Carbons derived from polymethylacrylonitrile (PMAN) have been studied for use as intercalation anodes in Li-ion cells. The effect of Si doping upon the electrochemical performance of PMAN carbons was studied using tetravinylsilane (TVS) and tetramethysilane (TMS) as sources of Si during the formation of the PMAN precursors. The carbons were characterized by galvanostatic cycling, cyclic voltammetry, and complex impedance. The presence of 9 to 11 w/o Si in the PMAN lattice greatly increased the irreversible capacity of these materials.

This paper presents a simple, systematic approach for developing accident scenarios using generic accident types. Result is a necessary and sufficient set of accident scenarios that can be used to establish the safety envelope for a facility or operation. Us of this approach along with the methodology of SAND95-0320 will yield more consistent accident analyses between facilities and provide a sound basis for allocating limited risk reduction resources.

The US Air Force (USAF) Environmental Compliance Assessment and Management Program (ECAMP) is an effective and comprehensive system to evaluate environmental compliance at individual USAF installations. The ECAMP assessment is typically performed by a team of experts from the installation`s Major Command (MAJCOM) Headquarters, and is often augmented with technical contractor support. As directed by Air Force policy, an external ECAMP assessment is required at a minimum of every three years for each installation. In the intervening years, each installation is required to perform an internal ECAMP assessment, with its own personnel and resources. Even though team composition differs, the internal and external ECAMP assessments are likely to be very similar in scope, objectives, and deliverables. For over nine years, Argonne National Laboratory (ANL) has supported several Air Force MAJCOMs in performing their external ECAMP assessments. More recently, ANL has also had the opportunity to provide technical support and training at individual installations during their preparation and conduct of internal ECAMP assessments. From that experience, the authors have learned that the quality and value of the internal assessment is enhanced by making it a vehicle for training, planning, and interaction among organizations. Various strategies and techniques have been successfully employed …

An installation`s compliance with Resource Conservation and Recovery Act (RCRA) hazardous waste regulations is strongly dependent on the knowledge, skill, and behavior of all individuals involved in the generation and management of hazardous waste. Recognizing this, Headquarters Air Force Materiel Command (HQ/AFMC) determined that an in-depth evaluation of hazardous waste training programs at each AFMC installation was an appropriate element in assessing the overall effectiveness of installation hazardous waste management programs in preventing noncompliant conditions. Consequently, pursuant to its authority under Air Force Instruction (AFI) 32-7042, Solid and Hazardous Waste Compliance (May 12, 1994) to support and maintain hazardous waste training, HQ/AFMC directed Argonne National Laboratory to undertake the Hazardous Waste Training Initiative. This paper summarizes the methodology employed in performing the evaluation and presents the initiative`s salient conclusions.

Large catchment basins may be viewed as ecosystems with interactive natural and cultural attributes. Stream regulation severs ecological connectivity between channels and flood plains by reducing the range of natural flow and temperature variation, reduces the capacity of the ecosystem to sustain native biodiversity and bioproduction and promotes proliferation of non-native biota. However, regulated rivers regain normative attributes, which promote recovery of native biota, as distance from the dam increases and in relation to the mode of regulation. Therefore, reregulation of flow and temperature to normative pattern, coupled with elimination of pollutants and constrainment of nonnative biota, can naturally restore damaged habitats from headwaters to mouth. The expectation is rapid recovery of depressed populations of native species. The protocol requires: restoration of seasonal temperature patterns; restoration of peak flows needed to reconnect and periodically reconfigure channel and floodplain habitats; stabilization of base flows to revitalize the shallow water habitats; maximization of dam passage to allow restoration of metapopulation structure; change in the management belief system to rely on natural habitat restoration as opposed to artificial propagation, installation of artificial instream structures (river engineering) and artificial food web control; and, practice of adaptive ecosystem management.

