Publications

Results 93601–93800 of 99,299

Search results

Jump to search filters

A risk-based decision-aiding tool for waste disposal

Weiner, Ruth F.

N-CART (the National Spent Nuclear Fuel Program Cost Analysis and Risk Tool) is being developed to aid in low-risk, cost-effective, timely management of radioactive waste and spent nuclear fuel, and can therefore be used in management of mixed waste. N-CART provides evaluation of multiple alternatives and presents the consequences of proposed waste management activities in a clear and concise format. N-CART`s decision-aiding analyses include comparisons and sensitivity analyses of multiple alternatives and allows the user to perform quick turn-around {open_quotes}what if{close_quotes} studies to investigate various scenarios. Uncertainties in data (such as cost and schedule of various activities) are represented as distributions. N-CART centralizes documentation of the bases of program alternatives and program decisions, thereby supporting responses to stakeholders concerns. The initial N-CART design considers regulatory requirements, costs, and schedules for alternative courses of action. The final design will include risks (public health, occupational, economic, scheduling), economic benefits, and the impacts of secondary waste generation. An optimization tool is being incorporated that allows the user to specify the relative importance of cost, time risks, and other bases for decisions. The N-CART prototype can be used to compare the costs and schedules of disposal alternatives for mixed low-level radioactive waste (MLLW) and greater-than-Class-C (GTCC) waste, as well as spent nuclear fuel (SNF) and related scrap material.

More Details

Chemical sensors based on surface-confined dendrimers

Ricco, A.J.

The use of dendrimers for preparing chemically sensitive interfaces for detecting volatile organic compounds (VOCs) using surface acoustic wave (SAW) device transducers is described. Specifically, the synthesis of the dendrimers and the means by which they are affixed to SAW devices is discussed, followed by a detailed spectroscopic analysis of the surface-confined dendrimers and a discussion of their interaction with different VOCs. Most of these preliminary experiments focus on dendrimer surface modification using benzoylchloride, which leads to phenyl terminal groups linked to the dendrimer via amide groups. The results of this study lead us to conclude that dendrimers: (1) provide general specificity towards classes of functional groups and are therefore suitable for array-based sensing schemes; (2) are intermediate in structure between monolayers and polymers and exhibit the desirable properties of both; (3) can be straightforwardly attached to the surfaces of acoustic wave devices.

More Details

Boron-doped back-surface fields using an aluminum-alloy process

Gee, James M.

Boron-doped back-surface fields (BSF`s) have potentially superior performance compared to aluminum-doped BSF`s due to the higher solid solubility of boron compared to aluminum. However, conventional boron diffusions require a long, high temperature step that is both costly and incompatible with many photovoltaic-grade crystalline-silicon materials. We examined a process that uses a relatively low-temperature aluminum-alloy process to obtain a boron-doped BSF by doping the aluminum with boron. In agreement with theoretical expectations, we found that thicker aluminum layers and higher boron doping levels improved the performance of aluminum-alloyed BSF`s.

More Details

PbO-free glasses for low temperature packaging

Brow, R.K.

Zinc polyphosphate glasses were examined as potential candidates for low temperature sealing applications. Glass-formation and properties were determined for the ZnO-P{sub 2}O{sub 5}, ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} and ZnO-SnO-P{sub 2}O{sub 5} systems, and information about the short-range structures of these glasses was obtained by Raman and solid state nuclear magnetic resonance spectroscopies. In general, the most durable polyphosphate glasses have structures based on relatively short pyrophosphate chain lengths (i.e., 2 P-tetrahedra). Modified phosphate compositions are given, including compositions used to seal float glass substrates at temperatures as low as 500{degrees}C.

More Details

Response of elastomeric packaging components to a corrosive simulant mixed waste

Nigrey, Paul J.

The purpose of hazardous and radioactive materials packaging is to enable these materials to be transported without posing a threat to the health or property of the general public. To achieve this aim, regulations in the US have been written establishing general design requirements for such packagings. While no regulations have been written specifically for mixed waste packaging, regulations for the constituents of mixed wastes, i.e., hazardous and radioactive substances, have been codified by the US Department of Transportation and the US Nuclear Regulatory Commission. Based on these national requirements, a Chemical Compatibility Testing Program was developed in the Transportation Systems Department at SNL. In this paper, the authors present the results of Part B of the second phase of this testing program. The first phase screened five liner materials and six seal materials towards four simulant mixed wastes. Part A of the second phase involved the comprehensive testing of five candidate liner materials to an aqueous Hanford Tank simulant mixed waste. Part B involved similar testing on elastomeric materials, ethylene-propylene and butadiene-acrylonitrile rubber. The comprehensive testing protocol involved exposing the respective materials to a matrix of four gamma radiation doses ({approximately}1, 3, 6, and 40 kGy), three temperatures (18, 50, and 60 C), and four exposure times (7, 14, 28, and 180 days). Following their exposure to these combinations of conditions, the materials were evaluated by measuring six material properties. These properties were specific gravity, dimensional changes, hardness, vapor transport rates, compression set, and mechanical properties.

More Details

RHOBOT: Radiation hardened robotics

Bennett, Phil C.

A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

More Details

The confluence of ancient wisdom and future technology in our profession

Miller, Dwight P.

The theme of this year`s Annual Meeting is ``Ancient Wisdom-Future Technology.`` The panel assembled for this session has been asked to think metaphorically about the theme and how it relates to their profession of human factors and ergonomics. Originally conceived as a debate centering around the older technologies and research techniques versus the newer ways of finding answers, it was soon realized that there was no dichotomy, but more of a synergy between the old and the new. If human factors is truly a philosophy of design rather than simply a body of knowledge, then one would expect consistency in approach regardless of field of application or new discoveries of human performance. Just as when two or more rivers combine to become a force mightier than the simple summation, the synergistic power of established techniques or knowledge and recent innovation is available to everyone in the profession. The invited panelists represent diverse perspectives in human factors and ergonomics, and this made for a stimulating discussion.

More Details

Tritium removal by CO{sub 2} laser heating

Wampler, William R.

Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO{sub 2} or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm{sup 2} flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally.

More Details

Simultaneous PVDF/VISAR measurement technique for isentropic loading with graded density impactors

Anderson, Mark U.

A simultaneous PVDF/VISAR measurement technique was used for isentropic-loading experiments with a polymethyl methacrylate (PMMA) specimen. The experiments used a graded density impactor accelerated onto a tantalum driver backed with PMMA and then lithium fluoride windows for each experiment. Simultaneous measurements made at each window interface provided precise transit time and particle velocity measurements which can be used to determine the stress-vs-strain loading path using Lagrangian analysis techniques. The experimental technique provides access to 40 GPa stress levels in PMMA under isentropic-loading conditions.

More Details

Comparison of M46 broad-band visible data with ELF data from the Sprites `96 campaign

Mitchell, E.A.

Lightning data, recorded with satellite optical sensors, are compared with extremely low frequency (ELF) and Schumann resonance (SR) data from the Sprites `96 Campaign. The satellite data are broad-band visible events recorded by the M46 satellite payload. Full width at half maximum and optical tail durations from the satellite data are compared with ELF slow tail features and Schumann resonance spectral color. In addition, continuing current estimates were computed for several positive cloud-to-ground (PCG) strokes. These estimates were derived using relative optical intensities from the satellite data and a peak current measurement from National Lightning Detection Network (NLDN) data. This assessment of M46 lightning data supports correlations between visible and ELF signatures. More data must be studied for compelling proof.

More Details

Enhanced Gas Analysis for Diagnostics and Surveillance (EGADS): Contamination-free sampling and analysis

Maestas, L.M.

Providing uncontaminated weapon internal atmosphere samples and measuring their dew points is of paramount importance for enhanced surveillance and accelerated aging. The authors are developing and integrating four types of gas sampling systems for use throughout the weapons complex. They are utilizing tools to extract time/age information from the gas analysis of weapon internal atmospheres.

More Details

Photovoltaic system reliability

Maish, Alexander B.

This paper discusses the reliability of several photovoltaic projects including SMUD`s PV Pioneer project, various projects monitored by Ascension Technology, and the Colorado Parks project. System times-to-failure range from 1 to 16 years, and maintenance costs range from 1 to 16 cents per kilowatt-hour. Factors contributing to the reliability of these systems are discussed, and practices are recommended that can be applied to future projects. This paper also discusses the methodology used to collect and analyze PV system reliability data.

More Details

Pore-scale modeling of enhanced vapor diffusion in porous media

Webb, Stephen W.

Vapor diffusion in porous media in the presence of its liquid has often been analyzed like air diffusion. The diffusion rate is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. The mechanisms postulated to lead to this enhancement include condensation/evaporation across isolated liquid islands in the porous media and an increased temperature gradient in the gas phase. In order to try to understand the mechanisms involved in such an enhancement, pore-scale models have been developed. Vapor diffusion in the presence of liquid islands has been evaluated for a one-dimensional pore network under a concentration gradient. The simulations show that significant enhancement of vapor diffusion is indeed possible in the presence of liquid islands, while air diffusion decreases slightly. While the present pore-scale model indicates that enhanced vapor diffusion is possible, only experimental data can confirm the relevant processes.

More Details

Evaluation of the metal/adhesive interfaces in the MC2370 fire set

Zavadil, Kevin R.

Several analysis methods have been applied to evaluate the structure and composition of the electrode/adhesive interfaces i previously fielded M2370 Fire Sets. A method of interfacial fracture at cryogenic temperatures as been employed to expose regions of these interfaces at multiple levels in a SFE stack. Electron microscopy shows that bond failure induced by the fracture is predominantly adhesive with an equal probability of failure of the Au and Cu interfaces. Some evidence for cohesive, indicative of a possible microstructure related to electrical breakdown. Pinhole-free larger regions of adhesive also exist which may explain the observed high resistance in impedance measurements.

More Details

Dynamic electromechanical characterization of the ferroelectric ceramic PZT 95/5

Setchell, Robert E.

Shock-induced depoling of the ferroelectric PZT 95/5 has been utilized in pulsed power applications for many years. Recently, new design and certification requirements have generated a strong interest in numerically simulating the operation of pulsed power devices. Because of a scarcity of relevant experimental data obtained within the past twenty years, we have initiated an extensive experimental study of the dynamic behavior of this material in support of simulation efforts. The experiments performed to date have been limited to examining the behavior of unpoled material. Samples of PZT 95/5 have been shocked to axial stresses from 0.5 to 5.0 GPa in planar impact experiments. Impact face conditions have been recorded using PVDF stress gauges, and transmitted wave profiles have been recorded either at window interfaces or at a free surface using laser interferometry (VISAR). The results significantly extend the stresses examined in prior studies of unpoled material, and ensure that a comprehensive experimental characterization of the mechanical behavior under shock loading is available for continuing development of PZT 95/5 material models.

More Details

{open_quotes}Quadrupoled{close_quotes} materials for second-order nonlinear optics

Hubbard, S.F.; Petschek, R.G.; Singer, K.D.

We describe a new approach to second-order nonlinear optical materials, namely quadrupoling. This approach is valid in the regime of Kleinman (full permutation) symmetry breaking, and thus requires a two- or three dimensional microscopic nonlinearity at wavelengths away from material resonances. This {open_quotes}quadrupolar{close_quotes} nonlinearity arises from the second rank pseudotensor of the rotationally invariant representation of the second-order nonlinear optical tensor. We have experimentally investigated candidate molecules comprised of chiral camphorquinone derivatives by measuring the scalar invariant associated with the rank two pseudotensor using hyper-Rayleigh scattering. We have found sizable scalar figures of merit for several compounds using light for which the second harmonic wavelengths are greater than 100 nm longer than the absorption peak location. At these wavelengths, the quadrupolar scalar is as large as the polar (EFISH) scalar of p-nitroaniline. Prospects for applications are discussed.

More Details

Electromagnetic methods for development and production: State of the art

Alumbaugh, D.

Electromagnetic (EM) methods, long used for borehole logging as a formation evaluation tool in developed oil fields, are rarely applied in surface or crosshole configurations or applied in cased wells. This is largely due to the high levels of cultural noise and the preponderance of steel well casing. However, recent experimental success with crosshole EM systems for water and steam flood monitoring using fiberglass cased wells has shown promise in applying these techniques to development and production (D & P) problems. This paper describes technological solutions that will allow for successful application of EM techniques in oil fields, despite surface noise and steel casing. First an example sites the application of long offset logging to map resistivity structure away from the borehole. Next, a successful application of crosshole EM where one of the wells is steel cased is described. The potential application of earth`s field nuclear magnetic resonance (NMR) to map fluid saturation at large distances from the boreholes is also discussed.

More Details

Characterization of aging in organic materials on atomic-, meso- and macro-length scales by {sup 13}C NMR spectroscopy

Assink, Roger A.

A fundamental understanding of aging in an organic material requires that one understand how aging affects the chemical structure of a material, and how these chemical changes are related to the material`s macroscopic properties. This level of understanding is usually achieved by examining the material on a variety of length scales ranging from atomic to meso-scale to macroscopic. The authors are developing and applying several {sup 13}C nuclear magnetic resonance (NMR) spectroscopy experiments to characterize the aging process of organic materials over a broad range of length scales. Examples of studies which range from atomic to macroscopic will be presented.

More Details

Measuring worst-case errors in a robot workcell

Simon, Ronald W.

Errors in model parameters, sensing, and control are inevitably present in real robot systems. These errors must be considered in order to automatically plan robust solutions to many manipulation tasks. Lozano-Perez, Mason, and Taylor proposed a formal method for synthesizing robust actions in the presence of uncertainty; this method has been extended by several subsequent researchers. All of these results presume the existence of worst-case error bounds that describe the maximum possible deviation between the robot`s model of the world and reality. This paper examines the problem of measuring these error bounds for a real robot workcell. These measurements are difficult, because of the desire to completely contain all possible deviations while avoiding bounds that are overly conservative. The authors present a detailed description of a series of experiments that characterize and quantify the possible errors in visual sensing and motion control for a robot workcell equipped with standard industrial robot hardware. In addition to providing a means for measuring these specific errors, these experiments shed light on the general problem of measuring worst-case errors.

More Details

The effect of gettering on areal inhomogeneities in large-area multicrystalline-silicon solar cells

Gee, James M.

Multicrystalline-silicon (mc-Si) materials and cells feature large areal variations in material and junction quality. The regions with poor device quality have been predicted to have more recombination current at forward bias than a simple area-weighted average due to the parallel interconnection of the good and bad regions by the front junction. The authors have examined the effect of gettering on areal inhomogeneities in large-area mc-Si cells. Cells with large areal inhomogeneities were found to have increased non-ideal recombination current, which is in line with theoretical predictions. Phosphorus-diffusion and aluminum-alloy gettering of mc-Si was found to reduce the areal inhomogeneities and improve large-area mc-Si device performance.

More Details

ICP dry etching of III-V nitrides

Shul, Randy J.

Inductively coupled plasma etching of GaN, AlN, InN, InGaN and InAlN was investigated in CH{sub 4}/H{sub 2}/Ar plasmas as a function of dc bias, and ICP power. The etch rates were generally quite low, as is common for III-nitrides in CH{sub 4} based chemistries. The etch rates increased with increasing dc bias. At low rf power (150 W), the etch rates increased with increasing ICP power, while at 350 W rf power, a peak was found between 500 and 750 W ICP power. The etched surfaces were found to be smooth, while selectivities of etch were {le} 6 for InN over GaN, AlN, InGaN and InAlN under all conditions.

More Details

Impact of AD995 alumina rods

Chhabildas, L.C.

Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.

More Details

Solder joint aging characteristics from the MC2918 firing set of a B61 accelerated aging unit (AAU)

Vianco, Paul T.

The B61 accelerated aging unit (AAU) provided a unique opportunity to document the effects of a controlled, long-term thermal cycling environment on the aging of materials used in the device. This experiment was of particular interest to solder technologists because thermal cycling environments are a predominant source of solder joint failures in electronic assemblies. Observations of through hole solder joints in the MC2918 Firing Set from the B61 AAU did not reveal signs of catastrophic failure. Quantitative analyses of the microstructural metrics of intermetallic compound layer thickness and Pb-rich phase particle distributions indicated solder joint aging that was commensurate with the accelerated aging environment. The effects of stress-enhanced coarsening of the Pb-rich phase were also documented.

More Details

The passive autocatalytic recombiner test program at Sandia National Laboratories

Blanchat, Thomas K.

Passive autocatalytic recombiners (PARs) are being considered by the nuclear power industry as a combustible gas control system in operating plants and advanced light water reactor (ALWR) containments for design basis events. Sandia National Laboratories (SNL) has developed systems and methodologies to measure the amount of hydrogen that can be depleted in a containment by a PAR. Experiments were performed that determined the hydrogen depletion rate of a PAR in the presence of steam and also evaluated the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.

More Details

On current US strategy and technologies for spent fuel handling

Bennett, Phil C.

The US Department of Energy has recently completed a topical safety analysis report outlining the design and operation of a Centralized Interim Storage Facility for spent commercial nuclear fuel. During the course of the design, dose assessments indicated the need for remote operation of many of the cask handling operations. Use of robotic equipment was identified as a desirable handling solution that is capable of automating many of the operations to maintain throughput, and sufficiently flexible to handle five or more different storage cask designs in varying numbers on a given day. This paper discusses the facility and the dose assessment leading to this choice, and reviews factors to be considered when choosing robotics or automation. Further, a new computer simulation tool to quantify dose to humans working in radiological environments, the Radiological Environment Modeling System (REMS), is introduced. REMS has been developed to produce a more accurate estimate of dose to radiation workers in new activities with radiological hazards.

More Details

Software development methodology for high consequence systems

Baca, L.S.

This document describes a Software Development Methodology for High Consequence Systems. A High Consequence System is a system whose failure could lead to serious injury, loss of life, destruction of valuable resources, unauthorized use, damaged reputation or loss of credibility or compromise of protected information. This methodology can be scaled for use in projects of any size and complexity and does not prescribe any specific software engineering technology. Tasks are described that ensure software is developed in a controlled environment. The effort needed to complete the tasks will vary according to the size, complexity, and risks of the project. The emphasis of this methodology is on obtaining the desired attributes for each individual High Consequence System.

More Details

User manual for CSP{_}VANA: A check standards measurement and database program for microwave network analyzers

Duda, L.E.

Vector network analyzers are a convenient way to measure scattering parameters of a variety of microwave devices. However, these instruments, unlike oscilloscopes for example, require a relatively high degree of user knowledge and expertise. Due to the complexity of the instrument and of the calibration process, there are many ways in which an incorrect measurement may be produced. The Microwave Project, which is part of SNL`s Primary Standards laboratory, routinely uses check standards to verify that the network analyzer is operating properly. In the past, these measurements were recorded manually and, sometimes, interpretation of the results was problematic. To aid the measurement assurance process, a software program was developed to automatically measure a check standard and compare the new measurements with a historical database of measurements of the same device. The program acquires new measurement data from selected check standards, plots the new data against the mean and standard deviation of prior data for the same check standard, and updates the database files for the check standard. The program is entirely menu-driven requiring little additional work by the user. This report describes the function of the software, including a discussion of its capabilities, and the way in which the software is used in the lab.

More Details

Milliwatt generator heat source shelf-life-related pressure-burst capsule evaluations

Ritchey, B.D.

More Details

Chemical sensors for classification of mine-like objects by identification of explosives

Woodfin, R.L.

This paper briefly describes a prototype sensor for detecting land mines placed in shallow water. An automatic system was developed which incorporates chemical concentration technology, an ion mobility spectrometer, and control and fluid movement subsystems. The system design was successfully demonstrated using laboratory instruments and equipment. Components for the portable unit, which will weigh less than 20 pounds, have been fabricated; field demonstrations will be completed by spring 1998. 4 figs.

More Details

Experiments in micromanipulation and CAD-driven microassembly

Feddema, John T.

This paper discusses recent experiments in the manipulation and assembly of parts with 100 micron outside dimensions and submicron tolerances. The objective of this work is to develop a micromanipulation workcell which can automatically assemble LIGA (Lithography Galvonoforming Abforming) parts using an assembly plan and a CAD drawing of each of the components. The workcell consists of an AdeptOne robot, precision stages, long distance microscope, and a high aspect ratio modeled polysilicon tweezers for picking up the parts. Fourier optics methods are used to generate synthetic microscope images from CAD drawings. These synthetic images are used off-line to test image processing routines under varying magnifications an depths of field. They also provide reference image features which are used to visually servo the true part to the desired position.

More Details

Context sensitivity and ambiguity in component-based systems design

Bespalko, S.J.

Designers of components-based, real-time systems need to guarantee to correctness of soft-ware and its output. Complexity of a system, and thus the propensity for error, is best characterized by the number of states a component can encounter. In many cases, large numbers of states arise where the processing is highly dependent on context. In these cases, states are often missed, leading to errors. The following are proposals for compactly specifying system states which allow the factoring of complex components into a control module and a semantic processing module. Further, the need for methods that allow for the explicit representation of ambiguity and uncertainty in the design of components is discussed. Presented herein are examples of real-world problems which are highly context-sensitive or are inherently ambiguous.

