The performance of a polymer electrolyte fuel cell (PEFC) system that is fueled directly by hydrogen has been evaluated for transportation vehicles. The performance was simulated using a systems analysis code and a vehicle analysis code. The results indicate that, at the design point for a 50-kW PEFC system, the system efficiency is above 50%. The efficiency improves at partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the voltage-current characteristic curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and, eventually, the fuel cell. The results also indicate that the PEFC system can start rapidly from ambient temperatures. Depending on the specific weight of the fuel cell (1.6 kg/kW in this case), the system takes up to 180s to reach its design operating conditions. The PEFC system has been evaluated for three mid-size vehicles: the 1995 Chrysler Sedan, the near-term Ford AIV (Aluminum Intensive Vehicle) Sable, and the future P2000 vehicle. The results show that the PEFC system can meet the demands of the Federal Urban Driving Schedule and the Highway driving cycles, for both warm and …

The corrosion of spent nuclear fuel and subsequent mobilization of radionuclides is of great concern in a geologic repository, particularly if conditions are oxidizing. Corroding A516 steel may offset these transport processes within the proposed waste packages at the Yucca Mountain Repository (YMR) by retaining radionuclides, creating locally reducing conditions, and reducing porosity. Ferrous iron, Fe{sup 2+}, has been shown to reduce UO{sub 2}{sup 2+} to UO{sub 2(s)} [1], and some ferrous iron-bearing ion-exchange materials adsorb radionuclides and heavy metals [2]. Of particular interest is magnetite, a potential corrosion product that has been shown to remove TcO{sub 4}{sup -} from solution [3]. Furthermore, if Fe{sup 2+} minerals, rather than fully oxidized minerals such as goethite, are produced during corrosion, then locally reducing conditions may be present. High electron availability leads to the reduction and subsequent immobilization of problematic dissolved species such as TcO{sub 4}{sup -}, NpO{sub 2}{sup +}, and UO{sub 2}{sup 2+} and can also inhibit corrosion of spent nuclear fuel. Finally, because the molar volume of iron material increases during corrosion due to oxygen and water incorporation, pore space may be significantly reduced over long time periods. The more water is occluded, the bulkier the corrosion products, and the …

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The heat exchanger of the calciner consists of a vessel into which unfired, horizontal, bayonet tubes extend in a fluidized bed. Strain measurements were taken on several of the tubes under simulated operating conditions and the associated dynamic stresses were calculated. Vibrations greater than design limitations for indefinite operation were found to exist. To restrict these vibrations and prevent further tube fatigue cracking, a tube support was installed. Since the installation of the support, the calciner has operated satisfactorily over 1275 hours. (auth)

The objectives of this study were to demonstrate that the pump speed control system will respond as defined in the equipment specifications and to determine optimum values of controlling variables that will minimize the oscillations that occur in the Na flow rate when transient signals are imposed on the pump speed control system. (W.L.H.)

The traveler spent the year at CERN primarily to test, calibrate, and prepare a BGO photon detector system for use in the August 1990 run of WA80 with sulfur beams and for use in future planned runs with an expanded BGO detector. The BGO was used in test-beam runs in December 1989 and April--May 1990 and in the August data-taking run. The Midrapidity Calorimeters (MIRAC) were also prepared in a new geometry for the August run with a new transverse energy trigger. The traveler also continued to refine and carry out simulations of photon detector systems in present and future planned photon detection experiments. The traveler participated in several WA80 collaboration meetings, which were held at CERN throughout the period of stay. Invited talks were presented at the Workshop on High Resolution Electromagnetic Calorimetry in Stockholm, Sweden, November 9--11, 1989, and at the International Workshop on Software Engineering, Artificial Intelligence, and Expert Systems for High-Energy and Nuclear Physics at Lyon, France, March 19--24, 1990. The traveler participated in an experiment to measure particle--particle correlations at 30-MeV/nucleon incident energies at the SARA facility in Grenoble from November 11--24, 1989.

This packaging design criteria provides the criteria for the design, fabrication, safety evaluation, and use of the steel waste package (SWP) to transport remote-handled waste and special-case waste from the 324 facility to Central Waste Complex (CWC) for interim storage.