A post-processing, selective micro-chemical vapor deposition (``micro-CVD``) technology for the deposition of catalytic films on surface-micromachined, nitride-passivated polysilicon filaments has been investigated. Atmospheric pressure deposition of Pt on microfilaments was accomplished by thermal decomposition of Pt acetylacetonate; deposition occurs selectively only on those filaments which are electrically heated. Catalyst morphology, characterized by SEM, can be controlled by altering deposition time, filament temperature, and through the use of pulsed heating of the filament during deposition. Morphology plays an important role in determining the sensitivity of these devices when used as combustible gas sensors.

Flurofullerenes were among the first chemical derivatives prepared from new spherical forms of carbon, yet it took 3 years of research to isolate the first single compound, C{sub 60}F{sub 48}. Subsequent studies provided a better understanding of physical and chemical properties of this compound. Here we present new data concerning synthesis, reactions, and properties of C{sub 60}F{sub 48}.

Mullite and aluminum titanate precursor polymeric sols were developed for applying as coatings on Nicalon{trademark} fabrics and tows. A Nicalon{trademark}/SiC composite with a mullite interface was fabricated. The mullite precursor interface coatings were applied by a vacuum infiltration method and the SiC matrix was deposited by a forced flow chemical vapor infiltration process. Thin, uniform mullite interface coatings were obtained. However, the Nicalon{trademark}/SiC composite exhibited brittle fracture. Mullite and alumina-titania coatings were applied on Nicalon{trademark} tows and the effect of heat treatment at 1000{degrees}C in air is discussed.

The evolution of the Rayleigh-Taylor (RT) instability in a compressible medium has been investigated at an accelerating embedded interface and at the ablation front in a series of experiments on the Nova laser. The x-ray drive generated in a gold hohlraum ablatively accelerated a planar target consisting of a doped plastic pusher backed by a higher density titanium payload with perturbations placed at the plastic-Ti interface. The targets were diagnosed by face-on and side-on radiography. In previous work focusing on single mode perturbations, wavelengths as short as 10 m have been observed to grow strongly at the embedded interface. Here multimode perturbations consisting of either 2, 10 or 20 modes superposed in phase have been investigated.

The potential predictability (PP) of seasonal anomalies in continental hydrology may be thought of as the upper bound in forecast accuracy to be expected when the state of the oceans is known perfectly. We assume that the PP of the seasonal anomalies of continental hydrology is related to their degree of reproducibility in the presence of identical ocean boundary conditions across a number of simulations. In this study, the PP of seasonal anomalies in surface hydrological variables is estimated from an ensemble of 6 decadal integration of the ECMWF global atmospheric model coupled to a land-surface scheme which includes interception and transpiration by a simple vegetation canopy. Identical observed (AMIP) monthly sea surface temperatures are specified in each simulation, while the initial condition of the atmosphere and land surface are allowed to vary.

A non-conventional type of heating system is being tested at Sandia National Laboratories for solar thermal power tower applications. In this system, called impedance heating, electric current flows directly through the pipe to maintain the desired temperature. The pipe becomes the resistor where the heat is generated. Impedance heating has many advantages over previously used mineral insulated (MI) heat trace. An impedance heating system should be much more reliable than heat trace cable since delicate junctions and cabling are not used and the main component, a transformer, is inherently reliable. A big advantage of impedance heating is the system can be sized to rapidly heat up the piping to provide rapid response times necessary in cyclic power plants such as solar power towers. In this paper, experimental results from testing an impedance heating system are compared to MI cable heat trace. We found impedance heating was able to heat piping rapidly and effectively. There were not significant stray currents and impedance heating did not affect instrumentation.

The incorporation of a three-dimensional neutron kinetics capability into the DOE version of the RELAP5/MOD3.2 reactor safety code is discussed. A brief discussion of the kinetics method is given along with a discussion of the cross section parameterization models available in RELAP5/MOD3.2. The RELAP5/MOD3.2 code is then used to perform calculations of the NEACRP rod ejection and rod withdrawal benchmarks, and results are presented.