More Details

New codes and standards for utility - interconnection of AC PV modules

Bower, Ward

Photovoltaic (PV) modules that provide only ac power give new dimensions to the use of, and utility interface of, PV systems because all of the dc issues are virtually eliminated. These AC PV modules offer the important advantage that customers may now purchase a PV system without hiring a design engineer. A qualified electrician will be able to install a complete PV system that performs as expected and meets local electrical codes. Simple installations of additional AC PV modules will be possible once the proper branch circuit wiring and protection have been installed. Codes and standards are currently being written to address the utility-interconnect issues for AC PV modules and other interactive inverters. An industry-supported Task Group has recently written and submitted proposals for changes to bring Article 690 of the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}) up to the state-of-the-art for PV devices such as AC PV modules. This paper summarizes the proposed code changes and standards related to the evolving AC PV module technology in the United States. Topics such as the need for dedicated branch circuits for AC PV modules in residential applications are discussed and analyzed. Requirements for limiting the number of AC modules on a branch circuit and the listing requirements that make safe installations are discussed. Coordination of all standards activities for AC module installations, the building-integrated perspectives, and utility-interface issues is discussed.

More Details

Overview of PV balance-of-systems technology: Experience and guidelines for utility ties in the United States of America

Bower, Ward

The U.S. National Photovoltaic Program began in 1975 by supporting the development of terrestrial PV modules and hardware associated with grid-connected PV systems. Early PV-system demonstration programs were also supported and cost shared by the U.S. Department of Energy (DOE). A wide variety of PV systems were deployed, usually with utility participation. The early demonstration projects provided, and continue to provide, valuable PV system experience to utilities, designers and suppliers. As a result of experience gained, several important milestones in codes and standards pertaining to the design, installation and operation of photovoltaic (PV) systems have been completed. These code and standard activities were conducted through collaboration of participants from all sectors of the PV industry, utilities and the US DOE National Photovoltaic Program. Codes and standards that have been proposed, written, or modified include changes and additions for the 1999 National Electric Code{reg_sign} (NEC{reg_sign}), standards for fire and personnel safety, system testing, field acceptance, component qualification, and utility interconnection. Project authorization requests with the Institute of Electrical and Electronic Engineers (IEEE) have resulted in standards for component qualification and were further adapted for standards used to list PV modules and balance-of-system components. Industry collaboration with Underwriter Laboratories, Inc., with the American Society for Testing and Materials, and through critical input and review for international standards with the International Electrotechnical Commission have resulted in new and revised domestic and international standards for PV applications. Activities related to work on codes and standards through the International Energy Agency are also being supported by the PV industry and the US DOE. The paper shows relationships between activities in standards writing.

More Details

Results of a nuclear power plant Application of a new technique for human error analysis (ATHEANA)

Forester, John A.

A new method to analyze human errors has been demonstrated at a pressurized water reactor (PWR) nuclear power plant. This was the first application of the new method referred to as A Technique for Human Error Analysis (ATHEANA). The main goals of the demonstration were to test the ATHEANA process as described in the frame-of-reference manual and the implementation guideline, test a training package developed for the method, test the hypothesis that plant operators and trainers have significant insight into the error-forcing-contexts (EFCs) that can make unsafe actions (UAs) more likely, and to identify ways to improve the method and its documentation. A set of criteria to evaluate the {open_quotes}success{close_quotes} of the ATHEANA method as used in the demonstration was identified. A human reliability analysis (HRA) team was formed that consisted of an expert in probabilistic risk assessment (PRA) with some background in HRA (not ATHEANA) and four personnel from the nuclear power plant. Personnel from the plant included two individuals from their PRA staff and two individuals from their training staff. Both individuals from training are currently licensed operators and one of them was a senior reactor operator {open_quotes}on shift{close_quotes} until a few months before the demonstration. The demonstration was conducted over a 5 month period and was observed by members of the Nuclear Regulatory Commission`s ATHEANA development team, who also served as consultants to the HRA team when necessary. Example results of the demonstration to date, including identified human failure events (HFEs), UAs, and EFCs are discussed. Also addressed is how simulator exercises are used in the ATHEANA demonstration project.

More Details

CTBT Integrated Verification System Evaluation Model

Edenburn, Michael W.

Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

More Details

Report of work done for technical assistance agreement 1269 between Sandia National Laboratories and the Watkins-Johnson Company: Chemical reaction mechanisms for computational models of SiO{sub 2} CVD

Ho, Pauline H.

The use of computational modeling to improve equipment and process designs for chemical vapor deposition (CVD) reactors is becoming increasingly common. Commercial codes are available that facilitate the modeling of chemically-reacting flows, but chemical reaction mechanisms must be separately developed for each system of interest. One f the products of the Watkins-Johnson Company (WJ) is a reactor marketed to semiconductor manufacturers for the atmospheric-pressure chemical vapor deposition (APCVD) of silicon oxide films. In this process, TEOS (tetraethoxysilane, Si(OC{sub 2}H{sub 5}){sub 4}) and ozone (O{sub 3}) are injected (in nitrogen and oxygen carrier gases) over hot silicon wafers that are being carried through the system on a moving belt. As part of their equipment improvement process, WJ is developing computational models of this tool. In this effort, they are collaborating with Sandia National Laboratories (SNL) to draw on Sandia`s experience base in understanding and modeling the chemistry of CVD processes.

More Details

Modeling and characterization of molecular structures in self assembled and Langmuir-Blodgett films for controlled fabrication

Cesarano III, J.

Self Assembled (SA) thin films and Langmuir-Blodgett (LB) thin films are emerging technologies for the development of chemical and bio-chemical sensors, electrooptic films, second harmonic generators (frequency doublers), templates for biomimetic growth etc. One of the goals of this project was to extend Sandia`s characterization techniques and molecular modeling capabilities for these complex two-dimensional geometries with the objective of improving the control of the fabrication of these structures for specific applications. Achieving this requires understanding both the structure throughout the thickness of the films and the in-plane lattice of the amphiphilic molecules. To meet these objectives they used atomic force microscopy (AFM), X-ray reflectivity, and molecular modeling. While developing these capabilities, three different materials systems were fabricated and characterized: (1) Self Assembled Monolayers (SAMs) of octadecyltrichlorosilane (OTS) and LB films of arachidic acid on silicon wafers; (2) SAMs on PZT substrates; and (3) electrochemical deposition of CdS on LB film templates.

More Details

Public problems: Still waiting on the marketplace for solutions

Gover, J.

This report addresses the need for government sponsored R and D to address real public problems. The motivation is that a public benefit of the money spent must be demonstrated. The areas identified as not having appropriate attention resulting in unmet public needs include healthcare cost, cost and benefits of regulations, infrastructure problems, defense spending misaligned with foreign policy objectives, the crime problem, energy impact on the environment, the education problem, low productivity growth industry sectors, the income distribution problem, the aging problem, the propagation of disease and policy changes needed to address the solution of these problems.

More Details

Oriented inorganic thin film channel structures with uni-directional monosize micropores

Cesarano III, J.; Sasaki, D.Y.; Singh, S.; Brinker, C.J.

The goal of this project was to develop a novel technology that may be used to eventually manufacture a new generation of inorganic membranes and sensors with oriented, unidirectional monosized pores. The premise is that very thin membranes with oriented channels as pores will have a high flux in addition to being highly selective. Applications include: (1) gas separation membranes for oxygen enrichment, partial oxidation, dehydrogenation, and purification of natural gas; (2) refractory catalytic membrane reactors; and (3) molecular recognition sensors. The methodology for making such membranes was to combine Langmuir - Blodgett (LB) technology with sol-gel chemistry to engineer pore channels within the range 3 to 20 K The channel structure was fabricated of amorphous SiO{sub 2} because of its good thermal, chemical, and mechanical stability. Our approach was to use LB techniques to uniformly place organic molecular spacers throughout a thin silica precursor matrix and apply this film to a substrate. LB films of solid solutions of commercially available silane amphiphiles and organic amphiphiles were fabricated. The siloxane groups were then hydrolyzed to form silica and the organic portions of the amphiphiles removed by thermal decomposition. With the completely fugitive organic spacer amphiphiles removed, a thin silica film with micropores resulted. The pore size was in the range of 6 - 8 {angstrom} and in an ultra-thin configuration. With further development this technique may be useful for fabrication of inorganic membranes which satisfy all the criteria of the ideal membrane.

More Details

Effects of smoke on functional circuits

Martin, Tina T.

Nuclear power plants are converting to digital instrumentation and control systems; however, the effects of abnormal environments such as fire and smoke on such systems are not known. There are no standard tests for smoke, but previous smoke exposure tests at Sandia National Laboratories have shown that digital communications can be temporarily interrupted during a smoke exposure. Another concern is the long-term corrosion of metals exposed to the acidic gases produced by a cable fire. This report documents measurements of basic functional circuits during and up to 1 day after exposure to smoke created by burning cable insulation. Printed wiring boards were exposed to the smoke in an enclosed chamber for 1 hour. For high-resistance circuits, the smoke lowered the resistance of the surface of the board and caused the circuits to short during the exposure. These circuits recovered after the smoke was vented. For low-resistance circuits, the smoke caused their resistance to increase slightly. A polyurethane conformal coating substantially reduced the effects of smoke. A high-speed digital circuit was unaffected. A second experiment on different logic chip technologies showed that the critical shunt resistance that would cause failure was dependent on the chip technology and that the components used in the smoke exposures were some of the most smoke tolerant. The smoke densities in these tests were high enough to cause changes in high impedance (resistance) circuits during exposure, but did not affect most of the other circuits. Conformal coatings and the characteristics of chip technologies should be considered when designing circuitry for nuclear power plant safety systems, which must be highly reliable under a variety of operating and accident conditions. 10 refs., 34 figs., 18 tabs.

More Details

The development and performance of a message-passing version of the PAGOSA shock-wave physics code

Gardner, David R.

A message-passing version of the PAGOSA shock-wave physics code has been developed at Sandia National Laboratories for multiple-instruction, multiple-data stream (MIMD) computers. PAGOSA is an explicit, Eulerian code for modeling the three-dimensional, high-speed hydrodynamic flow of fluids and the dynamic deformation of solids under high rates of strain. It was originally developed at Los Alamos National Laboratory for the single-instruction, multiple-data (SIMD) Connection Machine parallel computers. The performance of Sandia`s message-passing version of PAGOSA has been measured on two MIMD machines, the nCUBE 2 and the Intel Paragon XP/S. No special efforts were made to optimize the code for either machine. The measured scaled speedup (computational time for a single computational node divided by the computational time per node for fixed computational load) and grind time (computational time per cell per time step) show that the MIMD PAGOSA code scales linearly with the number of computational nodes used on a variety of problems, including the simulation of shaped-charge jets perforating an oil well casing. Scaled parallel efficiencies for MIMD PAGOSA are greater than 0.70 when the available memory per node is filled (or nearly filled) on hundreds to a thousand or more computational nodes on these two machines, indicating that the code scales very well. Thus good parallel performance can be achieved for complex and realistic applications when they are first implemented on MIMD parallel computers.

More Details

An algorithm for enforcement of contact constraints in quasistatic applications using matrix-free solution algorithms

Heinstein, Martin

A contact enforcement algorithm has been developed for matrix-free quasistatic finite element techniques. Matrix-free (iterative) solution algorithms such as nonlinear Conjugate Gradients (CG) and Dynamic Relaxation (DR) are distinctive in that the number of iterations required for convergence is typically of the same order as the number of degrees of freedom of the model. From iteration to iteration the contact normal and tangential forces vary significantly making contact constraint satisfaction tenuous. Furthermore, global determination and enforcement of the contact constraints every iteration could be questioned on the grounds of efficiency. This work addresses this situation by introducing an intermediate iteration for treating the active gap constraint and at the same time exactly (kinematically) enforcing the linearized gap rate constraint for both frictionless and frictional response.

More Details

Biomimetic processing of oriented crystalline ceramic layers

Cesarano, J.; Shelnutt, J.A.

The aim of this project was to develop the capabilities for Sandia to fabricate self assembled Langmuir-Blodgett (LB) films of various materials and to exploit their two-dimensional crystalline structure to promote the growth of oriented thin films of inorganic materials at room temperature. This includes the design and synthesis of Langmuir-active (amphiphilic) organic molecules with end groups offering high nucleation potential for various ceramics. A longer range goal is that of understanding the underlying principles, making it feasible to use the techniques presented in this report to fabricate unique oriented films of various materials for electronic, sensor, and membrane applications. Therefore, whenever possible, work completed in this report was completed with the intention of addressing the fundamental phenomena underlying the growth of crystalline, inorganic films on template layers of highly organized organic molecules. This problem was inspired by biological processes, which often produce exquisitely engineered structures via templated growth on polymeric layers. Seashells, for example, exhibit great toughness owing to their fine brick-and-mortar structure that results from templated growth of calcium carbonate on top of layers of ordered organic proteins. A key goal in this work, therefore, is to demonstrate a positive correlation between the order and orientation of the template layer and that of the crystalline ceramic material grown upon it. The work completed was comprised of several parallel efforts that encompassed the entire spectrum of biomimetic growth from solution. Studies were completed on seashells and the mechanisms of growth for calcium carbonate. Studies were completed on the characterization of LB films and the capability developed for the in-house fabrication of these films. Standard films of fatty acids were studied as well as novel polypeptides and porphyrins that were synthesized.

More Details

RSMASS-D models: An improved method for estimating reactor and shield mass for space reactor applications

Marshall, Albert C.

Three relatively simple mathematical models have been developed to estimate minimum reactor and radiation shield masses for liquid-metal-cooled reactors (LMRs), in-core thermionic fuel element (TFE) reactors, and out-of-core thermionic reactors (OTRs). The approach was based on much of the methodology developed for the Reactor/Shield Mass (RSMASS) model. Like the original RSMASS models, the new RSMASS-derivative (RSMASS-D) models use a combination of simple equations derived from reactor physics and other fundamental considerations, along with tabulations of data from more detailed neutron and gamma transport theory computations. All three models vary basic design parameters within a range specified by the user to achieve a parameter choice that yields a minimum mass for the power level and operational time of interest. The impact of critical mass, fuel damage, and thermal limitations are accounted for to determine the required fuel mass. The effect of thermionic limitations are also taken into account for the thermionic reactor models. All major reactor component masses are estimated, as well as instrumentation and control (I&C), boom, and safety system masses. A new shield model was developed and incorporated into all three reactor concept models. The new shield model is more accurate and simpler to use than the approach used in the original RSMASS model. The estimated reactor and shield masses agree with the mass predictions from separate detailed calculations within 15 percent for all three models.

More Details

Penetration equations

Hansen, Ned R.

In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

More Details

Experiences implementing the MPI standard on Sandia`s lightweight kernels

Brightwell, Ronald B.

This technical report describes some lessons learned from implementing the Message Passing Interface (MPI) standard, and some proposed extentions to MPI, at Sandia. The implementations were developed using Sandia-developed lightweight kernels running on the Intel Paragon and Intel TeraFLOPS platforms. The motivations for this research are discussed, and a detailed analysis of several implementation issues is presented.

More Details

A reevaluation of the National Emission Standards for Hazardous Air Pollutants (NESHAP - 40 CFR 61, Subpart H) program at Sandia National Laboratories, New Mexico

Culp, Todd A.

The initial National Emission Standards for Hazardous Air Pollutants (NESHAP - 40 CFR 61, Subpart H) Program at Sandia National Laboratories, New Mexico (SNL/NM) required: (1) continuous air monitoring of sources if the calculated effective dose equivalent (EDE) to the maximum exposed individual (MEI) was > 0.1 mrem/yr; (2) the determination of emissions based on measurements or measured parameters if the EDE to the MEI was < 0.1 mrem/yr; and (3) the calculation of worst case releases when the expected air concentrations were below detection limits using standard monitoring equipment. This conservative interpretation of the regulation guided SNL/NM to model, track, and trend virtually all emission sources with the potential to include any radionuclides. The level of effort required to implement these activities was independent of the EDE contributing from individual sources. A recent programmatic review found the NESHAP program to be in excess of the legal requirements. A further review found that, in summation, 13 of 16 radionuclide sources had a negligible impact on the final calculated EDE to the MEI used to demonstrate compliance at 20 separate on-site receptor locations. A reevaluation was performed to meet the legal requirements of 40 CFR 61, Subpart H, and still be reasonable and appropriate under the existing circumstances.

More Details

A study of the feasibility of monitoring sealed geological repositories using seismic sensors

Garbin, H.D.

Questions have arisen regarding the applicability of seismic sensors to detect mining (re-entry) with a tunnel boring machine (TBM). Unlike cut and blast techniques of mining which produce impulsive seismic signals, the TBM produces seismic signals which are of long duration. (There are well established techniques available for detecting and locating the sources of the impulsive signals.) The Yucca Mountain repository offered an opportunity to perform field evaluations of the capabilities of seismic sensors because during much of 1996, mining there was progressing with the use of a TBM. During the mining of the repository`s southern branch, an effort was designed to evaluate whether the TBM could be detected, identified and located using seismic sensors. Three data acquisition stations were established in the Yucca Mountain area to monitor the TBM activity. A ratio of short term average to long term average algorithm was developed for use in detection based on the characteristics shown in the time series. For location of the source of detected signals, FK analysis was used on the array data to estimate back azimuths. The back azimuth from the 3 component system was estimated from the horizontal components. Unique features in the timing of the seismic signal were used to identify the source as the TBM.

More Details

Site selection and characterization processes for deep geologic disposal of high level nuclear waste

Costin, Laurence S.

In this paper, the major elements of the site selection and characterization processes used in the US high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the US program, these processes, which are well defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the US program.

More Details

Wafer bonding of GaAs, InP, and Si annealed without hydrogen for advanced device technologies

Choquette, Kent D.

In this paper the authors report on the direct bonding of compound semiconductors and silicon annealed at low temperatures (400 C) using hydrogen and nitrogen. Pressure and temperature relationships on interface characteristics were investigated with high resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. It was found that no morphology differences existed between hydrogen and nitrogen annealed samples. applying the N{sub 2} bonding process, 850nm bottom emitting vertical cavity surface emitting lasers (VCSELs), were bonded to a transparent AlGaAs substrate. Finally, high anneal temperatures (up to 450 C) and shear stress values (> 1.6 MPa) were obtained for GaAs bonded to Si using a dry (plasma) activation technique.

More Details

CONTAIN 2.0 code release and the transition to licensing

Murata, Kenneth K.

CONTAIN is a reactor accident simulation code developed by Sandia National Laboratories under US Nuclear Regulatory Commission (USNRC) sponsorship to provide integrated analysis of containment phenomena, including those related to nuclear reactor containment loads and radiological source terms. The recently released CONTAIN 2.0 code version represents a significant advance in CONTAIN modeling capabilities over the last major code release (CONTAIN 1.12V). The new modeling capabilities are discussed here. The principal motivation for many of the recent model improvements has been to allow CONTAIN to model the special features in advanced light water reactor (ALWR) designs. The work done in this area is also summarized. In addition to the ALWR work, the USNRC is currently engaged in an effort to qualify CONTAIN for more general use in licensing, with the intent of supplementing or possibly replacing traditional licensing codes. To qualify the CONTAIN code for licensing applications, studies utilizing CONTAIN 2.0 are in progress. A number of results from this effort are presented in this paper to illustrate the code capabilities. In particular, CONTAIN calculations of the NUPEC M-8-1 and ISP-23 experiments and CVTR test {number_sign}3 are presented to illustrate (1) the ability of CONTAIN to model non-uniform gas density and/or temperature distributions, and (2) the relationship between such gas distributions and containment loads. CONTAIN and CONTEMPT predictions for a large break loss of coolant accident scenario in the San Onofre plant are also compared.

More Details

Finnish remote environmental monitoring field demonstration

Torres, Juan J.

Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland and Sandia National Laboratories (SNL), working under the Finnish Support Program to IAEA Safeguards and the United States Department of Energy (DOE) funded International Remote Monitoring Program (Task FIN E 935), have undertaken a joint effort to demonstrate the use of remote monitoring for environmental air sampling and safeguards applications. The results of the task will be used by the IAEA to identify the feasibility, cost-effectiveness, reliability, advantages, and problems associated with remote environmental monitoring. An essential prerequisite for a reliable remote air sampling system is the protection of samples against tampering. Means must be developed to guarantee that the sampling itself has been performed as designed and the original samples are not substituted with samples produced with other equipment at another site. One such method is to label the samples with an unequivocal tag. In addition, the inspection personnel must have the capability to remotely monitor and access the automated environmental air sampling system through the use of various sensors and video imagery equipment. A unique aspect to this project is the network integration of remote monitoring equipment with a STUK radiation monitoring system. This integration will allow inspectors to remotely view air sampler radiation data and sensor/image data through separate software applications on the same review station. A sensor network and video system will be integrated with the SNL developed Modular Integrated Monitoring System (MIMS) to provide a comprehensive remote monitoring approach for safeguards purposes. This field trial system is being implemented through a multiphase approach for use by STUK, SNL, and for possible future use by the IAEA.

More Details

Uncertainty and error in computational simulations

Oberkampf, William L.

The present paper addresses the question: ``What are the general classes of uncertainty and error sources in complex, computational simulations?`` This is the first step of a two step process to develop a general methodology for quantitatively estimating the global modeling and simulation uncertainty in computational modeling and simulation. The second step is to develop a general mathematical procedure for representing, combining and propagating all of the individual sources through the simulation. The authors develop a comprehensive view of the general phases of modeling and simulation. The phases proposed are: conceptual modeling of the physical system, mathematical modeling of the system, discretization of the mathematical model, computer programming of the discrete model, numerical solution of the model, and interpretation of the results. This new view is built upon combining phases recognized in the disciplines of operations research and numerical solution methods for partial differential equations. The characteristics and activities of each of these phases is discussed in general, but examples are given for the fields of computational fluid dynamics and heat transfer. They argue that a clear distinction should be made between uncertainty and error that can arise in each of these phases. The present definitions for uncertainty and error are inadequate and. therefore, they propose comprehensive definitions for these terms. Specific classes of uncertainty and error sources are then defined that can occur in each phase of modeling and simulation. The numerical sources of error considered apply regardless of whether the discretization procedure is based on finite elements, finite volumes, or finite differences. To better explain the broad types of sources of uncertainty and error, and the utility of their categorization, they discuss a coupled-physics example simulation.

