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Thermal batteries: A technology review and future directions

Guidotti, Ronald A.

Thermally activated (``thermal``) batteries have been used for ordnance applications (e.g., proximity fuzes) since World War II and, subsequent to that, in nuclear weapons. This technology was developed by the Germans as a power source for their V2 rockets. It was obtained by the Allies by interrogation of captured German scientists after the war. The technology developed rapidly from the initial primitive systems used by the Germans to one based on Ca/CaCrO{sub 4}. This system was used very successfully into the late 1970s, when it was replaced by the Li-alloy/FeS{sub 2} electrochemical system. This paper describes the predominant electrochemical couples that have been used in thermal batteries over the years. Major emphasis is placed on the chemistry and electrochemistry of the Ca/CaCrO{sub 4} and Li-alloy/FeS{sub 2} systems. The reason for this is to give the reader a better appreciation for the advances in thermal-battery technology for which these two systems are directly responsible. Improvements to date in the current Li-alloy/FeS{sub 2} and related systems are discussed and areas for possible future research and development involving anodes, cathodes, electrolytes, and insulations are outlined. New areas where thermal-battery technology has potential applications are also examined.

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ITS Version 4.0: Electron/photon Monte Carlo transport codes

Halbleib, J.A.; Kensek, R.P.; Seltzer, S.M.

The current publicly released version of the Integrated TIGER Series (ITS), Version 3.0, has been widely distributed both domestically and internationally, and feedback has been very positive. This feedback as well as our own experience have convinced us to upgrade the system in order to honor specific user requests for new features and to implement other new features that will improve the physical accuracy of the system and permit additional variance reduction. This presentation we will focus on components of the upgrade that (1) improve the physical model, (2) provide new and extended capabilities to the three-dimensional combinatorial-geometry (CG) of the ACCEPT codes, and (3) permit significant variance reduction in an important class of radiation effects applications.

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Progress toward using hydraulic data to diagnose lost circulation zones

Mansure, Arthur J.

Several wellbore hydraulic models have been examined to determine their applicability in measuring the characteristics of lost circulation zones encountered in geothermal drilling. Characteristics such as vertical location in the wellbore, fracture size, effective permeability, and formation pressure must be known in order to optimize treatment of such zones. The models that have been examined to date are a steady-state model, a standpipe-pressure model, a raising-the-drill-bit model, a mud-weight model, a hydrofracture model, and several time-dependent models. None of these models yet have been found to adequately match the field data obtained from six loss zones in three geothermal wells. The development of these models is presented in this paper, and a discussion of their limitations is provided.

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La{sub 0.5}Sr{sub 0.5}CoO{sub 3} electrode technology for Pb(Zr, Ti)O{sub 3} thin film nonvolatile memories

Tuttle, Bruce T.

Oxide electrode technology is investigated for optimization of Pb(Zr,Ti)O{sub 3} (PZT) thin film capacitor properties for high density nonvolatile memory applications. PZT thin film capacitors with RF sputter deposited La{sub 0.5}Sr{sub 0.5}CoO{sub 3} (LSCO) electrodes have been characterized with respect to the following parameters: initial dielectric hysteresis loop characteristics, fatigue performance, microstructure and imprint behavior. Our studies have determined that the fatigue of PZT capacitors with LSCO electrodes is less sensitive to B site cation ratio and underlying electrode stack technology than with RuO{sub 2} electrodes. Doping PZT thin films with Nb (PNZT) improves imprint behavior of LSCO//PZT//LSCO capacitors considerably. We have demonstrated that PNZT 4/30/70 // LSCO capacitors thermally processed at either 550{degrees}C or 675{degrees}C have almost identical initial hysteresis properties and exhibit essentially no fatigue out to approximately 10{sup 10} cycles.

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A method for managing the storage of fissile materials using criticality indices

Philbin, Jeffrey S.

This paper describes a method for criticality control at fissile material storage facilities. The method involves the use criticiality indices for storage canisters. The logic, methodology, and results for selected canisters are presented. A concept for an interactive computer program using the method is also introduced. The computer program can be used in real time (using precalulated data) to select a Criticality Index (CI) for a container when it is delivered to or packaged at a site. Criticality safety is assured by controlling the sum of the CIs at each storage location below a defined Emit value when containers are moved.

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User`s guide for the KBERT 1.0 code: For the knowledge-based estimation of hazards of radioactive material releases from DOE nuclear facilities

Browitt, Debra S.

The possibility of worker exposure to radioactive materials during accidents at nuclear facilities is a principal concern of the DOE. The KBERT software has been developed at Sandia National Laboratories under DOE support to address this issue by assisting in the estimation of risks posed by accidents at chemical and nuclear facilities. KBERT is an acronym for Knowledge-Based system for Estimating hazards of Radioactive material release Transients. The current prototype version of KBERT focuses on calculation of doses and consequences to in-facility workers due to accidental releases of radioactivity. This report gives detailed instructions on how a user who is familiar with the design, layout and potential hazards of a facility can use KBERT to assess the risks to workers in that facility. KBERT is a tool that allows a user to simulate possible accidents and observe the predicted consequences. Potential applications of KBERT include the evaluation of the efficacy of evacuation practices, worker shielding, personal protection equipment and the containment of hazardous materials.

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Development of an Image Compression and Authentication Module for video surveillance systems

Hale, W.R.

An Image Compression and Authentication Module (ICAM) has been designed to perform the digitization, compression, and authentication of video images in a camera enclosure. The ICAM makes it possible to build video surveillance systems that protect the transmission and storage of video images. The ICAM functions with both NTSC 525 line and PAL 625 line cameras and contains a neuron chip (integrated circuit) permitting it to be interfaced with a local operating network which is part of the Modular Integrated Monitor System (MIMS). The MIMS can be used to send commands to the ICAM from a central controller or any sensor on the network. The ICAM is capable of working as a stand alone unit or it can be integrated into a network of other cameras. As a stand alone unit it sends its video images directly over a high speed serial digital link to a central controller for storage. A number of ICAMs can be multiplexed on a single coaxial cable. In this case, images are captured by each ICAM and held until the MIMS delivers commands for an individual image to be transmitted for review or storage. The ICAM can capture images on a time interval basis or upon receipt of a trigger signal from another sensor on the network. An ICAM which collects images based on other sensor signals, forms the basis of an intelligent {open_quotes}front end{close_quotes} image collection system. The burden of image review associated with present video systems is reduced by only recording the images with significant action. The cards used in the ICAM can also be used to decompress and display the compressed images on a NTSC/PAL monitor.

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Wire melting and droplet atomization in a high velocity oxy-fuel jet

Neiser, R.A.; Brockmann, J.E.; O'Hern, T.J.

Coatings produced by feeding a steel wire into a high-velocity oxy-fuel (HVOF) torch are being intensively studied by the automotive industry as a cost-effective alternative to the more expensive cast iron sleeves currently used in aluminum engine blocks. The microstructure and properties of the sprayed coatings and the overall economics of the process depend critically on the melting and atomization occurring at the wire tip. This paper presents results characterizing several aspects of wire melting and droplet breakup in an HVOF device. Fluctuations in the incandescent emission of the plume one centimeter downstream from the wire tip were recorded using a fast photodiode. A Fourier transform of the light traces provided a measure of the stripping rate of molten material from the wire tip. Simultaneous in-flight measurement of atomized particle size and velocity distributions were made using a Phase Doppler Particle Analyzer (PDPA). The recorded size distributions approximate a log-normal distribution. Small particles traveled faster than large particles, but the difference was considerably smaller than simple aerodynamic drag arguments would suggest. A set of experiments was carried out to determine the effect that variations in torch gas flow rates have on wire melt rate, average particle size, and average particle velocity. The observed variation of particle size with spray condition is qualitatively consistent with a Weber breakup of the droplets coming off the wire. The measurements also showed that it was possible to significantly alter atomized particle size and velocity without appreciably changing the wire melt rate.

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A comparison of two laser-based diagnostics for analysis of particles in thermal spray streams

Smith, Mark F.

This paper discusses two commercially-available laser diagnostics that have been used in thermal spray research at Sandia National Laboratories: (1) a Phase Doppler Particle Analyzer (PDPA) and (2) a Laser Two-Focus (L2F) velocimeter. The PDPA provides simultaneous, correlated measurements of particle velocity and particle size distributions; but, particle sizing doesn`t work well with non-spherical particles or particles with rough surfaces. The L2F is used to collect particle velocity and number density distributions, and it can readily distinguish and separately measure particles with off-axis velocity vectors. PDPA and L2F principles of operation are presented along with potential advantages and limitations for thermal spray research. Four experiments were conducted to validate and compare measurement results with the PDPA and L2F instruments: (1) spinning wire, (2) powder in a High-Velocity Oxy-Fuel (HVOF) jet, (3) powder in a cold jet, and (4) droplets in a wire-fed HVOF jet. TWO DIFFERENT TYPES of commercially-available laser velocimeter systems, a Phase Doppler Particle Analyzer and a Laser-Two-Focus velocimeter have been used in the Thermal Spray Research Laboratory at Sandia National Laboratories. Each of these techniques has inherent advantages and limitations for thermal spray, and each involves assumptions that may not be valid for some experimental conditions. This paper describes operating principles and possible sources of measurement error for these two diagnostic systems. Some potential advantages and limitations are also presented. Four types of experiments were also conducted to validate and compare PDPA and L2F measurement results: (1) spinning wire, (2) powder in a High-Velocity Oxy-Fuel (HVOF) jet, (3) powder in a cold jet, and (4) droplets in a wire-fed HVOF jet. We also offer a few observations related to practical issues such as ease-of-use, reliability, and effects of dust and vibration in a thermal spray lab.

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Demonstration of bilateral U.S. and Russian remote monitoring system for special nuclear materials

Corbell, Bobby H.

In the context of U.S. and Russian lab-to-lab initiatives, Sandia National Laboratories contracted with Kurchatov Institute Russian Research Center to demonstrate the feasibility of remotely monitoring the storage of nuclear material. The cooperative experiment was to demonstrate the Remote Monitoring System (RMS) with a minimum of 10 kg of HEU in storage at reciprocal facilities. The Kurchatov Institute selected a site at their facility and the DOE selected a site at the Argonne National Laboratory-West facility. At Kurchatov, there is material for monitoring in a floor vault, a cabinet, and shipping containers. At Argonne West, material stored in two types of storage systems is available for material monitoring. This paper discusses the system concept from both perspectives: the operator of a facility where a RMS is deployed and the user of the RMS at the remote site. The demonstration provides a unique opportunity to have a bilateral demonstration/evaluation where each participant examines all aspects of the system. The hardware and software needed to implement this system is discussed. The impacts to the operation of the facilities are discussed as well as the use of the system to remotely monitor a facility. This technology provides the capability of remotely monitoring the access to the stored nuclear materials but is not a real time security alarm system. Several enhancements to the Remote Monitoring System have been identified for future consideration.

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Modular Integrated Monitoring System (MIMS) field test installations

Martinez, R.L.; Waymire, D.R.; Fuess, D.A.

The MIMS program is funded by the Department of Energy under the Office of Nonproliferation and National Security. The program objective is to develop cost effective, modular, multi-sensor monitoring systems. Both in-plant and ground based sensors are envisioned. It is also desirable to develop sensors/systems that can be fielded/deployed in a rapid fashion. A MIMS architecture was selected to allow modular integration of sensors and systems and is based on LonWorks technology, commercially developed by Echelon Corporation. The first MIMS fieldable hardware was demonstrated at Lawrence Livermore National Laboratory. The field test, known within the DOE as the Item Tracking and Transparency (IT&I) demonstration, involved the collaboration and cooperation of five DOE laboratories (Sandia (SNL), Lawrence Livermore (LLNL), Pacific Northwest (PNL), Los Alamos (LANL), and Oak Ridge (ORNL)). The IT&T demonstration involved the monitoring of special nuclear material as it was transported around the facility utilizing sensors from the participating labs. The scenario was programmed to ignore normal activity in the facility until entry into the room where the material was stored. A second demonstration, which involved three separate scenarios, was conducted at Idaho National Engineering Laboratory (INEL). The participants included representatives from SNL, LLNL, PNL, and INEL. DOE has selected INEL as the long term testbed for MIMS developed sensors, systems, and scenarios. This paper will describe the installation, intended purpose, and results of the field demonstrations at LLNL and INEL under the MIMS program.

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Preventing unauthorized use of firearms by implementing use control technologies

Weiss, D.R.

A goal among many law enforcement and security professionals, and the National Institute of Justice, is to decrease the risk that an officer or security guard may encounter. One risk that officers confront is unpredictable persons who sometimes try to gain control of the officer`s firearm. The addition of user-recognizing-and-authorizing technologies to a firearm could eliminate the capability of an unauthorized user from firing an officer`s firearm. Sandia National Laboratories has been active in the research and development of nuclear security systems that include access and use control technologies. Sandia is being sponsored by the National Institute of Justice to perform a research and development project to determine the feasibility of a user authorized firearm, or {open_quotes}smart gun.{close_quotes} The focus group for the research is law enforcement officers because of the number of firearm take aways that have occurred in the past and the severe use requirements placed on their firearms. A comprehensive look at the problem of weapon take aways in the United States was conducted using information available from the Federal Bureau of Investigation and other law enforcement sources. An investigation into the end user requirements for smart gun technologies has been completed. During the remainder of the project, the user requirements are being transformed into engineering requirements. which will then be used to evaluate numerous technologies that could be used in a smart gun. Demonstration models will be made of the most promising technologies. Other potential applications are remote enabling and disabling of firearms, transportation of prisoners by corrections officers, military use in operations other than war, and use by private citizens.

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Solution synthesis and characterization of lithium manganese oxide cathode materials

Voigt, James A.

A nonaqueous coprecipitation process has been developed to prepare controlled stoichiometry lithium manganese oxalate precipitates. The process involved mixing a methanolic Li-Mn nitrate solution with a methanolic solution containing tetramethylammonium oxalate as the precipitating agent. The resulting oxalates were readily converted to a variety of phase pure lithium manganese oxides at moderate temperatures ({le}600{degrees}C), where the phase formed was determined by the initial Li/Mn ratio in the starting solution. Metal cation dopants have been incorporated into the oxalate precipitate by dissolving the appropriate metal nitrate in the Li-Mn precursor solution The various starting solutions, oxalate precipitates, and calcined oxides have been extensively characterized using a variety of techniques, including {sup 7}Li NMR, TGA/DTA, SEM, and XRD. Results indicate that a strong interaction occurs between Li and Mn in the nitrate solution which carries over into the oxalate phase during precipitation. The morphology and the crystallite size of the oxide powders were shown to be controlled by the morphology of the oxalate precursor and the oxalate calcination temperature, respectively. The results of initial cathode performance tests with respect to dopant type (Al, Ni, Co) and concentration for LiMn{sub 2}O{sub 4} are also reported.

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An SNM Cutoff regime and the Treaty on Open Skies Technology

Sandoval, M.B.

The Treaty on Open Skies has very specific requirements as a confidence building measure, but it could also serve as a component of an SNM Cutoff monitoring strategy. The participants to the Treaty are European countries, the United States, and Canada and would have to be extended to include other than the present signatories if it were to be used in a worldwide SNM verification Cutoff role. The major nuclear powers with the exception of China are signatories to the Treaty and the inclusion of other member states will only be considered once entry into force has started. The technology and data sharing provisions of the Treaty have defined the airborne sensor performance specifications. Therefore, the Treaty allowed sensor technology may not be adequate for the purposes of monitoring an SNM Cutoff regime. New sensors and sensor performance levels to adequately monitor an SNM Cutoff regime may be proposed only after entry into force of the Treaty on Open Skies. The utility of an aerial inspection component to the monitoring strategy for an SNM Cutoff regime would best be evaluated with field trials using realistic scenarios. This would allow the testing of synergism among other components of an overall monitoring strategy and would lend insight into the appropriate sensor technology to be recommended for future implementation.

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Investment cast AISI H13 tooling for automotive applications

Maguire, Michael C.

While many techniques exist for production of soft tooling, for die casting there is limited recent experience with cast tooling. The most common US alloy used for manufacture of die casting tooling is wrought AISI H13. If the performance of the cast material is comparable to the wrought counterpart, the use of investment cast HI 3 tooling directly from patterns made via rapid prototyping is of considerable interest. A metallurgical study of investment cast H13 was conducted to evaluate the mechanical behavior in simulated die casting applications. Variable thickness plate investment castings of AISI H13 hot work die steel were produced and characterized in the as-cast and heat-treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 were heat-treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples produced in different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat-treatment, microstructural differences between the wrought material and cast materials were slight regardless of section thickness.The mechanical properties of the cast and heat-treated material proved similar to the properties of the standard heat-treated wrought material. A thermal fatigue testing unit was to con-elate the heat checking susceptibility of H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was observed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat-treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking.

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Control of the reactant ion chemistry for the analysis of explosives by ion mobility spectroscopy

Rodacy, Philip J.

Changes in the reactant ion composition in the ion mobility spectrometer (IMS) can result in a change in the ionization processes occurring in the ionization region, ultimately leading to an altered instrumental response for the analyte, and exacerbating the problem of qualitative and quantitative analysis. Some species are very susceptible to changes in reactant ions, while other species are relatively unaffected. These types of behavior are observed for two common explosives, namely, hexahydro-1,3,5-trinitrol,3,5-triazine (RDX) and 1,3,5-trinitrotoluene (TNT), respectively. To control the reactant ion composition, and hence the gas phase chemistry, it is necessary to control the composition of gases present in the ionization region of the IMS. A series of modifications are described for the PCP Phemto-Chem 100 IMS that afford the requisite control. The effectiveness of these modifications for analysis of RDX and TNT are described and contrasted with that observed for the unmodified system.

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Sputter deposition of ZnS:Mn/SrS:Ce multilayer stacks for use as white phosphor thin film electroluminscent panels

Ruffner, Judith A.

Sputter deposition of ZnS:Mn/SrS:Ce multilayered broad-band ``white`` emission thin film electroluminescent (TFEL) stacks has been investigated. To date, deposition of these multilayers has been limited to vacuum evaporation techniques and atomic layer epitaxy, both of which require two different substrate temperatures for growth of high quality ZnS and SrS. This repeated thermal cycling during multilayer deposition can induce stress, defects, and interdiffusion with adversely affect EL performance. Sputter deposition of ZnS and SrS produces high quality TFELs for a wider range of substrate temperatures. Both materials can be sputter deposited at a common temperature (300-350{degrees}C) which eliminates the need for thermal cycling and increases manufacturability. Luminance outputs from sputter deposited ZnS and SrS thin films are comparable to those from evaporated films, making sputtering an attractive alternative deposition technique for these materials. We report on the effects of sputter deposition parameters including chamber pressure, substrate temperature, and H2S process gas partial pressure on the resultant composition and morphology of ZnS:Mn and SrS:Ce thin films and multilayers. Their EL performance was evaluated and correlated to composition and morphology.

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Physical protection cooperation with Former Soviet Union countries

Williams, J.D.