Both the efficiency of an implosion and the growth rate of hydrodynamic instability increase with the aspect ratio of an implosion. In order to study the physics of implosions with high Rayleigh-Taylor growth factors, we use doped ablators which should minimize x-ray preheat and shell decompression, and hence increase in-flight aspect ratio. We use x-ray backlighting techniques to image the indirectly-driven capsules. We record backlit 4.7 keV images of the full capsule throughout the implosion phase with 55 ps and 15 {mu}m resolution. We use these images to measure the in-flight aspect ratios for doped ablators, and we inferred the radial density profile as a function of time by Abel inverting the x-ray transmission profiles.

Near-edge x-ray absorption fine structure (NEXAFS) is used to examine the chemical bonding in boron and boron-nitride films sputter deposited from a fully-dense, pure boron target. Reactive sputtering is used to prepare the boron-nitride and multilayered films. Although the process of sputter deposition often produces films that lack long range order, NEXAFS reveals the distinguishing features of sp{sup 2} and sp{sup 3} hybridization that are associated with different crystalline structures. The sensitivity of NEXAFS to local order further provides details in bonding modifications that exist in these films.

The authors have developed an active and passive computed tomography scanner for assaying radioactive waste drums. They describe the hardware and software components of the system used for data acquisition, gamma-ray spectroscopy analysis, and image reconstruction. They have measured the performance of the system using mock waste drums and calibrated radioactive sources. They describe the results of measurements using this system to assay a real TRU waste drum with relatively low Pu content.

The Burma Road Rubble Pit (BRRP) is located at the Savannah River Site (SRS). The BRRP unit consists of two unlined earthen pits dug into surficial soil and filled with various waste materials. It was used from 1973--1983 for the disposal of dry inert rubble such as metal, concrete, lumber, poles, light fixtures, and glass. No record of the disposal of hazardous substances at the BRRP has been found. In 1983, the BRRP was closed by covering it with soil. In September 1988, a Ground Penetrating Radar survey detected three disturbed areas of soil near the BRRP, and a detailed and combined RCRA Facility Investigation/Remedial Investigation was conducted from November 1993 to February 1994 to determine whether hazardous substances were present in the subsurface, to evaluate the nature and extent of contamination, and to evaluate the risks posed to the SRS facility due to activities conducted at the BRRP site. Metals, semi-volatile organic compounds, volatile organic compounds, radionuclides and one pesticide (Aldrin) were detected in soil and groundwater samples collected from seventeen BRRP locations. A baseline risk assessment (BRA) was performed quantitatively to evaluate whether chemical and radionuclide concentrations detected in soil and groundwater at the BRRP posed an unacceptable …

For fast, reliable determination of U and Pu concentrations in samples, ICP/AES (inductively coupled plasma/atomic emission spectrometry) and alpha counting can be used. Data show that ICP/AES or alpha counting can be used to obtain high-quality results for Pu determination. When high accuracy is needed for mass balance, however, MSID (mass spectrometric isotope dilution) is the better choice. Also, ICP/AES is a poor method to use for Pu determination, when samples contain large amounts of spectrally interfering elements, such as U, rare earths, and Zr. In these cases, if ICP/AES is used, chemical separation of Pu is needed prior to analysis, or the alpha counting method can be used. Because of the poor sensitivity for U in ICP/AES, use of MSID is the only practical method for samples low in uranium.

Results of experiments on the absorption of niobium in a hot, dense plasma are presented. These results represent a major step in the development of absorption techniques necessary for the quantitative characterization of hot, dense matter. A general discussion is presented of the requirements for performing quantitative analysis of absorption spectra. Hydrodynamic simulations are used to illustrate the behavior of tamped X-ray-heated matter and to indicate effects that can arise from the two dimensional aspects of the experiment. The absorption spectrum of a low-Z material, in this case aluminum, provides a temperature diagnostic and indicates the advance of the absorption measurement technique to the level of application. The experimental technique is placed in context with a review of other measurements using absorption spectroscopy to probe hot, dense matter.