More Details

Tritium retention and removal on TFTR

Wampler, William R.

Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

More Details

Replacement of liquid H{sub 2}SO{sub 4} and HF with solid acid catalysts: A study of mixed metal phosphates as solid acid catalysts

Jackson, Nancy B.

The primary purpose of this LDRD was to identify and optimize materials as solid acid catalysts for the replacement of environmentally hazardous liquid acids such as H{sub 2}SO{sub 4} and HF which are used as catalysts in both the petroleum and chemical industries. Liquid acids have significant safety, environmental and engineering difficulties associated with their use in process chemistry. Special equipment/materials need to be used with liquid acids. Hydrofluoric acid poses unique safety problems due to it insipid attack on skin and tissue as well as its tendency to plume and travel long distances as a plume when it is released in the atmosphere. Therefore, any time a solid acid catalyst can be used to replace a liquid acid in a processes step, significant environmental, safety, and financial gains can be realized. The majority of work in this LDRD was performed on novel mixed metal phosphates which are a new solid acid catalyst material. Primarily the model reaction, 2-methyl-2-pentene isomerization, was used to determine acidity. These materials were tested for their activity, their deactivation and their stability. In addition, some of the phosphate materials were synthesized using templates in order to try to form a three dimensional network material from these phosphates. The amorphous sulfated zirconium-titanium phosphates were more acidic, as measured by olefin isomerization, than sulfated zirconia. However, they showed some of the same failings as sulfated zirconia in that they deactivated quickly and lost sulfur in a reducing atmosphere. Certain of the mixed metal phosphates, particularly tantalum-containing phosphates, showed strong acidity compared to sulfated zirconia as measured by olefin isomerization reaction.

More Details

Field tests of the surface area modulation downhole telemetry system

Keefe, Russell G.

Two field tests of the surface area modulation (SAM) downhole wireless telemetry system were performed at the DOE Rocky Mountain Oilfield Testing Center near Casper, Wyoming in November, 1995 and September, 1996. SAM telemetry involves the introduction of a gap of electrically insulating material in the tubular conductors in the well. The electrical resistance of a switch in this gap can then be modulated to alter the electrical characteristics of a circuit involving the well tubulars. These changes affect the current in the circuit, which is monitored with a surface ammeter. Downhole data are encoded and transmitted to the surface as a pattern of current oscillations. The tests successfully demonstrated the ability of the system to transmit information from depths exceeding 2,000 feet to the surface at up to 2,400 baud.

More Details

6th International Meshing Roundtable '97

White, D.

The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral mesh generation Unstructured quadrilateral and hexahedral mesh generation Automated blocking and structured mesh generation Mixed element meshing Surface mesh generation Geometry decomposition and clean-up techniques Geometry modification techniques related to meshing Adaptive mesh refinement and mesh quality control Mesh visualization Special purpose meshing algorithms for particular applications Theoretical or novel ideas with practical potential Technical presentations from industrial researchers.

More Details

Calculation of O-ring failure due to material aging

Segalman, Daniel J.

Applications where O-rings are used to isolate atmospheric environments within a structure are critical to weapon reliability. Failure occurs when gases are able to travel from one side of the O-ring to the other. The anticipated cause of failure is the relaxation of the rubber over decades, the reduction in closure force, and the O-ring`s consequent inability to offer a barrier to gas transport. A predictive model with tractable complexity has been developed to predict the time over which an O-ring is able to maintain an acceptable value of closure force.

More Details

Laser engineered net shaping for direct fabrication of metal components

Dimos, Duane B.

Sandia National Laboratories is developing a new technology to fabricate three-dimensional metallic components directly from CAD solid models. This process, called Laser Engineered Net Shaping (LENS{trademark}), exhibits enormous potential to revolutionize the way in which metal parts, such as complex prototypes, tooling, and small lot production parts, are produced. To perform the process, metal powder is injected into a molten pool created by a focused, high powered laser beam. Simultaneously, the substrate on which the deposition is occurring is scanned under the beam/powder interaction zone to fabricate the desired cross-sectional geometry. Consecutive layers are sequentially deposited, thereby producing a three-dimensional metal component.

More Details

Surface emitting laser technology and its application to the space radiation environment

Carson, R.F.

Present and future space-based applications such as sensors, low-weight and low-power data links for satellites, communication between electromagnetically-shielded modules, and short-distance cross-links within satellite constellations may benefit from the inclusion of small, low-power, and high-efficiency lasers such as the recently-developed Vertical Cavity Surface-Emitting Laser (VCSEL). Many factors influence the application of these devices to space. Temperature response, operational lifetime and reliability, and power consumption are all important considerations for space applications. In addition, the space radiation environments must be considered. In this work, the effects of ionizing radiation on VCSELs are studied with an emphasis on proton damage, and with comparisons to related neutron and gamma-induced phenomena. The influence of proton irradiation is studied in-depth for selected VCSEL structures by the use of an ion microbeam. The experiments indicate that VCSELs exhibit much less threshold current shift for a given radiation dose, compared to the more traditional edge-emitting semiconductor lasers, but that self-heating is a more important consideration for VCSELs. The high current densities associated with VCSELs also lead to a strong influence from forward-bias annealing. These effects are common to various VCSEL types (780 nm and 850 nm) and their magnitude at a given dose is strongly dependent on device size. This indicates that, while VCSELs appear to be very insensitive to ionizing radiation when compared with alternative technologies, there are a number of factors that must be taken into account when optimizing for the space environment.

More Details

Results from FAA program to validate bonded composite doublers for commercial aviation use

Roach, Dennis P.

The number of commercial airframes exceeding twenty years of service continues to grow. In addition, Service Life Extension Programs are attempting to extend the {open_quotes}economic{close_quotes} service life of commercial airframes to thirty years. The use of bonded composites may offer the airframe manufacturers and aircraft maintenance facilities a cost effective method to extend the lives of their aircraft. The Federal Aviation Administration Assurance NDI Validation Center (AANC) to validate the use of bonded composite doublers on commercial aircraft.

More Details

Prediction of elastomer lifetimes from accelerated thermal-aging experiments

Gillen, Kenneth T.

For elastomers that will be used in applications involving long lifetimes, it is often necessary to first carry out and model accelerated aging experiments at higher than ambient temperatures, and then extrapolate the results in order to make lifetime predictions at the use temperature. Continuing goals in such endeavors are to better understand potential problems with such modeling approaches and to find ways of improving confidence in the predictions when the data are extrapolated. In this paper we will address several important issues involved in these procedures for elastomers exposed to air (oxygen), and discuss some potentially useful techniques and approaches which can increase confidence in lifetime predictions.

More Details

Extremely secure identification documents

Tolk, Keith M.

The technology developed in this project uses biometric information printed on the document and public key cryptography to ensure that an adversary cannot issue identification documents to unauthorized individuals or alter existing documents to allow their use by unauthorized individuals. This process can be used to produce many types of identification documents with much higher security than any currently in use. The system is demonstrated using a security badge as an example. This project focused on the technologies requiring development in order to make the approach viable with existing badge printing and laminating technologies. By far the most difficult was the image processing required to verify that the picture on the badge had not been altered. Another area that required considerable work was the high density printed data storage required to get sufficient data on the badge for verification of the picture. The image processing process was successfully tested, and recommendations are included to refine the badge system to ensure high reliability. A two dimensional data array suitable for printing the required data on the badge was proposed, but testing of the readability of the array had to be abandoned due to reallocation of the budgeted funds by the LDRD office.

More Details

LDRD report nonlinear model reduction

Segalman, Daniel J.

The very general problem of model reduction of nonlinear systems was made tractable by focusing on the very large subclass consisting of linear subsystems connected by nonlinear interfaces. Such problems constitute a large part of the nonlinear structural problems encountered in addressing the Sandia missions. A synthesis approach to this class of problems was developed consisting of: detailed modeling of the interface mechanics; collapsing the interface simulation results into simple nonlinear interface models; constructing system models by assembling model approximations of the linear subsystems and the nonlinear interface models. These system models, though nonlinear, would have very few degrees of freedom. A paradigm problem, that of machine tool vibration, was selected for application of the reduction approach outlined above. Research results achieved along the way as well as the overall modeling of a specific machine tool have been very encouraging. In order to confirm the interface models resulting from simulation, it was necessary to develop techniques to deduce interface mechanics from experimental data collected from the overall nonlinear structure. A program to develop such techniques was also pursued with good success.

More Details

Weighted partial least squares method to improve calibration precision for spectroscopic noise-limited data

Haaland, David M.

Multivariate calibration methods have been applied extensively to the quantitative analysis of Fourier transform infrared (FT-IR) spectral data. Partial least squares (PLS) methods have become the most widely used multivariate method for quantitative spectroscopic analyses. Most often these methods are limited by model error or the accuracy or precision of the reference methods. However, in some cases, the precision of the quantitative analysis is limited by the noise in the spectroscopic signal. In these situations, the precision of the PLS calibrations and predictions can be improved by the incorporation of weighting in the PLS algorithm. If the spectral noise of the system is known (e.g., in the case of detector-noise-limited cases), then appropriate weighting can be incorporated into the multivariate spectral calibrations and predictions. A weighted PLS (WPLS) algorithm was developed to improve the precision of the analysis in the case of spectral-noise-limited data. This new PLS algorithm was then tested with real and simulated data, and the results compared with the unweighted PLS algorithm. Using near-infrared (NIR) calibration precision when the WPLS algorithm was applied. The best WPLS method improved prediction precision for the analysis of one of the minor components by a factor of nearly 9 relative to the unweighted PLS algorithm.

More Details

Ultra-high-speed studies of shock phenomena in a miniaturized system: A preliminary evaluation

Trott, Wayne M.

A laboratory-scale experimental test system for small-scale of shock phenomena has been assembled. This system uses a variety of miniature test platforms in which shock loading is provided by laser-driven flyer impact. Acceptor materials include thin-film explosives and high-density metal foils. Optical access is provided for high-speed optical diagnostics such as optically recording velocity interferometry and single-pulse Raman spectroscopy. The experimental assembly for Raman studies features a common laser source for both flyer generation and excitation of Raman scattering (to achieve high timing precision) and a detection scheme that uses the coupling fiber for the excitation source to collect with high efficiency backscattered Raman light. Preliminary system evaluation experiments indicate that detailed particle velocity studies of the dynamic material properties of high-density metals under short-pulse, high-strain-rate loading can be performed in a miniaturized test configuration. Single-pulse Raman studies on shock compressed thin film explosives also appear feasible if the thickness and grain structure of these films can be tailored to enhance the Raman scattering signal sufficiently. Possible improvements in the experimental design and a number of likely applications of these techniques are also discussed.

More Details

Processing challenges for GaN-based photonic and electronic devices

Shul, Randy J.

The wide gap materials SiC, GaN and to a lesser extent diamond are attracting great interest for high power/high temperature electronics. There are a host of device processing challenges presented by these materials because of their physical and chemical stability, including difficulty in achieving stable, low contact resistances, especially for one conductivity type, absence of convenient wet etch recipes, generally slow dry etch rates, the high temperatures needed for implant activation, control of suitable gate dielectrics and the lack of cheap, large diameter conducting and semi-insulating substrates. The relatively deep ionization levels of some of the common dopants (Mg in GaN; B, Al in SiC; P in diamond) means that carrier densities may be low at room temperature, and thus contact resistances will be greatly improved provided the metallization is stable and reliable. Some recent work with CoSi{sub x} on SiC and W-alloys on GaN show promise for improved ohmic contacts. The issue of unintentional hydrogen passivation of dopants will also be covered - this leads to strong increases in resistivity of p-SiC and GaN, but to large decreases in resistivity of diamond. Recent work on development of wet etches has found recipes for AlN (KOH), while photochemical etching of SiC and GaN has been reported. In the latter cases p-type materials is not etched, which can be a major liability in some devices. The dry etch results obtained with various novel reactors, including ICP, ECR and LE4 will be compared - the high ion densities in the former techniques produce the highest etch rates for strongly-bonded materials, but can lead to preferential loss of N from the nitrides and therefore to a highly conducting surface. This is potentially a major problem for fabrication of dry etched, recessed gate FET structures.

More Details

A user`s guide to GAETR: Sandia`s {open_quotes}Graphical Analysis of Event Trees{close_quotes} software

Hays, K.M.

This document is a reference guide for GAETR, Graphical Analysis of Event Trees, a software package developed at Sandia National Laboratories. GAETR may be used as a stand-alone code or as a module in the ARRAMIS{trademark} risk and reliability code suite. GAETR is designed to graphically create event trees and plot SETAC (Sandia Event Tree Analysis Code) output on IBM-compatible personal computers using the Microsoft{reg_sign} Windows{trademark} 95/NT operating environment. This manual explains the fundamentals of creating an event tree, including formatting, saving sequence information, printing, editing, and importing graphics to other software packages.

More Details

Creep properties of the Paintbrush tuff recovered from borehole USW NRG-7/7A: Data report

Price, Ronald H.

Experimental results are presented for seven creep experiments on welded specimens of the Paintbrush tuff recovered from borehole USW NRG-7/7A at Yucca Mountain, Nevada. The measurements were performed at differential stresses of 40, 70, 100, and 130 MPa. The confining pressure and temperature for each of the experiments was 10 MPa and 225 {degrees}C respectively. All of the specimens were tested drained, in a room dry condition. All of the experiments were terminated prior to failure. The duration of the experiments range from 2.6 x 10{sup 6} seconds to 5.9 x 10{sup 6} seconds. Creep strain is observed for those specimens tested at a stress difference. The strain rate is not constant. A primary creep stage is observed. Secondary creep does not exhibit a constant strain rate, but decreases with increasing time.

More Details

General application of rapid 3-D digitizing and tool path generation for complex shapes

Kwok, Kwan S.

A system for automatic tool path generation was developed at Sandia National Laboratories for finish machining operations. The system consists of a commercially available 5-axis milling machine controlled by Sandia developed software. This system was used to remove overspray on cast turbine blades. A laser-based, structured-light sensor, mounted on a tool holder, is used to collect 3D data points around the surface of the turbine blade. Using the digitized model of the blade, a tool path is generated which will drive a 0.375 inch grinding pin around the tip of the blade. A fuzzified digital filter was developed to properly eliminate false sensor readings caused by burrs, holes and overspray. The digital filter was found to successfully generate the correct tool path for a blade with intentionally scanned holes and defects. The fuzzified filter improved the computation efficiency by a factor of 25. For application to general parts, an adaptive scanning algorithm was developed and presented with simulation and experimental results. A right pyramid and an ellipsoid were scanned successfully with the adaptive algorithm in simulation studies. In actual experiments, a nose cone and a turbine blade were successfully scanned. A complex shaped turbine blade was successfully scanned and finished machined using these algorithms.

More Details

A simulation and decision analysis approach to locating DNAPL in subsurface sediments

Cox, Roger G.

This report presents a strategy for delineating the location of residual dense non-aqueous phase liquids (DNAPL) that combines probabilistic simulations of DNAPL spill location and volume, geologic texture constraining migration pathways, migration physics through percolation modeling, and a decision analysis model to pick optimal locations for sampling wells. The authors` strategy is an iterative process of simulating the residual DNAPL location, selecting new locations for data collection, gathering data, and then using the data to condition further simulations of DNAPL migration. As they iterate through this process, data worth analysis is used to determine an appropriate stopping point. The authors present the results from a preliminary version of their model, showing how the process was used to delineate hypothetical DNAPL spills.

More Details

Navigating nuclear science: Enhancing analysis through visualization

Irwin, N.H.

Data visualization is an emerging technology with high potential for addressing the information overload problem. This project extends the data visualization work of the Navigating Science project by coupling it with more traditional information retrieval methods. A citation-derived landscape was augmented with documents using a text-based similarity measure to show viability of extension into datasets where citation lists do not exist. Landscapes, showing hills where clusters of similar documents occur, can be navigated, manipulated and queried in this environment. The capabilities of this tool provide users with an intuitive explore-by-navigation method not currently available in today`s retrieval systems.

More Details

Reactant ion chemistry for detection of TNT, RDX, and PETN using an ion mobility spectrometer

Klassen, Sandra E.

This report describes the responses of three energetic materials (TNT, RDX, and PETN) to varying reactant ion chemistries and IMS cell temperatures. The following reactant ion chemistries were evaluated; air-dry; air-wet; methylene chloride-dry; methylene chloride-wet; methylene bromide-dry; nitrogen dioxide-wet; sulfur dioxide-wet. The temperature was varied between 160 - 220{degrees}C.

More Details

LDRD final report on nano-scale engineering of smart membranes

Loy, Douglas A.

A new approach to the fabrication of porous, amorphous inorganic membranes using organic pore templates was investigated. The pore templates were a new family of hybrid organic-inorganic monomers. As background for membrane work, the monomers were polymerized by sol-gel techniques to make crosslinked polymers. Molecular modeling was used to create computer simulations of the materials and provide insight into their composites, were then converted into porous silicas using low temperature oxygen plasma techniques. A select few of the monomers were copolymerized with silica monomers to form non-porous thin films on mesoporous substrates. The films were converted into porous silica thin films with thermal oxidations and the resulting membranes were tested for gas selectivities and flux.

More Details

Development of an automated pit packaging system for Pantex

Fahrenholtz, J.C.

Sandia National Laboratories is developing a system that uses robots to package pits at Pantex in the AT-400A pit storage and transportation container. This report will give an overview of the AT-400A packaging process, and the parts of the overall AT-400A packaging operation that will be performed robotically. The process employed to move from development in the laboratory at Sandia to production use at Pantex will be described. Finally, important technology components being developed for and incorporated into the robotic system will be described. 7 refs., 9 figs.

More Details

SECPOP90: Sector population, land fraction, and economic estimation program

Humphreys, Steven L.

In 1973 Mr. W. Athey of the Environmental Protection Agency wrote a computer program called SECPOP which calculated population estimates. Since that time, two things have changed which suggested the need for updating the original program - more recent population censuses and the widespread use of personal computers (PCs). The revised computer program uses the 1990 and 1992 Population Census information and runs on current PCs as {open_quotes}SECPOP90.{close_quotes} SECPOP90 consists of two parts: site and regional. The site provides population and economic data estimates for any location within the continental United States. Siting analysis is relatively fast running. The regional portion assesses site availability for different siting policy decisions; i.e., the impact of available sites given specific population density criteria within the continental United States. Regional analysis is slow. This report compares the SECPOP90 population estimates and the nuclear power reactor licensee-provided information. Although the source, and therefore the accuracy, of the licensee information is unknown, this comparison suggests SECPOP90 makes reasonable estimates. Given the total uncertainty in any current calculation of severe accidents, including the potential offsite consequences, the uncertainty within SECPOP90 population estimates is expected to be insignificant. 12 refs., 55 figs., 7 tabs.

More Details

The effects of confining pressure on the strength and elastic properties of the Paintbrush tuff recovered from boreholes USW NRG-6 and USW NRG-7/7A: Data report

Price, Ronald H.

Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from the USW NRG-6 and USW NRG-7/7A borehole at Yucca Mountain, Nevada. Measurements have been performed on five thermal/mechanical units: TCw, PTn, TSw2, and TSw3. The following bulk properties are reported for each specimen: dry bulk density, saturated bulk density, average grain density and porosity. Confined compression to failure tests were performed on selected specimens recovered from the boreholes at confining pressures of 5 and 10 MPa. In addition, compressional and shear wave velocities were measured on the specimens prior to testing. Measurements were conducted under drained conditions at room temperature on nominally water saturated specimens. The nominal strain rate for the experiments was 10{sup -5} s{sup -1}.

More Details

Development and experimental evaluation of models for low capillary number two-phase flows in rough walled fractures relevant to natural gradient conditions

Glass, R.J.; Yarrington, L.; Nicholl, M.J.

The major results from SNL`s Conceptual Model Development and Validation Task (WBS 1.2.5.4.6) as developed through exploration of small scale processes were synthesized in Glass et al. to give guidance to Performance Assessment on improving conceptual models for isothermal flow in unsaturated, fractured rock. There, pressure saturation and relative permeability curves for single fractures were proposed to be a function of both fracture orientation within the gravity field and initial conditions. We refer the reader to Glass et al. for a discussion of the implications of this behavior for Performance Assessment. The scientific research we report here substantiates this proposed behavior. We address the modeling of phase structure within fractures under natural gradient conditions relevant to unsaturated flow through fractures. This phase structure underlies the calculation of effective properties for individual fractures and hence fracture networks as required for Performance Assessment. Standard Percolation (SP) and Invasion Percolation (IP) approaches have been recently proposed to model the underlying phase saturation structures within the individual fractures during conditions of two-phase flow. Subsequent analysis of these structures yields effective two-phase pressure-saturation and relative permeability relations for the fracture. However, both of these approaches yield structures that are at odds with physical reality as we see in experiments and thus effective properties calculated from these structures are in error. Here we develop and evaluate a Modified Invasion Percolation (MIP) approach to better model quasi-static immiscible displacement in fractures. The effects of gravity, contact angle, local aperature field geometry, and local in-plane interfacial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field.

More Details

Novel low-permittivity dielectrics for Si-based microelectronics

Sullivan, John P.