This paper presents an overview of physical protection cooperation activities between Sandia (SNL) and the Former Soviet Union (FSU) regarding Material Protection Control and Accounting (MPC&A) responsibilities. Begun four years ago as part of the Safe, Secure Dismantlement Program, this project is intended to stem proliferation of weapons of mass destruction. Purpose of the program is to accelerate progress toward a goal shared by both Russia and the United States: to reduce the risk of nuclear weapons proliferation, including such threats as theft, diversion, and unauthorized possession of nuclear materials. This will be accomplished by strengthening the MPC&A systems in both, countries. This new program (US Department of Energy Laboratory-to-Laboratory MPC&A program) is designed to complement Government-to-Government programs sponsored by US Senators Nunn and Lugar. US and Russian representatives exchange visits and discuss physical protection philosophies. Russian representatives have received formal training in the US process of system design and analysis to include the design of an effective physical protection system, determination of physical protection system objectives, initial design of a physical protection system, evaluation of the design, and often redesign or refinement of the existing system. Some Russian organizations have philosophies similar to those of the United States, but when they differ, the US and Russian representatives must negotiate. Other Russian organizations, because of heavy reliance on guard forces, have not developed a systematic design process. Cooperative work between US national laboratories and Russian counterparts has resulted in major physical protection enhancements at a Russian demonstration site and other advancements for Laboratory-to-Laboratory projects.

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Light hydrocarbon gas conversion using porphyrin catalysts

Showalter, M.C.

The objective of this project is to develop novel catalysts for the direct conversion of natural gas to a liquid fuel. The current work investigates the use of biomimetic metalloporphyrins as catalysts for the partial oxidation of light alkanes to alcohols.

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Description of a system for interlocking elevated temperature mechanical tests

Schmale, David T.

Long term mechanical creep and fatigue testing at elevated temperatures requires reliable systems with safeguards to prevent destruction of equipment, loss of data and negative environmental impacts. Toward this goal, a computer controlled system has been developed and built for interlocking tests run on elevated temperature mechanical test facilities. Sensors for water flow, water pressure, water leakage, temperature, power and hydraulic status are monitored to control specimen heating equipment through solid state relays and water solenoid valves. The system is designed to work with the default interlocks present in the RF generators and mechanical tests systems. Digital hardware consists of two National Instruments 1/0 boards mounted in a Macintosh IIci computer. Software is written in National Instruments LabVIEW. Systems interlocked include two MTS closed loop servo controlled hydraulic test frames, one with an RF generator and one with both an RF generator and a quartz lamp furnace. Control for individual test systems is modularized making the addition of more systems simple. If any of the supporting utilities fail during tests, heating systems, chill water and hydraulics are powered down, minimizing specimen damage and eliminating equipment damage. The interlock control is powered by an uninterruptible power supply. Upon failure the cause is documented in an ASCII file.

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Software and Information Life Cycle (SILC) for the Integrated Information Services Organization. Analysis and implementation phase adaptations of the Sandia software guidelines: Issue A, April 18, 1995

Eaton, D.; Cassidy, A.; Cuyler, D.

This document describes the processes to be used for creating corporate information systems within the scope of the Integrated information Services (IIS) Center. This issue A describes the Analysis and Implementation phases within the context of the entire life cycle. Appendix A includes a full set of examples of the analysis set deliverables. Subsequent issues will describe the other life cycle processes as we move toward enterprise-level management of information assets, including information meta-models and an integrated corporate information model. The analysis phase as described here, when combined with a specifications repository, will provide the basis for future reusable components and improve traceability of information system specifications to enterprise business rules.

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The role of ECM in bringing about pollution prevention

Davis, R.L.; Costa, J.E.

In an R&D environment, Environmentally Conscious Manufacturing (ECM), which focuses on specific materials processing and manufacturing operations, can be used to bring about a broader objective: pollution prevention. Decreasing the impact a product or process has on the environment is quickly becoming the way to do business. In the past, the impact on the environment was considered separately from manufacturing processes. Now, companies are beginning to see the benefits of designing to minimize environmental impact. Incorporating upfront the process changes that reduce environmental impact offers improved process efficiency and long-term cost savings not only for manufacturing operations but also for R&D. Among the approaches used, all with the same objective of decreasing pollution and environmental impact from manufacturing or other business operations, are Environmentally Conscious Manufacturing (ECM), Design for Environment (DfE), and Pollution Prevention (P2).

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The implementation of the upwind leapfrog scheme for 3D electromagnetic scattering on massively parallel computers

Hutchinson, Scott A.

The upwind leapfrog scheme for electromagnetic scattering is briefly described. Its application to the 3D Maxwell`s time domain equations is shown in detail. The scheme`s use of upwind characteristic variables and a narrow stencil result in a smaller demand in communication overhead, making it ideal for implementation on distributed memory parallel computers. The algorithm`s implementation on two message passing computers, a 1024-processor nCUBE 2 and a 1840-processor Intel Paragon, is described. Performance evaluation demonstrates that the scheme performs well with both good scaling qualities and high efficiencies on these machines.

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Guest-host crosslinked polyimides for integrated optics

Kowalczyk, T.C.; Kosc, T.Z.; Singer, K.D.; Beuhler, A.J.; Wargowski, D.A.; Cahill, P.A.; Seager, C.H.; Meinhardt, M.B.

We report on the optical and electrical characterization of aromatic, fluorinated, fully imidized, organic soluble, thermally and photochemically, crosslinkable, guest-host polyimides for integrated optics. Refractive indices and optical losses were measured to evaluate the performance of these materials for passive applications. Materials were doped with two high temperature nonlinear optical chromophores, and poled during crosslinking to produce nonlinear optical materials. Measurements of electro-optic coefficient, macroscopic second order susceptibility, and conductivity were performed to assess these materials as potential candidates for active devices.

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High strain-rate model for fiber-reinforced composites

Aidun, John B.

Numerical simulations of dynamic uniaxial strain loading of fiber-reinforced composites are presented that illustrate the wide range of deformation mechanisms that can be captured using a micromechanics-based homogenization technique as the material model in existing continuum mechanics computer programs. Enhancements to the material model incorporate high strain-rate plastic response, elastic nonlinearity, and rate-dependent strength degradation due to material damage, fiber debonding, and delamination. These make the model relevant to designing composite structural components for crash safety, armor, and munitions applications.

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Characterization of solder flow on PWB surfaces

Hosking, F.M.; Yost, F.G.

Different solderability tests have been developed to determine the wetting behavior of solder on metallic surfaces. None offer an exact measure of capillary flow associated with conventional mixed technology soldering. With shrinking package designs, increasing reliability requirements, and the emergence of new soldering technologies, there is a growing need to better understand and predict the flow of solder on printed wiring board (PWB) surfaces. Sandia National Laboratories has developed a capillary flow solderability test, through a joint effort with the National Center for Manufacturing Sciences, that considers this fundamental wetting issue for surface mount technology. The test geometry consists of a metal strip (width, {delta}) connected to a circular metal pad (radius, r{sub c}). Test methodology, experimental results, and validation of a flow model are presented in this paper.

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Performance comparison of streak camera recording systems

Derzon, Mark S.

Streak camera based diagnostics are vital to the inertial confinement fusion program at Sandia National Laboratories. Performance characteristics of various readout systems coupled to an EGG-AVO streak camera were analyzed and compared to scaling estimates. The purpose of the work was to determine the limits of the streak camera performance and the optimal fielding conditions for the Amador Valley Operations (AVO) streak camera systems. The authors measured streak camera limitations in spatial resolution and sensitivity. Streak camera limits on spatial resolution are greater than 18 lp/mm at 4% contrast. However, it will be difficult to make use of any resolution greater than this because of high spatial frequency variation in the photocathode sensitivity. They have measured a signal to noise of 3,000 with 0.3 mW/cm{sup 2} of 830 nm light at a 10 ns/mm sweep speed. They have compared lens coupling systems with and without micro-channel plate intensifiers and systems using film or charge coupled device (CCD) readout. There were no conditions where film was found to be an improvement over the CCD readout. Systems utilizing a CCD readout without an intensifier have comparable resolution, for these source sizes and at a nominal cost in signal to noise of 3, over those with an intensifier. Estimates of the signal-to-noise for different light coupling methods show how performance can be improved.

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Materials and process engineering projects for the Sandia National Laboratories/Newly Independent States Industrial Partnering Program. Volume 1

Zanner, F.J.; Moffatt, W.C.

In July, 1994, a team of materials specialists from Sandia and U S Industry traveled to Russia and the Ukraine to select and fund projects in materials and process technology in support of the Newly Independent States/Industrial Partnering Program (NIS/IPP). All of the projects are collaborations with scientists and Engineers at NIS Institutes. Each project is scheduled to last one year, and the deliverables are formatted to supply US Industry with information which will enable rational decisions to be made regarding the commercial value of these technologies. This work is an unedited interim compilation of the deliverables received to date.

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Steam reforming as a method to treat Hanford underground storage tank (UST) wastes

Kuehne, P.B.

This report summarizes a Sandia program that included partnerships with Lawrence Livermore National Laboratory and Synthetica Technologies, Inc. to design and test a steam reforming system for treating Hanford underground storage tank (UST) wastes. The benefits of steam reforming the wastes include the resolution of tank safety issues and improved radionuclide separations. Steam reforming destroys organic materials by first gasifying, then reacting them with high temperature steam. Tests indicate that up to 99% of the organics could be removed from the UST wastes by steam exposure. In addition, it was shown that nitrates in the wastes could be destroyed by steam exposure if they were first distributed as a thin layer on a surface. High purity alumina and nickel alloys were shown to be good candidates for materials to be used in the severe environment associated with steam reforming the highly alkaline, high nitrate content wastes. Work was performed on designing, building, and demonstrating components of a 0.5 gallon per minute (gpm) system suitable for radioactive waste treatment. Scale-up of the unit to 20 gpm was also considered and is feasible. Finally, process demonstrations conducted on non-radioactive waste surrogates were carried out, including a successful demonstration of the technology at the 0.1 gpm scale.

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Managing risk in software systems

Fletcher, S.K.; Jansma, R.M.; Murphy, M.D.

A methodology for risk management in the design of software systems is presented. It spans security, safety, and correct operation of software within the context of its environment, and produces a risk analysis and documented risk management strategy. It is designed to be iteratively applied, to attain appropriate levels of detail throughout the analysis. The methodology and supporting tools are discussed. The methodology is critiqued relative to other research in the field. Some sample applications of the methodology are presented.

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Technical and policy issues related to semantically and spatially incompatible geodata

Ganter, John H.

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Safeguards and security benefits of project straight-line

Jaeger, Cal

As a result of a number of events the inventory of fissile materials no longer in nuclear weapons in the United States is increasing. This has led to a growing concern regarding the potential for theft and/or diversion and accountability of this material. Straight-Line is a project whose purpose is to demonstrate a site-independent system to monitor stored nuclear material (e.g. plutonium) and integrate the collection, processing and dissemination of information regarding this material. Safeguards and security (S&S) goals of this project include data transfer of information on nuclear material to appropriate users to enhance S&S, continuous on-line accountability, reduction of hands-on access to nuclear materials, incorporation of information security technologies, and early detection of tampering or unauthorized material movement. This paper addresses threat considerations, S&S requirements, S&S objectives, and issues for the Straight-Line project. S&S features and benefits of this project are discussed with respect to existing item monitoring systems and/or other material tracking systems being developed.

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Recognition and use of induced fractures and other features in core produced by the coring process

Lorenz, John C.

There are several distinctive types of coring-induced fractures that can be recognized in core on the basis of morphology, assisted by certain characteristics such as edge effects and surface ornamentation. The shape and orientation of many of these induced fractures offer information on the in-situ stress conditions and the coring process. Petal, petal-centerline, scribe-knife, disc, and torque-related fractures may all be caused by coring in vertical wells. Saddle fractures, (related to petal fractures) are unique to horizontal core, as is the polishing of fracture surfaces during coring. other features such as scribe-line rotation, hammer marks, and rotary-bit patterns are important in making correct interpretations of the in situ stress and reservoir permeability, and in making the maximum use of the evidence bearing on reservoir fracture-system permeability provided by both induced and natural fractures.

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Replacement fuel scoping studies for the Annular Core Research Reactor

Hays, K.; Martin, L.; Parma, E.

Sandia National Laboratories Annular Core Research Reactor (ACRR) is undertaking a new mission for the Department of Energy: production of the radioisotope {sup 99}Mo used in nuclear medicine applications. Isotope production is significantly different from previous programs conducted at the ACRR that typically required high intensity, short duration pulses. The current UO{sub 2}-BeO fuel will power the initial startup phase of the production program, and can perform exceptionally well for this mission. However, this type of fuel is no longer available, commercially or otherwise. This paper presents the results of some preliminary studies of commercially available fuels.

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US/Russian Laboratory-to-Laboratory MPC&A at the RRC Kurchatov Institute

Williams, J.D.

Formal interactions with Kurchatov Institute (KI) began summer 1994 on material protection, control and accountability (MPC&A). Contracts were placed by LANL and Sandia with KI to implement a nuclear material accounting system and a physical security system at a KI demonstration facility which contain two critical assemblies with special nuclear material. LLNL implemented May 1995 a task to measure by gamma-ray spectroscopy the uranium enrichment of fuel in the facility. This laboratory-to-laboratory effort is part of the cooperative program between US and Russian institutes in nuclear material nonproliferation. In 1994-5, KI personnel demonstrated the physical security system. The next facility for work in MPC&A at KI is the Central Storage Facility, which is important for the computerized material accounting system for KI.

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EcoSys{trademark}: Supporting Green Design through an extensible life cycle analysis approach

Gockel, B.C.

EcoSys is an environmental decision support tool to assist in the design of green products and process. EcoSys consist of an information and expert system that contains input from experts in products, processes and the environment as well as a flexible, goal driven, rule based decision model that can accommodate many environmental management perspectives. This includes allowing specific users to specify weighting factors for the impact decision model. This tool is extensible in that it can be utilized within the boundaries of a company and migrated to include suppliers and customers until full life cycles are assessed. We discussed the details and use of the environmental models available for the experts. We also showed how interviews with manufacturing experts led to the design of a goal-driven rule based reasoning system to support the problem solving. Finally, we offered a number of examples that detailed the types of analysis possible with EcoSys. Our ongoing work is to increase the precision of the environmental attributes database and to extend the product-process database to support a wider set of product analyses. Based on user feedback, we are also continuing to improve the X-Window user interface.

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Measuring the dynamic compression and release behavior of rocks associated with HYDROPLUS (Part 2)

Furnish, Michael D.

Three sets of rock samples have been subjected to planar impact to characterize loading, Hugoniot and release responses. A slate form Pennsylvania was tested over the stress range of 5 GPa to 140 GPa. Phyllite from the Lupin Mine (Canada) was tested over the 14--50 GPa stress region. Finally, granite samples from the SHIST test site (New Mexico) were tested over the 10--20 GPa stress region. The granite tests included a transmitted-wave experiment at about 10 GPa. In 12 of the 13 tests, a reverse-ballistic configuration (optimized for Hugoniot and release measurements) was used. The remaining test (conducted on the granite) provided a transmitted waveform from which precursor, Hugoniot and release properties were obtained. Velocity interferometry (VISAR) was used as the primary diagnostic throughout. The slate data showed an unexpected inflection downward in the Hugoniot at around 8 GPa. The slate and granite showed release paths lying below the Hugoniot for lower stress levels (below {approx} 60 GPa), while the slate release paths were ``normal`` (above the Hugoniot) at higher stress levels. In addition, the granite releases were found to lie substantially below the Hugoniot in the 30--40 GPa region; this may be related to the quartz-stishovite transition. The present results are generally consistent with earlier work.

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Hydrodynamic particle migration in a concentrated suspension undergoing flow between rotating eccentric cylinders

Mondy, L.A.

We report on experimental measurements and numerical predictions of shear-induced migration of particles in concentrated suspensions subjected to flow in the wide gap between a rotating inner cylinder placed eccentrically within a fixed outer cylinder (a cylindrical bearing). The suspensions consists of large, noncolloidal spherical particles suspended in a viscous Newtonian liquid. Nuclear magnetic resonance (NMR) imaging is used to measure the time evolution of concentration and velocity profiles as the flow induced particle migration from the initial, well-mixed state. A model originally proposed by Phillips et al. (1992) is generalized to two dimensions. The coupled equations of motion and particle migration are solved numerically using an explicit pseudo-transient finite volume formulation. While not all of the qualitative features observed in the experiments are reproduced by this general numerical implementation, the velocity predictions show moderately good agreement with the experimental data.

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An evaluation of prototype surface mount circuit boards assembled with three non-lead bearing solders

Vianco, Paul T.

Prototype circuit board test vehicles wee assembled with three candidate lead-free solders: 96.5Sn-3.5Ag (wt %), 58Bi-42Sn, and 91.84Sn-3.33 Ag 83Bi., using a forced-convection/infrared furnace and RMA flux based pastes. Wettability of circuit board features and packages was best with Sn-Ag-Bi alloy followed in order by Bi-Sn and Sn-Ag solders. The Sn-Ag-Bi solder had a greater propensity for void formation in the joints. The reliability assessment was based upon solder joint microstructure and the shear strength of selected leadless packages. Solder joint damage was of a greater extent after thermal shock exposures rather than thermal cycling. The Sn-Ag-Bi alloy on the largest package appeared most susceptible to thermal shock. Test vehicle performance clearly demonstrated that, with the non-lead solders, local thermal expansion mismatch can be as detrimental to joint integrity as the traditional global mismatch damage.

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Wave soldering with Pb-free solders

Vianco, Paul T.

The manufacturing feasibility and attachment reliability of a series of newly developed lead-free solders were investigated for wave soldering applications. Some of the key assembly aspects addressed included: wettability as a function of board surface finish, flux activation and surface tension of the molten solder, solder joint fillet quality and optimization of soldering thermal profiles. Generally, all new solder formulations exhibited adequate wave soldering performance and can be considered as possible alternatives to eutectic SnPb for wave soldering applications. Further process optimization and flux development is necessary to achieve the defect levels associated with the conventional SnPb process.

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The effect of microstructure on the thermal fatigue resistance of investment cast and wrought AISI H13 hot work die steel

Maguire, Michael C.

Variable thickness plate investment castings of AISI H13 hot work die steel were pour and characterized in the as-cast and heat treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 steel were heat treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples poured to different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat treatment, however, Microstructural differences between the wrought material and cast materials were slight regardless of section thickness. The mechanical properties of the cast and heat treated material proved similar to the properties of the standard heat treated wrought material. A thermal fatigue testing unit was designed and built to correlate the heat checking susceptibility of AISI H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was noticed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking; however, the heat-treat cast and as-cast H13 tool steel (made from standard grade wrought H13 tool steel) provided comparable resistance to heat checking in terms Of area fraction of heat checking and maximum crack length.

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An introduction to video image compression and authentication technology for safeguards applications

Johnson, C.S.