We have previously described a practical micromachined power source: the polysilicon, surface-micromachined, electrostatically actuated microengine. Here we report on 3 aspects of implementing the microengine. First, we discuss demonstrations of the first-generation microengine actuating geared micromechanisms including gear trains with elements having dimensions comparable to the drive gear (about 50 {mu}m) and a relatively large (1600-{mu}m-diameter) rotating optical shutter element. These configurations span expected operating extremes for the microengine and address the coupling and loading issues for very-low-aspect-ratio micromechanisms which are common to the design of surface-micromachined devices. Second, we report on a second-generation of designs that utilize improved gear teeth design, a gear speed-reduction unit, and higher force-per-unit-area electrostatic comb drives. The speed-reduction unit produces an overall angular speed reduction of 9.63 and requires dual-level compound gears. Third, we discuss a dynamics model developed to accomplish 3 objectives: drive inertial loads in a controlled fashion, minimize stress and frictional forces during operation, and determine as a function of time the forces associated with the drive gear (eg load torque on drive gear from friction).

We describe here recent mathematical results that form the basis of our forthcoming space experiment, developed jointly with Mark Weislogel of NASA Lewis Research Center, which is scheduled for the Glovebox on the Mir 23 / NASA 4 Mission in December 1996. The mathematical basis for the Angular Liquid Bridge is described. The anticipated liquid behavior used in the apparatus is illustrated.

The {sup 252}Cf-source-driven frequency analysis method can be used for measuring the subcritical neutron multiplication factor of arrays of LWR fuel and as little as a single PWR fuel assembly. These measurements can be used to verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. In addition, the data can be used to validate calculational methods for criticality safety. These measurements provide parameters that have a higher sensitivity to changes in fissile mass than neutron multiplication factor and thus serve as a better test of calculational methods. The analysis have also shown that measurement of the cross power spectral density (CPSD) between detectors on one side of a single fuel assembly and an internal or external {sup 252}Cf source driving the fission chain multiplication process can be used for nondestructive assay of fissile mass along the length of the assembly. This CPSD is a smooth function of fissile mass and does not depend on the varying inherent source in the fuel assembly and thus is ideal for fissile mass assay.

Over 100 candidates were examined, including commercial materials and many that were synthesized in house. The mixed oxides were based on Ti, V, Nb, Cr, Mo, W, Mn, Fe, Co, Ni, and Cu doped with other transition metals. A number of individual (single-metal) oxides were included for comparison. The candidates were tested in single cells with Li(Si) anodes and separators based on LiCl-KCl eutectic. Screening was done under constant-current conditions at current densities of 125 me/cm{sup 2} and, to a lesser extent, 50 me/cm{sup 2} at 500 C. Relative performance and limitations of the oxide cathodes are discussed.

Under the Materials-in-Inventory (MIN) initiative, US DOE intends to develop policies to ensure that materials are managed and use efficiently, cost-effectively, and safely throughout DOE. The MIN initiative covers depleted uranium, scrap metals, chemicals, explosives, spent nuclear fuel, lead, alkali metals, etc.; by far the largest component is depleted uranium hexafluoride (DUF6). A technically defensible approach has been developed and is being used to select a long-term management strategy for DOE`s DUF6 inventory. The same approach can be adapted to management of other materials in inventory that have the potential to be reutilized.

The Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC), which is associated with NASA`s Earth Observing System Data and Information System (EOSDIS), provides access to a large number of tabular and imagery datasets used in ecological and environmental research. Because of its large and diverse data holdings, the challenge for the ORNL DAAC is to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them. Therefore, the ORNL DAAC developed the Biogeochemical Information Ordering Management Environment (BIOME), a search and order system for the World Wide Web (WWW). The WWW provides a new vehicle that allows a wide range of users access to the data. This paper describes the specialized attributes incorporated into BIOME that allow researchers easy access to an otherwise bewildering array of data products.