The purpose of this laboratory-directed research and development (LDRD) project was to develop and assess novel low-permittivity dielectric materials for applications as interlevel dielectrics (ILDs) in Si-based microelectronics. There were three classes of materials investigated: (1) novel covalently-bonded ceramics containing carbon, boron, and/or nitrogen, (2) fluorinated SiO{sub 2} (SiOF), and (3) plasma polymerized fluorocarbon (PPFC). The specific advantages and disadvantages for each potential low k ILD material were evaluated. It was discovered that highly energetic deposition processes are required for the formation of thermally and environmentally stable carbon or boron nitride ceramics, and the resulting films may have many potentially valuable applications, such as diffusion barriers, tribological coatings, micro-sensor materials, etc. The films are not suitable as low k ILDs, however, because the highly energetic deposition process leads to films with high atomic density, and this leads to high dielectric constants. SiOF shows a promise as low k ILD material for near-term applications, but special passivation or encapsulation strategies may be required in order to reduce two instability problems that the authors have discovered: moisture absorption and thermal instability of the SiOF/Al interface. PPFC films offer promise for even lower dielectric constant ILDs than SiOF, but it will be necessary to develop new strategies to passivate the free radicals in the films generated during deposition. These free radicals lead to increase in dielectric loss over time when the films are exposed to room ambient conditions.

More Details

Network-based collaborative research environment LDRD final report

Davies, B.R.

The Virtual Collaborative Environment (VCE) and Distributed Collaborative Workbench (DCW) are new technologies that make it possible for diverse users to synthesize and share mechatronic, sensor, and information resources. Using these technologies, university researchers, manufacturers, design firms, and others can directly access and reconfigure systems located throughout the world. The architecture for implementing VCE and DCW has been developed based on the proposed National Information Infrastructure or Information Highway and a tool kit of Sandia-developed software. Further enhancements to the VCE and DCW technologies will facilitate access to other mechatronic resources. This report describes characteristics of VCE and DCW and also includes background information about the evolution of these technologies.

More Details

Massively parallel solution of the inverse scattering problem for integrated circuit quality control

Leland, Robert W.

The authors developed and implemented a highly parallel computational algorithm for solution of the inverse scattering problem generated when an integrated circuit is illuminated by laser. The method was used as part of a system to measure diffraction grating line widths on specially fabricated test wafers and the results of the computational analysis were compared with more traditional line-width measurement techniques. The authors found they were able to measure the line width of singly periodic and doubly periodic diffraction gratings (i.e. 2D and 3D gratings respectively) with accuracy comparable to the best available experimental techniques. They demonstrated that their parallel code is highly scalable, achieving a scaled parallel efficiency of 90% or more on typical problems running on 1024 processors. They also made substantial improvements to the algorithmics and their original implementation of Rigorous Coupled Waveform Analysis, the underlying computational technique. These resulted in computational speed-ups of two orders of magnitude in some test problems. By combining these algorithmic improvements with parallelism the authors achieve speedups of between a few thousand and hundreds of thousands over the original engineering code. This made the laser diffraction measurement technique practical.

More Details

Growing a market economy

Pryor, Richard J.

This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

More Details

Apparent spatial blurring and displacement of a point optical source due to cloud scattering

Brower, K.L.

A Monte Carlo algorithm is used to determine the apparent spatial blurring of a terrestrial 1.07 micron optical point source due to cloud scattering as seen from space. The virtual image of a point source over a virtual source plane area 22.4 x 22.4 square kilometers arising from cloud scattering was determined for stratus clouds (NASA cloud number 5) and altostratus clouds optical source arises from photon scattering by cloud water droplets. Displacement of the virtual source is due to the apparent illumination of the cloud top region directly about the actual source which when viewed at a nonzero look angle gives a projected displacement of the apparent source relative to the actual source. These features are quantified by an analysis of the Monte Carlo computational results.

More Details

Smart packaging for photonics

Palmer, David W.

Unlike silicon microelectronics, photonics packaging has proven to be low yield and expensive. One approach to make photonics packaging practical for low cost applications is the use of {open_quotes}smart{close_quotes} packages. {open_quotes}Smart{close_quotes} in this context means the ability of the package to actuate a mechanical change based on either a measurement taken by the package itself or by an input signal based on an external measurement. One avenue of smart photonics packaging, the use of polysilicon micromechanical devices integrated with photonic waveguides, was investigated in this research (LDRD 3505.340). The integration of optical components with polysilicon surface micromechanical actuation mechanisms shows significant promise for signal switching, fiber alignment, and optical sensing applications. The optical and stress properties of the oxides and nitrides considered for optical waveguides and how they are integrated with micromechanical devices were investigated.

More Details

GaAs series connected photovoltaic converters for high voltage capacitor charging applications

Rose, B.H.

This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.

More Details

Finite element analysis of sucker rod couplings with guidelines for improving fatigue life

Hoffman, Edward L.

The response of a variety of sucker rod couplings to an applied axial load was simulated using axisymmetric finite element models. The calculations investigated three sucker rod sizes and various combinations of the slimhole, Spiralock, and Flexbar modifications to the coupling. In addition, the effect of various make-ups (assembly tightness) on the performance of coupling was investigated. An axial load was applied to the sucker rod ranging from {minus}5 ksi to 40 ksi, encompassing three load cycles identified on a modified Goodman diagram as acceptable for indefinite service life of the sucker rods. The simulations of the various coupling geometries and make-ups were evaluated with respect to how well they accomplish the two primary objectives of preloading threaded couplings: (1) to lock the threaded coupling together so that it will not loosen and eventually uncouple, and (2) to improve the fatigue resistance of the threaded connection by reducing the stress amplitude in the coupling when subjected to cyclic loading. Perhaps the most significant finding in this study was the characterization of the coupling parameters which affect two stress measures. The mean hydrostatic stress, which determines the permissible effective alternating stress, is a function of the coupling make-up. Whereas, the alternating effective stress is a function of the relative stiffnesses of the pin and box sections of the coupling and, as long as the coupling does not separate, is unaffected by the amount of circumferential displacement applied during make-up. The results of this study suggest approaches for improving the fatigue resistance of sucker rod couplings.

More Details

Thermal expansion of the Paintbrush tuff recovered from borehole USW SD-12 at pressures 30 MPa: Data report

Price, Ronald H.

Experimental results are presented for 24 thermal expansion experiments performed on 5 welded specimens of the Paintbrush tuff recovered from borehole USW SD-12 at Yucca Mountain, Nevada. The thermal expansion experiments were performed at constant confining pressures between 1 and 30 MPa. On three specimens, the highest confining pressure measurements were performed first to inhibit thermally induced damage which might occur at lower confining pressures. At each confining pressure two complete thermal cycles were performed. The specimens were heated (to a nominal temperature of 250 C) and cooled at the nominal rate of 0.319 C per minute. The change in specimen length as a function of temperature was measured with two linear variable displacement transducers mounted on endcaps secured to the specimen. The strain increases with increasing temperature and the strain vs temperature curves are concave upward. On cooling, there is hysteresis at the higher temperatures at all confining pressures. The first heating/cooling cycle is anomalous; hysteresis is pronounced, and a permanent shortening of the specimen is observed at the termination of the cycle. The magnitude of the effect was similar for all five specimens regardless of whether the first cycle was carried out at the highest or lowest confining pressure. For subsequent cycles at all confining pressures, no permanent strain develops, and the strain versus temperature curves re very similar. The mean coefficients of thermal expansion ({alpha}) range from 7.9 to 10.8{sup {minus}6} C{sup {minus}1} at temperatures below 100 C, to 14.2 to 20.6 x 10{sup {minus}6} C{sup {minus}1} at temperatures approaching 250 C. The effect of confining pressure on thermal expansion is small. For temperatures above 175 C, the mean coefficients of thermal expansion decreases by 10--12% as the pressure increases from 1 to 30 MPa.

More Details

Calculation of shipboard fire conditions for radioactive materials packages with the methods of computational fluid dynamics

Koski, Jorman A.

Shipboard fires both in the same ship hold and in an adjacent hold aboard a break-bulk cargo ship are simulated with a commercial finite-volume computational fluid mechanics code. The fire models and modeling techniques are described and discussed. Temperatures and heat fluxes to a simulated materials package are calculated and compared to experimental values. The overall accuracy of the calculations is assessed.

More Details

Preliminary evaluation of the use of the greater confinement disposal concept for the disposal of Fernald 11e(2) byproduct material at the Nevada Test Site

Cochran, John R.

This report documents a preliminary evaluation of the ability of the greater confinement disposal boreholes at the Nevada Test Site to provide long-term isolation of radionuclides from the disposal of vitrified byproduct material. The byproduct material is essentially concentrated residue from processing uranium ore that contains a complex mixture of radionuclides, many of which are long-lived and present in concentrations greater than 100,000 picoCuries per gram. This material has been stored in three silos at the fernald Environmental Management Project since the early 1950s and will be vitrified into 6,000 yd{sup 3} (4,580 m{sup 3}) of glass gems prior to disposal. This report documents Sandia National Laboratories` preliminary evaluation for disposal of the byproduct material and includes: the selection of quantitative performance objectives; a conceptual model of the disposal system and the waste; results of the modeling; identified issues, and activities necessary to complete a full performance assessment.

More Details

TDR calibration for the alternative landfill cover demonstration (ALCD)

Lopez, J.

The Alternative Landfill Cover Demonstration is a large scale field test that compares the performance of various landfill cover designs in dry environments. An important component of the comparison is the change in the moisture content of the soils throughout the different cover test plots. Time Domain Reflectometry (TDR) is the primary method for the measurement of the volumetric moisture content. Each of the covers is composed of layers of varying types and densities of soils. The probes are therefore calibrated to calculate the volumetric moisture content in each of the different soils in order to gain the optimum performance of the TDR system. The demonstration plots are constructed in two phases; a different probe is used in each phase. The probe that is used in Phase 1 is calibrated for the following soils: compacted native soil, uncompacted native soil, compacted native soil mixed with 6% sodium bentonite by weight, and sand. The probe that is used in Phase 2 is calibrated for the following soils: compacted native soil, uncompacted native soil, and sand. In addition, the probes are calibrated for the varying cable lengths of the TDR probes. The resulting empirically derived equations allow for the calculation of in-situ volumetric moisture content of all of the varying soils throughout the cover test plots in the demonstration.

More Details

A survey of grid-free methods for the simulation of 3-D incompressible flows in bounded domains

Gharakhani, A.

The state-of-the-art in Lagrangian methods for the grid-free simulation of three-dimensional, incompressible, high Reynolds number, internal and/or external flows is surveyed. Specifically, vortex and velicity (or impulse) element methods are introduced. The relative merits of various available techniques and the outstanding challenges in simulating the processes of convection and diffusion, as well as in satisfying the wall boundary conditions are discussed individually. Issues regarding the stretch and solenoidality of vorticity are also discussed. A potentially successful algorithm for simulating the flow around a parachute is proposed as well.

More Details

Inverse scattering code

Hale, A.

A methodology for the evaluation of complex electromagnetics problems is presented. The methodology reduces the computational requirements for the analysis of large scale computational electromagnetics problems by hybridizing the method of moments and physical optics techniques. The target model is based on triangular facets and the incident field source by its system response function. Data which can be obtained from the analysis are radar cross section, power spectral density, and range profiles.

More Details

Planar silicon fabrication process for high-aspect-ratio micromachined parts

Barron, C.C.

Surface-micromachined silicon inertial sensors are limited to relatively high-G applications in part because of the fundamental limitations on proof mass imposed by the manufacturing technology. At the same time, traditional micromolding technologies such as LIGA do not lend themselves to integration with electronics, a capability which is equally necessary for high-performance inertial sensors. The silicon micromolding processes described in this report promise to offer both larger proof masses and integrability with on-chip electronics. In Sandia`s silicon micromolding process, the proof mass is formed using a mold which is first recessed into the substrate using a deep silicon trench etch, then lined with a sacrificial or etch-stop layer, and filled with mechanical polysilicon. Since the mold is recessed into the substrate, the whole micromechanical structure can be formed, planarized, and integrated with standard silicon microelectronic circuits before the release etch. In addition, unlike surface-micromachined parts, the thickness of the molded parts is limited by the depth of the trench etch (typically 10--50 {micro}m) rather than the thickness of deposited polysilicon (typically 2 {micro}m). The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. The authors anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems including high-performance inertial sensing systems.

More Details

Evaluation of field enforced antiferroelectric to ferroelectric phase transition dielectrics and relaxor ferroelectrics for pulse discharge capacitors

Tuttle, Bruce

Discharge capacitors were designed based on materials with antiferroelectric (AFE) to ferroelectric (FE) field enforced transitions that had 10 times the capacitance of relaxor ferroelectric or state of the art BaTiO{sub 3} materials in the voltage range of interest. Nonlinear RLC circuit analysis was used to show that the AFE to FE materials have potentially more than 2 times the peak discharge current density capability of the BaTiO{sub 3} or lead magnesium niobate (PMN) based relaxor materials. Both lead lanthanum zirconium tin titanate (PLZST) AFE to FE field enforced phase transition materials and PMN based relaxor materials were fabricated and characterized for Sandia`s pulse discharge capacitor applications. An outstanding feature of the PLZST materials is that there are high field regimes where the dielectric constant increases substantially, by a factor of 20 or more, with applied field. Specifically, these materials have a low field dielectric constant of 1,000, but an effective dielectric constant of 23,000 in the electric field range corresponding to the FE to AFE transition during discharge. Lead magnesium niobate (PMN) based relaxor materials were also investigated in this project because of their high dielectric constants. While the PMN based ceramics had a low field dielectric constant of 25,000, at a field corresponding to half the charging voltage, approximately 13 kV/cm, the dielectric constant decreases to approximately 7,500.

More Details

Atomic-scale measurement of liquid metal wetting and flow

Shinn, Neal D.

The flow behavior of liquid metals at solid interfaces is critically important to successful welding, brazing, soldering and the synthesis of metal/ceramic composites. Continuum flow models frequently fail to reliably predict wetting behavior because they are based upon bulk fluid properties, rather than microscopic flow processes at the actual solid/liquid interface. Improved understanding of interfacial liquid flow is hindered by the paucity of experimental measurements at this microscopic level. This report describes a new approach, Acoustic Wave Damping (AWD), to measuring viscoelastic properties of liquid metal layers in the nanometer thickness regime. The AWD experiment measures the frequency response of a quartz crystal microbalance in contact with a viscoelastic layer. An equivalent circuit model and continuum acoustic theory relate this electrical response to mechanical energy storage and dissipative loss. For viscoelastic layers of known thickness and density, a quantitative complex shear modulus can be determined from the AWD data. Studies of self-assembled monolayers (SAMs) demonstrate sensitivity to monolayer structure and bonding. Molecular dynamics simulations relate these atomistic properties to the ensemble response. AWD measurements of ultra-thin liquid indium layers reveal metastable undercooling for 10--50 nm thick indium layers. Continued refinement of the AWD technique and the addition of complementary interface characterization techniques will enable definitive studies of ultra-thin molten metals.

More Details

User`s guide for the Augmented Computer Exercise for Inspection Training (ACE-IT) software

Dobranich, Pauline R.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (host). Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for challenge inspections under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. This User`s Guide describes the use of the ACE-IT training software.

More Details

Technical manual for the Augmented Computer Exercise for Inspection Training (ACE-IT) software

Dobranich, Pauline R.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (host). Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for challenge inspections under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. This Technical Manual describes many of the technical aspects of the ACE-IT training software.

More Details

Exercise manual for the Augmented Computer Exercise for Inspection Training (ACE-IT) software

Dobranich, Pauline R.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspected Party and the Inspection Team. Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for a hypothetical challenge inspection under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. The Exercise Manual supplements the ACE-IT software by providing general information on on-site inspections and detailed information for the CWC challenge inspection exercise. The detailed information includes the pre-inspection briefing, maps, list of sensitive items, medical records, and shipping records.

More Details

Structure-property relationships of antiferroelectric Pb(Zr, Ti)O{sub 3} based materials: Hydrostatic depoling characteristics

Tuttle, Bruce

A novel technique has been developed for the synthesis of homogeneous, weakly agglomerated highly filterable Pb(Zr, Ti)O{sub 3} (PZT) powders. PZT 95/5 based ceramics were fabricated from these powders to determine interrelationships among microstructure, dielectric properties and pressure induced ferroelectric (FE) to antiferroelectric (AFE) phase transitions. Initial measurements indicate that microstructure has a substantial effect on hydrostatic depoling characteristics. While smaller grain size materials and higher switching pressures, subtleties in microstructure, which may include entrapped porosity, resulted in a more diffuse depoling characteristic. In addition, greater than 90% dense materials were obtained at process temperatures as low at 900{degrees}C. were only 30% of the values of PZT 95/5 fired at 1300{degrees}C, the dielectric constants of the 900{degrees}C materials were almost a factor of two higher. Backscattered electron Kikuchi pattern analysis determined that adjacent, nonlinear, irregularly shaped domain structures observed by electron channel imaging were 109{degrees} domains.

More Details

Thermal expansion, thermal conductivity, and heat capacity measurements for boreholes UE25 NRG-4, UE25 NRG-5, USW NRG-6, and USW NRG-7/7A

Brodsky, Nancy S.

Specimens were tested from four thermal-mechanical units, namely Tiva Canyon (TCw), Paintbrush Tuff (PTn), and two Topopah Spring units (TSw1 and TSw2), and from two lithologies, i.e., welded devitrified (TCw, TSw1, TSw2) and nonwelded vitric tuff (PTn). Thermal conductivities in W(mk){sup {minus}1} averaged over all boreholes, ranged (depending upon temperature and saturation state) from 1.2 to 1.9 for TCw, from 0.4 to 0.9 for PTn, from 1.0 to 1.7 for TSw1, and from 1.5 to 2.3 for TSw2. Mean coefficients of thermal expansion were highly temperature dependent and values, averaged over all boreholes, ranged (depending upon temperature and saturation state) from 6.6 {times} 10{sup {minus}6} to 49 {times} 10{sup {minus}6} C{sup {minus}1} for TCw, from the negative range to 16 {times} 10{sup {minus}6} {center_dot} {degree}C{sup {minus}1} for PTn, from 6.3 {times} 10{sup {minus}6} to 44 {times} 10{sup {minus}6} C{sup {minus}1} for TSw1, and from 6.7 {times} 10{sup {minus}6} to 37 {times} 10{sup {minus}6} {center_dot} {degree}C{sup {minus}1} for TSw2. Mean values of thermal capacitance in J/cm{sup 3}K (averaged overall specimens) ranged from 1.6 J to 2.1 for TSw1 and from 1.8 to 2.5 for TSw2. In general, the lithostratigraphic classifications of rock assigned by the USGS are consistent with the mineralogical data presented in this report.

More Details

Battery energy storage market feasibility study -- Expanded report

Kraft, S.; Akhil, A.

Under the sponsorship of the US Department of Energy`s Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories (SNL) contracted Frost and Sullivan to conduct a market feasibility study of energy storage systems. The study was designed specifically to quantify the battery energy storage market for utility applications. This study was based on the SNL Opportunities Analysis performed earlier. Many of the groups surveyed, which included electricity providers, battery energy storage vendors, regulators, consultants, and technology advocates, viewed battery storage as an important technology to enable increased use of renewable energy and as a means to solve power quality and asset utilization issues. There are two versions of the document available, an expanded version (approximately 200 pages, SAND97-1275/2) and a short version (approximately 25 pages, SAND97-1275/1).

More Details

Models and correlations of the DEBRIS Late-Phase Melt Progression Model

Gasser, R.D.

The DEBRIS Late Phase Melt Progression Model is an assembly of models, embodied in a computer code, which is designed to treat late-phase melt progression in dry rubble (or debris) regions that can form as a consequence of a severe core uncover accident in a commercial light water nuclear reactor. The approach is fully two-dimensional, and incorporates a porous medium modeling framework together with conservation and constitutive relationships to simulate the time-dependent evolution of such regions as various physical processes act upon the materials. The objective of the code is to accurately model these processes so that the late-phase melt progression that would occur in different hypothetical severe nuclear reactor accidents can be better understood and characterized. In this report the models and correlations incorporated and used within the current version of DEBRIS are described. These include the global conservation equations solved, heat transfer and fission heating models, melting and refreezing models (including material interactions), liquid and solid relocation models, gas flow and pressure field models, and the temperature and compositionally dependent material properties employed. The specific models described here have been used in the experiment design analysis of the Phebus FPT-4 debris-bed fission-product release experiment. An earlier DEBRIS code version was used to analyze the MP-1 and MP-2 late-phase melt progression experiments conducted at Sandia National Laboratories for the US Nuclear Regulatory Commission.

More Details

Systems study of drilling for installation of geothermal heat pumps

Finger, John T.

Geothermal, or ground-source, heat pumps (GHP) are much more efficient than air-source units such as conventional air conditioners. A major obstacle to their use is the relatively high initial cost of installing the heat-exchange loops into the ground. In an effort to identify drivers which influence installation cost, a number of site visits were made during 1996 to assess the state-of-the-art in drilling for GHP loop installation. As an aid to quantifying the effect of various drilling-process improvements, we constructed a spread-sheet based on estimated time and material costs for all the activities required in a typical loop-field installation. By substituting different (improved) values into specific activity costs, the effect on total project costs can be easily seen. This report contains brief descriptions of the site visits, key points learned during the visits, copies of the spread-sheet, recommendations for further work, and sample results from sensitivity analysis using the spread-sheet.

More Details

Scaling vectors and multiwavelets in numerical differential equations -- Some approximation-theoretic and numerical issues

Massopust, P.T.

Galerkin approximations and finite element methods for operator equations of the form Lu = f play an important role in the theory of numerical differential equations. This report summarizes some of the approximation-theoretic and numerical issues encountered in solving operator equations of the form Lu = f. Particular emphasis is placed on Galerkin and finite element approximations using multiwavelets. Examples are used to illustrate some of the issues.

More Details

Method for measuring deuterium in erbium deuteride films

Brangan, J.R.