Verification of a video image has been a major problem for safeguards for several years. Various verification schemes have been tried on analog video signals ever since the mid-1970`s. These schemes have provided a measure of protection but have never been widely adopted. The development of reasonably priced complex video processing integrated circuits makes it possible to digitize a video image and then compress the resulting digital file into a smaller file without noticeable loss of resolution. Authentication and/or encryption algorithms can be more easily applied to digital video files that have been compressed. The compressed video files require less time for algorithm processing and image transmission. An important safeguards application for authenticated, compressed, digital video images is in unattended video surveillance systems and remote monitoring systems. The use of digital images in the surveillance system makes it possible to develop remote monitoring systems that send images over narrow bandwidth channels such as the common telephone line. This paper discusses the video compression process, authentication algorithm, and data format selected to transmit and store the authenticated images.

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The International Remote Monitoring Project: Results of the Swedish Nuclear Power Facility field trial

Johnson, C.S.; Af Ekenstam, G.; Sallstrom, M.

The Swedish Nuclear Power Inspectorate (SKI) and the US Department of Energy (DOE) sponsored work on a Remote Monitoring System (RMS) that was installed in August 1994 at the Barseback Works north of Malmo, Sweden. The RMS was designed to test the front end detection concept that would be used for unattended remote monitoring activities. Front end detection reduces the number of video images recorded and provides additional sensor verification of facility operations. The function of any safeguards Containment and Surveillance (C/S) system is to collect information which primarily is images that verify the operations at a nuclear facility. Barseback is ideal to test the concept of front end detection since most activities of safeguards interest is movement of spent fuel which occurs once a year. The RMS at Barseback uses a network of nodes to collect data from microwave motion detectors placed to detect the entrance and exit of spent fuel casks through a hatch. A video system using digital compression collects digital images and stores them on a hard drive and a digital optical disk. Data and images from the storage area are remotely monitored via telephone from Stockholm, Sweden and Albuquerque, NM, USA. These remote monitoring stations operated by SKI and SNL respectively, can retrieve data and images from the RMS computer at the Barseback Facility. The data and images are encrypted before transmission. This paper presents details of the RMS and test results of this approach to front end detection of safeguard activities.

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A{prime} (A-PRIMED): A case study in teamwork

Ashby, Rodema

June 1993, the A-PRIMED project (Agile Product Realization of electrMEchanical Devices) was formed with a concurrent engineering team of product designers, analysts, CNC machinists, robotic assembly scientists, electronics communications developers, statisticians and human factors scientists at Sandia National Laboratories, to develop and demonstrate a process for a much faster design-to-production cycle for precision electromechanical devices. The team had to develop the culture and infrastructure to support communications between remotely located members, as well as demonstrate a shortened cycle time made possible by developing new technologies. These new technologies were then adopted by the team and introduced to their work partners to support new work processes. By March 1995, the A-PRIMED team has used the new technologies and work processes to design and build qualified new products in only 24 days.

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Iodide retention by cinnabar (HgS) and chalcocite (Cu{sub 2}S)

Anderson, H.L.; Balsley, S.D.; Brady, P.V.

Sorption of iodide (I{sup {minus}}) on cinnabar (HgS) and chalcocite (Cu{sub 2}S) was examined as a function of pH at 25{degrees}C in a series of batch experiments. Calculated distribution ratios (K{sub d}) far exceed those reported for other minerals; maximal K{sub d}`s of 1375 cc/g (Cu{sub 2}S) and 3080 c/g (HgS) were observed between pH 4-5, but wre substantial at all pH`s measured (4 < pH < 10). Iodide sorption apparently occurs by the formation of an insoluble surface solid solution with exposed Hg and Cu sites. Surface solid solution formation is favored at low pH due to the lessened electrostatic repulsion of the iodide ion by the sulfide surfaces.

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Resistor capacitor, primitive variable solution of buoyant fluid flow within an enclosure with highly temperature dependent viscosity

Gianoulakis, Steven E.

A numerical solution for buoyant natural convection within a square enclosure containing a fluid with highly temperature dependent viscosity is presented. Although the fluid properties employed do not represent any real fluid, the large variation in the fluid viscosity with temperature is characteristic of turbulent flow modeling with eddy-viscosity concepts. Results are obtained using a primitive variable formulation and the resistor method. The results presented include velocity, temperature and pressure distributions within the enclosure as well as shear stress and heat flux distributions along the enclosure walls. Three mesh refinements were employed and uncertainty values are suggested for the final mesh refinement. These solutions are part of a contributed benchmark solution set for the subject problem.

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Reactor physics calculations for {sup 99}Mo production at the Annular Core Research Reactor

Parma, E.J.

The isotope {sup 99}Mo would be produced at Sandia using ACRR and the collocated Hot Cell Facility. {sup 99}Mo would be produced by irradiating targets coated with {sup 235}U in the form of highly enriched U{sub 3}O{sub 8}; after 7 days, the target would be removed and the isotope extracted using the Cintichem process. The Monte Carlo neutronics computer code MCNP was used to determine the optimum configuration for production, using various fractions of the US demand. Although ACRR operates at a low power level, the US demand for {sup 99}Mo can be easily met using a reasonable number of targets.

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Characterization techniques to validate models of density variations in pressed powder compacts

Garino, Terry J.

Techniques for characterizing density gradients generated during typical powder compaction processes are reviewed and several are evaluated. The techniques reviewed are ultrasonic velocity measurements, laser ultrasonic velocity measurements, x-ray radiography, autoradiography, computer tomography (CT), magnetic resonance imaging (MRI), and simple image analysis of polished cross-sections. Experimental results are reported for all of these techniques except autoradiography, CT and MRI. The test specimens examined were right circular cylinders of a high length/diameter ratio (to ensure significant density variation) pressed from commercial spray-dried alumina powders. Although the density gradients could be detected with all four techniques, ultrasonic velocity measurements gave the best contour map of gradients and is therefore most suitable for model validation. On the other hand, it was concluded that x-ray radiography is preferable in situations where cost and/or number of samples are more important that high resolution.

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A bimodal spacecraft bus based on a cermet fueled heat pipe reactor

Polansky, Gary F.

Bimodal space reactor systems provide both thermal propulsion for the spacecraft orbital transfer and electrical power to the spacecraft bus once it is on station. These systems have the potential to increase both the available payload in high energy orbits and the available power to that payload. These increased mass and power capabilities can be used to either reduce mission cost by permitting the use of smaller launch vehicles or to provide increased mission performance from the current launch vehicle. A major barrier to the deployment of these bimodal systems has been the cost associated with their development. This paper describes a bimodal spacecraft bus with performance potential to permit more than 70% of the instrumented payload of the Titan IV/Centaur to be launched from the Atlas IIAS. The development cost is minimized by basing the design on existing component technologies.

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Low temperature pyrotechnic smokes: A potential low cost alternative to nonpyrotechnic smoke for access delay applications

Greenholt, Charles J.

Smokes are frequently used as visual obscurants in access delay applications. A new generation of low temperature pyrotechnic smokes is being developed. Terephthalic Acid (TPA) smoke was developed by the U.S. Army and Sebacic Acid (SA) smoke is being developed by Thiokol Corp. The advantages these smokes offer over traditional pyrotechnic smokes include; low generation temperature (approximately 450{degree}C), lower toxicity, and lower corrosivity. The low generation temperature reduces smoke layering effects and allows the addition of sensory irritants, such as o-Chlorobenzylidene Malononitrile (CS), to the formulation. Some advantages low temperature pyrotechnic smokes offer over nonpyrotechnic smokes include; low cost, simplicity, compactness, light weight, long storage life, and orientation insensitive operation. Low cost permits distribution of multiple units for reduced vulnerability and refill flexibility. Some disadvantages may include the combustibility of the smoke particulate; however, the published lower explosive limit of the mentioned materials is approximately ten times greater than the concentration required for effective obscuration. The TPA smoke cloud contains small quantities of benzene, formaldehyde, and carbon monoxide; no benzene or formaldehyde was identified during preliminary SA smoke analyses performed by Thiokol Corp. Sandia performed tests and analyses on TPA smoke to determine the smoke cloud composition, the quantity of particulate produced per canister, and the relationship between airborne particulate concentration and measured optical density values. Current activities include characterization of SA smoke.

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Explosion proofing the ``explosion proof`` vacuum cleaner

Jones, R.D.; Chen, K.C.; Holmes, S.W.

Because of the low humidity environments required in the fabrication of nuclear explosives, assembly technicians can be charged to tens of kilovolts while operating, for example, compressed air, venturi-type, `explosion proof` vacuum cleaners. Nuclear explosives must be isolated from all sources of, and return paths for, AC power and from any part of the lightning protection system. This requirement precludes the use of static ground conductors to drain any charge accumulations. Accordingly, an experimental study of the basic charging mechanisms associated with vacuum operations were identified, the charge generation efficacies of various commercial cleaners were established, and a simple method for neutralizing the charge was devised.

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Use of silica sols in inorganic molecular sieving membranes

Brinker, C.J.

Polymeric silica sols, were deposited on commercial {gamma}-alumina supports to prepare gas separation membranes. Optimization of the sol fractal dimension and radius of gyration and minimization of condensation rate led to formation of a discrete film with pores of molecular dimensions. Two coatings of this sol (A2{sup **}) led to a membrane with ideal separation factor of 7 for helium versus nitrogen after calcination to 400C (helium permeance 0.002 cm{sup 3}/cm{sup 2}-s-cm Hg). Partial sintering of these membranes resulted in a further reduction in pore size or narrowing of pore size distribution as evidenced by larger separation factors e.g. 9 for helium versus nitrogen (helium permeance 0.0028 cm{sup 3}/cm{sup 2}-s-cm Hg) with only one A2{sup **} coating. Single gas measurements also showed high ideal separation factors for helium versus methane, propylene, sulfur hexafluoride and carbon dioxide. The deposited A2{sup **} membrane was reacted with titanium isopropoxide (Ti(O i-Pr){sub 4}) to improve both its thermal and chemical stability and modify its pore size. This reaction led to an increase in the membrane selectivity to >300 for He versus N{sub 2} below to 120C, and CO{sub 2} versus CH{sub 4}, when measured below 200C. A2{sup **} was also used as a host matrix for preparing imogolite composite membranes that showed molecular sieving behavior.

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Beneficial effects of the aluminum alloy process as practiced in the photovoltaic device fabrication laboratory

Schubert, William K.

The aluminum alloy process implemented in Sandia`s Photovoltaic Device Fabrication Laboratory (PDFL) has major beneficial effects on the performance of commercial multicrystalline-silicon (mc-Si) substrates. Careful analysis of identically processed cells (except for the alloyed layer) in matched mc-Si substrates clearly indicates that the majority of the benefit arises from improved bulk minority carrier diffusion length. Based on spectral response measurements and PC-1D modeling the authors have observed improvements due to the alloy process of up to 400% in the average diffusion length in moderate-area cells and around 50% in large-area cells. The diffusion length is dramatically improved in the interior of the silicon grains in alloyed substrates, resulting in the majority of the recombination occurring at the grain boundaries and localized areas with high defect densities.

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The spent fuel safety experiment

Harms, Gary A.

The Department of Energy is conducting an ongoing investigation of the consequences of taking fuel burnup into account in the design of spent fuel transportation packages. A series of experiments, collectively called the Spent Fuel Safety Experiment (SFSX), has been devised to provide integral benchmarks for testing computer-generated predictions of spent fuel behavior. A set of experiments is planned in which sections of unirradiated fuel rods are interchanged with similar sections of spent PWR fuel rods in a critical assembly. By determining the critical size of the arrays, one can obtain benchmark data for comparison with criticality safety calculations. The integral reactivity worth of the spent fuel can be assessed by comparing the measured delayed critical fuel loading with and without spent fuel. An analytical effort to model the experiments and anticipate the core loadings required to yield the delayed critical conditions runs in parallel with the experimental effort.

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Proposal for broader United States-Russian transparency of nuclear arms reductions

Percival, C.M.

During the January 1994 Summit Presidents Clinton and Yeltsin agreed on the goal of ensuring the ``transparency and irreversibility`` of the nuclear arms reduction process. As a result, negotiations are presently underway between the United States Government and the Russian Federation to confirm the stockpiles of plutonium and highly enriched uranium removed from nuclear weapons. In December 1994 the United States presented a paper to the Russian Federation proposing additional measures to provide broader transparency of nuclear arms reduction. The US Department of Energy is studying the implementation of these broader transparency measures at appropriate DOE facilities. The results of the studies include draft protocols for implementation, assessments of the implementation procedures and the impacts on the facilities and estimates of the cost to implement these measures at various facilities.

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Development and design of a high pressure carbon dioxide system for the separation of hazardous contaminants from non-hazardous debris

Adkins, Carol L.

Under the Department of Energy (DOE)/United States Air Force (USAF) Memorandum of Understanding, a system is being designed that will use high pressure carbon dioxide for the separation of oils, greases, and solvents from non-hazardous solid waste. The contaminants are dissolved into the high pressure carbon dioxide and precipitated out upon depressurization. The carbon dioxide solvent can then be recycled for continued use. Excellent extraction capability for common manufacturing oils, greases, and solvents has been measured. It has been observed that extraction performance follows the dilution model if a constant flow system is used. The solvents tested are extremely soluble and have been extracted to 100% under both liquid and mild supercritical carbon dioxide conditions. These data are being used to design a 200 liter extraction system.

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Remote video assessment for missile launch facilities

Wagner, George G.

The widely dispersed, unmanned launch facilities (LFs) for land-based ICBMs (intercontinental ballistic missiles) currently do not have visual assessment capability for existing intrusion alarms. The security response force currently must assess each alarm on-site. Remote assessment will enhance manpower, safety, and security efforts. Sandia National Laboratories was tasked by the USAF Electronic Systems Center to research, recommend, and demonstrate a cost-effective remote video assessment capability at missile LFs. The project`s charter was to provide: system concepts; market survey analysis; technology search recommendations; and operational hardware demonstrations for remote video assessment from a missile LF to a remote security center via a cost-effective transmission medium and without using visible, on-site lighting. The technical challenges of this project were to: analyze various video transmission media and emphasize using the existing missile system copper line which can be as long as 30 miles; accentuate and extremely low-cost system because of the many sites requiring system installation; integrate the video assessment system with the current LF alarm system; and provide video assessment at the remote sites with non-visible lighting.

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A sensitivity analysis of the WIPP disposal room model: Phase 1

Labreche, D.A.; Beikmann, M.A.; Osnes, J.D.; Butcher, B.M.

The WIPP Disposal Room Model (DRM) is a numerical model with three major components constitutive models of TRU waste, crushed salt backfill, and intact halite -- and several secondary components, including air gap elements, slidelines, and assumptions on symmetry and geometry. A sensitivity analysis of the Disposal Room Model was initiated on two of the three major components (waste and backfill models) and on several secondary components as a group. The immediate goal of this component sensitivity analysis (Phase I) was to sort (rank) model parameters in terms of their relative importance to model response so that a Monte Carlo analysis on a reduced set of DRM parameters could be performed under Phase II. The goal of the Phase II analysis will be to develop a probabilistic definition of a disposal room porosity surface (porosity, gas volume, time) that could be used in WIPP Performance Assessment analyses. This report documents a literature survey which quantifies the relative importance of the secondary room components to room closure, a differential analysis of the creep consolidation model and definition of a follow-up Monte Carlo analysis of the model, and an analysis and refitting of the waste component data on which a volumetric plasticity model of TRU drum waste is based. A summary, evaluation of progress, and recommendations for future work conclude the report.

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A survey of early warning technologies

Williams, J.D.

This paper presents a survey of technologies useful in providing early warning in physical security systems. Early warning is important in virtually all types of security systems whether they are used for temporary (tactical, portable, or semi-permanent) applications, border warning, fixed-site detection, or standoff surveillance detection. With the exception of the standoff surveillance detection systems, all systems discussed in this paper usually involve a moving target. The fact that a person(s) to be detected in a standoff surveillance scenario is not moving presents challenging problems and requires different applications of technology. The technologies commonly used to detect moving targets and some suggestions for detection of stationary targets are addressed in this paper.

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Safeguards and security issues for the disposition of fissile materials

Jaeger, Cal

The Department of Energy`s Office of Fissile Material Disposition (FMD) is analyzing long-term storage and disposition options for surplus weapons-usable fissile materials, preparing a programmatic environmental impact statement (PEIS), preparing for a record of decision (ROD) regarding this material and conducting other activities. The primary security objectives of this program are to reduce major security risks and strengthen arms reduction and nonproliferation (NP). To help achieve these objectives, a safeguards and security (S&S) team consisting of participants from Sandia, Los Alamos, and Lawrence Livermore National Laboratories was established. The S&S activity for this program is a cross-cutting task which addresses all of the FMD program options. It includes both domestic and international safeguards and includes areas such as physical protection, nuclear materials accountability and material containment and surveillance. This paper will discuss the activities of the Fissile Materials Disposition Program (FMDP) S&S team as well as some specific S&S issues associated with various FMDP options/facilities. Some of the items to be discussed include the threat, S&S requirements, S&S criteria for assessing risk, S&S issues concerning fissile material processing/facilities, and international and domestic safeguards.

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Active control of bending vibrations in thick bars using PZT stack actuators

Redmond, James M.

An experimental investigation into active control of bending vibrations in thick bar and plate-like structural elements is described. This work is motivated by vibration problems in machine tools and photolithography machines that require greater control authority than available from conventional surface mounted PZT patches or PVDF films. Focus of this experiment is a cantilevered circular steel bar in which PZT stacks are mounted in cutouts near the bar root. Axially aligned and offset from the neutral axis, these actuators control the bending vibrations by generating moments in the bar through their compressive loads. A Positive Feedback control law is used to significantly augment the damping in the first bending mode. Implications of the experimental results for machine tool stability enhancement are discussed.

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Photonics at Sandia National Laboratories: Applying device technology to communication systems

Carson, R.F.

Photonic device activities at Sandia National Laboratories are founded on an extensive materials research program that has expanded to include device development, and an applications focus that heavily emphasizes communications and interconnects. The resulting program spans a full range of photonics research, development, and applications projects, from materials synthesis and device fabrication to packaging, test, and subsystem development. The heart of this effort is the Compound Semiconductor Research Laboratory which was established in 1988 to bring together device and materials research and development to support Sandia`s role in weapons technologies. This paper presents an overview of Sandia`s photonics program and its directions, using three communications-based applications as examples.

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New PAMTRAK features

Dahly, B.

Sandia is developing a Personnel and Material Tracking System (PAMTRAK) which uses a variety of techniques to monitor material inside a vault in real-time. It can detect material movement using video cameras inside the vault or motion sensors attached to the material. It also contains two prototype attribute monitoring systems that continuously measure material weight, temperature or movement. A site can use any of these alone or together to extend physical inventory intervals. PAMTRAK can reduce the cost of storing material by reducing inventory frequency and radiation exposure to workers. Analysis at Savannah River in 1992 estimated that installing PAMTRAK in the 7 active and future vaults at that site would save $1,073,000 per year by reducing inventory frequency from monthly to yearly. Performing similar calculations now, assuming lower radiation exposure limits of 700m Rem per year, new inventory reduction guidelines allowing a baseline interval of 6 months, and an achieved inventory interval of 3 years, results in an estimated average savings of $400,000 per year. PAMTRAK, since it is real-time, can detect theft or diversion soon enough to give the guard force a chance of recovering the material and apprehending the perpetrator. In performing an inventory a site typically checks only a fraction of the material using random, statistical sampling, while PAMTRAK monitors all material in the vault. In addition to static environments such as vaults, PAMTRAK can be used to protect material in active work areas. Several of the sensor types can ignore activity around material but still report alarms if the material is moved or handled. PAMTRAK includes a personnel tracking capability that allows a site to monitor and restrict personnel movements. It can exclude workers from designated areas unless they have explicit permission to be there. It can also enforce the 2-person rule by requiring a worker to be accompanied by at least one other qualified worker.