Soft X-ray imager mirrors have been designed, calibrated and fabricated at Lawrence Livermore National Laboratory and characterized at the Advanced Light Source for their performance between 200 and 1300 eV. The mirrors are coated with a multilayer coating consisting of 70 bilayers of W/ SiC. The mirrors are to reflect at 22.5 deg from grazing angle at 1.50 nm wavelength and the width of the reflectivity peak should be at least 1.3%. Also, the mirrors should be non-reflective elsewhere. Our multilayer design was optimized to satisfy these requirements. The coating is very challenging since the individual layer thicknesses need to be less than 1 nm thick and reproducibility from layer to layer is crucial. To minimize the second harmonic peak we designed a multilayer with {Gamma} = 0.5 (W and SiC layer thicknesses are the same). This way we end up with a mirror that has only the 1st and 3rd harmonic peak as shown in Figure 1. To suppress reflectivity outside the first peak we used our novel approach, an antireflective coating. Modeling predicted substantial reduction in reflectivity, especially for lower energies as shown in Figure 1. The experimental results of the soft x-ray imager mirror as measured at …

Insight into plasma microturbulence and transport is being sought using linear simulations of drift waves on the National Spherical Torus Experiment (NSTX), following a study of drift wave modes on the Alcator C-Mod Tokamak. Microturbulence is likely generated by instabilities of drift waves, which cause transport of heat and particles. Understanding this transport is important because the containment of heat and particles is required for the achievement of practical nuclear fusion. Microtearing modes may cause high heat transport through high electron thermal conductivity. It is hoped that microtearing will be stable along with good electron transport in the proposed low collisionality International Thermonuclear Experimental Reactor (ITER). Stability of the microtearing mode is investigated for conditions at mid-radius in a high density NSTX high performance (H-mode) plasma, which is compared to the proposed ITER plasmas. The microtearing mode is driven by the electron temperature gradient, and believed to be mediated by ion collisions and magnetic shear. Calculations are based on input files produced by TRXPL following TRANSP (a time-dependent transport analysis code) analysis. The variability of unstable mode growth rates is examined as a function of ion and electron collisionalities using the parallel gyrokinetic computational code GS2. Results show the microtearing …

The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the seismic hazard and design parameters at the Pantex Plant. The probabilistic seismic hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attention was given to soil amplification factors for the site. Horizontal Peak Ground Acceleration (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.

This project originated as a result of the Strontium-90 Action Plan, a response to the abnormal release of radionuclides that occurred from White Oak Creek (WOC) during late November and early December 1985. Several notable problems became obvious during ORNL`s response to this release: (1) no predetermined criteria existed for the operation of White Oak Dam (WOD) in response to spills, (2) the hydrodynamics of contaminant transport and dispersion within the WOC watershed and downstream were not adequately understood to support requests for modified reservoir releases, and (3) real-time data on streamflow, precipitation, and water quality within the watershed were not readily available in sufficient quantity and usable format. The modeling study was initiated to help address these problems. This report describes FY 87 accomplishments, including: improvements in data acquisition and evaluation; implementation and calibration of a model to forecast discharges of water and contaminants from the WOC watershed; implementation, documentation, and checking of a model to forecast concentrations of contaminants from WOC in the Clinch River; and three field studies that provide essential calibration data. Data from the field studies and user documentation of the Clinch River model are included as appendices to this report.

This project originated as a result of the Strontium-90 Action Plan, a response to the abnormal release of radionuclides that occurred from White Oak Creek (WOC) during late November and early December 1985. Several notable problems became obvious during ORNL's response to this release: (1) no predetermined criteria existed for the operation of White Oak Dam (WOD) in response to spills, (2) the hydrodynamics of contaminant transport and dispersion within the WOC watershed and downstream were not adequately understood to support requests for modified reservoir releases, and (3) real-time data on streamflow, precipitation, and water quality within the watershed were not readily available in sufficient quantity and usable format. The modeling study was initiated to help address these problems. This report describes FY 87 accomplishments, including: improvements in data acquisition and evaluation; implementation and calibration of a model to forecast discharges of water and contaminants from the WOC watershed; implementation, documentation, and checking of a model to forecast concentrations of contaminants from WOC in the Clinch River; and three field studies that provide essential calibration data. Data from the field studies and user documentation of the Clinch River model are included as appendices to this report.

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The BAGPIPE sub-critical experiment was executed on September 26, 1998, at about 13:07 hours. A steel and fibercrete containment barrier had been built at the entrance to the U1a.101b drift at the Nevada Test Site to form the BAGPIPE zero-room. The invert of the zero-room was covered with concrete and the ribs and back were covered with about 15 cm of fibercrete. The face was left uncovered to facilitate gas bleed-off into the alluvial formation. The volume of the room was approximately 3894 ft{sup 3}. Four small experimental packages were detonated. The LLNL containment goal for the BAGPIPE experiment was to confine all special nuclear material (SNM) to the zero-room and the alluvium surrounding the zero-room. The experiment and containment objectives are discussed more fully in the BAGPIPE Containment Prospectus and the associated addendum. Alpha-particle radiation detectors outside the BAGPIPE zero-room remained at pre-shot background levels after the experiment. A large number of swipes were taken around the BAGPIPE primary containment barrier and in the diagnostics room. No evidence that any SNM was released into the tunnel complex was found and the BAGPIPE containment was considered successful.