Determining the quantity of deuterium in an erbium deuteride (ErD{sub 2}) film is essential for assessing the quality of the hydriding process but is a challenging measurement to make. First, the ideal gas law cannot be applied directly due to high temperature (950{degrees}C) and low temperature (25{degrees}C) regions in the same manifold. Additionally, the metal hydride does not release all of the deuterium rapidly upon heating and metal evaporation occurs during extended heating periods. Therefore, the method developed must provide a means to compensate for temperature inhomogeneities and the amount of deuterium retained in the metal film while heating for a minimal duration. This paper presents two thermal desorption methods used to evaluate the kinetics and equilibria of the deuterium desorption process at high temperatures (950{degrees}C). Of primary concern is the evaluation of the quantity of deuterium remaining in these films at the high temperature. A multiple volume expansion technique provided insight into the kinetics of the deuterium evolution and metal evaporation from the film. Finally a repeated pump-down approach yielded data that indicated approximately 10% of the deuterium is retained in the metal film at 950{degrees}C and approximately 1 Torr pressure. When the total moles of deuterium determined by this method were divided by the moles of erbium determined by ICP/AES, nearly stochiometric values of 2:1 were obtained for several erbium dideuteride films. Although this work presents data for erbium and deuterium, these methods are applicable to other metal hydrides as well.

More Details

Simulation of orthogonal cutting with smooth particle hydrodynamics

Heinstein, Martin

There is an active literature on the simulation of cutting processes through finite element methods. Such efforts are motivated by the enormous economic importance of machining processes and the desire to adjust processes so as to optimize product and throughput, but suffer from some difficulties inherent to the finite element method. An alternative approach, which appears to overcome most of those difficulties, is that of Smooth Particle Hydrodynamics (SPH).Though some finite element work is reviewed here, the focus of this paper is on the demonstration of the SPH technique of to simulate orthogonal cutting.

More Details

Radiation transport phenomena and modeling. Part A: Codes; Part B: Applications with examples

Beutler, David E.

This report contains the notes from the second session of the 1997 IEEE Nuclear and Space Radiation Effects Conference Short Course on Applying Computer Simulation Tools to Radiation Effects Problems. Part A discusses the physical phenomena modeled in radiation transport codes and various types of algorithmic implementations. Part B gives examples of how these codes can be used to design experiments whose results can be easily analyzed and describes how to calculate quantities of interest for electronic devices.

More Details

Structural health monitoring of wind turbines

Simmermacher, Todd W.

To properly determine what is needed in a structural health monitoring system, actual operational structures need to be studied. We have found that to effectively monitor the structural condition of an operational structure four areas must be addressed: determination of damage-sensitive parameters, test planning, information condensation, and damage identification techniques. In this work, each of the four areas has been exercised on an operational structure. The structures studied were all be wind turbines of various designs. The experiments are described and lessons learned will be presented. The results of these studies include a broadening of experience in the problems of monitoring actual structures as well as developing a process for implementing such monitoring systems.

More Details

Department of Energy nuclear material physical protection program in the Republic of Kazakstan

Eras, A.; Berry, R.B.; Case, R.S.

As part of the joint U.S. and Republic of Kazakstan nuclear Material Protection, Control, and Accounting (MPC{ampersand}A) program, the U.S. Department of Energy (DOE) is providing assistance at four nuclear facilities in Kazakstan. These facilities are the Ulba Metallurgical Plant, the National Nuclear Center (NNC) Institute of Atomic Energy at Kurchatov (IAE-K), the Mangyshlak Atomic Energy Complex (BN-350) Reactor, and the NNC Institute of Atomic Energy at Almaty (IAE-A). This paper describes the DOE MPC{ampersand}A physical protection program at each of the facilities.

More Details

Remote monitoring for international safeguards

Dupree, S.A.

Remote monitoring is not a new technology, and its application to safeguards relevant activities has been examined for a number of years. On behalf of the US Department of Energy and international partners, remote monitoring systems have been emplaced in nuclear facilities and laboratories in various parts of the world. The experience gained from these field trials of remote monitoring systems has shown the viability of the concept of using integrated monitoring systems. Although a wide variety of sensors has been used in the remote monitoring field trials conducted to date, the possible range of instrumentation that might be used has scarcely been touched. As the technology becomes widespread, large amounts of data will become available to inspectors responsible for safeguards activities at the sites. Effective use of remote monitoring will require processing, archiving, presenting, and assessing of these data. To provide reasonable efficiency in the application of this technology, data processing should be done in a careful and organized manner. The problem will be not an issue of poring over scant records but of surviving under a deluge of information made possible by modern technology. Fortunately, modern technology, which created the problem of the data glut, is available to come to the assistance of those inundated by data. Apart from the technological problems, one of the most important aspects of remote monitoring is the potential constraint related to the transmission of data out of a facility or beyond national borders. Remote monitoring across national borders can be seriously considered only in the context of a comprehensive, transparent, and open implementation regime.

More Details

Evidence that Arrhenius high-temperature aging behavior for an EPDM o-ring does not extrapolate to lower temperatures

Gillen, Kenneth T.

Because of the need to significantly extend the lifetimes of weapons, and because of potential implications of environmental O-ring failure on degradation of critical internal weapon components, the authors have been working on improved methods of predicting and verifying O-ring lifetimes. In this report, they highlight the successful testing of a new predictive method for deriving more confident lifetime extrapolations. This method involves ultrasensitive oxygen consumption measurements. The material studied is an EPDM formulation use for the environmental O-ring the W88. Conventional oven aging (155 C to 111 C) was done on compression molded sheet material; periodically, samples were removed from the ovens and subjected to various measurements, including ultimate tensile elongation, density and modulus profiles. Compression stress relaxation (CSR) measurements were made at 125 C and 111 C on disc shaped samples (12.7 mm diameter by 6 mm thick) using a Shawbury Wallace Compression Stress Relaxometer MK 2. Oxygen consumption measurements were made versus time, at temperatures ranging from 160 C to 52 C, using chromatographic quantification of the change in oxygen content caused by reaction with the EPDM material in sealed containers.

More Details

Critical heat flux performance of hypervapotrons proposed for use in the ITER divertor vertical target

Youchison, Dennis L.

Task T-222 of the International Thermonuclear Experimental Reactor (ITER) program addresses the manufacturing and testing of permanent components for use in the ITER divertor. Thermalhydraulic and critical heat flux performance of the heat sinks proposed for use in the divertor vertical target are part of subtask T-222.4. As part of this effort, two single channel, medium scale, bare copper alloy, hypervapotron mockups were designed, fabricated, and tested using the EB-1200 electron beam system. The objectives of the effort were to develop the design and manufacturing procedures required for construction of robust high heat flux (HHF) components, verify thermalhydraulic, thermomechanical and critical heat flux (CHF) performance under ITER relevant conditions, and perform analyses of HHF data to identify design guidelines and failure criteria and possibly modify any applicable CHF correlations. The design, fabrication, and finite element modeling of two types of hypervapotrons are described; a common version already in use at the Joint European Torus (JET) and a new attached fin design. HHF test data on the attached fin hypervapotron will be used to compare the CHF performance under uniform heating profiles on long heated lengths with that of localized, highly peaked, off nominal profiles.

More Details

Public outcomes: Building a 21st century national innovation system that serves the public

Gover, J.

Federal R and D must be principally focused on solving public problems that the marketplace is failing to address. With few exceptions programs must be supported by roadmaps that show how the R and D is linked to public outcomes. Federal R and D and those who perform it must be judged in terms of the public outcomes. The overarching issues of federal R and D policy, what it should address, how to manage it, who should perform it, how to perform it, what works best, etc. are highly complex and lack a strong theoretical foundation. (In fact, the linear, assembly-line model used by policymakers is wrong.) It is time that policymakers recognize and acknowledge the uncertainty of their work and conduct a wide array of policy experiments (the authors consider SEMATECH such an experiment) that are supported by public outcome metrics. In addition to making federal R and D better address public needs, such an approach to policy making could raise the public`s interest in T and S policy. Of course, as in any experiment the results may be measured and if failures aren`t observed, it is likely that policies lack vision and imagination. It is time to abandon the budget driven federal R and D system where performers of federal R and D are treated as constituents, and replace it with a public problem--public outcome driven system where public problems are prioritized and the budget is distributed to agencies according to these priorities.

More Details

A hardware review of electrical contact aging and performance in electromechanical stronglinks

Peebles, Diane

Contacts from the functional switch assembly have been examined for a series of MC2969 stronglinks varying from 9 to 14 years of age. Wear tracks are apparent on the contacts as a result of oxide removal by wiping action as the switch is exercised. Typical contaminants observed on the contacts include C, O, S, Cl, F and Si, all of which vary with position on the contacts. All of the contacts show segregation of Ag into the near-surface region. Measurement of the local contact resistance on the ends of the contacts provide resistance values that are reasonable for this material, but with variation among contacts as a result of changes in the local surface chemistry.

More Details

Battery evaluation methods and results for stationary applications

Butler, Paul C.

Evaluation of flooded lead-acid, Valve Regulated Lead-Acid (VRLA), and advanced batteries is being performed in the power sources testing labs at Sandia National Laboratories (SNL). These independent, objective tests using computer-controlled testers capable of simulating application-specific test regimes provide critical data for the assessment of the status of these technologies. Several different charge/discharge cycling regimes are performed. Constant current and constant power discharge tests are conducted to verify capacity and measure degradation. A utility test is imposed on some units which consists of partial depths of discharge (pulsed constant power) cycles simulating a frequency regulation operating mode, with a periodic complete discharge simulating a spinning reserve test. This test profile was developed and scaled based on operating information from the Puerto Rico Electric Power Authority (PREPA) 20 MW battery energy storage system. Another test conducted at SNL is a photovoltaic battery life cycle test, which is a partial depth of discharge test (constant current) with infrequent complete recharges that simulates the operation of renewable energy systems. This test profile provides renewable system designers with critical battery performance data representative of field conditions. This paper will describe the results of these tests to date, and include analysis and conclusions.

More Details

Recycling readiness of advanced batteries for electric vehicles

Jungst, Rudolph G.

Maximizing the reclamation/recycle of electric-vehicle (EV) batteries is considered to be essential for the successful commercialization of this technology. Since the early 1990s, the US Department of Energy has sponsored the ad hoc advanced battery readiness working group to review this and other possible barriers to the widespread use of EVs, such as battery shipping and in-vehicle safety. Regulation is currently the main force for growth in EV numbers and projections for the states that have zero-emission vehicle (ZEV) programs indicate about 200,000 of these vehicles would be offered to the public in 2003 to meet those requirements. The ad hoc Advanced Battery Readiness Working Group has identified a matrix of battery technologies that could see use in EVs and has been tracking the state of readiness of recycling processes for each of them. Lead-acid, nickel/metal hydride, and lithium-ion are the three EV battery technologies proposed by the major automotive manufacturers affected by ZEV requirements. Recycling approaches for the two advanced battery systems on this list are partly defined, but could be modified to recover more value from end-of-life batteries. The processes being used or planned to treat these batteries are reviewed, as well as those being considered for other longer-term technologies in the battery recycling readiness matrix. Development efforts needed to prepare for recycling the batteries from a much larger EV population than exists today are identified.

More Details

Data quality improvements for FAA

Perry, Richard L.

Effective communication among air safety professionals is only as good as the information being communicated. Data sharing cannot be effective unless the data are relevant to aviation safety problems, and decisions based on faulty data are likely to be invalid. The validity of aviation safety data depends on satisfying two primary characteristics. Data must accurately represent or conform to the real world (conformance), and it must be relevant or useful to addressing the problems at hand (utility). The FAA, in efforts to implement the Safety Performance Analysis System (SPAS), identified significant problems in the quality of the data which SPAS and FAA air safety professionals would use in defining the state of aviation safety in the US. These finding were reinforced by Department of Transportation Inspector General and General Accounting Office investigations into FAA surveillance of air transport operations. Many recent efforts to improve data quality have been centered on technological solutions to the problems. They concentrate on reducing errors in the data (conformance), but they cannot adequately address the relationship of data to need (utility). Sandia National Laboratories, working with the FAA`s Airport and Aircraft Safety Research and Development Division and the Flight Standards Service, has been involved in four programs to assist FAA in addressing their data quality problems. The Sandia approach has been data-driven rather than technology-driven. In other words, the focus has been on first establishing the data requirements by analyzing the FAA`s surveillance and decision-making processes. This process analysis looked at both the data requirements and the methods used to gather the data in order to address both the conformance and utility problems inherent in existing FAA data systems. This paper discusses Sandia`s data quality programs and their potential improvements to the safety analysis processes and surveillance programs of the FAA.

More Details

Lifetime predictions for alumina ceramics used in nuclear weapons stockpile components

Glass, Sarah J.

Ceramic materials are used extensively in non-nuclear components in the weapons stockpile including neutron tubes, firing sets, radar, strong link and weak link assemblies, batteries, and current/voltage stacks. Ceramics also perform critical functions in electronics, passively as insulators and actively as resistors and capacitors. Glass and ceramic seals also provide hermetic electrical feedthroughs in connectors for many weapons components. The primary goal of the ceramic material lifetime prediction program is to provide the enhanced surveillance program with the capability to specify the reliability and lifetimes of glass and ceramic-containing components under conditions typical of the stockpile environment. The authors have studied the reliability and subcritical crack growth (SCG) behavior of 94% alumina (Al{sub 2}O{sub 3}), which is likely the most common ceramic in the stockpile. Measurements have been made on aluminas manufactured by four war reserve qualified vendors (Coors, Wesgo, AlSiMag, and Diamonite). These materials are expected to be representative of typical product obtained from vendors who have supplied alumina for weapons components during the past several decades.

More Details

Aging model for solid lubricants used in weapon stronglinks: tribological performance and hardware review

Dugger, Michael T.

More Details

Independent communication messages: methodology and applications

Cooper, James A.

Information flowing on communication buses is ordinarily ``non-random`` in the sense that data entities are not equally likely and independent. This is because they have relationships to each other and to physical occurrences to which they may be responding. Random data would convey no information or meaning. From a different viewpoint, there can be applications for creating randomness characteristics, and four of these are described in this paper. Two examples derive from cryptology and the other two from safety. One cryptology application described is the generation of random numbers for use as, for example, keys, hash functions, nonces, and seeds. The other is for inter-message ``padding`` to resist traffic analysis by masking when data are being transmitted and when the channel is conveying no information. One of the safety applications described is the ``unique signal`` approach used in modern nuclear weapon electrical safety. The other is the use of unique signals as non-weapon critical-operation control functions. Both of these safety applications require provisions to help assure randomness characteristics in any inadvertently occurring inputs. In order to satisfy these cryptology and safety needs, communication strategies are described that generate or selectively encourage independent (unrelated) symbols or messages.

More Details

Laser assisted non-consumable arc welding process development

Fuerschbach, Phillip W.

The employment of Laser Beam Welding (LBW) for many traditional arc welding applications is often limited by the inability of LBW to compensate for variations in the weld joint gap. This limitation is associated with fluctuations in the energy transfer efficiency along the weld joint. Since coupling of the laser beam to the workpiece is dependent on the maintenance of a stable absorption keyhole, perturbations to the weld pool can lead to decreased energy transfer and resultant weld defects. Because energy transfer in arc welding does not similarly depend on weld pool geometry, it is expected that combining these two processes together will lead to an enhanced fusion welding process that exhibits the advantages of both arc welding and LBW. Laser assisted non-consumable arc welds have been made on thin section aluminum. The welds combine the advantages of arc welding and laser welding, with enhanced penetration and fusion zone size. The use of a pulsed Nd:YAG laser with the combined process appears to be advantageous since this laser is effective in removing the aluminum oxide and thereby allowing operation with the tungsten electrode negative. The arc appears to increase the size of the weld and also to mitigate hot cracking tendencies that are common with the pulsed Nd:YAG laser.

More Details

Aging model for solid lubricants used in weapon stronglinks: Oxidation chemistry and hardware review

Peebles, Diane

More Details

Orthogonal spectra and cross sections: Application to optimization of multi-spectral absorption and fluorescence lidar

Shokair, Isaac R.

This report addresses the problem of selection of lidar parameters, namely wavelengths for absorption lidar and excitation fluorescence pairs for fluorescence lidar, for optimal detection of species. Orthogonal spectra and cross sections are used as mathematical representations which provide a quantitative measure of species distinguishability in mixtures. Using these quantities, a simple expression for the absolute error in calculated species concentration is derived and optimization is accomplished by variation of lidar parameters to minimize this error. It is shown that the optimum number of wavelengths for detection of a species using absorption lidar (excitation fluorescence pairs for fluorescence lidar) is the same as the number of species in the mixture. Each species present in the mixture has its own set of optimum wavelengths. There is usually some overlap in these sets. The optimization method is applied to two examples, one using absorption and the other using fluorescence lidar, for analyzing mixtures of four organic compounds. The effect of atmospheric attenuation is included in the optimization process. Although the number of optimum wavelengths might be small, it is essential to do large numbers of measurements at these wavelengths in order to maximize canceling of statistical errors.

More Details

A multi-objective dynamic programming approach to constrained discrete-time optimal control

Driessen, B.J.; Kwok, K.S.

This work presents a multi-objective differential dynamic programming approach to constrained discrete-time optimal control. In the backward sweep of the dynamic programming in the quadratic sub problem, the sub problem input at a stage or time step is solved for in terms of the sub problem state entering that stage so as to minimize the summed immediate and future cost subject to minimizing the summed immediate and future constraint violations, for all such entering states. The method differs from previous dynamic programming methods, which used penalty methods, in that the constraints of the sub problem, which may include terminal constraints and path constraints, are solved exactly if they are solvable; otherwise, their total violation is minimized. Again, the resulting solution of the sub problem is an input history that minimizes the quadratic cost function subject to being a minimizer of the total constraint violation. The expected quadratic convergence of the proposed algorithm is demonstrated on a numerical example.

More Details

Decentralized fuzzy control of multiple nonholonomic vehicles

Driessen, B.J.; Feddema, J.T.; Kwok, K.S.

This work considers the problem of controlling multiple nonholonomic vehicles so that they converge to a scent source without colliding with each other. Since the control is to be implemented on simple 8-bit microcontrollers, fuzzy control rules are used to simplify a linear quadratic regulator control design. The inputs to the fuzzy controllers for each vehicle are the (noisy) direction to the source, the distance to the closest neighbor vehicle, and the direction to the closest vehicle. These directions are discretized into four values: Forward, Behind, Left, and Right, and the distance into three values: Near, Far, Gone. The values of the control at these discrete values are obtained based on the collision-avoidance repulsive forces and the change of variables that reduces the motion control problem of each nonholonomic vehicle to a nonsingular one with two degrees of freedom, instead of three. A fuzzy inference system is used to obtain control values for inputs between the small number of discrete input values. Simulation results are provided which demonstrate that the fuzzy control law performs well compared to the exact controller. In fact, the fuzzy controller demonstrates improved robustness to noise.

More Details

A system safety approach to the FAA surveillance process

Werner, Paul W.

As commercial air travel grows in terms of the number of passenger miles flown, there is expected to be a corresponding dramatic increase in the absolute number of accidents. This despite an enviable safety record and a very low accident rate. The political environment is such that an increase in the absolute number of accidents is not acceptable, with a stated goal of a factor of five reduction in the aviation fatal accident rate within ten years. The objective of this project is to develop an improved surveillance process that will provide measurements of the current state-of-health and predictions of future state of health of aircraft, operators, facilities, and personnel. Methodologies developed for nuclear weapon safety, in addition to more well known system safety and high-consequence engineering techniques, will be used in this approach.

More Details

Direct-write fabrication of integrated, multilayer ceramic components

Dimos, Duane B.

The need for advanced (electronic) ceramic components with smaller size, greater functionality, and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. For rapid prototyping and small-lot manufacturing, traditional tape casting and screen printing approaches are poorly suited. To address this need, the authors are developing a direct-write approach for fabricating highly integrated, multilayer components using a micropen to deposit slurries in precise patterns. With this technique, components can be constructed layer by layer, simplifying fabrication. It can also be used to produce structures combining several materials in a single layer. The parts are either cofired or sequentially fired, after each layer is deposited. Since differential shrinkage can lead to defects in these multilayer structures, they are characterizing the sintering behavior of individual layers. This technique has been used to fabricate devices such integrated RC filters, multilayer voltage transformers, and other passive components. The direct-write approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way.

More Details

NN-SITE: A remote monitoring testbed facility

Ystesund, Kenneth J.

DOE, Aquila Technologies, LANL and SNL recently launched collaborative efforts to create a Non-Proliferation Network Systems Integration and Test (NN-Site, pronounced N-Site) facility. NN-Site will focus on wide area, local area, and local operating level network connectivity including Internet access. This facility will provide thorough and cost-effective integration, testing and development of information connectivity among diverse operating systems and network topologies prior to full-scale deployment. In concentrating on instrument interconnectivity, tamper indication, and data collection and review, NN-Site will facilitate efforts of equipment providers and system integrators in deploying systems that will meet nuclear non-proliferation and safeguards objectives. The following will discuss the objectives of ongoing remote monitoring efforts, as well as the prevalent policy concerns. An in-depth discussion of the Non-Proliferation Network Systems Integration and Test facility (NN-Site) will illuminate the role that this testbed facility can perform in meeting the objectives of remote monitoring efforts, and its potential contribution in promoting eventual acceptance of remote monitoring systems in facilities worldwide.

More Details

US Department of Energy (DOE)/Gosatomnadzor (GAN) of Russia project at the Petersburg Nuclear Physics Institute (PNPI)

Hauser, Gene C.