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Understanding and managing risk in software systems

Fletcher, S.K.; Jansma, R.; Lim, J.; Murphy, M.; Wyss, G.

When software is used in safety-critical, security-critical, or mission-critical situations, it is imperative to understand and manage the risks involved. A risk assessment methodology and toolset have been developed which are specific to software systems. This paper describes the concepts of the methodology, with emphasis on the experience of designing a toolset to support the methodology. Also presented are results of applying the methodology to two real software-based products: the software toolset itself, and a network firewall.

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English/Russian and Russian/English glossary of physical protection terms

Rudolfo, Gerald F.

This glossary was prepared in fulfillment of the Glossary Preparation Task identified in the Program Plan for providing Assistance to the Russian Federation in Nuclear Material Control and Accounting and Physical Protection. The Program Plan is part of the Cooperative Threat Reduction Program as provided for under House Resolution (H.R.) 3807 (Title II, as referenced under Public Law (P.L.) 102-229. The terms in this glossary were derived from physical protection training material prepared at Sandia. The training material, and thus refinements to the glossary, has undergone years of development in presentation to both domestic and international audiences. Also, Russian Colleagues and interpreters have reviewed the translations for accuracy.

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Assessment of utility side cost savings from battery energy storage

Jungst, Rudolph G.

A method of determining the dynamic operating cost benefits of energy storage systems for utility applications is presented. The production costing program DYNASTORE is used to analyze economic benefits for ``utility B,`` an isolated island utility, using heuristic unit commitment algorithms. The unit commitment is done using chronologic load data and a detailed model of the utility characteristics. Several unit commitment scenarios are run for utility B, and the results are presented. Comparisons between various Battery Energy Storage System (BESS) applications, as well as cases with and without battery storage, are shown. Results show that for utility B, a BESS of 300 MW size used for either load leveling or spinning reserve provides the greatest economic benefit.

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Investigation of the effect of microstructure on the R-Curve behavior of metal-ceramic composites

Ewsuk, Kevin G.

An investigation was made into the effect of microstructure on the peak toughness and shape of the crack growth resistance curves for two ceramic-metal composites. An Al{sup 2}O{sup 3}/Al composite formed by Reactive Metal Penetration was used along with an AlN/Al composite formed using a reactive infiltration technique. The results indicate that the toughness increases with an increase in the volume fraction of the metal phase for a particular composite composition, and the peak toughness and shape of the R-Curve also depend on the composite microstructure and metal composition.

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Air intake shaft performance tests (Shaft 5): In situ data report (May 1988--July 1995). Waste Isolation Pilot Plant (WIPP) Thermal/Structural Interactions Program

Munson, Darrell E.

Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991.

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VR/IS Lab Virtual Actor research overview

Stansfield, S.

This overview presents current research at Sandia National Laboratories in the Virtual Reality and Intelligent Simulation Lab. Into an existing distributed VR environment which we have been developing, and which provides shared immersion for multiple users, we are adding virtual actor support. The virtual actor support we are adding to this environment is intended to provide semi-autonomous actors, with oversight and high-level guiding control by a director/user, and to allow the overall action to be driven by a scenario. We present an overview of the environment into which our virtual actors will be added in Section 3, and discuss the direction of the Virtual Actor research itself in Section 4. We will briefly review related work in Section 2. First however we need to place the research in the context of what motivates it. The motivation for our construction of this environment, and the line of research associated with it, is based on a long-term program of providing support, through simulation, for situational training, by which we mean a type of training in which students learn to handle multiple situations or scenarios. In these situations, the student may encounter events ranging from the routine occurance to the rare emergency. Indeed, the appeal of such training systems is that they could allow the student to experience and develop effective responses for situations they would otherwise have no opportunity to practice, until they happened to encounter an actual occurance. Examples of the type of students for this kind of training would be security forces or emergency response forces. An example of the type of training scenario we would like to support is given in Section 4.2.

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Micro-telerobotic applications for microsurgery

Kozlowski, David M.

MicroDexterity Systems Inc. and Sandia National Laboratories are collaborating on the design of a six degree-of-freedom surgeon-controlled micropositioner and a six degree-of-freedom surgeon-controlled master for use in microsurgery. A control system will provide the linkage between the force-reflecting master and micropositioner for force scaling, position scaling, and tremor filtering. The technologies developed by this project are expected to enhance the skills of surgeons, improve the success rates for existing microsurgical procedures, make new high-dexterity procedures possible, and ultimately reduce surgical costs by increasing the precision and speed of operations. This paper discusses the motivation, approach, and accomplishments to date.

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GaAs integrated circuit process characterization and non-destructive process monitoring by atomic force microscopy

Baca, A.G.

We report a new application of atomic force microscopy (AFM) for process characterization of GaAs integrated circuit fabrication. By using the near atomic-level z-resolution of AFM, we are able to gain information not available by other imaging techniques in a number of steps in the sequence for GaAs IC fabrication. A nondestructive method of determining whether micron-sized vias have been etched to completion is presented. In addition, the AFM has been used to evaluate material removal following several of fabrication steps. Shallow trench formation occurs as a result of GaAs removal during the sidewall etch for a commonly used sidewall spacer process. This effect has been not been observed previously by other techniques. Other examples of unintentional removal of small amounts of GaAs during shallow wet and dry etches are presented. These examples show the utility of AFM as an in-line process characterization tool.

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Performance benefits of telerobotics and teleoperation - enhancements for an arm-based tank waste retrieval system

Horschel, Daniel S.

This report evaluates telerobotic and teleoperational arm-based retrieval systems that require advanced robotic controls. These systems will be deployed in waste retrieval activities in Hanford`s Single Shell Tanks (SSTs). The report assumes that arm-based, retrieval systems will combine a teleoperational arm and control system enhanced by a number of advanced and telerobotic controls. The report describes many possible enhancements, spanning the full range of the control spectrum with the potential for technical maturation. The enhancements considered present a variety of choices and factors including: the enhancements to be included in the actual control system, safety, detailed task analyses, human factors, cost-benefit ratios, and availability and maturity of technology. Because the actual system will be designed by an offsite vendor, the procurement specifications must have the flexibility to allow bidders to propose a broad range of ideas, yet build in enough restrictions to filter out infeasible and undesirable approaches. At the same time they must allow selection of a technically promising proposal. Based on a preliminary analysis of the waste retrieval task, and considering factors such as operator limitations and the current state of robotics technology, the authors recommend a set of enhancements that will (1) allow the system to complete its waste retrieval mission, and (2) enable future upgrades in response to changing mission needs and technological advances.

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An ``exact`` treatment of self-shielding and covers in neutron spectra determinations

Griffin, Patrick J.

Most neutron spectrum determination methodologies ignore self-shielding effects in dosimetry foils and treat covers with an exponential attenuation model. This work provides a quantitative analysis of the approximations in this approach. It also provides a methodology for improving the fidelity of the treatment of the dosimetry sensor response to a level consistent with the user`s spectrum characterization approach. A library of correction functions for the energy-dependent sensor response has been compiled that addresses dosimetry foils/configurations in use at the Sandia National Laboratories Radiation Metrology Laboratory.

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An up-scaled, buoyant invasion percolation model for use in delineating subsurface DNAPL location

Conrad, Stephen H.

We introduce an up-scaled, buoyant invasion percolation model (UIP) for application to non-wetting, dense, non-aqueous phase liquid (DNAPL) migration at the geologic formation scale within the saturated zone of an aquifer. The UEP model incorporates a gravitational potential to model the displacement of fluids of different densities and can be used for either LNAPLs (lighter than water) or DNAPLs (denser than water). We demonstrate model behavior in a simulated braided stream deposit. Simulations show the influence of textural changes across layers and gravity forces in controlling DNAPL migration. While our results are encouraging, the application of this up-scaled percolation model requires a series of tests both in the laboratory and in the field before judgment of sufficient validity for its intended purpose is achieved.

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Technical status of the Dish/Stirling Joint Venture Program

Bean, J.R.; Diver, R.B.

Initiated in 1991; the Dish/Stirling Joint Venture Program (DSJVP) is a 5-year, $17.2 million joint venture which is funded by Cummins Power Generation, Inc. (CPG) of Columbus, Indiana and the United States Department of Energy`s (DOE) Solar Thermal and Biomass Power Division. Sandia National Laboratories administers and provides technical management for this contract on the DOE`s behalf. In January, 1995; CPG advanced to Phase 3 of this three-phase contract. The objective of the DSJVP is to develop and commercialize a 7-kW. Dish/Stirling System for remote power markets by 1997. In this paper, the technical status of the major subsystems which comprise the CPG 7-kW{sub e} Dish/Stirling System is presented. These subsystems include the solar concentrator, heat pipe receiver, engine/alternator, power conditioning, and automatic controls.

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Preliminary evaluation of techniques for transforming regional climate model output to the potential repository site in support of Yucca Mountain future climate synthesis

Church, H.W.; Zak, B.D.; Behl, Y.K.

The report describes a preliminary evaluation of models for transforming regional climate model output from a regional to a local scale for the Yucca Mountain area. Evaluation and analysis of both empirical and numerical modeling are discussed which is aimed at providing site-specific, climate-based information for use by interfacing activities. Two semiempirical approaches are recommended for further analysis.

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Formulation and numerical analysis of nonisothermal multiphase flow in porous media

Martinez, Mario J.

A mathematical formulation is presented for describing the transport of air, water and energy through porous media. The development follows a continuum mechanics approach. The theory assumes the existence of various average macroscopic variables which describe the state of the system. Balance equations for mass and energy are formulated in terms of these macroscopic variables. The system is supplemented with constitutive equations relating fluxes to the state variables, and with transport property specifications. Specification of various mixing rules and thermodynamic relations completes the system of equations. A numerical simulation scheme, employing the method of lines, is described for one-dimensional flow. The numerical method is demonstrated on sample problems involving nonisothermal flow of air and water. The implementation is verified by comparison with existing numerical solutions.

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Modeling of capillary barriers and comparison to data

Webb, Stephen W.

Measurements of capillary barrier performance have been conducted in above-grade wooden structures (boxes) configured to measure the water balance. The capillary-barrier portion of the boxes is 6.0 m long, 2.0 m wide, and 1.2 m high with a slope of 5%. A coarse-grained material was placed in the bottom 25-cm of the box with a 90-cm deep fine-grained material (local soil) on top. A region for laterally diverted water to accumulate and drain was created in the last 1.0 m of the box. The soil at the top is terraced into five, 1.4 m long, level intervals to prevent runoff when adding water. Water is added uniformly to the entire top of the box at a rate of about 66 l/day, or an infiltration rate of 1.7 m/year. The top of the box is covered with fiber-reinforced plastic to minimize evaporation of water, discourage plant growth, and prevent rainfall from contacting the soil. Five drains are spaced along the bottom of the coarse layer. These drains discretize the coarse layer into five collection regions to provide a means of identifying the breakthrough location into the coarse layer. A drain is also located in the downdip collection region of the box. Soil moisture changes were measured in the fine-grained material with a frequency-domain reflectometry (FDR) probe, which was calibrated using soil from the field site at a known moisture content and density.

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Hydrotreating of coal-derived liquids

Stohl, F.V.

The objective of Sandia`s refining of coal-derived liquids project is to determine the relationship between hydrotreating conditions and Product characteristics. The coal-derived liquids used in this work were produced In HTI`s first proof-of-concept run using Illinois No. 8 coal. Samples of the whole coal liquid product, distillate fractions of this liquid, and Criterion HDN-60 catalyst were obtained from Southwest Research Inc. Hydrotreating experiments were performed using a continuous operation, unattended, microflow reactor system. A factorial experimental design with three variables (temperature, (310{degrees}C to 388{degrees}C), liquid hourly space velocity (1 to 3 g/h/cm{sup 3}(cat)), pressure (500 to 1000 psig H{sub 2}) is being used in this project. Sulfur and nitrogen contents of the hydrotreated products were monitored during the hydrotreating experiments to ensure that activity was lined out at each set of reaction conditions. Results of hydrotreating the whole coal liquid showed that nitrogen values in the products ranged from 549 ppM at 320{degrees}C, 3 g/h/cm{sup 3}(cat), 500 psig H{sub 2} to <15 ppM at 400{degrees}C, 1 g/h/ cm{sup 3}(cat), 1000 psig H{sub 2}.

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Creep in Topopah Spring Member welded tuff. Yucca Mountain Site Characterization Project

Price, Ronald H.

A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 {times} 10{sup 5} seconds and for as long as 1.8 {times} 10{sup 6} seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress.

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Evaluation of commercially available exterior digital VMDs

Ringler, C.E.

This report discusses the testing and evaluation of thirteen commercially available exterior digital video motion detection (VMD) systems. The systems were evaluated for use in a specific outdoor application. The report focuses primarily on the testing parameters, each system`s advertised features, and the nuisance alarm and detection test results.

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Bridged polysilsesquioxane xerogels: A molecular based approach for the preparation of porous hybrid organic-inorganic materials

Loy, Douglas A.

Bridged polysilsesquioxanes represent an interesting family of hybrid organic-inorganic composite materials. It has been shown that manipulation of the organic bridging component offers the potential for the synthesis of a variety of materials with a range of surface areas and porosities. In addition, incorporation of a heteroatom within the bridging organic component allows for further chemical transformation of the polysilsesquioxane material.

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Multicomponent three-phase equilibria

Ho, Clifford K.

This paper presents the relations that describe thermodynamic equilibrium in a three-phase system. Multiple components, including air, water, and oil components, are considered in three phases: (1) aqueous, (2) oil, and (3) gas. Primary variables are specified for each of seven possible phase combinations. These primary variables are then used to determine the necessary secondary variables to completely describe the system. Criteria are also developed to check the stability of each phase configuration and determine possible transitions from one phase configuration to another phase configuration via phase appearances and disappearances.

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Trapping of radiation in plasmas

Riley, Merle E.

The authors analyze the problem of radiation trapping (imprisonment) by the method of Holstein. The process is described by an integrodifferential equation which shows that the effective radiative decay rate of the system depends on the size and the shape of the active medium. Holstein obtains a global decay rate for a particular geometry by assuming that the radiating excited species evolves into a steady state spatial mode. The authors derive a new approximation for the trapped decay which has a space dependent decay rate and is easy to implement in a detailed computer simulation of a plasma confined within an arbitrary geometry. They analyze the line shapes that are relevant to a near-atmospheric-pressure mixture of He and Xe. This line-shape analysis can be utilized in either the Holstein formulae or the space-dependent decay approximation.

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Polyelectrolyte gels

Segalman, Daniel J.

Polyelectrolyte (PE) gels are swollen polymer/solvent networks that undergo a reversible volume collapse/expansion through various types of stimulation. Applications that could exploit this large deformation and solvent expulsion/absorption characteristics include robotic {open_quotes}fingers{close_quotes} and drug delivery systems. The goals of the research were to first explore the feasibility of using the PE gels as {open_quotes}smart materials{close_quotes} - materials whose response can be controlled by an external stimulus through a feedback mechanism. Then develop a predictive capability to simulate the dynamic behavior of these gels. This involved experimentally characterizing the response of well-characterized gels to an applied electric field and other stimuli to develop an understanding of the underlying mechanisms which cause the volume collapse. Lastly, the numerical analysis tool was used to simulate various potential engineering devices based on PE gels. This report discusses the pursuit of those goals through experimental and computational means.

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Observations of the boiling process from a downward-facing torispherical surface: Confirmatory testing of the heavy water new production reactor flooded cavity design

Chu, Tze Y.

Reactor-scale ex-vessel boiling experiments were performed in the CYBL facility at Sandia National Laboratories. The boiling flow pattern outside the RPV bottom head shows a center pulsating region and an outer steady two-phase boundary layer region. The local heat transfer data can be correlated in terms of a modified Rohsenow correlation.

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CONTAIN code analyses of direct containment heating (DCH) experiments

Williams, D.C.; Griffith, R.O.; Tadios, E.L.; Washington, K.E.

In some nuclear reactor core melt accidents, a potential exists for molten core debris to be dispersed into the containment under high pressure. Resulting energy transfer to the containment atmosphere can pressurize the containment. This process, known as direct containment heating (DCH), has been the subject of extensive experimental and analytical programs sponsored by the US Nuclear Regulatory Commission (NRC). DCH modeling has been a major focus for the development of the CONTAIN code. In support of the peer review, extensive analyses of DCH experiments were performed in order to assess the CONTAIN code`s DCH models and improve understanding of DCH phenomenology. The present paper summarizes this assessment effort.

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Aging assessment for active fire protection systems

Martin, Tina T.

This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

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Identification of remediation needs and technology development focus areas for the Environmental Restoration (ER) Project at Sandia National Laboratories/New Mexico (SNL/NM)

Tucker, Mark D.

The Environmental Restoration (ER) Project has been tasked with the characterization, assessment, remediation and long-term monitoring of contaminated waste sites at Sandia National Laboratories/New Mexico (SNL/NM). Many of these sites will require remediation which will involve the use of baseline technologies, innovative technologies that are currently under development, and new methods which will be developed in the near future. The Technology Applications Program (TAP) supports the ER Project and is responsible for development of new technologies for use at the contaminated waste sites, including technologies that will be used for remediation and restoration of these sites. The purpose of this report is to define the remediation needs of the ER Project and to identify those remediation needs for which the baseline technologies and the current development efforts are inadequate. The area between the remediation needs and the existing baseline/innovative technology base represents a technology gap which must be filled in order to remediate contaminated waste sites at SNL/NM economically and efficiently. In the first part of this report, the remediation needs of the ER Project are defined by both the ER Project task leaders and by TAP personnel. The next section outlines the baseline technologies, including EPA defined Best Demonstrated Available Technologies (BDATs), that are applicable at SNL/NM ER sites. This is followed by recommendations of innovative technologies that are currently being developed that may also be applicable at SNL/NM ER sites. Finally, the gap between the existing baseline/innovative technology base and the remediation needs is identified. This technology gap will help define the future direction of technology development for the ER Project.

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1994 Ergonomics Program Quality Evaluation

Miller, Dwight P.

A telephone survey was conducted to evaluate the quality of service provided to the primary customers of the Corporate Ergonomics Group (CEG). One hundred clients who received services between October 1993 and June 1994 were asked questions on their expectations, implementation of ergonomic recommendations, follow-ups, time required, productivity improvements, symptom alleviation, and satisfaction. Suggestions on how processes could be improved were also solicited. In general, recommendations are being implemented, worksite evaluations are going smoothly, and customers are satisfied with the process. The CEG was pleased to learn that half of the people who implemented recommendations experienced improvements in productivity, and four out of five symptomatic customers experienced partial or complete relief. Through analysis of the data and by studying clients` suggestions for process improvement, the CEG has developed a strategy for changing and improving current procedures and practices. These plans can be found in the last section of this report.

