous, bimetallic RuMo catalysts derived from mixtures of Ru sub 3 (CO) sub 12 (or RuCl sub 3 ) and a molybdenum heteropolyanion. The reactions of ethanol with tetrahydroquinoline (open access)

Sulfided heterogeneous, bimetallic RuMo catalysts derived from mixtures of Ru sub 3 (CO) sub 12 (or RuCl sub 3 ) and a molybdenum heteropolyanion. The reactions of ethanol with tetrahydroquinoline

Efforts have been made to develop Ru/Mo bimetallic catalyst systems for hydrodenitrogenation (HDN) of tetrahydroquinoline (THQ)- In the course of these studies, it was discovered that in ethanol, under H{sub 2} and in the presence Of CS2, Precatalyst solutions containing Ru (as Ru{sub 3} (CO){sub 12} or RuCl{sub 3}) and Mo (as the H{sub 3}PMO{sub 12}0{sub 40} heteropolyanion (HPA)) decompose to form bimetallic, sulfided particles. Particle diameters run from 0.1 to 5 {mu}m depending on the rate of stirring. Catalyst particles with sizes ranging from 0.1--1 {mu}m can be prepared reproducibly. BET measured surface areas for these size particles ranged from 2 to 20 m2/g. These sulfided particles were found to catalyze, at temperatures of 200--250{degrees}C and hydrogen pressures of 200--1000 psig H{sub 2}, the N-ethylation of THQ to form NEt-THQ; rather than the formation of propylcyclohexane or propylbenzene, reaction products expected for HDN of THQ. Monometallic heterogeneous catalysts prepared from the individual precatalyst complexes, under identical conditions, show minimal activity for N-ethylation by comparison with the bimetallic catalyst. In the absence of H{sub 2}, the reaction proceeds such that THQ is converted to Q, N-EtTHQ, N-C{sub 6}H{sub 9}-THQ, and N-C{sub 6}H{sub 13}-THQ. The latter products appear to arise via …
Date: January 1, 1992
Creator: Koo, Sang-Man; Ryan, D. & Laine, R. M.
System: The UNT Digital Library
A comparative analysis of energy demand and expenditures by minority and majority households within the context of a conditional demand system (open access)

A comparative analysis of energy demand and expenditures by minority and majority households within the context of a conditional demand system

Analysis and evaluation of the impact that programs and policies have on energy consumption and expenditures are confounded by many intervening variables. A clear understanding of how these variables influence energy consumption patterns should be grounded in a rigorously developed framework. In this regard much is documented in the literature. However, an analysis of the comparative relationship between energy demand and variables which influence it among different socioeconomic groups has not been thoroughly explored with any theoretical rigor. It is proposed that differences in patterns of energy use between black, Hispanic, and majority households (where the household head is neither black nor Hispanic) are due to both structural and distribution differences. It is felt that the structural dissimilarities are primarily due to the dynamic nature in which energy consumption patterns evolve, with differences in changing housing patterns playing a significant role. For minorities, this implies a potential difference in the effect of policy and programs on economic welfare when compared to majority households.To test this hypothesis, separate conditional demand systems are estimated for majority, black, and Hispanic households. With the use of separate variance/covariance matrices, various parameter groups are tested for statistically significant differences.
Date: January 1, 1992
Creator: Poyer, D. A.
System: The UNT Digital Library
Neutrino mass and mixing, and non-accelerator experiments (open access)

Neutrino mass and mixing, and non-accelerator experiments

We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.
Date: January 1, 1992
Creator: Robertson, Robert Graham Hamish
System: The UNT Digital Library
Department of Energy/US Air Force Memorandum of Agreement Program (open access)

Department of Energy/US Air Force Memorandum of Agreement Program

This document discusses the Department of Energy/United States Air Force Memorandum of Agreement (DOE/USAF MOA) Program which was formed as a result of the DOE and the US Air Force combining forces to reduce waste generation in areas common to both agencies. This program will develop pollution prevention technologies such as material substitution and advanced manufacturing techniques to reduce or eliminate the generation of hazardous waste (see Figures 1). Joint Agency development of solutions to shared problems, including substitution of chlorinated solvents and metal coating/manufacturing process development, leverages DOE funds. The Program will cover all phases involved in industrial processes. It will expedite future selection and implementation of the best technologies to show immediate and long-term effectiveness for DOE and USAF sites. The Program provides for technical performance comparisons, under actual field conditions, of different available technologies. The comparisons will be based on effectiveness, with respect to the technology itself, risk reduction and general acceptability. The goal is to develop and transfer environmentally compliant manufacturing and repair technologies.
Date: January 1, 1992
Creator: Copeland, A. E.
System: The UNT Digital Library
Development of Hollow-Fiber Catalytic-Membrane Reactors for High-Temperature Gas Cleanup (open access)