This paper presents a summary of work accomplished within the scope of the DOE-Gosatomnadzor (GAN) Agreement to reduce vulnerability to theft of direct-use nuclear materials in Russia. The DOE-GAN agreement concerns the Russian Academy of Science B.P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), located 45 kilometers from St. Petersburg. The PNPI operates facilities to research basic nuclear physics. Current world conditions require particular attention to the issue of Material Protection, Control, and Accounting (MPC&A) of nuclear materials. The long-term plan to increase security at the facility is outlined, including training, physical protection upgrades, and material control and accountability. 4 figs.

More Details

International remote monitoring project Argentina Nuclear Power Station Spent Fuel Transfer Remote Monitoring System

Schneider, Sigfried L.

The Autoridad Regulataria Nuclear (ARN) and the United States Department of Energy (DOE) are cooperating on the development of a Remote Monitoring System for nuclear nonproliferation efforts. A Remote Monitoring System for spent fuel transfer will be installed at the Argentina Nuclear Power Station in Embalse, Argentina. The system has been designed by Sandia National Laboratories (SNL), with Los Alamos National Laboratory (LANL) and Oak Ridge National Laboratory (ORNL) providing gamma and neutron sensors. This project will test and evaluate the fundamental design and implementation of the Remote Monitoring System in its application to regional and international safeguards efficiency. This paper provides a description of the monitoring system and its functions. The Remote Monitoring System consists of gamma and neutron radiation sensors, RF systems, and video systems integrated into a coherent functioning whole. All sensor data communicate over an Echelon LonWorks Network to a single data logger. The Neumann DCM 14 video module is integrated into the Remote Monitoring System. All sensor and image data are stored on a Data Acquisition System (DAS) and archived and reviewed on a Data and Image Review Station (DIRS). Conventional phone lines are used as the telecommunications link to transmit on-site collected data and images to remote locations. The data and images are authenticated before transmission. Data review stations will be installed at ARN in Buenos Aires, Argentina, ABACC in Rio De Janeiro, IAEA Headquarters in Vienna, and Sandia National Laboratories in Albuquerque, New Mexico. 2 refs., 2 figs.

More Details

Rapid deployment intrusion detection system

Graham, Robert H.

A rapidly deployable security system is one that provides intrusion detection, assessment, communications, and annunciation capabilities; is easy to install and configure; can be rapidly deployed, and is reusable. A rapidly deployable intrusion detection system (RADIDS) has many potential applications within the DOE Complex: back-up protection for failed zones in a perimeter intrusion detection and assessment system, intrusion detection and assessment capabilities in temporary locations, protection of assets during Complex reconfiguration, and protection in hazardous locations, protection of assets during Complex reconfiguration, and protection in hazardous locations. Many DOE user-need documents have indicated an interest in a rapidly deployable intrusion detection system. The purpose of the RADIDS project is to design, develop, and implement such a system. 2 figs.

More Details

Beloyarsk Nuclear Power Plant

Soo Hoo, Mark S.

The Beloyarsk Nuclear Power Plant (BNPP) is located in Zarechny, approximately 60 km east of Ekaterinberg along the Trans-Siberian Highway. Zarechny, a small city of approximately 30,000 residents, was built to support BNPP operations. It is a closed city to unescorted visitors. Residents must show identification for entry. BNPP is one of the first and oldest commercial nuclear power plants in Russia and began operations in 1964. As for most nuclear power plants in the Russian Federation, BNPP is operated by Rosenergoatom, which is subordinated to the Ministry of Atomic Energy of the Russian Federation (Minatom). BNPP is the site of three nuclear reactors, Units 1, 2, and 3. Units 1 and 2, which have been shut-down and defueled, were graphite moderated reactors. The units were shut-down in 1981 and 1989. Unit 3, a BN-600 reactor, is a 600 MW(electric) sodium-cooled fast breeder reactor. Unit 3 went on-line in April 1980 and produces electric power which is fed into a distribution grid and thermal power which provides heat to Zarechny. The paper also discusses the SF NIKIET, the Sverdiovsk Branch of NIKIET, Moscow, which is the research and development branch of the parent NIKEIT and is primarily a design institute responsible for reactor design. Central to its operations is a 15 megawatt IVV research reactor. The paper discusses general security and fissile material control and accountability at these two facilities.

More Details

Developing indigenous safeguards capabilities within the MPC&A program: A transition from near-term upgrades to long-term sustainability

Soo Hoo, Mark S.

Approximately five years ago, the United States and countries of & Former Soviet Union (FSU) started the Cooperative Threat Reduction program. The program`s purpose was to accelerate reduction of the risk of nuclear proliferation, including such threats as theft, diversion, and unauthorized possession of nuclear materials. This goal would be accomplished through near-term upgrades to strengthen the nuclear material protection, control, and accounting systems within the FSU countries. In addition to this near-term goal, a long-term goal of the U.S. Department of Energy`s (DOE) Material Protection, Control, and Accounting (MPC&A) program is to promote a new safeguards culture and to support the establishment of a sustaining MPC&A infrastructure in the FSU. This long-term goal is vital to assuring that the near-term upgrades remain effective for safeguarding nuclear material as these countries experience political and social changes. The MPC&A program is managed by DOE`s Russia/Newly Independent States (NIS) Nuclear Materials Security Task Force. A coordinated effort is underway to promote and to help establish a new safeguards culture and a sustaining infrastructure. Elements being implemented at both the national and site levels include system operational performance evaluations, development of MPC&A training, operational procedures, national MPC&A regulations, and adaptation of modern MPC&A methodologies to suit the conditions in the FSU countries. This paper identifies current efforts in several countries that are undergoing transition from near-term upgrades to sustainable MPC&A systems.

More Details

Modular Integrated Monitoring System (MIMS) - architecture and implementation

Funkhouser, D.R.

The MIMS is being developed as a cost-effective means of performing safeguards in unattended remote monitoring applications. Based on industry standards and an open systems approach, the MIMS architecture supports both data acquisition and data review subsystems. Data includes images as well as discrete and analog sensor outputs. The MIMS uses an Echelon LonWorks network as a standard means and method of data acquisition from the sensor. A common data base not only stores sensor and image data but also provides a structure by which dynamic changes to the sensor system can be reflected in the data acquisition and data review subsystems without affecting the execution software. The architecture includes standards for wide area communications between data acquisition systems and data review systems. Data authentication is provided as an integral part of the design. The MIMS software implements this architecture by combining the use of commercial applications with a set of custom 16 and 32 bit Microsoft Windows applications which are run under Windows NT and Windows 95 operating systems.

More Details

Technical results of Y-12/IAEA field trial of remote monitoring system

Corbell, Bobby H.

A Remote Monitoring System (RMS) field trial has been conducted with the International Atomic Energy Agency (IAEA) on highly enriched uranium materials in a vault at the Oak Ridge Y-12 Plant. The RMS included a variety of Sandia, Oak Ridge, and Aquila sensor technologies which provide containment seals, video monitoring, radiation asset measurements, and container identification data to the on-site DAS (Data Acquisition System) by way of radio-frequency and Echelon LonWorks networks. The accumulated safeguards information was transmitted to the IAEA via satellite (COMSAT/RSI) and international telephone lines. The technologies tested in the remote monitoring environment are the RadCouple, RadSiP, and SmartShelf sensors from the ORSENS (Oak Ridge Sensors for Enhancing Nuclear Safeguards) technologies; the AIMS (Authenticated Item Monitoring System) motion sensor (AMS), AIMS fiber-optic seal (AFOS), ICAM (Image Compression and Authentication Module) video surveillance system, DAS (Data Acquisition System), and DIRS (Data and Image Review Station) from Sandia; and the AssetLAN identification tag, VACOSS-S seal, and Gemini digital surveillance system from Aquila. The field trial was conducted from October 1996 through May 1997. Tests were conducted during the monthly IAEA Interim Inventory Verification (IIV) inspections for evaluation of the equipment. Experience gained through the field trials will allow the technologies to be applied to various monitoring scenarios.

More Details

Pulsed power performance of PBFA Z

Spielman, Rick

PBFA Z is a new 60-TW/5-MJ electrical driver located at Sandia National Laboratories. The authors use PBFA Z to drive z pinches. The pulsed power design of PBFA Z is based on conventional single-pulse Marx generator, water-line pulse-forming technology used on the earlier Saturn and PBFA II accelerators. PBFA Z stores 11.4 MJ in its 36 Marx generators, couples 5 MJ in a 60-TW/105-ns pulse to the output water transmission lines, and delivers 3.0 MJ and 50 TW of electrical energy to the z-pinch load. Depending on the initial load inductance and the implosion time, the authors attain peak currents of 16-20 MA with a rise time of 105 ns. Current is fed to the z-pinch load through self magnetically-insulated transmission lines (MITLs). Peak electric fields in the MITLs exceed 2 MV/cm. The current from the four independent conical-disk MITLs is combined together in a double post-hole vacuum convolute with an efficiency greater than 95%. The authors achieved x-ray powers of 200 TW and x-ray energies of 1.9 MJ from tungsten wire-array z-pinch loads.

More Details

Seismic monitoring of the Yucca Mountain facility

Garbin, H.D.

Questions have arisen regarding the applicability of seismic sensors to detect mining (re-entry) with a tunnel boring machine (TBM). Unlike cut and blast techniques of mining which produce impulsive seismic signals, the TBM produces seismic signals which are of long duration. (There are well established techniques available for detecting and locating the sources of the impulsive signals.) The Yucca Mountain repository offered an opportunity to perform field evaluations of the capabilities of seismic sensors because during much of 1996, mining there was progressing with the use of a TBM. During the mining of the repository`s southern branch, an effort was designed to evaluate whether the TBM could be detected, identified and located using seismic sensors. Three data acquisition stations were established in the Yucca Mountain area to monitor the TBM activity. A ratio of short term average to long term average algorithm was developed for use in signal detection based on the characteristics shown in the time series. For location of the source of detected signals, FK analysis was used on the array data to estimate back azimuths. The back azimuth from the 3 component system was estimated from the horizontal components. Unique features in the timing of the seismic signal were used to identify the source as the TBM.

More Details

US remote monitoring operational experience

Dupree, S.A.

Under international partnerships and bilateral agreements with the U.S. Department of Energy, Sandia National Laboratories, other national laboratories, and international partner organizations have emplaced remote monitoring systems in nuclear facilities and laboratories in various parts of the world for the purpose of conducting field trials of remote monitoring. The purpose of the present report is to review the results from these field trials and draw general conclusions regarding the trials. Many thousands of hours of sensor and system operation have been logged, and data have been retrieved from many locations. In virtually all cases the system components have functioned as intended and data have been successfully collected and transmitted for review. Comparisons between front-end-triggered video and time-lapse video have shown that the triggered record has captured all relevant monitored operations at the various nuclear facilities included in the field trials. We believe the utility and functional reliability of remote monitoring for international safeguards has been shown. However, it should be kept in mind that openness and transparency, including some form of short-notice inspections, are likely to be prerequisites to the safeguards implementation of remote monitoring in any State.

More Details

Verification of operating software for cooperative monitoring applications

Tolk, Keith M.

Monitoring agencies often use computer based equipment to control instruments and to collect data at sites that are being monitored under international safeguards or other cooperative monitoring agreements. In order for this data to be used as an independent verification of data supplied by the host at the facility, the software used must be trusted by the monitoring agency. The monitoring party must be sure that the software has not be altered to give results that could lead to erroneous conclusions about nuclear materials inventories or other operating conditions at the site. The host might also want to verify that the software being used is the software that has been previously inspected in order to be assured that only data that is allowed under the agreement is being collected. A description of a method to provide this verification using keyed has functions and how the proposed method overcomes possible vulnerabilities in methods currently in use such as loading the software from trusted disks is presented. The use of public key data authentication for this purpose is also discussed.

More Details

American-Russian remote monitoring transparency program accomplishments during the past year

Martinez, R.L.; Croessmann, D.; Sazhnev, M.

During the past year, Sandia National Laboratories and Kurchatov Institute have continued collaborations under the Remote Monitoring Transparency Program (RMTP). The emphasis has been on promoting the concept of remote monitoring within the Russian Federation along with some hands-on technical training of Kurchatov personnel. The program has progressed in the direction to include the participation of Kurchatov personnel in the promotion, design, and implementation of Remote Monitoring Systems (RMS). The program has evolved from a system that was completely designed and implemented by Sandia (system that is currently installed at the Kurchatov gas plant) to a functional demonstration RMS that was designed and implemented by Kurchatov personnel with guidance and assistance from Sandia. This paper will present a brief history on the remote monitoring collaborations between Sandia and Kurchatov with an emphasis on the activities/accomplishments of the past year. The major accomplishments include a Remote Monitoring Workshop in Moscow organized by Kurchatov; integration of Russian sensors into the existing gas plant system; feedback from Kurchatov on the operation of the existing system; a training course conducted by Echelon Corporation in Albuquerque for Kurchatov and Sandia developers on the sensor network technology currently utilized in remote monitoring applications; an International Remote Monitoring Project (IRMP) technical workshop in Albuquerque organized by Sandia on software tools and development that included the participation of Kurchatov personnel; the development of a functional lab-based RMS by Kurchatov utilizing current technology; and the development of a remote monitoring Web homepage at Kurchatov.

More Details

US - Russian government-to-government MPC&A upgrades at the institute of theoretical and experimental physics

Soo Hoo, Mark S.

Materials Protection, Control, and Accounting (MPC&A) upgrades have begun at the Institute of Theoretical and Experimental Physics (ITEP), a site that has significant quantities of direct-use nuclear materials. Cooperative work was initiated at this Moscow facility as a part of the U.S.-Russian Government-to-Government program to upgrade MPC&A systems. An initial site visit and assessment was conducted in September 1996 to establish communication between ITEP and the U.S. Department of Energy (DOE) and the participating U.S. national laboratories. Subsequently, the parties reached an agreement to develop two master plans for MPC&A upgrades. Los Alamos National Laboratory (LANL) and Oak Ridge National Laboratory (ORNL) would assist in developing a plan for Material Control and Accounting (MC&A) upgrades, and Sandia National Laboratories (SNL) would assist in developing a plan for Physical Protection (PP) upgrades. The MC&A plan included MC&A training, a mass measurement program, nondestructive assay instrumentation, item identification (bar coding), physical inventory taking, and a nuclear materials accounting system. The PP plan included basic PP system design training, Central Alarm Station (CAS) location and equipment upgrades, site and critical-building access control system, intrusion detection alarm assessment, and guard force communications.

More Details

Cooperative nonproliferation activities

Ystesund, Kenneth J.

Sandia National Laboratories (SNL) under DOE sponsorship is engaged in nuclear nonproliferation activities with the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. From 1995 to the present SNL and PNC have been participating in a cooperative project to implement and assess the use of remote monitoring to achieve nuclear nonproliferation objectives. Implementation of remote monitoring at the PNC Joyo facility took place during 1996 and continues to date. An International Fellowship began in the Fall of 1995 and has complemented the nonproliferation study. Plans are underway to extend the Fellowship and to upgrade the existing Remote Monitoring System to include another area at the Joyo facility. SNL and PNC are currently exploring the possibility of exchanging experts with the objective of promoting regional confidence building in Northeast Asia, possibly using some of the same remote monitoring technologies. This paper will provide an overview of these activities and report on the status of cooperative nonproliferation activities being conducted by PNC and SNL.

More Details

Barriers to creating a secure MPI

Brightwell, Ronald B.

This paper explores some of the many issues in developing security enhanced MPI for embedded real-time systems supporting the Department of Defense`s Multi-level Security policy (DoD MLS) are presented along with the preliminary design for such an MPI variant. In addition some of the many issues that need to be addressed in creating security enhanced versions of MPI for other domains are discussed. 19 refs.

More Details

Summary of collaborative photovoltaic industry work to proactively improve codes and standards for photovoltaic power system applications

Bower, Ward

Several important milestones in codes and standards pertaining to the design, installation and operation of photovoltaic (PV) systems have recently been completed with collaboration of participants from all sectors of the PV industry, utilities and the US Department of Energy`s National Photovoltaic Program. Codes and standards that have been proposed, written or modified include changes and additions for the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}), standards for fire and personnel safety, system testing, component qualification, and utility interconnect. Project authorization requests with the Institute of Electrical and Electronic Engineers (IEEE) have resulted in standards for listing PV modules and balance-of-system components. Industry collaboration with Underwriter Laboratories, Inc. (UL), with the American Society for Testing and Materials (ASTM), and through critical input and review for international standards with the International Electrotechnical Commission (IEC) have resulted in domestic and international standards for PV. Work related to the codes and standards activities through the International Energy Agency (IEA) is also being supported by the PV industry and the US DOE. This paper will concentrate on and summarize the important new NEC proposals for PV systems and will also describe and show the bonds between the activities in other standards writing activities. The paper will also provide an analysis of changes and resulting impacts of selected proposed NEC changes on PV designs, installations and performance.

More Details

Augmented Computer Exercise for Inspection Training (ACE-IT) - an interactive training tool for {open_quotes}challenge inspections{close_quotes} under the chemical weapons convention

Dobranich, Pauline R.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams and the Inspected Parties. Current training techniques include lectures, table-top inspections, and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. Under the Chemical Weapons Convention (CWC) challenge inspections are short-notice inspections that may occur anywhere, anytime, and with no right of refusal. The time interval between notice of intent to inspect a facility and the arrival of inspectors at the facility may be as short as 72 hours. Therefore, advance training is important. ACE-IT is used for training both the Inspection Team (inspector) and the Inspected Party (host) to conduct a hypothetical challenge inspection under the CWC. An exercise moderator controls the exercise. The training covers all of the events in the challenge inspection regime, from initial notification of an inspection through post-inspection activities. But the primary emphasis of the training tool is on conducting the inspection itself, and in particular, the concept of managed access. Managed access is used to assure the inspectors that the facility is in compliance with the CWC, while protecting sensitive information that is not related to the CWC.

More Details

Final disposal room structural response calculations

Butcher, Barry M.

Finite element calculations have been performed to determine the structural response of waste-filled disposal rooms at the WIPP for a period of 10,000 years after emplacement of the waste. The calculations were performed to generate the porosity surface data for the final set of compliance calculations. The most recent reference data for the stratigraphy, waste characterization, gas generation potential, and nonlinear material response have been brought together for this final set of calculations.

More Details

Containment and surveillance -- A principle IAEA safeguards measure

Drayer, Darryl D.

In October 1954, the Statue of the IAEA (International Atomic Energy Agency) had been signed by 70 nations. The Agency was established in 1957, and at the end of its first year of operation 130 professionals were employed in all departments. By the end of 1990, the number of professionals in the Safeguards Department had increased to over 270, over 200 of whom are designated inspectors. One of the unique features of the IAEA which directly interfaces with Member States is that of on-site inspections by international officials of the IAEA. This growth cycle, spanning some 40 years, has produced a variety of interesting subjects (legal, technical, political, etc.) for recollection, discussion, and study. This paper addresses the specific subject of technical means to maintain continuity of knowledge between inspection intervals--classically referred to as Containment and Surveillance.

More Details

Potential cooperative measures on nuclear issues in Asia

Olsen, John N.

Cooperation on nuclear issues is receiving increased attention in Asia. In Northeast Asia, where the nuclear industry is well-developed, cooperation in the back end of the nuclear fuel cycle could help deal with issues such as disposition of spent fuel and long term storage options. In Southeast Asia, where countries are just beginning to introduce nuclear energy, cooperation would be useful in developing standards for the nuclear industry. Throughout Asia, nuclear research and power activities can raise concerns about safety, environmental pollution and proliferation. The sharing of relevant information, i.e. cooperative monitoring, will be essential to addressing these issues. In fact, a number of regional interactions on nuclear issues are already occurring. These range from training exchanges sponsored by the more advanced states to participation in environmental monitoring of the East Sea (Sea of Japan). Several states are considering sharing information from their nuclear facilities; some exchanges of radiation data are already in place. The KEDO reactor project will involve close working relations between the nuclear experts of South Korea, North Korea, Japan, and the US. Areas for further regional cooperation are discussed.

More Details

Modeling an optical micromachine probe

Mittas, Anthony

Silicon micromachines are fabricated using Surface Micro-Machining (SMM) techniques. Silicon micromachines include engines that consist of orthogonally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small a 50-{micro}m in diameter and can be driven at rotation rates exceeding 300,000-rpm. Measuring and analyzing microengine performance is basic to micromachine development and system applications. Optical techniques offer the potential for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. The authors describe the modeling of an optical probe developed at Sandia National Laboratories. Experimental data will be compared with output from the model.

More Details

Beyond pretty pictures: Quantifying porous media properties and transport processes using transmission and emission CT

Lucero, Daniel A.

While gaining increasing interest, the use of Computerized Tomography (CT) in porous media studies has been limited by the availability of quantitative methods of analysis. Three methods are presented for the analysis of CT data and applied to images obtained from gamma transmission and gamma emission systems. The first utilizes measurement statistics and image histograms to provide exact estimates of multiple component volume contents. An improved thresholding technique in the second method allows an identification of individual voxel composition. The threshold utilizes error statistics to eliminate the arbitrary nature of current methods. Emission tomography images of solute transport are shown in the third procedure to provide in-situ measures of transport in fractured media. Application of each method is demonstrated on samples of the Culebra Dolomite of the Rustler Formation, New Mexico. Dolomite cores were collected by horizontal drilling at a depth of 218 m in the air intake shaft of the Waste Isolation Pilot Plant located near Carlsbad, New Mexico.

More Details

VSHOT measurement uncertainty and sensitivity study

Jones, Scott A.