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The pulsed linear induction motor concept for high-speed trains

Turman, Bobby N.

The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

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Developing New Mexico Health Care Policy: An application of the Vital Issues Process

Engi, Dennis E.

The Vital Issues Process, developed by the Sandia National Laboratories Strategic Technologies Department, was utilized by the Health Care Task Force Advisory Group to apply structure to their policy deliberations. By convening three expert panels, an overarching goal for the New Mexico health care system, seven desired outcomes, nine policy options, and 17 action items were developed for the New Mexico health care system. Three broadly stated evaluation criteria were articulated and used to produce relative rankings of the desired outcomes and policy options for preventive care and information systems. Reports summarizing the policy deliberations were submitted for consideration by the Health Care Task Force, a Joint Interim Committee of the New Mexico Legislature, charged with facilitating the development and implementation of a comprehensive health care delivery system for New Mexico. The Task Force reported its findings and recommendations to the Second Session of the 41st New Mexico State Legislature in January 1994.

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The Automated Assembly Team contributions to the APRIMED Agile Manufacturing Project

Jones, R.E.

The Automated Assembly Team of the APRIMED Project (abbreviated as A{prime}) consists of two parts: the Archimedes Project, which is an ongoing project developing automated assembly technology, and the A{prime} Robot Team. Archimedes is a second generation assembly planning system that both provides a general high-level assembly sequencing capability and, for a smaller class of products, facilitates automatic programming of a robotic workcell to assemble them. The A{prime} robot team designed, developed, and implemented a flexible robot workcell which served as the automated factory of the A{prime} project. In this document we briefly describe the role of automated assembly planning in agile manufacturing, and specifically describe the contributions of the Archimedes project and the A{prime} robot team to the A{prime} project. We introduce the concepts of the Archimedes automated assembly planning project, and discuss the enhancements to Archimedes which were developed in response to the needs of the A{prime} project. We also present the work of the A{prime} robot team in designing and developing the A{prime} robot workcell, including all tooling and programming to support assembly of the A{prime} discriminator devices. Finally, we discuss the process changes which these technologies have enabled in the A{prime} project.

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Team learning center design principles

Tapp, Charles M.

This is a preliminary report of a multi-year collaboration of the authors addressing the subject: Can a facility be designed for team learning and would it improve the efficiency and effectiveness of team interactions? Team learning in this context is a broad definition that covers all activities where small to large groups of people come together to work, to learn, and to share through team activities. Multimedia, networking, such as World Wide Web and other tools, are greatly enhancing the capability of individual learning. This paper addresses the application of technology and design to facilitate group or team learning. Many organizational meetings need tens of people to come together to do work as a large group and then divide into smaller subgroups of five to ten to work and then to return and report and interact with the larger group. Current facilities were not, in general, designed for this type of meeting. Problems with current facilities are defined and a preliminary design solution to many of the identified problems is presented.

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Summary evaluation of Yucca Mountain surface transects with implications for downhole sampling. Yucca Mountain Site Characterization Project

Mckenna, Sean A.

The results of previously completed vertical outcrop sampling transacts are summarized with respect to planning downhole sampling. The summary includes statistical descriptions and descriptions of the spatial variability of the sampled parameters. Descriptions are made on each individual transect, each thermal/mechanical unit and each previously defined geohydrologic unit. Correlations between parameters indicate that saturated hydraulic conductivity is not globally correlated to porosity. The correlation between porosity and saturated hydraulic conductivity is both spatially and lithologically dependent. Currently, there are not enough saturated hydraulic conductivity and sorptivity data to define relationships between these properties and porosity on a unit by unit basis. Also, the Prow Pass member of the Crater Flat Tuff and stratigraphically lower units have gone essentially unsampled in these outcrop transacts. The vertical correlation length for hydrologic properties is not constant across the area of the transacts. The average sample spacing within the transacts ranges from 1.25 to 2.1 meters. It appears that, with the exception of the Topopah Spring member units, a comparable sample spacing will give adequate results in the downhole sampling campaign even with the nonstationarity of the vertical correlation. The properties within the thermal/mechanical units and geohydrologic units of the Topopah Spring member appear to have a spatial correlation range less than or equal to the current sample spacing within these units. For the downhole sampling, a sample spacing of less than 1.0 meters may be necessary within these units.

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Non-invasive current and voltage imaging techniques for integrated circuits using scanning probe microscopy. Final report, LDRD Project FY93 and FY94

Campbell, Ann N.

This report describes the first practical, non-invasive technique for detecting and imaging currents internal to operating integrated circuits (ICs). This technique is based on magnetic force microscopy and was developed under Sandia National Laboratories` LDRD (Laboratory Directed Research and Development) program during FY 93 and FY 94. LDRD funds were also used to explore a related technique, charge force microscopy, for voltage probing of ICs. This report describes the technical work performed under this LDRD as well as the outcomes of the project in terms of publications and awards, intellectual property and licensing, synergistic work, potential future work, hiring of additional permanent staff, and benefits to DOE`s defense programs (DP).

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NCMS PWB program report surface finishes team task WBS No. 3.1.1: Phase 1, Etching Studies: Chemical etching of copper for improved solderability

Stevenson, Joel O.

Sandia National Laboratories has established a Cooperative Research and Development Agreement with consortium members of the National Center for Manufacturing Sciences (NCMS) to develop fundamental generic technology in the area of printed wiring board materials and surface finishes. Improved solderability of copper substrates is an important component of the Sandia-NCMS program. We are investigating the effects of surface roughness on the wettability and solderability behavior of several different types of copper board finishes. In this paper, we present roughness and solderability characterizations for a variety of chemically-etched copper substrates. Initial testing on six chemical etches demonstrate that surface roughness can be greatly enhanced through chemical etching. Noticeable improvements in solder wettability were observed to accompany increases in roughness. A number of different algorithms and measures of roughness were used to gain insight into surface morphologies that lead to improved solderability.

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Test report on the Abacus 30 kW bimode{reg_sign} inverter and maximum power tracker (MPT)

Bonn, Russell H.

Sandia National Laboratories conducts the photovoltaic balance of systems (BOS) program, which is sponsored by the US Department of Energy`s Office of Energy Management. Under this program, SNL lets commercialization contracts and conducts a laboratory program designed to advance BOS technology, improve BOS component reliability, and reduce the BOS life-cycle-cost. This report details the testing of the first large US manufactured hybrid inverter and its associated maximum power tracker.

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Separate effects testing and analyses to investigate liner tearing of the 1:6-scale reinforced concrete containment building

Spletzer, Barry L.

The overpressurization of a 1:6-scale reinforced concrete containment building demonstrated that liner tearing is a plausible failure mode in such structures under severe accident conditions. A combined experimental and analytical program was developed to determine the important parameters which affect liner tearing and to develop reasonably simple analytical methods for predicting when tearing will occur. Three sets of test specimens were designed to allow individual control over and investigation of the mechanisms believed to be important in causing failure of the liner plate. The series of tests investigated the effect on liner tearing produced by the anchorage system, the loading conditions, and the transition in thickness from the liner to the insert plate. Before testing, the specimens were analyzed using two- and three-dimensional finite element models. Based on the analysis, the failure mode and corresponding load conditions were predicted for each specimen. Test data and post-test examination of test specimens show mixed agreement with the analytical predictions with regard to failure mode and specimen response for most tests. Many similarities were also observed between the response of the liner in the 1:6-scale reinforced concrete containment model and the response of the test specimens. This work illustrates the fact that the failure mechanism of a reinforced concrete containment building can be greatly influenced by details of liner and anchorage system design. Further, it significantly increases the understanding of containment building response under severe conditions.

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Environmentally Conscious Manufacturing Solvent Substitution Program/switch tube assemblies final report

Lopez, Edwin P.

As part of an Environmentally Conscious Manufacturing (ECM) Program, a study was conducted at Sandia National Laboratories to identify an alternative cleaning process that would effectively replace trichloroethylene (TCE) for cleaning mechanical piece parts of Switch Tube assemblies. Eight aqueous alkaline cleaners, as well as an isopropyl alcohol and isopropyl alcohol/Cyclohexane cleaning process, were studied as potential replacements. Cleaning efficacy, materials compatibility, etch rate and corrosion studies were conducted and used to screen potential candidates. Cleaning efficacy was determined using visual examination, goniometer/contact angle measurements, Auger electron spectroscopy, X-ray Photoelectron spectroscopy and an evaporative rate analysis technique known as MESERAN Surface Analysis. Several cleaners were identified as potential replacements for TCE based solely on the cleaning efficacy results. Some of the cleaners, however, left undesirable residues studies were completed, Brulin 815GD (an aqueous alkaline cleaner) was selected as the replacement for TCE.

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Planning for evaluation of the US Department of Energy`s Energy Partnerships/Climate Change Programs

Jordan, Gretchen B.

This paper describes the planning of evaluation for one large-scale national energy program with-scale, national energy program with international reporting requirements, US. Climate Change Action Plant. Referred to as Energy Partnerships for a Strong Economy, this program includes 19 DOE Office of Energy Efficiency and Renewable Energy (EE) initiatives and three other DOE projects. The evaluation strategy is to have a six year effort with ongoing performance measurement, market studies and process evaluations when deviations from targeted outcomes occur, and a final evaluation report that combines these results with other impact evaluations deemed necessary. The evaluation planning and implementation will use a collaborative approach involving program managers and stakeholders, including program partners and customers, to ensure that evaluation results are useful and utilized. Performance mapping will be used to describe the programs to be evaluated and determine data collection needs and key evaluation questions. The evaluation plan uses multiple evaluation methods, including model and engineering estimates, self-reporting by partners, case studies, surveys, and modified peer/expert review in order to accommodate the scope and diversity of programs and the need to measure progress as well as impact.

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Simulation of the part-load behavior of a 30 MWe SEGS plant

Lippke, F.

The part-load behavior of a typical 30-MWe SEGS (solar electric generating systems) plant was studied using a detailed thermodynamic model. As part of this analysis, a new solar field model was derived, based on measurement results of an LS-2 Collector and accounting for various conditions of receiver tubes, lost mirrors and measured reflectivity. A comparison was made of the model results to real plant conditions for a winter and summer day in order to test the accuracy of the model. The effects of bare tubes, different wind speeds, mirror reflectivity and other factors were studied showing, e.g., that heat losses due to wind are predicted to be very low. The comparison also shows that the model still lacks the capability to fully account for actual solar field conditions. The model was also compared to the SOLERGY model, showing differences between the assumptions used in both models. Finally different operating conditions of the plant were studied for a summer, fall, and winter day to provide a better understanding of how changing solar field outlet temperatures affect gross and net output of the plant. This clearly indicates that the lowest possible superheating temperature maximizes the gross electric output. On a net basis this conclusion is modified due to the high parasitics of the HTF (heat transfer fluid) pumps. It was found that the optimum operating strategy depends on the insolation conditions, e.g., different superheating temperatures should be chosen in summer, fall and winter. If the pressure drop in the solar field is reduced due to replacement of flex hoses with ball joints, increasing the HTF flow is more reasonable, so that at low isolation conditions the lowest possible superheating temperature also leads to the maximum net output.

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The US uranium industry: Regulatory and policy impediments

Drennen, Thomas E.

The Energy Policy Act of 1992 required the DOE to develop recommendations and implement government programs to assist the domestic uranium industry in increasing export opportunities. In 1993, as part of that effort, the Office of Nuclear Energy identified several key factors that could (or have) significantly impact(ed) export opportunities for domestic uranium. This report addresses one of these factors: regulatory and policy impediments to the flow of uranium products between the US and other countries. It speaks primarily to the uranium market for civil nuclear power. Changes in the world political and economic order have changed US national security requirements, and the US uranium industry has found itself without the protected market it once enjoyed. An unlevel playing field for US uranium producers has resulted from a combination of geology, history, and a general US political philosophy of nonintervention that precludes the type of industrial policy practiced in other uranium-exporting countries. The US has also been hampered in its efforts to support the domestic uranium-producing industry by its own commitment to free and open global markets and by international agreements such as GATT and NAFTA. Several US policies, including the imposition of NRC fees and licensing costs and Harbor Maintenance fees, directly harm the competitiveness of the domestic uranium industry. Finally, requirements under US law, such as those in the 1979 Nuclear Nonproliferation Act, place very strict limits on the use of US-origin uranium, limitations not imposed by other uranium-producing countries. Export promotion and coordination are two areas in which the US can help the domestic uranium industry without violating existing trade agreements or other legal or policy constraints.

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3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

Morimoto, A.K.

The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

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Estimating the hydrogen ion concentration in concentrated NaCl and Na{sub 2}SO{sub 4} electrolytes

Novak, Craig F.

Combination glass electrodes were tested for determining H{sup +} concentrations in concentrated pure and mixed NaCl and Na{sub 2}SO{sub 4} solutions, as well as natural brine systems. NaCl, Na{sub 2}SO{sub 4}, and mixtures of NaCl and Na{sub 2}SO{sub 4} solutions were analyzed. Correction factors for estimating pC{sub H}{sup +} (negative logarithm of H{sup +} concentration) were determined from measured/observed pH values. Required Gran-type titrations were done with HCl and/or NaOH. The titration method is described and a step-by-step procedure provided; it has been used previously for determining pC{sub H}{sup +} values of synthetic chloride-dominated brines. Precautions are required to determine correction factors for electrolytes that react with H{sup +} or OH{sup {minus}} [sulfate brines for titration with acid; magnesium brines for titration with base because of precipitation of Mg(OH)2]. Correction factors A (pC{sub H}{sup +} = pH{sub ob} + A) from HCl titrations were similar to those from NaOH titrations where the concentration of free H{sup +} was calculated using a thermodynamic model. These values should be applicable to solns with a very large range in measured pH values (2 to 12). Because a large number of solns were titrated with HCl and the A values are similar for HCl and NaOH titrations, the A values for NaCl and Na2SO4 solns were fit as a function of molality to allow extrapolation. For NaCl solns 0 to 6.0 M, A can be obtained by multiplying the molality by 0.159. For Na2SO4 solns 0 to 2.0 M, the values of A can be obtained from (0.221 {minus} 0.549X + 0.201X{sup 2}), where X is the molality of Na{sub 2}SO{sub 4}. Orion-Ross electrode evaluations indicated that the A values did not differ significantly for different electrodes. Results suggest that the data in this report can be used to estimate A values for different NaCl and Na{sub 2}SO{sub 4} solns even for noncalibrated electrodes.

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Implementing and testing ATM in a production LAN

Naegle, John H.

Asynchronous Transfer Mode (ATM) technology is currently receiving extensive attention in the computer networking arena. Many experts predict that ATM will be the future networking technology for both the Local Area Network (LAN) and the Wide Area Network (WAN). This paper presents the results of a collaboration between Sandia National Laboratories` Advanced Networking Department and Engineering Sciences Center to study the implementation of ATM in one of Sandia`s most heavily loaded production networks. The network consists of over 120 Sun Sparc 10s and 20s, two SparcCenter 2000s, a 12 node parallel IBM SP-2, and several other miscellaneous high-end workstations. The existing network was first characterized through extensive traffic measurements to better understand the capabilities and limitations of the existing network technologies and to provide a baseline for comparison to an ATM network. This characterization was used to select a subset of the network elements which would benefit most from conversion to the ATM technology. This subset was then converted to equipment based on the latest ATM standards. With direct OC-3c (155 Mbps) host connections for the workstations and the file and compute servers, we demonstrated as much as 122 Mbps throughput (memory-to-memory TCP/IP transfers) between endpoints. Flow control in the classical many-to-one client server environment was also investigated. Throughout all of our tests, the interaction of the user applications with the network technologies was documented and possible improvements were tested. The performance and reliability of the ATM network was compared to the original network to determine the benefits and liabilities of the ATM technology.

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CONTAIN code analyses of direct containment heating (DCH) experiments: Model assessment and phenomenological interpretation

Williams, D.C.; Griffith, R.O.; Tadios, E.L.; Washington, K.E.

Models for direct containment heating (DCH) in the CONTAIN code for severe accident analysis have been reviewed and a standard input prescription for their use has been defined. The code has been exercised against a large subset of the available DCH data base. Generally good agreement with the experimental results for containment pressurization ({Delta}P) and hydrogen generation has been obtained. Extensive sensitivity studies have been performed which permit assessment of many of the strengths and weaknesses of specific model features. These include models for debris transport and trapping, DCH heat transfer and chemistry, atmosphere-structure heat transfer, interactions between nonairborne debris and blowdown steam, potential effects of debris-water interactions, and hydrogen combustion under DCH conditions. Containment compartmentalization is an important DCH mitigator in the calculations, in agreement with experimental results. The CONTAIN model includes partially parametric treatments for some processes that are not well understood. The importance of the associated uncertainties depends upon the details of the DCH scenario being analyzed. Recommended sensitivity studies are summarized that allow the user to obtain a reasonable estimate of the uncertainties in the calculated results.

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Lower bounds for randomized Exclusive Write PRAMs

Mackenzie, P.D.

In this paper we study the question: How useful is randomization in speeding up Exclusive Write PRAM computations? Our results give further evidence that randomization is of limited use in these types of computations. First we examine a compaction problem on both the CREW and EREW PRAM models, and we present randomized lower bounds which match the best deterministic lower bounds known. (For the CREW PRAM model, the lower bound is asymptotically optimal.) These are the first non-trivial randomized lower bounds known for the compaction problem on these models. We show that our lower bounds also apply to the problem of approximate compaction. Next we examine the problem of computing boolean functions on the CREW PRAM model, and we present a randomized lower bound, which improves on the previous best randomized lower bound for many boolean functions, including the OR function. (The previous lower bounds for these functions were asymptotically optimal, but we improve the constant multiplicative factor.) We also give an alternate proof for the randomized lower bound on PARITY, which was already optimal to within a constant additive factor. Lastly, we give a randomized lower bound for integer merging on an EREW PRAM which matches the best deterministic lower bound known. In all our proofs, we use the Random Adversary method, which has previously only been used for proving lower bounds on models with Concurrent Write capabilities. Thus this paper also serves to illustrate the power and generality of this method for proving parallel randomized lower bounds.

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A lower bound for the QRQW PRAM

Mackenzie, P.D.

The queue-read, queue-write (QRQW) parallel random access machine (PRAM) model is a shared memory model which allows concurrent reading and writing with a time cost proportional to the contention. This is designed to model currently available parallel machines more accurately than either the CRCW PRAM or EREW PRAM models. Many algorithmic results have been developed for the QRQW PRAM. However, the only lower bound results have been fairly simple reductions from lower bounds for other models, such as the EREW PRAM or the ``few-write`` CREW PRAM. Here we present a lower bound specific to the QRQW PRAM. This lower bound is on the problem of Linear Approximate Compaction (LAC), whose input consists of at most m marked items in an array of size n, and whose output consists of the rn marked items in an array of size 0(m). There is an O({radical}log n), expected time randomized algorithm for LAC on the QRQW PRAM. We prove a lower bound of {Omega}(log log log n) expected time for any randomized algorithm for LAC. This bound applies regardless of the number of processors and memory cells of the QRQW PRAM. The previous best lower bound was {Omega}(log* n) time, taken from the known lower bound for LAC on the CRCW PRAM.