The use of self-supported fuel elements in ribless Zircaloy-2 tubes at C-Reactor requires some inlet nozzle modification to allow charging of the larger overall diameter fuel pieces. A new nozzle assembly has been developed (by Equipment Development Operation -- IPD) which will allow use of the new fuel pieces and at the same time increase the reliability of the header-to-tube piping and reduce pumping power losses. Flow test data were requested for the new assembly and the results of these tests are presented herein. This report also presents a comparison of the header to tube energy losses for the various reactor inlet nozzle assemblies which are currently used on the Hanford production reactors.

The synthesis of relatively complex organic molecules by ionizing and radical mechanisms (induced by high energy radiations, ultraviolet and electric discharge) from methane, ammonia, water, and hydrogen is described, both theoretically and experimentally. It is shown that the molecules which tend to be formed under such random conditions are the very ones which today are the common building blocks in the biological reconstruction of organic material. Such molecules are the amino acids, the simple carboxylic and hydroxy acids, purines, pyrimidines, etc. The appearance of order among such random molecules is induced by two forces, namely, autocatalysis and crystallization. The latter is particularly important in the appearance of highly efficient macromolecular structures and arrangements which are so characteristic of present-day living organisms. Points of contact of these theories with experiment are indicated, and where confirmation has been obtained it is described, and the areas of ignorance, requiring further experimentation, are defined. A first step in a possible test of these prebiotic organic syntheses on other astral bodies has been made by examining the organic material found in meteorites. The nature of the structures appearing therein is indicated.

The W-259 project will provide upgrades to the 2706-T/TA Facility to comply with Federal and State of Washington environmental regulations for secondary containment and leak detection. The project provides decontamination activities supporting the environmental restoration mission and waste management operations on the Hanford Site.

This report is a compilation of 7 studies conducted for the U.S. Army Corps of Engineers between 1995 and 1998 which used hydroacoustic methods to study the behavior of migrating salmon in response to navigation channel maintenance activities in the lower Columbia River near river mile 45. Differences between daytime and nighttime behavior and fish densities were noted. Comparisons were made of fish distribution across the river (in the channel, channel margin or near shore) and fish depth upstream and downstream of dikes, dredges, and pile driving areas.

This report is a compilation of 7 studies conducted for the U.S. Army Corps of Engineers between 1995 and 1998 which used hydroacoustic methods to study the behavior of migrating salmon in response to navigation channel maintenance activities in the lower Columbia River near river mile 45. Differences between daytime and nighttime behavior and fish densities were noted. Comparisons were made of fish distribution across the river (in the channel, channel margin or near shore) and fish depth upstream and downstream of dikes, dredges, and pile driving areas.

This report highlights progress achieved during FY 1999 under the Light-duty Fuels Utilization R and D Program. The program is comprised of two elements: the Advanced Petroleum-Based APB Fuels Program which focused on developing and testing advanced fuels for use with compression-ignition direct-injection (CIDI) engines and fuel cells and the Alternative Fuels Program which focused on Natural gas and natural gas derived fuels. The report contains 17 summaries of industry and National Laboratory projects. Fuel efficient vehicles with very low emissions are essential to meet the challenges of climate change, energy security, and improved air quality. The authors anticipate cooperative efforts with the auto and energy industries to develop new and innovative technologies that will be used to make advanced transportation vehicles that are fuel efficient, clean, and safe.

One of the striking features of Dirac's theory of the electron was the appearance of solutions to his equations which required the existence of an antiparticle, later identified as the positron.

Our proposal focuses on cloud-radiation processes in a general 3D cloud situation, with particular emphasis on cloud optical depth and effective particle size. We also focus on zenith radiance measurements, both active and passive. The proposal has three main parts. Part One exploits the “solar-background” mode of ARM lidars to allow them to retrieve cloud optical depth not just for thin clouds but for all clouds. This also enables the study of aerosol cloud interactions with a single instrument. Part Two exploits the large number of new wavelengths offered by ARM’s zenith-pointing ShortWave Spectrometer (SWS), especially during CLASIC, to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also propose to take advantage of the SWS’ 1 Hz sampling to study the “twilight zone” around clouds where strong aerosol-cloud interactions are taking place. Part Three involves continuing our cloud optical depth and cloud fraction retrieval research with ARM’s 2NFOV instrument by, first, analyzing its data from the AMF-COPS/CLOWD deployment, and second, making our algorithms part of ARM’s operational data processing.

This document presents the Pros and Cons of using a cloud chamber for field use. Historical aspects are briefly discussed. A cloud chamber experiment on Midi Mist is described. Plans for fielding an experiment on Hupmobile are presented.

The development of several metallic fuei element systems for air-cooled reactors is reviewed, and the hightemperature properties of Type 310 stainless steel and Nichrome V clad fuel elements are discussed. Early work on cladding of Mo is reviewed, and recent developments in ferrous-base alloys and Cr-base alloys as hightemperature cladding materials are presented. (auth)