The Video Scanning Hartmann Optical Tester (VSHOT) is a slope-measuring tool for large, imprecise reflectors. It is a laser ray trace device developed to measure the optical quality of point-focus solar concentrating mirrors. A unique tool was needed because of the diverse geometry and very large size of solar concentrators, plus their large optical errors. To study the accuracy of VSHOT as well as its sensitivity to changes in test setup variables, a series of experiments were performed with a very precise, astronomical-grade mirror. The slope errors of the reference mirror were much smaller than the resolution of the VSHOT, so that any measured slope errors were caused by the instrument itself rather than the mirror. The VSHOT exceeded its accuracy goals by achieving about {+-}0.5% (68% confidence) error in the determination of focal length and {+-} 0.1 mrad (68% confidence) error in the determination of RMS slope error. Displacement of the test mirror from the optical axis caused the largest source of measured errors.

More Details

Virtual Tower

Wayne, R.A.

The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems.

More Details

An introduction to the architectural surety program

Matalucci, R.V.

This paper provides a summary introduction to the nationally emerging area of Architectural and Infrastructure Surety that is under development at Sandia National Laboratories. This program area, addressing technology requirements at the national level, includes four major elements: education, research, development, and application. It involves a risk management approach to solving problems of the as-built environment through the application of security, safety, and reliability principles developed in the nuclear weapons programs of the Department of Energy. The changing responsibilities of engineering design professionals is addressed in light of the increased public awareness of structural and facility systems vulnerabilities to malevolent, normal, and abnormal environment threats. A brief discussion is presented of the education and technology outreach programs initiated through an infrastructure surety graduate Civil Engineering Department course taught at the University of New Mexico and through the architectural surety workshops and conferences already held and planned for the future. A summary description is also presented of selected technologies with strong potential for application to specific national architectural and infrastructure surety concerns. These technologies include super-computational modeling and structural simulations, window glass fragmentation modeling, risk management procedures, instrumentation and health monitoring systems, and three-dimensional CAD virtual reality visualization techniques.

More Details

Application of spatial and angular domain based parallelism to a discrete ordinates formulation with unstructured spatial discretization

Burns, Shawn P.

A parallel discrete ordinate formulation employing a general, unstructured finite element spatial discretization is presented for steady, gray, nonscattering radiative heat transport within a participating medium. The formulation is based on the first order form of the boltzmann transport equation and allows for any combination of spatial and angular domain based parallelism. The formulation is tested on a massively parallel, distributed memory architecture using a standard three-dimensional benchmark calculation. The results show that the formulation presented provides better parallel performance and accuracy than the author`s previously published work. The ultimate objective of both the current and previous efforts is to develop a computationally efficient radiative transport model for use in large scale numerical fire simulations.

More Details

Risk management for buildings -- Has the time come?

Berry, Dennis L.

There are both incentives and challenges for applying formal risk management processes to buildings and other structures, including bridges, highways, dams, stadiums, shopping centers, and private dwellings. Based on an assessment of several issues, the authors conclude that for certain types of buildings and structures the time has come for the use of a formal risk-management approach, including probabilistic risk assessment methods, to help identify dominant risks to public health, safety, and security and to help manage these risks in a cost-effective manner.

More Details

A thin-foil Faraday collector as a radiation-hard, high fluence charged particle spectrometer

Barbour, J.C.

The authors have developed a radiation-hard, charged particle spectrometer, consisting of thin parallel conducting foils as current collectors. Prototype detectors have been tested in accelerator bombardments and at the fusion plasma facilities TFTR and JET. In the case of the accelerator bombardments, a detector consisting of 6 Al foils, each of thickness about 6 {micro}m, demonstrated an energy resolution of about 7% for 7 MeV alpha particles. The prototype tested immediately outside TFTR demonstrated the expected insensitivity to moderately high levels of fast neutrons and hard gamma rays. The prototype tested inside JET similarly indicated operational capability at elevated temperatures as a lost alpha particle detector for d-t tokamak fusion plasmas. The robustness and moderately good energy resolution of these detectors should permit the application to tasks such as the first wall measurement of lost alpha particles from tokamak fusion plasmas, the real time measurement of light ion fission fragments from fission reactor experiments and the in-beam measurement of accelerator beam energies as a control diagnostic.

More Details

Contents and structure of the SME digital signature buffer

Tarman, Thomas D.

This contribution proposes additional text for Section 7.1.5.5 of [1] which defines the contents of the digital signature buffer for each relevant flow in the Two-Way and Three-Way Security Message Exchange Protocols. This is clearly an interoperability issue because these signature buffers must be constructed identically at the sender (signature generator) and receiver (signature validator) in order for the protocols to proceed correctly. Sections 2 and 3 of this contribution are intended to be placed in Section 7.1.5.5 of [1]. In addition, text is proposed in Motion 2 of Section 4 of this contribution which clarifies the scope of encryption of the Confidential Section, which is defined in Section 7.1.4 of [1].

More Details

An information model based weld schedule database

Kleban, Stephen

As part of a computerized system (SmartWeld) developed at Sandia National Laboratories to facilitate agile manufacturing of welded assemblies, a weld schedule database (WSDB) was also developed. SmartWeld`s overall goals are to shorten the design-to-product time frame and to promote right-the-first-time weldment design and manufacture by providing welding process selection guidance to component designers. The associated WSDB evolved into a substantial subproject by itself. At first, it was thought that the database would store perhaps 50 parameters about a weld schedule. This was a woeful underestimate: the current WSDB has over 500 parameters defined in 73 tables. This includes data bout the weld, the piece parts involved, the piece part geometry, and great detail about the schedule and intervals involved in performing the weld. This complex database was built using information modeling techniques. Information modeling is a process that creates a model of objects and their roles for a given domain (i.e. welding). The Natural-Language Information Analysis methodology (NIAM) technique was used, which is characterized by: (1) elementary facts being stated in natural language by the welding expert, (2) determinism (the resulting model is provably repeatable, i.e. it gives the same answer every time), and (3) extensibility (the model can be added to without changing existing structure). The information model produced a highly normalized relational schema that was translated to Oracle{trademark} Relational Database Management Systems for implementation.

More Details

Equilibrium characteristics of tartrate and EDTA-based electroless copper deposition baths

Chen, Ken S.

Electroless deposition of copper is being used for a variety of applications, one of them being the development of seed metallic layers on non-metals, which are widely used in electronic circuitry. Solution equilibrium characteristics of two electroless copper baths containing EDTA and tartrate as the complexing agents were studied as functions of pH, chelating agent and metal ion concentrations. Equilibrium diagrams were constructed for both cu-tartrate and Cu-EDTA systems. It was determined that copper is chiefly complexed as Cu(OH){sub 2}L{sub 2}{sup {minus}4} in the tartrate bath, and as CuA{sup {minus}2} in the EDTA bath, where L and A are the complexing tartrate and EDTA ligands, respectively. The operating ranges for electroless copper deposition were identified for both baths. Dependence of Cu(OH){sub 2} precipitation on the pH and species concentrations was also studied for these systems.

More Details

A plasma process monitor/control system

Stevenson, Joel O.

Sandia National Laboratories has developed a system to monitor plasma processes for control of industrial applications. The system is designed to act as a fully automated, sand-alone process monitor during printed wiring board and semiconductor production runs. The monitor routinely performs data collection, analysis, process identification, and error detection/correction without the need for human intervention. The monitor can also be used in research mode to allow process engineers to gather additional information about plasma processes. The plasma monitor can perform real-time control of support systems known to influence plasma behavior. The monitor can also signal personnel to modify plasma parameters when the system is operating outside of desired specifications and requires human assistance. A notification protocol can be selected for conditions detected in the plasma process. The Plasma Process Monitor/Control System consists of a computer running software developed by Sandia National Laboratories, a commercially available spectrophotometer equipped with a charge-coupled device camera, an input/output device, and a fiber optic cable.

More Details

Architectural design for reliability

Cranwell, Robert M.

Design-for-reliability concepts can be applied to the products of the construction industry, which includes buildings, bridges, transportation systems, dams, and other structures. The application of a systems approach to designing in reliability emphasizes the importance of incorporating uncertainty in the analyses, the benefits of optimization analyses, and the importance of integrating reliability, safety, and security. 4 refs., 3 figs.

More Details

On angularly perturbed Laplace equations in the unit ball of IR{sup n+2} and their distributional boundary values

Massopust, P.R.

All solutions of an in its angular coordinates continuously perturbed Laplace-Beltrami equation in the open unit ball IB{sup n+2} {contained_in} IR{sup n+2}, n {ge} 1, are characterized. Moreover, it is shown that such pertubations yield distributional boundary values which are different from, but algebraically and topologically equivalent to, the hyperfunctions of Lions & Magenes. This is different from the case of radially perturbed Laplace-Beltrami operators (cf. [7]) where one has stability of distributional boundary values under such perturbations.

More Details

Activity-based costing of security services for a Department of Energy nuclear site

Snell, Mark K.

Department of Energy (DOE) nuclear facilities are being encouraged to reduce costs but the accounting data typically in use by the financial organizations at these laboratories cannot easily be used to determine which security activities offer the best reduction in cost. For example, labor costs have historically been aggregated over various activities, making it difficult to determine the true costs of performing each activity. To illustrate how this problem can be solved, a study was performed applying activity-based costing (ABC) to a hypothetical DOE facility. ABC is a type of cost-accounting developed expressly to determine truer costs of company activities. The hypothetical facility was defined to have features similar to those found across the DOE nuclear complex. ABC traced costs for three major security functions - Protective Force Operations, Material Control and Accountability, and Technical Security - to various activities. Once these costs had been allocated, we compared the cost of three fictitious upgrades: (1) an improvement in training or weapons that allows the protective force to have better capabilities instead of adding more response forces; (2) a change in the frequency of inventories; and (3) a reduction in the annual frequencies of perimeter sensor tests.

More Details

Evaluation of a prototype infrasound system

Breding, D.

Under Department of Energy sponsorship, Sandia National Laboratories and Los Alamos National Laboratory cooperated to develop a prototype infrasonic array, with associated documentation, that could be used as part of the International Monitoring System. The United States Government or foreign countries could procure commercially available systems based on this prototype to fulfill their Comprehensive Test Ban Treaty (CTBT) obligations. The prototype is a four-element array in a triangular layout as recommended in CD/NTB/WP.224 with an element at each corner and one in the center. The prototype test configuration utilize an array spacing of 1 km. The prototype infrasound system has the following objectives: (1) Provide a prototype that reliably acquires and transmits near real-time infrasonic data to facilitate the rapid location and identification of atmospheric events. (2) Provide documentation that could be used by the United States and foreign countries to procure infrasound systems commercially to fulfill their CTBT responsibilities. Infrasonic monitoring is an effective, low cost technology for detecting atmospheric explosions. The low frequency components of explosion signals propagate to long ranges (few thousand kilometers) where they can be detected with an array of sensors. Los Alamos National Laboratory`s expertise in infrasound systems and phenomenology when combined with Sandia`s expertise in providing verification quality system for treaty monitoring make an excellent team to provide the prototype infrasound sensor system. By September 1997, the prototype infrasound system will have been procured, integrated, evaluated and documented. Final documentation will include a system requirements document, an evaluation report and a hardware design document. The hardware design document will describe the various hardware components used in the infrasound prototype and their interrelationships.

More Details

Oxidation in HVOF-sprayed steel

Smith, Mark F.

It is widely held that most of the oxidation in thermally sprayed coatings occurs on the surface of the droplet after it has flattened. The evidence in this paper suggests that, for the conditions studied here, oxidation of the top surface of flattened droplets is not the dominant oxidation mechanism. In this study, a mild steel wire (AISI 1025) was sprayed using a high-velocity oxy-fuel (HVOF) torch onto copper and aluminum substrates. Ion milling and Auger spectroscopy were used to examine the distribution of oxides within individual splats. Conventional metallographic analysis was also used to study oxide distributions within coatings that were sprayed under the same conditions. An analytical model for oxidation of the exposed surface of a splat is presented. Based on literature data, the model assumes that diffusion of iron through a solid FeO layer is the rate limiting factor in forming the oxide on the top surface of a splat. An FeO layer only a few thousandths of a micron thick is predicted to form on the splat surface as it cools. However, the experimental evidence shows that the oxide layers are typically 100x thicker than the predicted value. These thick, oxide layers are not always observed on the top surface of a splat. Indeed, in some instances the oxide layer is on the bottom, and the metal is on the top. The observed oxide distributions are more consistently explained if most of the oxide formed before the droplets impact the substrate.

More Details

Travel-time correction surface generation for the DOE Knowledge Base

Hipp, James R.

The DOE Knowledge Base data storage and access model consists of three parts: raw data processing, intermediate surface generation, and final output surface interpolation. The paper concentrates on the second step, surface generation, specifically applied to travel-time correction data. The surface generation for the intermediate step is accomplished using a modified kriging solution that provides robust error estimates for each for each interpolated point and satisfies many important physical requirements including differing quality data points, user-definable range of influence for each point, blend to background values for both interpolated values and error estimates beyond the ranges, and the ability to account for the effects of geologic region boundaries. These requirements are outlined and discussed and are linked to requirements specified for the final output model in the DOE Knowledge Base. Future work will focus on testing the entire Knowledge Base model using the regional calibration data sets which are being gathered by researchers at Los Alamos and Lawrence Livermore National Laboratories.

More Details

Visualization tools for comprehensive test ban treaty research

Edwards, T.L.

This paper focuses on tools used in Data Visualization efforts at Sandia National Laboratories under the Department of Energy CTBT R&D program. These tools provide interactive techniques for the examination and interpretation of scientific data, and can be used for many types of CTBT research and development projects. We will discuss the benefits and drawbacks of using the tools to display and analyze CTBT scientific data. While the tools may be used for everyday applications, our discussion will focus on the use of these tools for visualization of data used in research and verification of new theories. Our examples focus on uses with seismic data, but the tools may also be used for other types of data sets. 5 refs., 6 figs., 1 tab.

More Details

The software engineering journey: From a naieve past into a responsible future

Fitzpatrick-Fletcher, Sharon K.

All engineering fields experience growth, from early trial & error approaches, to disciplined approaches based on fundamental understanding. The field of software engineering is making the long and arduous journey, accomplished by evolution of thinking in many dimensions. This paper takes the reader along a trio of simultaneous evolutionary paths. First, the reader experiences evolution from a zero-risk mindset to a managed-risk mindset. Along this path, the reader observes three generations of security risk management and their implications for software system assurance. Next is a growth path from separate surety disciplines to an integrated systems surety approach. On the way, the reader visits safety, security, and dependability disciplines and peers into a future vision which coalesces them. The third and final evolutionary path explored here transitions the software engineering field from best practices to fundamental understanding. Along this road, the reader observes a framework for developing a {open_quotes}science behind the engineering{close_quotes}, and methodologies for software surety analysis.

More Details

A summary of the GPS system performance for STARS Mission 3

Creel, E.E.

This paper describes the performance of the GPS system on the most recent flight of the STARS missile, STARS Mission 3 (M3). This mission was conducted under the Ballistic Missile Defense Organization`s (BMDO`s) Consolidated Targets Program. The United States Army Space and Strategic Defense Command (USASSDC) is the executing agent for this mission and the Department of Energy`s (DOE`s) Sandia National Laboratories (SNL) is the vehicle developer and integrator. The M3 flight, dually designated as the MSX Dedicated Targets II (MDT-II) mission occurred on August 31, 1996. This mission was conducted for the specific purpose of providing targets for viewing by the MSX satellite. STARS M3 was the first STARS flight to use GPS-derived data for missile guidance, and proved to be instrumental in the procurement of a wealth of experimental data which is still undergoing analysis by numerous scientific agencies within the BMDO complex. GPS accuracy was required for this mission because of the prescribed targeting requirements for the MDT-II payload deliveries with respect to the MSX satellite flight path. During the flight test real time GPS-derived state vector data was also used to generate pointing angles for various down range sensors involved in the experiment. Background information describing the STARS missile, GPS subsystem architecture, and the GPS Kalman filter design is presented first, followed by a discussion of the telemetry data records obtained from this flight with interpretations and conclusions.

More Details

The data dictionary: A view into the CTBT knowledge base

Shepherd, E.R.; Keyser, R.G.; Armstrong, H.M.

The data dictionary for the Comprehensive Test Ban Treaty (CTBT) knowledge base provides a comprehensive, current catalog of the projected contents of the knowledge base. It is written from a data definition view of the knowledge base and therefore organizes information in a fashion that allows logical storage within the computer. The data dictionary introduces two organization categories of data: the datatype, which is a broad, high-level category of data, and the dataset, which is a specific instance of a datatype. The knowledge base, and thus the data dictionary, consist of a fixed, relatively small number of datatypes, but new datasets are expected to be added on a regular basis. The data dictionary is a tangible result of the design effort for the knowledge base and is intended to be used by anyone who accesses the knowledge base for any purpose, such as populating the knowledge base with data, or accessing the data for use with automatic data processing (ADP) routines, or browsing through the data for verification purposes. For these two reasons, it is important to discuss the development of the data dictionary as well as to describe its contents to better understand its usefulness; that is the purpose of this paper.

More Details

Testing the waveform correlation event detection system: Teleseismic, regional, and local distances

Young, Christopher J.

Waveform Correlation Event Detection System (WCEDS) prototypes have now been developed for both global and regional networks and the authors have extensively tested them to assess the potential usefulness of this technology for CTBT (Comprehensive Test Ban Treaty) monitoring. In this paper they present the results of tests on data sets from the IDC (International Data Center) Primary Network and the New Mexico Tech Seismic Network. The data sets span a variety of event types and noise conditions. The results are encouraging at both scales but show particular promise for regional networks. The global system was developed at Sandia Labs and has been tested on data from the IDC Primary Network. The authors have found that for this network the system does not perform at acceptable levels for either detection or location unless directional information (azimuth and slowness) is used. By incorporating directional information, however, both areas can be improved substantially suggesting that WCEDS may be able to offer a global detection capability which could complement that provided by the GA (Global Association) system in use at the IDC and USNDC (United States National Data Center). The local version of WCEDS (LWCEDS) has been developed and tested at New Mexico Tech using data from the New Mexico Tech Seismic Network (NMTSN). Results indicate that the WCEDS technology works well at this scale, despite the fact that the present implementation of LWCEDS does not use directional information. The NMTSN data set is a good test bed for the development of LWCEDS because of a typically large number of observed local phases and near network-wide recording of most local and regional events. Detection levels approach those of trained analysts, and locations are within 3 km of manually determined locations for local events.

More Details

Software design and operational model for the WCEDS prototype

Beiriger, Judy I.

To explore the potential of waveform correlation for CTBT, the Waveform Correlation Event Detection System (WCEDS) prototype was developed. The WCEDS software design followed the Object Modeling Technique process of analysis, system design, and detailed design and implementation. Several related executable programs are managed through a Graphical User Interface (GUI). The WCEDS prototype operates in an IDC/NDC-compatible environment. It employs a CSS 3.0 database as its primary input/output interface, reading in raw waveforms at the start, and storing origins, events, arrivals, and associations at the finish. Additional output includes correlation results and data for specified testcase origins, and correlation timelines for specified locations. During the software design process, the more general seismic monitoring functionality was extracted from WCEDS-specific requirements and developed into C++ object-oriented libraries. These include the master image, grid, basic seismic, and extended seismic libraries. Existing NDC and commercial libraries were incorporated into the prototype where appropriate, to focus development activities on new capability. The WCEDS-specific application code was built in a separate layer on top of the general seismic libraries. The general seismic libraries developed for the WCEDS prototype can provide a base for other algorithm development projects.

More Details

Magnetically-excited flexural plate wave resonator

Martin, Steve W.

A flexural plate wave (FPW) resonator was constructed by patterning current lines on a silicon nitride membrane suspended on a rectangular silicon frame. Eigenmodes of the rectangular membrane were excited using Lorentz forces generated between alternating surface currents and a static in-plane magnetic field. The magnetic field strength required for these devices can be achieved with small permanent magnets ({approx} 1 cm{sup 3}). Preferential coupling to a particular membrane mode was achieved by positioning current lines along longitudinal mode antinodes. An equivalent-circuit model was derived that characterizes the input impedance of a one-port device and the transmission response of a two-port device over a range of frequencies near a single membrane resonance. Experiments were performed to characterize the effects of varying magnetic field, ambient gas, gas pressure, and input power. To the authors` knowledge, this is the first experimental demonstration of a resonant FPW device.

More Details

Solidification modeling of Nb bearing superalloys

Robino, Charles V.

The solidification behavior of experimental Ni base and Fe base superalloys containing Nb, Si, and C was studied using differential thermal analysis (DTA) and microstructural characterization techniques. The solidification reaction sequences responsible for microstructural development were found to be similar to those expected in the Ni-Nb-C ternary system, where the solute-rich interdendritic liquid exhibited two eutectic-type reactions at the terminal stages of solidification: L {yields} ({gamma} + NbC) and L {yields} ({gamma} + Laves). A pseudo ternary {gamma}-Nb-C approach was developed to provide a quantitative description of solidification behavior for these experimental alloys. Solute redistribution calculations in the model are based on a previous approach developed by Mehrabian and Flemings, with modifications made to account for the high diffusion rate of C in the solid. Solidification parameters for Nb and C were determined through DTA and electron probe microanalysis techniques and used as inputs to the model. Reasonable agreement is found between calculated volume fractions of the {gamma}/NbC and {gamma}/Laves constituents and those measured experimentally. The modeling results permit detailed descriptions of the relation between alloy composition and microstructural evolution during solidification.

More Details

Data analysis for remote monitoring of safeguarded facilities

Deland, Sharon M.