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On the feasibility of using Smoothed Particle Hydrodynamics for underwater explosion calculations

Computational Mechanics

Swegle, Jeffrey W.

SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine the feasibility of using PRONTO/SPH for the analysis of various types of underwater explosion problems involving fluid-structure and shock-structure interactions. Of particular interest are effects of bubble formation and collapse and the permanent deformation of thin walled structures due to these loadings. These are exceptionally difficult problems to model. Past attempts with various types of codes have not been satisfactory. Coupling SPH into the finite element code PRONTO represents a new approach to the problem. Results show that the method is well-suited for transmission of loads from underwater explosions to nearby structures, but the calculation of late time effects due to acceleration of gravity and bubble buoyancy will require additional development, and possibly coupling with implicit or incompressible methods. © 1995 Springer-Verlag.

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The pyrochlore-to-perovskite transformation in solution-derived lead zirconate titanate thin films

Voigt, James A.

The authors have characterized the pyrochlore-to-perovskite crystallization process in solution-derived Pb(Zr{sub 0.20}Ti{sub 0.80})O{sub 3} thin films on (100) MgO single crystal substrates. It has been determined that the perovskite phase nucleated preferentially at the film/MgO interface out of a nanocrystalline ({approx}100{angstrom} grains) pyrochlore matrix. During the early stages of the pyrochlore-to-perovskite conversion process, perovskite growth proceeded nearly isotropically from the substrate to form hemispherically shaped grains. Deviations from isotropic growth were shown to result from a growth dependence based on the crystallographic orientation of a growing perovskite grain relative to the orientations of pyrochlore grains being transformed. The volume change that occurs during the pyrochlore-to-perovskite transformation along with two-dimensional grain growth has been used to develop a mechanism for formation of porosity that commonly is concentrated in grain boundary regions.

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Solderability enhancement of copper through chemical etching

Stevenson, Joel O.

Sandia National Laboratories has established a Cooperative Research and Development Agreement with consortium members of the National Center for Manufacturing Sciences (NCMS) to develop fundamental generic technology in the area of printed wiring board materials and surface finishes. Improved solderability of copper substrates is an important component of the Sandia-NCMS program. The authors are investigating the effects of surface roughness on the wettability and solderability behavior of several different types of copper board finishes. In this paper, the authors present roughness and solderability characterizations for a variety of chemically-etched copper substrates. Initial testing on six chemical etches demonstrate that surface roughness can be greatly enhanced through chemical etching. Noticeable improvements in solder wettability were observed to accompany increases in roughness. A number of different algorithms and measures of roughness were used to gain insight into surface morphologies that lead to improved solderability.

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Aqueous TiO{sub 2} photocatalysis of metal-EDTA complexes

Prairie, Michael R.

This report describes the results of experiments performed to determine the viability of titanium dioxide photocatalysis towards the treatment of water contaminated with different metal-EDTA complexes. Both the PB-EDTA and Ni-EDTA complexes were chosen for study, as they represent respectively metals that are and are not capable of photodeposition onto the TiO{sub 2} catalyst during the photoreaction. Batch reactions were carried out in a jacketed glass pot reactor using 300 ml of 50m g/l metal chelated with an equimolar amount of EDTA and 0.1wt% of TiO{sub 2} in the solution. The UV source used was a 100 W low-pressure Hg spot lamp. The two systems were studied using Degussa P-25 titanium dioxide, and Aldrich titanium dioxide loaded with Pt and Au. Around 80% removal of the Ni-EDTA complex was attained after 120 min using both catalysts with no photodeposition of Ni onto the catalyst. However, pH precipitation treatment of the reacted solutions indicated that the Ni was still complexed, probably to complexing agents that were EDTA oxidation products. Apparent zero-order kinetics was observed in the P-25 catalyst reaction, whereas apparent first-order kinetics was observed in the metal-loaded TiO{sub 2} catalyst. In contrast the Pb-EDTA complex was completely removed in 10 min using both catalysts. Also, complete Pb deposition onto the catalyst was attained in 30 min for both catalysts. The Pb deposition seemed to first require the degradation of the complex. Total organic carbon was reduced in the Ni-EDTA system 15--21% using both catalysts, and about 33% in the Pb-EDTA system using both catalysts. No reduction of either metal or metal complex was observed when no catalyst was present and the other conditions held constant.

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Borehole-to-surface electromagnetic methods -- System design and field examples

Bartel, Lewis C.

Borehole-to-surface electromagnetic (EM) methods are an attractive alternative to Surface-based EM methods for a variety of environmental and engineering applications. They have improved sensitivity to the subsurface resistivity distribution because of the closer proximity to the area of interest offered by the borehole for the source or the receiver. For the borehole-to-surface measurements the source is in the borehole and the receivers are on the surface. On the other hand, for the surface-to-borehole methods, the source is on the surface and the receiver is in a borehole. The surface-to-borehole method has an added advantage since measurements are often more accurate due to the lower noise environment for the receiver. For these methods, the source can be a grounded electric dipole or a vertical magnetic dipole source. An added benefit of these techniques is field measurements are made using a variety of arrays where the system is tailored to the application and where one can take advantage of some new imaging methods. In this short paper the authors describe the application of the borehole-to-surface method, discuss benefits and shortcomings, and give two field examples where they have been used for underground imaging. The examples were the monitoring of a salt water flooding of an oil well and the characterization of a fuel oil spill.

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X-ray diffraction study of clusters in a-tC films

Friedmann, Thomas A.

The authors performed an X-ray diffraction study of tetrahedral-coordinated-amorphous carbon (a-tC) films prepared by pulsed laser deposition (PLD). Samples properties were analyzed as a function of laser energy and thickness. For all thicknesses and laser energies, films were made up of clusters with a basic unit size of 7 - 11 nm. Thicker films, as well as films prepared at higher laser densities exhibit larger clusters, in the tens of nanometers. The clusters are not readily observable by AFM, which may indicate the presence of a flat (graphitized) top film surface.

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Extra-regulatory impact tests and analyses of the structural evaluation test unit

Ludwigsen, John S.

The structural evaluation test unit is roughly equivalent to a 1/3 scale model of a high level waste rail cask. The test unit was designed to just meet the requirements of NRC Regulatory Guide 7.6 when subjected to a 9 m (30 ft) free drop resulting in an impact velocity of 13.4 m/s (30 mph) onto an unyielding target in the end-on orientation. The test unit was then subjected to impacts with higher velocities to determine the amount of built-in conservatism in this design approach. Test impacts of 13.4, 20.1 and 26.8 m/s (30, 45, and 60 mph) were performed. This paper will describe the design, testing, and comparison of measured strains and deformations to the equivalent analytical predictions.

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Discrete element modeling of rock blasting in benches with joints and bedding planes - initial development

Preece, Dale S.

A Discrete element computer program named DMC (Distinct Motion Code) has been developed for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements which are represented as circles in 2-D. DMC calculations have been compared with measurements on bench blasts in the field with relatively good comparison. Structural rock mass characteristics have a significant impact on any blast and DMC has not, until now, included these effects. This paper discusses a recently added DMC capability for treating joints and bedding planes in bench blast simulations. Material strength is treated in DMC by creating links between spheres to hold them together. The links can be broken based on any criterion; simple tension, compression and shear are currently employed. Joint sets are treated in DMC by defining the dip of each set toward or away from the bench face along with the joint spacing. Strength links that cross joint planes can have their strength properties modified or they can be deleted. Modification of the link patterns based on joint sets creates distinct blocks of spheres outlined by the intersecting joints. These blocks of spheres move together as a solid unit unless stress and strain conditions within the block indicate that links should be broken. Simulations using this capability show some blocks remaining intact throughout the blast and some being partially or completely broken. When this occurs, the joint pattern is shown to influence the characteristics of the blast. Upon completion of this capability both rock breakage and motion will be modeled during the same simulation. Much work remains to be done on this concept making this paper a progress report on the development of this new capability.

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Hydrogen diffusion and passivation in InGaAlN alloys

Shul, Randy J.

Hydrogen is found to readily diffuse into InGaN, InAlN and InGaAlN epitaxial layers during plasma exposures at 170-250{degree}C for 40 sec-30 min. The diffusivity of hydrogen is > 10{sup -11} cm{sup 2} {center_dot} s{sup -1} at 170{degree}C, and the native donor species are passivated by association with the hydrogen. Reactivation of these species occurs at 450-500{degree}C, but the hydrogen remains in the material until {ge} 800{degree}C.

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A study of switching behavior in Pb(Zr,Ti)O{sub 3} thin films using x-ray diffraction

Eatough, Michael O.

Pb(Zr,Ti)O{sub 3} (PZT) thin films are being developed for use in optical and electronic memory devices. To study ferroelectric switching behavior, the authors have produced relatively untextured PZT thin films on Si substrates. They have developed a method for using X-ray diffraction to observe domain switching in situ. This study involved the use of a micro-diffractometer to monitor the switching behavior in relatively small (0.7 mm diameter) electroded areas. Diffraction analyses were done while DC voltages were applied and removed, representing several places in the hysteresis loop. In particular, the authors were looking for relative intensity changes in the [h00],[00l] diffraction peaks as a function of position in the hysteresis loop. This study indicates that the 90{degrees} domain switching exhibited by bulk ferroelectrics, is very limited in films on Si when grain sizes are less than about 1{mu}m.

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Achieving affordable manufacturing

Strip, David R.

Increasingly constrained budgets in the defense community, both DoD and DOE, have created a need to emphasize affordability in the development of future weapons systems and components. Increased use of commercially compatible components will play an important role, but there will always remain a need for specialized production, especially at the system level. We will present on-going work at Sandia National Laboratories (referred to from here as Sandia) aimed at insuring the affordability of low-volume, defence-specific systems.

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{sup 15}N hydrogen profiling of IC metallizations

Horn, Kevin M.

The 6.4 MeV p({sup l5}N,{alpha}{gamma}){sup 12}C resonant nuclear reaction has been used to investigate the role of hydrogen as a contributing factor in the formation of stress-induced voids in very large scale integrated circuit metallizations. Hydrogen profiles were measured from a series of layered structures consisting of aluminum-copper alloy metallizations deposited on borophosphosilicate glass and capped with a variety of commercial passivation materials in order to examine differences in the concentrations and depth distributions of hydrogen within the layered structures.

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Radioactive material transportation package design using numerical optimization techniques

Harding, David C.

Increasing computational speed has led to the development and use of sophisticated numerical methods in radioactive material (RAM) transportation container design. The design of a RAM container often involves a complex coupling of structural, thermal, and radioactive shielding analyses. Sandia National Laboratories has integrated automatic mesh generation, explicit structural finite element analysis, transient thermal finite element analysis, and numerical optimization techniques into a unified RAM container design tool to increase the efficiency of both the design process and the resultant design through coupled analyses. Although development of this technique has progressed significantly, inaccurate numerical gradients due to design space nonsmoothness and excessive computational time have hampered successful implementation of numerical optimization as a ``black box`` design tool. This paper presents the details of analysis tool integration, simplified model development, constraint boundary nonsmoothness difficulties, and numerical optimization results for a lightweight composite-overpack Type B RAM package subject to dynamic crush and fuel fire accident condition constraints.

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New security paradigms workshop white paper

Fletcher, S.K.; Halbgewachs, R.; Jansma, R.; Lim, J.; Murphy, M.; Wyss, G.

An historical look at software systems reveals a progression of thinking about protection and risk management. In this paper, three generations are defined. For each, we examine the prevalent views of risk, risk assessment, and risk mitigation. We also examine prevalent strategies for assurance. Many gaps exist in current knowledge of how to manage and assess risks in software systems. This paper presents a new perspective which enables comprehensive risk-based design and evaluation of systems, spanning a range of surety concerns (including correctness and safety, in addition to traditional security concerns), and addressing multiple system aspects. We believe this to be a new and unique multidisciplinary approach which transcends both traditional security approaches and traditional risk analysis methods. It facilitates a risk analysis completely tailored to the system at hand, instantiating its threats, its barriers, and its needs for risk reduction.

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High rate dry etching of GaN, AlN and InN in ECR Cl{sub 2}/CH{sub 4}/H{sub 2}/Ar plasmas

Shul, Randy J.

Etch rates for binary nitrides in ECR Cl{sub 2}/CH{sub 4}/H{sub 2}/Ar are reported as a function of temperature, rf-bias, microwave power, pressure and relative gas proportions. GaN etch rates remain relatively constant from 30 to 125{degrees}C and then increase to a maximum of 2340 {angstrom}-min{sup {minus}1} at 170{degrees}C. The AlN etch rate decreases throughout the temperature range studied with a maximum of 960 {angstrom}-min{sup {minus}1} at 30{degrees}C. When CH{sub 4} is removed from the plasma chemistry, the GaN and InN etch rates are slightly lower, with less dramatic changes with temperature. The surface composition of the III-V nitrides remains unchanged over the temperatures studied. The GaN and InN rates increase significantly with rf power, and the fastest rates for all three binaries are obtained at 2 mTorr. Surface morphology is smooth for GaN over a wide range of conditions, whereas InN surfaces are more sensitive to plasma parameters.

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The probability of containment failure by direct containment heating in surry

Pilch, M.M.; Allen, M.D.; Bergeron, K.D.; Tadios, E.L.; Stamps, D.W.; Spencer, B.W.; Quick, K.S.; Knudson, D.L.

In a light-water reactor core melt accident, if the reactor pressure vessel (RPV) fails while the reactor coolant system (RCS) at high pressure, the expulsion of molten core debris may pressurize the reactor containment building (RCB) beyond its failure pressure. A failure in the bottom head of the RPV, followed by melt expulsion and blowdown of the RCS, will entrain molten core debris in the high-velocity steam blowdown gas. This chain of events is called a high-pressure melt ejection (HPME). Four mechanisms may cause a rapid increase in pressure and temperature in the reactor containment: (1) blowdown of the RCS, (2) efficient debris-to-gas heat transfer, (3) exothermic metal-steam and metal-oxygen reactions, and (4) hydrogen combustion. These processes, which lead to increased loads on the containment building, are collectively referred to as direct containment heating (DCH). It is necessary to understand factors that enhance or mitigate DCH because the pressure load imposed on the RCB may lead to early failure of the containment.

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Simulations of hydrodynamic interactions among immersed particles in stokes flow using a massively parallel computer

Mondy, L.A.

In this paper, a massively parallel implementation of the boundary element method to study particle transport in Stokes flow is discussed. The numerical algorithm couples the quasistatic Stokes equations for the fluid with kinematic and equilibrium equations for the particles. The formation and assembly of the discretized boundary element equations is based on the torus-wrap mapping as opposed to the more traditional row- or column-wrap mappings. The equation set is solved using a block Jacobi iteration method. Results are shown for an example application problem, which requires solving a dense system of 6240 equations more than 1200 times.

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Characterization of microenvironment polarity and solvent accessibility of polysilsesquioxane xerogels by the fluorescent probe technique

Loy, Douglas A.

Poly (1, 4 bis(triethoxysilyl)benzene) (PTESB), a representative of a new type of organic-inorganic hybrid polysilsesquioxane material, was characterized by fluorescence spectroscopy for both microenvironmental polarity and solvent accessibility. A dansyl fluorescent molecule was incorporated into the bulk as well as onto the surface of both PTESB and silica materials. Information about the microenvironment polarity and accessibility of PTESB to various organic solvents was determined and compared to that of silica gel. This study found that both the bulk and surface of PTESB are less polar than that of the silica material. The silica material is accessible to polar solvents and water, while YMB is accessible to polar solvents but not to water. The hydrophobicity of PTESB differentiates these new materials from silica gel.

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Unified model of the rf plasma sheath

Riley, Merle E.

By developing an approximation to the first integral of the Poisson equation, one can obtain solutions for the voltage-current characteristics of a radio-frequency (rf) plasma sheath that are valid over the whole range of inertial response of the ions to an imposed rf voltage or current-specified conditions. The theory adequately reproduces the time-dependent voltage-current characteristics of the two extreme cases corresponding to the Lieberman rf sheath theory and the Metze-Ernie-Oskam theory. Contained within the approximation is a time constant which controls the amount of ion response to the rf electric field. A prescription is given for determining this ion relaxation time constant, which also determines the time-dependent ion impact energy on the electrode surface.

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Fundamental surface chemistry of GaAs OMVPE

Creighton, J.R.

Organometallic and hydride compounds are widely used as precursors for the epitaxial growth of GaAs and other compound semiconductors. These precursors are most commonly used to perform organometallic vapor phase epitaxy (OMVPE) and also in related deposition techniques such as atomic layer epitaxy (ALE) and metalorganic molecular beam epitaxy (MOMBE). We have investigated the surface chemical properties of these precursors on GaAs(100) using a variety of surface science diagnostics. Results have shed light on the mechanisms of precursor decomposition which lead to film growth and carbon doping. For instance, kinetics of trimethylgallium (TMGa) decomposition on the Ga-rich and As-rich surfaces, measured by TPD, are in semiquantitative agreement with ALE results; indicating that the dominant growth mechanism during ALE is heterogeneous. Furthermore, there is no compelling evidence for the production of methane (CH{sub 4}) on the GaAs surface when TMGa and arsine (AsH{sub 3}) are coadsorbed.

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A reconfigurable optoelectronic interconnect technology for multi-processor networks

Zolper, J.C.

This paper describes a new optical interconnect architecture and the integrated optoelectronic circuit technology for implementing a parallel, reconfigurable, multiprocessor network. The technology consists of monolithic array`s of optoelectronic switches that integrate vertical-cavity surface-emitting lasers with three-terminal heterojunction phototransistors, which effectively combined the functions of an optical transceiver and an optical spatial routing switch. These switches have demonstrated optical switching at 200 Mb/s, and electrical-to-optical data conversion at > 500 Mb/s, with a small-signal electrical-to-optical modulation bandwidth of {approximately} 4 GHz.

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A bimodal power and propulsion system based on cermet fuel and heat pipe energy transport

Polansky, Gary F.

Bimodal space reactor systems provide both thermal propulsion for the spacecraft orbital transfer and electrical power to the spacecraft bus once it is on station. These systems have the potential to increase both the available payload in high energy orbits and the available power to that payload. These increased mass and power capabilities can be used to either reduce mission cost by permitting the use of smaller launch vehicles or to provide increased mission performance from the current launch vehicle. A major barrier to the deployment of these bimodal systems has been the cost associated with their development. This paper describes a bimodal reactor system with performance potential to permit more than 70% of the instrumented payload of the Titan IV/Centaur to be launched from the Atlas IIAS. The development cost is minimized by basing the design on existing component technologies.

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Thin film circuit fabrication on diamond substrates for high power applications

Norwood, D.

Sandia Laboratories has developed a thin film diamond substrate technology to meet the requirements for high power and high density circuits. Processes were developed to metallize, photopattern, laser process, and, package diamond thin film networks which were later assembled into high power multichip modules (MCMS) to test for effectiveness at removing heat. Diamond clearly demonstrated improvement in heat transfer during 20 Watt, strip heating experiments with junction-to-ambient temperature increases of less than 24 C compared to 126 C and 265 C for the aluminum nitride and ceramic versions, respectively.