Development of Hollow-Fiber Catalytic-Membrane Reactors for High-Temperature Gas Cleanup

The project consist of the following main activities: (1) Design of catalytic hollow fiber membrane reactors. Single and multiple hollow-fiber membranes were studied in reactor/permeation cells made from stainless steel or quartz tubes. Modification of the hollow fiber membrane with catalysts was performed by aqueous impregnation, vapor deposition, and utilization of packed-bed reactors. (2) Investigation of gas separations and catalytic reactions in membrane reactors. Permeation of pure gases and gas mixtures was studied as a function of temperature. Pure component catalytic studies on the decomposition of H[sub 2]S was typically studied using 10% H[sub 2]S diluted in He. The H[sub 2]S and H[sub 2] concentrations were measured in both the tube and shell sides of the membrane reactor to determine the degree of chemical equilibrium shift. (3) Process development of the cleanup system using a simulated gas stream with a composition similar to that from an IGCC system. Catalytic studies using the IGCC gas composition will be performed according to the procedure used in the H[sub 2]S experiments. The conditions for optimum conversion in a gas mixture will be investigated.
Date: January 1, 1992
Creator: Ma, Yi H.; Moser, M. R. & Pien, S. M.
System: The UNT Digital Library
Pressure measurements in the AGS Booster ultra-high vacuum system (open access)

Pressure measurements in the AGS Booster ultra-high vacuum system

An average pressure of mid 10{sup {minus}11} Torr has been achieved and maintained in the AGS Booster ring vacuum system during its first year of operation. This ultra-high vacuum system is monitored through remote controlled Bayard-Alpert Gauges (BAGs). The characteristics of the pressure measurements with BAGs over the long cable lengths (up to 200 m) and under various accelerator operating conditions will be described. Two types of noise in the pressure readouts have been identified; the electromagnetic interference (EMI) associated with the acceleration cycles of the Booster and the environment noise associated with the temperature of the collector cables. The magnitude of the noise pickup depends on the routing of the collector cables and reaches the equivalent pressure of low 10{sup {minus}9} Torr.
Date: January 1, 1992
Creator: Gabusi, J.; Geller, J.; Hseuh, H. C.; Mapes, M. & Stattel, P.
System: The UNT Digital Library
High performance microchannel heat exchanger for cooling high heat load x-ray optical elements (open access)

High performance microchannel heat exchanger for cooling high heat load x-ray optical elements

Analysis has been carried out to demonstrate that a liquid nitrogen cooled microchannel heat exchanger can be designed to maximize the heat transfer from silicon to the working fluid. The results show that the performance of the liquid nitrogen cooled microchannel heat exchanger is significantly enhanced by approximately three times over flowing water through microchannels.
Date: January 1, 1992
Creator: Choi, U. S.; Rogers, C. S. & Mills, D. M.
System: The UNT Digital Library
Analysis of the OECD-LOFT International Standard Problem 31 using SCDAP/RELAP5/MOD3 (open access)

Analysis of the OECD-LOFT International Standard Problem 31 using SCDAP/RELAP5/MOD3

The CORA-13 bundle heating and melting experiment performed at the Kernforechungszentrum, Karlaruhe, (KfK) was analyzed at the Idaho National Engineering Laboratory (INEL) using SCDAP/RELAP5/MOD3. This analysis was part of a systematic assessment of SCDAP/RELAP5/MOD3 for the US Nuclear Regulatory Commission to (a) evaluate the variances between calculated and observed behavior, (b) identify outstanding modeling deficiencies, and (c) to evaluate the impact of ongoing modeling improvements. A brief discussion of the CORA-13 experiment including a description of the facility, important test conditions, and comparisons with other CORA experimental conditions and results is provided in this report. This report describes the results of the SCDAP/RELAPS/MOD3 analysis including a description of the SCDAP/RELAPS model of the facility, base case results, sensitivity results, and a comparison with other SCDAP/RELAP5/MOD3 code-to-data comparisons.
Date: January 1, 1992
Creator: Hohorst, J. K. & Allison, C. M.
System: The UNT Digital Library