The International Remote Monitoring Project (IRMP) sponsored by the US DOE allows DOE and its international partners to gain experience with the remote collection, transmission, and interpretation of safeguards-relevant data. This paper focuses on the interpretation of the data from these remote monitoring systems. Users of these systems need to be able to ascertain that the remote monitoring system is functioning as expected and that the events generated by the sensors are consistent with declared activity. The initial set of analytical tools being provided for IRMP installations this year include a suite of automatically generated views of user-selected data. The baseline set of tools, with illustrative examples, will be discussed. Plans for near-term enhancements will also be discussed. Finally, the applicability of more advanced analytical techniques such as expert systems will be discussed.

More Details

Low-level radioactive waste transportation safety history

Mcclure, J.D.

The Radioactive Materials Incident Report (RMIR) database was developed fin 1981 at the Transportation Technology Center of Sandia National Laboratories to support its research and development activities for the US department of Energy (DOE). This database contains information about radioactive material (RAM) transportation incidents that have occurred in the US since 1971. These data were drawn from the US Department of Transportation`s (DOT) Hazardous Materials Incident Report system, from Nuclear Regulatory Commission (NRC) files, and from various agencies including state radiological control offices. Support for the RMIR data base is funded by the US DOE National Transportation Program (NTP). Transportation events in RMIR are classified in one of the following ways: as a transportation accident, as a handling accident, or as a reported incident. This presentation will provide definitions for these classifications and give examples of each. The primary objective of this presentation is to provide information on nuclear materials transportation accident/incident events involving low-level waste (LLW) that have occurred in the US for the period 1971 through 1996. Among the areas to be examined are: transportation accidents by mode, package response during accidents, and an examination of accidents where release of contents has occurred. Where information is available, accident and incident history and package response for LLW packages in transportation accidents will be described.

More Details

Alumina strength degradation in the elastic regime

Furnish, Michael D.

Measurements of Kanel et. al. [1991] have suggested that deviatoric stresses in glasses shocked to nearly the Hugoniot Elastic limit (HEL) relax over a time span of microseconds after initial loading. Failure (damage) waves have been inferred on the basis of these measurements using time-resolved manganin normal and transverse stress gauges. Additional experiments on glass by other researchers, using time-resolved gauges, high-speed photography and spall strength determinations have also lead to the same conclusions. In the present study the authors have conducted transmitted-wave experiments on high-quality Coors AD995 alumina shocked to roughly 5 and 7 GPa (just below or at the HEL). The material is subsequently reshocked to just above its elastic limit. Results of these experiments do show some evidence of strength degradation in the elastic regime.

More Details

Use of z-pinch sources for high-pressure shock wave experiments

Konrad, C.H.; Trott, W.M.; Hall, C.A.

Recent developments have demonstrated the use of pulsed power for producing intense radiation sources (z-pinches) that can drive planar shock waves in samples with spatial dimensions significantly larger than possible with other radiation sources. In this paper, the authors will discuss the use of z-pinch sources for shock wave studies at multi-Mbar pressures. Experimental plans to use the technique for absolute shock Hugoniot measurements and with accuracies comparable to that obtained with gun launchers are discussed.

More Details

D-dot and B-dot monitors for Z-vacuum-section power-flow measurements

Stygar, William A.

The 36-module Z accelerator--designed to drive z-pinch loads at currents up to 20 MA--is contained in a 33-m-diameter tank with oil, water, and vacuum sections. The peak total forward-going power in the 36 water-section bi-plate transmission lines is approximately 63 TW. nine transmission lines deliver power to each of the four vacuum-section levels (referred to as levels A (the uppermost), B, C, and D). New differential D-dot and B-dot monitors were developed for the Z vacuum section. The D-dots measure voltage at the insulator stack. The B-dots measure current at the stack and in the outer magnetically-insulated transmission lines. Each monitor has two outputs that allow common-mode noise to be canceled to first order. The differential D-dot has one signal and one noise channel; the differential B-dot has two signal channels with opposite polarities. Each of the two B-dot sensors in the differential B-dot monitor has four 3-mm-diameter loops and is encased in copper to reduce flux penetration. For both types of probes, two 2.2-mm-diameter coaxial-cables connect the outputs to a Prodyn balun for common-mode-noise rejection. The cables provide reasonable bandwidth and generate acceptable levels of Compton drive in Z`s bremsstrahlung field. A new cavity B-dot is being developed to measure the total Z current 4.3 cm from the axis of the z-pinch load. All of the sensors are calibrated with 2--4% accuracy. The monitor signals are reduced with Barth or Weinschel attenuators, recorded on Tektronix 0.5-ns/sample digitizing oscilloscopes, and software cable compensated and integrated.

More Details

Design and performance of the Z magnetically-insulated transmission lines

Stygar, William A.

The 36-module Z accelerator was designed to drive z-pinch loads for weapon-physics and inertial-confinement-fusion experiments, and to serve as a testing facility for pulsed-power research required to develop higher-current drivers. The authors have designed and tested a 10-nH 1.5-m-radius vacuum section for the Z accelerator. The vacuum section consists of four vacuum flares, four conical 1.3-m-radius magnetically-insulated transmission lines, a 7.6-cm-radius 12-post double-post-hole convolute which connects the four outer MITLs in parallel, and a 5-cm-long inner MITL which connects the output of the convolute to a z-pinch load. IVORY and ELECTRO calculations were performed to minimize the inductance of the vacuum flares with the constraint that there be no significant electron emission from the insulator-stack grading rings. Iterative TLCODE calculations were performed to minimize the inductance of the outer MITLs with the constraint that the MITL electron-flow-current fraction be {le} 7% at peak current. The TLCODE simulations assume a 2.5 cm/{micro}s MITL-cathode-plasma expansion velocity. The design limits the electron dose to the outer-MITL anodes to 50 J/g to prevent the formation of an anode plasma. The TLCODE results were confirmed by SCREAMER, TRIFL, TWOQUICK, IVORY, and LASNEX simulations. For the TLCODE, SCREAMER, and TRIFL calculations, the authors assume that after magnetic insulation is established, the electron-flow current launched in the outer MITLs is lost at the convolute. This assumption has been validated by 3-D QUICKSILVER simulations for load impedances {le} 0.36 ohms. LASNEX calculations suggest that ohmic resistance of the pinch and conduction-current-induced energy loss to the MITL electrodes can be neglected in Z power-flow modeling that is accurate to first order. To date, the Z vacuum section has been tested on 100 shots. They have demonstrated they can deliver a 100-ns rise-time 20-MA current pulse to the baseline z-pinch load.

More Details

Application of reactors for testing neutron-induced upsets in commercial SRAMs

Griffin, Patrick J.

Reactor neutron environments can be used to test/screen the sensitivity of unhardened commercial SRAMs to low-LET neutron-induced upset. Tests indicate both thermal/epithermal (< 1 keV) and fast neutrons can cause upsets in unhardened parts. Measured upset rates in reactor environments can be used to model the upset rate for arbitrary neutron spectra.

More Details

Areal array jetting device for ball grid arrays

Frear, D.R.

Package designs for microelectronics devices have moved from through-hole to surface mount technology in order to increase the printed wiring board real estate available by utilizing both sides of the board. The traditional geometry for surface mount devices is peripheral arrays where the leads are on the edges of the device. As the technology drives towards high input/output (I/O) count (increasing number of leads) and smaller packages with finer pitch (less distance between peripheral leads), limitations on peripheral surface mount devices arise. A solution to the peripheral surface mount issue is to shift the leads to the area under the device. This scheme is called areal array packaging and is exemplified by the ball grid array (BGA) package. In a BGA package, the leads are on the bottom surface of the package in the form of an array of solder balls. The current practice of joining BGA packages to printed wiring boards involves a hierarchy of solder alloy compositions. A high melting temperature ball is typically used for standoff. A promising alternative to current methods is the use of jetting technology to perform monolithic solder ball attachment. This paper describes an areal array jetter that was designed and built to simultaneously jet arrays of solder balls directly onto BGA substrates.

More Details

Application & testing of high temperature materials for solenoid coils

Zich, John L.

Sandia National Laboratories has designed and proven-in two new Solenoid coils for a highly-reliable electromechanical switch. Mil-Spec Magnetics Inc., Walnut CA manufactured the coils. The new design utilizes two new materials: Liquid Crystal Polymer (Vectra C130) for the bobbin and Thermal Barrier Silicone (VI-SIL V-658) for the encapsulant. The use of these two new materials solved most of the manufacturing problems inherent in the old Sandia design. The coils are easier to precision wind and more robust for handling, testing, and storage. The coils have some unique weapon related safety requirements. The most severe of these requirements is the 400{degrees}C, 1600 V test. The coils must not, and did not, produce any outgassing products to affect the voltage breakdown between contacts in the switch at these temperatures and voltages. Actual coils in switches were tested under these conditions. This paper covers the prove-in of this new coil design.

More Details

Active chatter control in a milling machine

Dohner, Jeffrey L.

The use of active feedback compensation to mitigate cutting instabilities in an advanced milling machine is discussed in this paper. A linear structural model delineating dynamics significant to the onset of cutting instabilities was combined with a nonlinear cutting model to form a dynamic depiction of an existing milling machine. The model was validated with experimental data. Modifications made to an existing machine model were used to predict alterations in dynamics due to the integration of active feedback compensation. From simulations, subcomponent requirements were evaluated and cutting enhancements were predicted. Active compensation was shown to enable more than double the metal removal rate over conventional milling machines. 25 refs., 10 figs., 1 tab.

More Details

Copper in silicon: Quantitative analysis of internal and proximity gettering

Mchugo, S.A.; Flink, C.; Weber, E.R.

The behavior of copper in the presence of a proximity gettering mechanism and a standard internal gettering mechanism in silicon was studied. He implantation-induced cavities in the near surface region were used as a proximity gettering mechanism and oxygen precipitates in the bulk of the material provided internal gettering sites. Moderate levels of copper contamination were introduced by ion implantation such that the copper was not supersaturated during the anneals, thus providing realistic copper contamination/gettering conditions. Copper concentrations at cavities and internal gettering sites were quantitatively measured after the annealings. In this manner, the gettering effectiveness of cavities was measured when in direct competition with internal gettering sites. The cavities were found to be the dominant gettering mechanism with only a small amount of copper gettered at the internal gettering sites. These results reveal the benefits of a segregation-type gettering mechanism for typical contamination conditions.

More Details

A key management concept for the CTBT International Monitoring System

Craft, R.

Cryptographic authentication (commonly referred to as ``technical authentication`` in Working Group B) is an enabling technology which ensures the integrity of sensor data and security of digital networks under various data security compromise scenarios. The use of cryptographic authentication,however, implies the development of a key management infrastructure for establishing trust in the generation and distribution of cryptographic keys. This paper proposes security and operational requirements for a CTBT (Comprehensive Test Ban Treaty) key management system and, furthermore, presents a public key based solution satisfying the requirements. The key management system is instantiated with trust distribution technologies similar to those currently implemented in industrial public key infrastructures. A complete system solution is developed.

More Details

Optical measurement of micromachine engine performance

Holswade, Scott C.

Understanding the mechanisms that impact the performance of Microelectromechanical Systems (MEMS) is essential to the development of optimized designs and drive signals, as well as the qualification of devices for commercial applications. Silicon micromachines include engines that consist of orthogonally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small as 50 {mu}m in diameter and can be driven at rotation rates exceeding 300,000 rpm. Optical techniques offer the potential for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. The authors describe the development of Micromachine Optical Probe (MOP) technology for the evaluation of micromachine performance. The MOP approach is based on the detection of optical signals scattered by the gear teeth or other physical structures. They present experimental results for a prototype system designed to measure engine parameters as well as long term performance data.

More Details

Minimizing sulfur contamination and rinse water volume required following a sulfuric acid/hydrogen peroxide clean by performing a chemically basic rinse

Clews, Peggy J.

Sulfuric acid hydrogen peroxide mixtures (SPM) are commonly used in the semiconductor industry to remove organic contaminants from wafer surfaces. This viscous solution is very difficult to rinse off wafer surfaces. Various rinsing conditions were tested and the resulting residual contamination on the wafer surface was measured. The addition of small amounts of a chemical base such as ammonium hydroxide to the rinse water has been found to be effective in reducing the surface concentration of sulfur and also mitigates the particle growth that occurs on SPM cleaned wafers. The volume of room temperature water required to rinse these wafers is also significantly reduced.

More Details

Intelligent tools and process development for robotic edge finishing: LDRD project final report

Lewis, Christopher L.

This report describes a project undertaken to develop an agile automated, high-precision edge finishing system, for fabricating precision parts. The project involved re-designing and adding additional capabilities to an existing finishing work-cell. The resulting work-cell may serve as prototype for production systems to be integrated in highly flexible automated production lines. The system removes burrs formed in the machining process and produces precision chamfers. The system uses an expert system to predict the burr size from the machining history. Within the CAD system, tool paths are generated for burr removal and chamfer formation. Then, the optimal grinding process is automatically selected from a database of processes. The tool trajectory and the selected process definition is then downloaded to a robotic control system to execute the operation. The robotic control system implements a hybrid fuzzy logic-classical control scheme to achieve the desired performance goals regardless of tolerance and fixturing errors. This report describes the system architecture and the system`s performance.

More Details

Electro-thermal modeling of a microbridge gas sensor

Manginell, R.P.; Smith, J.H.; Ricco, A.J.; Hughes, R.C.; Moreno, D.J.; Huber, R.J.

Fully CMOS-compatible, surface-micromachined polysilicon microbridges have been designed, fabricated, and tested for use in catalytic, calorimetric gas sensing. To improve sensor behavior, extensive electro-thermal modeling efforts were undertaken using SPICE. The validity of the SPICE model was verified comparing its simulated behavior with experiment. Temperature distribution of an electrically heated microbridges was measured using an infrared microscope. Comparisons among the measured distribution, the SPICE simulation, and distributions obtained by analytical methods show that heating at the ends of a microbridges has important implications for device response. Additional comparisons between measured and simulated current-voltage characteristics, as well as transient response, further support the accuracy of the model. A major benefit of electro- thermal modeling with SPICE is the ability to simultaneously simulate the behavior of a device and its control/sensing electronics. Results for the combination of a unique constant-resistance control circuit and microbridges gas sensor are given. Models of in situ techniques for monitoring catalyst deposition are shown to be in agreement with experiment. Finally, simulated chemical response of the detector is compared with the data, and methods of improving response through modifications in bridge geometry are predicted.

More Details

Friction and wear in surface micromachined tribological test devices

Senft, D.C.; Dugger, M.T.

We report on the design, construction, and initial testing of surface micromachined devices for measuring friction and wear. The devices measure friction coefficients on both horizontal deposited polysilicon surfaces and vertical etched polysilicon surfaces. The contact geometry of the rubbing surfaces is well-defined, and a method is presented for the determination of the normal and frictional forces. Initial observations on test devices which have been dried with supercritical CO{sub 2} and devices coated with octadecyltrichlorosilane suggest that the coatings increase the lifetime of the devices and the repeatability of the results.

More Details

A summary of the sources of input parameter values for the Waste Isolation Pilot Plant final porosity surface calculations

Butcher, B.M.

A summary of the input parameter values used in final predictions of closure and waste densification in the Waste Isolation Pilot Plant disposal room is presented, along with supporting references. These predictions are referred to as the final porosity surface data and will be used for WIPP performance calculations supporting the Compliance Certification Application to be submitted to the U.S. Environmental Protection Agency. The report includes tables and list all of the input parameter values, references citing their source, and in some cases references to more complete descriptions of considerations leading to the selection of values.

More Details

Potts-model grain growth simulations: Parallel algorithms and applications

Wright, Steven A.

Microstructural morphology and grain boundary properties often control the service properties of engineered materials. This report uses the Potts-model to simulate the development of microstructures in realistic materials. Three areas of microstructural morphology simulations were studied. They include the development of massively parallel algorithms for Potts-model grain grow simulations, modeling of mass transport via diffusion in these simulated microstructures, and the development of a gradient-dependent Hamiltonian to simulate columnar grain growth. Potts grain growth models for massively parallel supercomputers were developed for the conventional Potts-model in both two and three dimensions. Simulations using these parallel codes showed self similar grain growth and no finite size effects for previously unapproachable large scale problems. In addition, new enhancements to the conventional Metropolis algorithm used in the Potts-model were developed to accelerate the calculations. These techniques enable both the sequential and parallel algorithms to run faster and use essentially an infinite number of grain orientation values to avoid non-physical grain coalescence events. Mass transport phenomena in polycrystalline materials were studied in two dimensions using numerical diffusion techniques on microstructures generated using the Potts-model. The results of the mass transport modeling showed excellent quantitative agreement with one dimensional diffusion problems, however the results also suggest that transient multi-dimension diffusion effects cannot be parameterized as the product of the grain boundary diffusion coefficient and the grain boundary width. Instead, both properties are required. Gradient-dependent grain growth mechanisms were included in the Potts-model by adding an extra term to the Hamiltonian. Under normal grain growth, the primary driving term is the curvature of the grain boundary, which is included in the standard Potts-model Hamiltonian.

More Details

Electric utility capacity expansion and energy production models for energy policy analysis

Edenburn, Michael W.

This report describes electric utility capacity expansion and energy production models developed for energy policy analysis. The models use the same principles (life cycle cost minimization, least operating cost dispatching, and incorporation of outages and reserve margin) as comprehensive utility capacity planning tools, but are faster and simpler. The models were not designed for detailed utility capacity planning, but they can be used to accurately project trends on a regional level. Because they use the same principles as comprehensive utility capacity expansion planning tools, the models are more realistic than utility modules used in present policy analysis tools. They can be used to help forecast the effects energy policy options will have on future utility power generation capacity expansion trends and to help formulate a sound national energy strategy. The models make renewable energy source competition realistic by giving proper value to intermittent renewable and energy storage technologies, and by competing renewables against each other as well as against conventional technologies.

More Details

The role of technology in reducing health care costs. Final project report

Warren, S.

Sandia National Laboratories applied a systems approach to identifying innovative biomedical technologies with the potential to reduce U.S. health care delivery costs while maintaining care quality. This study was conducted by implementing both top-down and bottom-up strategies. The top-down approach used prosperity gaming methodology to identify future health care delivery needs. This effort provided roadmaps for the development and integration of technology to meet perceived care delivery requirements. The bottom-up approach identified and ranked interventional therapies employed in existing care delivery systems for a host of health-related conditions. Economic analysis formed the basis for development of care pathway interaction models for two of the most pervasive, chronic disease/disability conditions: coronary artery disease (CAD) and benign prostatic hypertrophy (BPH). Societal cost-benefit relationships based on these analyses were used to evaluate the effect of emerging technology in these treatment areas. 17 figs., 48 tabs.

More Details

Design, demonstration and evaluation of a thermal enhanced vapor extraction system

Phelan, James M.

The Thermal Enhanced Vapor Extraction System (TEVES), which combines powerline frequency heating (PLF) and radio frequency (RF) heating with vacuum soil vapor extraction, was used to effectively remove volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) from a pit in the chemical waste landfill (CWL) at Sandia National Laboratories (SNL) within a two month heating period. Volume average temperatures of 83{degrees}C and 112{degrees}C were reached for the PLF and RF heating periods, respectively, within the 15 ft x 45 ft x 18.5 ft deep treated volume. This resulted in the removal of 243 lb of measured toxic organic compounds (VOCs and SVOCs), 55 gallons of oil, and 11,000 gallons of water from the site. Reductions of up to 99% in total chromatographic organics (TCO) was achieved in the heated zone. Energy balance calculations for the PLF heating period showed that 36.4% of the heat added went to heating the soil, 38.5% went to evaporating water and organics, 4.2% went to sensible heat in the water, 7.1% went to heating the extracted air, and 6.6% was lost. For the RF heating period went to heating the soil, 23.5% went to evaporating water and organics, 2.4% went to sensible heat in the water, 7.5% went to heating extracted air, and 9.7% went to losses. Energy balance closure was 92.8% for the PLF heating and 98% for the RF heating. The energy input requirement per unit soil volume heated per unit temperature increase was 1.63 kWH/yd{sup 3}-{degrees}C for PLF heating and 0.73 kWH/yd{sup 3}{degrees}C for RF heating.

More Details

Conceptual model for transport processes in the Culebra Dolomite Member, Rustler Formation

Holt, R.M.

The Culebra Dolomite Member of the Rustler Formation represents a possible pathway for contaminants from the Waste Isolation Pilot Plant underground repository to the accessible environment. The geologic character of the Culebra is consistent with a double-porosity, multiple-rate model for transport in which the medium is conceptualized as consisting of advective porosity, where solutes are carried by the groundwater flow, and fracture-bounded zones of diffusive porosity, where solutes move through slow advection or diffusion. As the advective travel length or travel time increases, the nature of transport within a double-porosity medium changes. This behavior is important for chemical sorption, because the specific surface area per unit mass of the diffusive porosity is much greater than in the advective porosity. Culebra transport experiments conducted at two different length scales show behavior consistent with a multiple-rate, double-porosity conceptual model for Culebra transport. Tracer tests conducted on intact core samples from the Culebra show no evidence of significant diffusion, suggesting that at the core scale the Culebra can be modeled as a single-porosity medium where only the advective porosity participates in transport. Field tracer tests conducted in the Culebra show strong double-porosity behavior that is best explained using a multiple-rate model.

More Details

Final report of the environmental measurement-while-drilling-gamma ray spectrometer system technology demonstration at the Savannah River Site F-Area Retention Basin

Williams, Cecelia V.

The environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes passed near previously sampled vertical borehole locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRs system during drilling are compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

More Details
Results 93601–93800 of 99,299
Results 93601–93800 of 99,299