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Evaluation of conductive, radiative, chemical, and convective heat transfer in complex systems using a fast-running, implicit, lumped-capacitance formulation

Benjamin, A.S.

Accurate finite-element simulation of 3-D nonlinear heat transfer in complex systems may require meshes composed of tens of thousands of finite elements and hours of CPU time on today`s fastest computers. To treat applications in which thousands of calculations may be necessary such as for risk assessment or design of high-temperature manufacturing processes, methods are needed which can solve these problems far more efficiently and maintain an acceptably high degree of accuracy. For this purpose, we developed the Thermal Evaluation and Matching Program for Risk Applications (TEMPRA). The primary differentiator between TEMPRA and comparable codes is its numerical formulation, which is designed to be unconditionally stable even with very large time steps, to afford good accuracy even with relatively coarse meshing, and to facilitate benchmarking/calibration through the use of adjustable parameters. Analysis for a sample problem shows that TEMPRA can obtain temperature response solutions with errors of less than 10% using approximately 1/1000 of the computer time required by a typical finite element code.

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Prosperity game for the national electronics manufacturing initiative

Berman, M.

Prosperity Games are an outgrowth and adaptation of move/countermove and seminar War Games. Prosperity Games are simulations that explore complex issues in a variety of areas including economics, politics, sociology, environment, education and research. These issues can be examined from a variety of perspectives ranging from a global, macroeconomic and geopolitical viewpoint down to the details of customer/supplier/market interactions in specific industries. All Prosperity Games are unique in that both the game format and the player contributions vary from game to game. This report documents the Prosperity Game conducted under the sponsorship of the Electronics Subcommittee of the Civilian Industrial Technology Committee (under the National Science and Technology Council), and the Electronics Partnership Project. Players were drawn from the electronics industry, from government, national laboratories, and universities, and from Japan and Austria. The primary objectives of this game were: To connect the technical and non-technical (i.e., policy) issues that were developed in the roadmap-making endeavor of the National Electronics Manufacturing Initiative (NENI);to provide energy, enthusiasm and people to help the roadmap succeed; and to provide insight into high-leverage public and private investments. The deliberations and recommendations of these teams provide valuable insights as to the views of this diverse group of decision makers concerning policy changes, foreign competition, the robustness of strategic thinking and planning, and the development, delivery and commercialization of new technologies.

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Surface micromachined microengine as the driver for micromechanical gears

Garcia, Ernest J.

The transmission of mechanical power is often accomplished through the use of gearing. The recently developed surface micromachined microengine provides us with an actuator which is suitable for driving surface micromachined geared systems. In this paper we will present aspects of the microengine as they relate to the driving of geared mechanisms, issues relating to the design of micro gear mechanisms, and details of a design of a microengine-driven geared shutter mechanism.

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Smart gun technology requirements preliminary report

Weiss, D.R.

Goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing user-recognizing-and-authorizing surety technologies. This project is funded by the National Institute of Justice. This document reports the projects first objective: to find and document the requirements for a user-recognizing-and-authorizing firearm technology that law enforcement officers will value. This report details the problem of firearm takeaways in law enforcement, the methodology used to develop the law enforcement officers` requirements, and the requirements themselves.

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The lustering of TBC-2

Diver, R.B.; Jones, S.; Robb, S.; Mahoney, A.R.

Two test bed concentrators (TBCs) were designed to provide high-performance test beds for advanced solar receivers and converters. However, the second-surface silvered-glass mirror facets on the TBCs, which were originally manufactured by the Jet Propulsion Laboratory, have experienced severe silver corrosion. To restore reflectance, TBC-2 was refurbished with a lustering technique developed at Sandia National Laboratories. In the lustering technique, second-surface silvered thin-glass mirrors were applied over the corroded facets, thereby increasing the dish reflectivity and raising the available power of TBC-2 from approximately 70 to 78 kW{sub t}. Degradation of the original optical accuracy of the TBC facets was determined to be minimal. Lustering was chosen over facet replacement because of the lower cost, the anticipated improvement in corrosion resistance, and the shorter project duration. This report includes background information, details of the lustering process, and test results from TBC-2 characterization, both before and after lustering.

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Synthesis of silicon nitride powders in pulsed RF plasmas

Buss, Richard J.

Nanometer size silicon nitride particles are synthesized using a pulsed radio frequency plasma technique. The plasma is modulated with a square-wave on/off cycle of varying period to control size and morphology and to deduce the growth kinetics. In situ laser light scattering and ex situ particle analysis are used to study the nucleation and growth. For SiH{sub 4}/Ar plasmas which nucleate silicon particles, an initial extremely rapid growth phase is followed by a slower growth rate, approaching the rate of thin film deposition on adjacent flat surfaces. In SiH{sub 4}/NH{sub 3} plasmas, silicon nitride particle size can be tightly controlled by adjusting the plasma-on time. The size dispersion of the particles is large and is consistent with a process of continual nucleation during the plasma-on period. The observed polydispersity differs dramatically from that reported from other laboratories.

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Capacitive sensor for high resolution weld seam tracking

Schmitt, D.J.

A non-contact capacitive sensing system has been developed for guiding automated welding equipment along typical v-groove geometries. The Multi-Axis Seam Tracking (MAST) sensor has been designed to produce four electric fields for locating and measuring the v-groove geometry. In this system, the MAST sensor is coupled with a set of signal conditioning electronics making it possible to output four varying voltages proportional to the electric field perturbations. This output is used for motion control purposes by the automated welding platform to guide the weld torch directly over the center of the v-groove. This report discusses the development of this capacitive sensing system. A functional description of the system and MAST sensor response characteristics for typical weld v-groove geometries are provided. The effects of the harsh thermal and electrical noise environments of plasma arc welding on sensor performance are discussed. A comparison of MAST sensor fabrication from glass-epoxy and thick-film ceramic substrates is provided. Finally, results of v-groove tracking experiments on a robotic welding platform are described.

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Self-consistent temperature compensation for resonant sensors with application to quartz bulk acoustic wave chemical sensors

Smith, J.H.; Senturia, S.D.

Since resonant sensors have a temperature sensitivity which is often greater than their sensitivity to the phenomena they are being used to detect, it is imperative to include either temperature control or temperature compensation in any resonant sensor system. The authors have developed a temperature-compensation scheme for resonant sensors which is amenable to integration into a resonator-driver integrated circuit. An integrated circuit incorporating this scheme has been designed, built, and tested.

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Enhancement of surface processes with low energy ions

Chason, E.

Continuing trends in device fabrication towards smaller feature sizes, lower thermal budgets and advanced device structures put greater emphasis on controlling the surface structure and reactivity during processing. Since the evolution of the semiconductor surface during processing is determined by the interaction of multiple surface processes, understanding how to control and modify these processes on the atomic level would enable us to exert greater control over the resulting morphology and composition. Low energy ions represent one method for bringing controlled amounts of energy to the surface to modify surface structure and kinetics. The kinetic energy deposited by the ions can break bonds and displace atoms, creating defect populations significantly in excess of the equilibrium concentration. Consequences of these non-equilibrium conditions include the enhancement of surface kinetic processes, increased surface reactivity and formation of metastable structures and compositions. These effects can be beneficial (ion enhanced mass transport can lead to surface smoothing) or they can be detrimental (residual defects can degrade electrical properties or lead to amorphization). The net results depend on a complex balance that depends on many parameters including ion mass, energy, flux and temperature. In the following section, we review progress both in our fundamental understanding of the production of low-energy ion-induced defects and in the use of low energy ions to enhance surface morphology, stimulate low temperature growth and obtain non-equilibrium structures and compositions.

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Kauai Test Facility hazards assessment document

Banda Jr., Zeferino

The Department of Energy Order 55003A requires facility-specific hazards assessment be prepared, maintained, and used for emergency planning purposes. This hazards assessment document describes the chemical and radiological hazards associated with the Kauai Test Facility, Barking Sands, Kauai, Hawaii. The Kauai Test Facility`s chemical and radiological inventories were screened according to potential airborne impact to onsite and offsite individuals. The air dispersion model, ALOHA, estimated pollutant concentrations downwind from the source of a release, taking into consideration the toxicological and physical characteristics of the release site, the atmospheric conditions, and the circumstances of the release. The greatest distance to the Early Severe Health Effects threshold is 4.2 kilometers. The highest emergency classification is a General Emergency at the {open_quotes}Main Complex{close_quotes} and a Site Area Emergency at the Kokole Point Launch Site. The Emergency Planning Zone for the {open_quotes}Main Complex{close_quotes} is 5 kilometers. The Emergency Planning Zone for the Kokole Point Launch Site is the Pacific Missile Range Facility`s site boundary.

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Determination of kinetic coefficients for the simultaneous reduction of sulfate and uranium by Desulfovibrio desulfuricans bacteria

Tucker, Mark D.

Uranium contamination of groundwaters and surface waters near abandoned mill tailings piles is a serious concern in many areas of the western United States. Uranium usually exists in either the U(IV) or the U(VI) oxidation state. U(VI) is soluble in water and, as a result, is very mobile in the environment. U(IV), however, is generally insoluble in water and, therefore, is not subject to aqueous transport. In recent years, researchers have discovered that certain anaerobic microorganisms, such as the sulfate-reducing bacteria Desulfovibrio desulfuricans, can mediate the reduction of U(VI) to U(IV). Although the ability of this microorganism to reduce U(VI) has been studied in some detail by previous researchers, the kinetics of the reactions have not been characterized. The purpose of this research was to perform kinetic studies on Desulfovibrio desulficans bacteria during simultaneous reduction of sulfate and uranium and to determine the phase in which uranium exists after it has been reduced and precipitated from solution. The studies were conducted in a laboratory-scale chemostat under substrate-limited growth conditions with pyruvate as the substrate. Kinetic coefficients for substrate utilization and cell growth were calculated using the Monod equation. The maximum rate of substrate utilization (k) was determined to be 4.70 days{sup {minus}1} while the half-velocity constant (K{sub s}) was 140 mg/l COD. The yield coefficient (Y) was determined to be 0.17 mg cells/mg COD while the endogenous decay coefficient (k{sub d}) was calculated as 0.072 days{sup {minus}1}. After reduction, U(IV) Precipitated from solution in the uraninite (UO{sub 2}) phase. Uranium removal efficiency as high as 90% was achieved in the chemostat.

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Design and analysis of a high-performance shipping container for large payloads

Slavin, Adam M.

The packaging, designated the H1636A is a high-performing packageing for large payloads. The H1636A is 50 in. in diameter and 113 in. in length and weighs approximately 4600 lb when empty. The design objective was to meet 1996 proposed IAEA Type C criteria for air transport of large quantities of radioactive material (RAM). That is, the package should survive the standard Type B tests and more severe tests such as an impact onto an unyielding target at 280 ft/s and a one-hour jet fuel fire. The packaging consists of a large double-walled stainless steel outer drum filled with uniform density polyurethane foam. A stainless steel containment vessel (CV) with an inside diameter of 23 in. and a length of 78 in. carries the RAM. The CV has a nominal thickness of 0.375 in. and seals with two elastomeric 0-rings. The lid of the CV is joined to the body with a unique closure called a tape joint. The tape joint utilizes interlocking features preloaded with wedges and can withstand significant deformation.

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High average power, high current pulsed accelerator technology

Neau, E.L.

Which current pulsed accelerator technology was developed during the late 60`s through the late 80`s to satisfy the needs of various military related applications such as effects simulators, particle beam devices, free electron lasers, and as drivers for Inertial Confinement Fusion devices. The emphasis in these devices is to achieve very high peak power levels, with pulse lengths on the order of a few 10`s of nanoseconds, peak currents of up to 10`s of MA, and accelerating potentials of up to 10`s of MV. New which average power systems, incorporating thermal management techniques, are enabling the potential use of high peak power technology in a number of diverse industrial application areas such as materials processing, food processing, stack gas cleanup, and the destruction of organic contaminants. These systems employ semiconductor and saturable magnetic switches to achieve short pulse durations that can then be added to efficiently give MV accelerating, potentials while delivering average power levels of a few 100`s of kilowatts to perhaps many megawatts. The Repetitive High Energy Puled Power project is developing short-pulse, high current accelerator technology capable of generating beams with kJ`s of energy per pulse delivered to areas of 1000 cm{sup 2} or more using ions, electrons, or x-rays. Modular technology is employed to meet the needs of a variety of applications requiring from 100`s of kV to MV`s and from 10`s to 100`s of kA. Modest repetition rates, up to a few 100`s of pulses per second (PPS), allow these machines to deliver average currents on the order of a few 100`s of mA. The design and operation of the second generation 300 kW RHEPP-II machine, now being brought on-line to operate at 2.5 MV, 25 kA, and 100 PPS will be described in detail as one example of the new high average power, high current pulsed accelerator technology.

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Qualification of environmentally friendly cleaners

De Marquis, G.; Lopez, E.P.

Sandia National Laboratories (SNL) has traditionally used chlorinated and fluorinated organic solvents for general degreasing applications. Many of these solvents have been labeled by the Federal Government as ozone depleting chemicals and as toxic and/or suspected carcinogens. As a result, these solvents will no longer be recommended for use within the DOE weapons complex. There are three major classes of materials that are of concern for cleaning: organics, metals and ceramics. Each of these materials has its own special cleaning problems. Solvents that were used in the past, such as 1,1,1-trichloroethane (TCA) and trichloroethylene (TCE), were extremely efficient at removing everything from oils and greases to salts without leaving corrosive residues or permanently absorbing into the materials. These traditional degreasing solvents were essentially ``all-inone`` cleaners: quick, reliable, and easy to use. Unfortunately, a ``drop-in`` cleaner for such a wide variety of materials and contaminants will probably never be identified. So far, it has been difficult to identify environmentally conscious cleaners that clean as well as TCE and TCA. Most alternative cleaners require more volume to do the job, and also require longer exposure to get the job done. With these things in mind, we are hoping to identify and qualify new cleaners that will take care of general classes of materials.

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An overview of weapons technologies used to improve US healthcare

Fahrenholtz, J.

At Sandia National Laboratories the Biomedical Engineering Program uses existing weapons-related technology in medical applications in order to reduce health care costs, improve diagnoses, and promote efficient health care delivery. This paper describes several projects which use Sandia technologies to solve biomedical problems. Specific technical capabilities that are important to this program include sensor data interpretation, robotics, lasers and optics, microelectronics, image processing and materials.

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The state-of-the-art port of entry workshop

Godfrey, B.

The increased demand for freight movements through international ports of entry and the signing of the North American Free Trade Agreement (NAFTA) have increased freight traffic at border ports of entry. The State-of-the-Art Port of Entry Workshop initiated a dialogue among technologists and stakeholders to explore the potential uses of technology at border crossings and to set development priorities. International ports of entry are both information and labor intensive, and there are many promising technologies that could be used to provide timely information and optimize inspection resources. Participants universally held that integration of technologies and operations is critical to improving port services. A series of Next Steps was developed to address stakeholder issues and national priorities, such as the National Transportation Policy and National Drug Policy. This report documents the views of the various stakeholders and technologists present at the workshop and outlines future directions of study.

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Damage evolution in metal matrix composites subjected to thermomechanical fatigue

Allen, D.H.; Hurtado, L.D.; Helms, K.L.E.

A thermomechanical analysis of unidirectional continuous fiber metal matrix composites is presented. The analysis includes the effects of processing induced residual thermal stresses, interface cracking, and inelastic matrix behavior on damage evolution. Due to the complexity of the nonlinear effects, the analysis is performed computationally using the finite element method. The interface fracture is modeled by a nonlinear constitutive model. The problem formulation is summarized and results are presented for a four-ply unidirectional SCS-6/{beta}21S titanium composite under high temperature isothermal mechanical fatigue.

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Fullerene-based materials research and development. LDRD final report

Cahill, P.A.; Henderson, C.C.; Rohlfing, C.M.; Loy, D.A.; Assink, R.A.; Gillen, K.T.; Jacobs, S.J.; Dugger, M.T.

The chemistry and physical properties of fullerenes, the third, molecular allotrope of carbon, have been studied using both experimental and computational techniques. Early computational work investigated the stability of fullerene isomers and oxides, which was followed by extensive work on hydrogenated fullerenes. Our work led to the first synthesis of a polymer containing C{sub 60} and the synthesis of the simplest hydrocarbon derivatives of C{sub 60} and C{sub 70}. The excellent agreement between theory and experiment ({plus_minus} 0.1 kcal/mol in the relative stability of isomers) has provided insight into the chemical nature of fullerenes and has yielded a sound basis for prediction of the structure of derivatized fullerenes. Such derivatives are the key to the preparation of fullerene-based materials.

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Measures of effectiveness for BMD mid-course tracking on MIMD massively parallel computers

Vandyke, John P.

The TRC code, a mid-course tracking code for ballistic missiles, has previously been implemented on a 1024-processor MIMD (Multiple Instruction -- Multiple Data) massively parallel computer. Measures of Effectiveness (MOE) for this algorithm have been developed for this computing environment. The MOE code is run in parallel with the TRC code. Particularly useful MOEs include the number of missed objects (real objects for which the TRC algorithm did not construct a track); of ghost tracks (tracks not corresponding to a real object); of redundant tracks (multiple tracks corresponding to a single real object); and of unresolved objects (multiple objects corresponding to a single track). All of these are expressed as a function of time, and tend to maximize during the time in which real objects are spawned (multiple reentry vehicles per post-boost vehicle). As well, it is possible to measure the track-truth separation as a function of time. A set of calculations is presented illustrating these MOEs as a function of time for a case with 99 post-boost vehicles, each of which spawns 9 reentry vehicles.

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Hanford coring bit temperature monitor development testing results report

Rey, D.

Instrumentation which directly monitors the temperature of a coring bit used to retrieve core samples of high level nuclear waste stored in tanks at Hanford was developed at Sandia National Laboratories. Monitoring the temperature of the coring bit is desired to enhance the safety of the coring operations. A unique application of mature technologies was used to accomplish the measurement. This report documents the results of development testing performed at Sandia to assure the instrumentation will withstand the severe environments present in the waste tanks.

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Deformation study of separator pellets for thermal batteries

Guidotti, Ronald A.

The deformation characteristics of pellets of electrolyte-binder (EB) mixes based on MgO were measured under simulated, thermal-battery conditions. Measurements (using a statistically designed experimental strategy) were made as a function of applied pressure, temperature, and percentage of theoretical density for four molten-salt electrolytes at two levels of MgO. The EB mixes are used as separators in Li-alloy thermal batteries. The electrolytes included LiCl-KCI eutectic, LiCl-LiBr-KBr eutectic, LiBr-KBr-LiF eutectic, and a LiCl-LiBr-LiF electrolyte with a minimum-melting composition. The melting points ranged from 313 C to 436 C. The experimental data were used to develop statistical models that approximate the deformation behavior of pellets of the various EB mixes over the range of experimental conditions we examined. This report, discusses the importance of the deformation response surfaces to thermal-battery design.

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Passive soil venting at the Chemical Waste Landfill Site at Sandia National Laboratories, Albuquerque, New Mexico

Phelan, James M.

Passive Soil Vapor Extraction was tested at the Chemical Waste Landfill (CWL) site at Sandia National Laboratories, New Mexico (SNLIW). Data collected included ambient pressures, differential pressures between soil gas and ambient air, gas flow rates into and out of the soil and concentrations of volatile organic compounds (VOCS) in vented soil gas. From the differential pressure and flow rate data, estimates of permeability were arrived at and compared with estimates from other studies. Flow, differential pressure, and ambient pressure data were collected for nearly 30 days. VOC data were collected for two six-hour periods during this time. Total VOC emissions were calculated and found to be under the limit set by the Resource Conservation and Recovery Act (RCRA). Although a complete process evaluation is not possible with the data gathered, some of the necessary information for designing a passive venting process was determined and the important parameters for designing the process were indicated. More study is required to evaluate long-term VOC removal using passive venting and to establish total remediation costs when passive venting is used as a polishing process following active soil vapor extraction.

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Sandia National Laboratories (SNL) and Oak Ridge National Laboratories (ORNL) joint development of SNL`s sample tracking, analysis and reporting (STAR) information system

Campbell, D.

A comprehensive environmental sample management program allocates much of its resources to collecting, managing, and manipulating information. A computerized system that collects information at the field sampling point, tracks the sample to analytical labs and loads electronic data deliverables from these labs, while maintaining chain of custody and data integrity, is efficient and cost effective for providing consistent and accurate, legally defensible sample data. In June 1993, a team was formed to gather Sample Management Office requirements and begin development of a sample tracking system. This paper is an overview of experiences encountered when Sandia transferred and implemented sample software from the Waste Area Group (WAG6) at ORNL.

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ITEP: A survey of innovative environmental restoration technologies in the Netherlands and France

Roberds, W.J.; Voss, C.F.; Hitchcock, S.A.

The International Technology Exchange Program (ITEP) of the Department of Energy`s (DOE`s) Office of Environmental Management (EM) is responsible for promoting the import of innovative technologies to better address EM`s needs and the export of US services into foreign markets to enhance US competitiveness. Under this program, potentially innovative environmental restoration technologies, either commercially available or under development in the Netherlands and France, were identified, described, and evaluated. It was found that 12 innovative environmental restoration technologies, which are either commercially available or under development in the Netherlands and France, may have some benefit for the DOE EM program and should be considered for transfer to the United States.

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The vital issues process: Strategic planning for a changing world

Engi, Dennis E.

The Vital Issues process (VIp) is a strategic planning tool initially developed by Sandia National Laboratories (SNL) for the Office of Foreign Intelligence (OFI)* of the US Department of Energy (DOE). It was further developed and refined through its application to a variety of strategic purposes for a range of public and semipublic organizations. The VIp provides a structured mechanism for assisting organizations in accomplishing specified objectives by identifying and prioritizing a portfolio of strategic issues, programmatic areas, or responses to a specified problem. It employs day-long panel meetings in a specified format to elicit a broad range of perspectives on a particular issue in a nonconfrontational manner and to facilitate the interaction and synthesis of diverse viewpoints on a specific topic. The VIp is unique in its incorporation of two primary approaches in each panel session: a qualitative or transactional segment, which entails the synthesis of the alternatives through negotiations or discussion, and a quantitative or net benefit maximization segment, an analytical approach, which involves prioritization of the alternatives using pairwise comparisons. This combination of facilitated group discussion and quantitative ranking provides input to strategic management decisions in the form of stakeholder-defined and -prioritized items as well as information on potential barriers to the implementation of policies and programs. This is the final volume in the series Identifying Vital Issues: New Intelligence Strategies for a New World, a three-volume set that gives an accounting of the VIp as implemented for OFI. This volume provides an in-depth description of the methodology used in the VIp.

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A survey of environmental needs and innovative technologies in Germany

Voss, C.F.; Roberds, W.J.

The International Technology Program (IT?), formerly the international Technology Exchange Program (ITEP), of the Department of Energy`s (DOE`s) Office of Environmental Restoration and Waste Management (EM) is responsible for promoting: (1) the import of innovative technologies to better address EM`s needs; and (2) the export of US services into foreign markets to enhance US competitiveness. Under this program: (1) the environmental restoration market in Germany was evaluated, including the description of the general types of environmental problems, the environmental regulations, and specific selected contaminated sites; and (2) potentially innovative environmental restoration technologies, either commercially available or under development in Germany, were identified, described and evaluated. It was found that: (1) the environmental restoration market in Germany is very large, on the order of several billion US dollars per year, with a significant portion possibly available to US businesses; and (2) a large number (54) of innovative environmental restoration technologies, which are either commercially available or under development in Germany, may have some benefit to the DOE EM program and should be considered for transfer to the US.

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Design, fabrication, and testing of a sodium evaporator for the STM4-120 kinematic Stirling engine

Rawlinson, K.S.; Adkins, D.R.

This report describes the development and testing of a compact heat-pipe heat exchanger kW(e) designed to transfer thermal energy from hot combustion gases to the heater tubes of a 25-kW(e) Stirling engine. In this system, sodium evaporates from a surface that is heated by a stream of hot gases. The liquid metal then condenses on the heater tubes of a Stirling engine, where energy is transferred to the engine`s helium working fluid. Tests on a prototype unit illustrated that a compact (8 cm {times} 13 cm {times} 16 cm) sodium evaporator can routinely transfer 15 kW(t) of energy at an operating vapor temperature of 760 C. Four of these prototype units were eventually used to power a 25-kW(e) Stirling engine system. Design details and test results from the prototype unit are presented in this report.

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Electron phase coherent effects in nanostructures and coupled 2D systems

Simmons, J.A.

This report describes the research accomplishments achieved under the LDRD Project ``Electron Phase Coherent Effects in Nanostructures and Coupled 2D Systems.`` The goal of this project was to discover and characterize novel quantum transport phenomena in small semiconductor structures at low temperatures. Included is a description of the purpose of the research, the various approaches used, and a detailed qualitative description of the numerous new results obtained. The first appendix gives a detailed listing of publications, presentations, patent applications, awards received, and various other measures of the LDRD project success. Subsequent appendices consist of reprinted versions of several specific,`` scientific journal publications resulting from this LDRD project.

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Bulk and mechanical properties of the Paintbrush tuff recovered from borehole USW NRG-7/7A: Data report. Yucca Mountain Site Characterization Project

Price, Ronald H.

An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada, involves prediction of the in situ rheology for the design and construction of the facility and the emplacement of canisters containing radioactive waste. The data used to model the thermal and mechanical behavior of the repository and surrounding lithologies include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. In this study, a suite of experiments was performed on cores recovered from the USW NRG-717A borehole drilled in support of the Exploratory Studies Facility (ESF) at Yucca Mountain. USW NRG-7/7A was drilled to a depth of 1,513.4 feet through five thermal/mechanical units of Paintbrush tuff and terminating in the tuffaceous beds of the Calico IEUS. The thermal/mechanical stratigraphy was defined by Orfiz et al. to group rock horizons of similar properties for the purpose of simplifying modeling efforts. The relationship between the geologic stratigraphy and the thermal/mechanical stratigraphy is presented. The tuff samples in this study have a wide range of welding characteristics, and a smaller range of mineralogy and petrology characteristics. Generally, the samples are silicic, ash-fall tuffs that exhibit large variability in their elastic and strength properties.

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Crisis Prevention Centers as confidence building measures: Suggestions for the Middle East

Pregenzer, Arian L.

Relationships between countries generally exist somewhere in the grey area between war and peace. Crisis prevention activities are important in this area, and should have two goals: stabilizing tense situations that could push countries toward war, and supporting or reinforcing efforts to move countries toward peace. A Crisis Prevention Center (CPC) should facilitate efforts to achieve these goals. Its functions can be grouped into three broad, interrelated categories: establishing and facilitating communication among participating countries; supporting negotiations and consensus-building on regional security issues; and supporting implementation of agreed confidence and security building measures. Technology will play a critical role in a CPC. Technology is required for establishing communication systems to ensure the timely flow of information between countries and to provide the means for organizing and analyzing this information. Technically-based cooperative monitoring can provide an objective source of information on mutually agreed issues, thereby supporting the implementation of confidence building measures and treaties. Technology can be a neutral subject of interaction and collaboration between technical communities from different countries, thereby providing an important channel for improving relationships. Potential first steps for a CPC in the Middle Ease could include establishing communication channels and a dedicated communications center in each country, together with an agreement to use the system as a ``Hot Line` in bilateral and multilateral-lateral emergency situations. Bilateral cooperative monitoring centers could be established to assist with implementation of agreements. A centrally located CPC could serve as a regional communications hub, coordinating a number of functions aimed at stabilizing regional tensions and supporting confidence building activities. Specific recommendations for confidence building activities are discussed.

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Smart substrates: Making multi-chip modules smarter

Wunsch, Thomas F.

A novel multi-chip module (MCM) design and manufacturing methodology which utilizes active CMOS circuits in what is normally a passive substrate realizes the `smart substrate` for use in highly testable, high reliability MCMS. The active devices are used to test the bare substrate, diagnose assembly errors or integrated circuit (IC) failures that require rework, and improve the testability of the final MCM assembly. A static random access memory (SRAM) MCM has been designed and fabricated in Sandia Microelectronics Development Laboratory in order to demonstrate the technical feasibility of this concept and to examine design and manufacturing issues which will ultimately determine the economic viability of this approach. The smart substrate memory MCM represents a first in MCM packaging. At the time the first modules were fabricated, no other company or MCM vendor had incorporated active devices in the substrate to improve manufacturability and testability, and thereby improve MCM reliability and reduce cost.

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Cooperative monitoring workshop: Focus on the Middle East

Pregenzer, Arian L.

Sandia National Laboratories and the Institute for Global Conflict and Cooperation hosted a workshop on the application of cooperative monitoring to the Middle East. The workshop, held in Albuquerque, New Mexico, from July 17 through 21, 1994, was sponsored by the US Department of Energy, the Arms Control and Disarmament Agency, and the US Department of State. The meeting, which focused on use of technical monitoring tools and sharing of collected information to facilitate regional agreements, included participants from five regional countries as well as from American universities, the US government, and US National Laboratories. Some attendees previously participated in meetings of the Arms Control and Regional Security working group of the Middle East Multilateral Peace Talks. The workshop combined presentations, demonstrations and hands-on experimentation with monitoring hardware and software. An exercise was conducted to evaluate and recommend cooperative monitoring options for a model agreement between two hypothetical countries. Historical precedents were reviewed and the role of environmental and natural resource conflicts explored. These activities were supplemented by roundtable discussions covering Middle East security issues, the relationship of ``national means`` to cooperative monitoring, and cooperative monitoring of ballistic missiles in the Middle East.

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Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

Rader, Daniel J.

This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 {mu}m and a geometric standard deviation, {sigma}{sub g} of about 2; the CMD was found to increase and {sigma}{sub g} decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 {mu}m and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented.

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Scheduling jobs that arrive over time

Phillips, Cynthia A.

A natural and basic problem in scheduling theory is to provide good average quality of service to a stream of jobs that arrive over time. In this paper we consider the problem of scheduling n jobs that are released over time in order to minimize the average completion time of the set of jobs. In contrast to the problem of minimizing average completion time when all jobs are available at time 0, all the problems that we consider are NP-hard, and essentially nothing was known about constructing good approximations in polynomial time. We give the first constant-factor approximation algorithms for several variants of the single and parallel machine model. Many of the algorithms are based on interesting algorithmic and structural relationships between preemptive and nonpreemptive schedules and linear programming relaxations of both. Many of the algorithms generalize to the minimization of average weighted completion time as well.

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Cryogenic thermometry in superconducting accelerators

Demko, J.A.

The cryogenic thermometers used in superconducting accelerators must function in very adverse environments. Typical conditions are a temperature range of 1.5--300 K, high irradiation doses and magnetic fields which must be endured for the 20 to 50 year life of the accelerator. The authors determined the principal requirements for cryogenic thermometers in accelerator installations and for industrial applications. Some constructions of the thermometer mounting fixtures used in the ``Nuclotron`` (Dubna, Russia) and the SSCL (Dallas, USA) accelerator installations are described. The experimental results for long-term stability of the cryogenic thermometers applied are presented. The basic recommendations on the application technology of the cryogenic thermometers in large superconducting accelerator systems are given.

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Benefits of improved environmental cooperation on a joint DoD/DOE facility

Gibson, J.D.

Numerous Federal facilities within the US involve multiple government agencies that face overlapping environmental concerns. This paper highlights the benefits of looking beyond the strict letter of environmental regulations that might affect a single tenant or environmental site to cooperative environmental efforts that focus on the entire facility, consistent with the missions of participating agencies. Using Kirtland Air Force Base (AFB) as a model, seven areas of Department of Defense (DoD) and Department of Energy (DOE) environmental cooperation are discussed that span technical, regulatory compliance, and administrative issues.

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Prediction of single-component NAPL behavior for the TEVES Project using T2VOC

Webb, Stephen W.

Detailed simulations have been performed for the TEVES (Thermal Enhanced Vapor Extraction System) Project using the TOUGH2 code considering air, water, and a single-component NAPL. A critical parameter varied in the simulations is the borehole vacuum which directly affects air flow through the system and indirectly influences soil temperatures and water and NAPL fluid masses. Contaminant migration from the heated zone into the unheated soil can occur if the borehole vacuum, or borehole flow rate, is not sufficient. Under these conditions, evaporation of liquids (water and NAPL) due to the heating can cause flow from the heated zone into the unheated soil. Insufficient air sweep may be indicated by a vapor dominated mass flow rate into the borehole, at least for the present configuration. Sufficient air flow through the heated zone must be provided to contain the contaminants within the heated zone.

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Encryption and networking applications

Long, J.P.

The DOE requires that sensitive unclassified data be protected while being transmitted electronically. On most large networks it is difficult and expensive to provide the required level of physical protection. At Sandia National Laboratories, we are assembling the structure necessary to protect sensitive unclassified data using software-based encryption. This approach has the advantage that the data can be protected after arrival at its destination without additional investment While Sandia has expertise in cryptography, we had not used cryptography in this field. This discussion deals with the client-server model of file-based data exchange and interactive access to on-line data bases using Unix workstations, Macs and PCs.

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Offsite demonstrations for MWLID technologies

Williams, Cecelia V.

The goal of the Offsite Demonstration Project for Mixed Waste Landfill Integrated Demonstration (MWLID)-developed environmental site characterization and remediation technologies is to facilitate the transfer, use, and commercialization of these technologies to the public and private sector. The meet this goal, the project identified environmental restoration needs of mixed waste and/or hazardous waste landfill owners (Native American, municipal, DOE, and DoD); documenting potential demonstration sites and the contaminants present at each site; assessing the environmental regulations that would effect demonstration activities; and evaluating site suitability for demonstrating MWLID technologies at the tribal and municipal sites identified. Eighteen landfill sites within a 40.2-km radius of Sandia National Laboratories are listed on the CERCLIS Site/Event Listing for the state of New Mexico. Seventeen are not located within DOE or DoD facilities and are potential offsite MWLID technology demonstration sites. Two of the seventeen CERCLIS sites, one on Native American land and one on municipal land, were evaluated and identified as potential candidates for off-site demonstrations of MWLID-developed technologies. Contaminants potentially present on site include chromium waste, household/commercial hazardous waste, volatile organic compounds, and petroleum products. MWLID characterization technologies applicable to these sites include Magnetometer Towed Array, Cross-borehole Electromagnetic Imaging, SitePlanner {trademark}/PLUME, Hybrid Directional Drilling, Seamist{trademark}/Vadose Zone Monitoring, Stripping Analyses, and x-ray Fluorescence Spectroscopy for Heavy Metals.

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Summary of the energy efficient, waste-reducing technology assessment conducted for DOE and EPAct 2108

Weinbrecht, Edward A.

The industrial sector is the most complex and diverse segment of the US economy. There are more than 360,000 industrial facilities in the US, using tens of thousands of processes with millions of different pieces of equipment and employing nearly 30 million people to make hundreds of thousands of products. These facilities consume large quantities of raw materials and energy resources every year. Their waste streams, as well as the technology options for preventing them, are very specific not only to individual industries, but even to plants within the same industry that produce similar products. On October 24, 1992, President Bush signed the Energy Policy Act of 1992 (EPAct) into law as Public Law 102-486. Section 2108 of the Act requires the DOE to identify opportunities to demonstrate energy efficient pollution prevention technologies and processes. As a first step in DOE`s response to congress, Sandia National Laboratories lead a fast tracked project to compile information from the open literature, and pilot a process for identifying and prioritizing opportunity areas from industrial and federal experts. Approximately 300 documents were collected and reviewed, and knowledgeable individuals in government, universities, and trade associations were interviewed. A panel of experts from petroleum industry was assembled for the future opportunity assessments pilot These activities were conducted between May and August, 1993. Project background and results are summarized.

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Modification and application of TOUGH2 as a variable-density, saturated-flow code and comparison to SWIFT II results

Christian-Frear, T.L.

Human intrusion scenarios at the Waste Isolation Pilot Plant (WIPP) involve penetration of the repository and an underlying brine reservoir by a future borehole. Brine and gas from the brine reservoir and the repository may flow up the borehole and into the overlying Culebra formation, which is saturated with water containing different amounts of dissolved `solids resulting in a spatially varying density. Current modeling approaches involve perturbing a steady-state Culebra flow field by inflow of gas and/or brine from a breach borehole that has passed through the repository. Previous studies simulating steady-state flow in the Culebra have been done. One specific study by LaVenue et al. (1990) used the SWIFT 2 code, a single-phase flow and transport code, to develop the steady-state flow field. Because gas may also be present in the fluids from the intrusion borehole, a two-phase code such as TOUGH2 can be used to determine the effect that emitted fluids may have on the steady-state Culebra flow field. Thus a comparison between TOUGH2 and SWIFT2 was prompted. In order to compare the two codes and to evaluate the influence of gas on flow in the Culebra, modifications were made to TOUGH2. Modifications were performed by the authors to allow for element-specific values of permeability, porosity, and elevation. The analysis also used a new equation of state module for a water-brine-air mixture, EOS7 (Pruess, 1991), which was developed to simulate variable water densities by assuming a miscible mixture of water and brine phases and allows for element-specific brine concentration in the INCON file.

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Summary of applications of TOUGH2 to the evaluation of multiphase flow processes at the WIPP

Webb, Stephen W.

The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) research and development facility for the underground disposal of transuranic waste in southeastern New Mexico. The WIPP repository is located 655 m below the land surface in the lower portion of the Salado Formation, which is comprised of beds of pure and impure halite with thin interbeds of anhydrite and related clay seams. The regional dip of the Salado Formation is approximately 1{degree} southeast in the vicinity of the repository. The proposed waste storage area has eight waste disposal panels, each of which will contain seven rooms. The repository is designed to follow a single stratigraphic horizon. Due to the dip, the north end of the repository will be about 10 meters higher than the south end. Waste that is emplaced in the disposal rooms will generate gas due to microbial degradation, anoxic corrosion, and radiolysis. Brine inflow to the rooms from the surrounding Salado Formation may significantly influence the gas generation rate and the total amount of gas generated. The salt surrounding the repository will creep in response to the excavation, reducing the room volume. Gas generation in the room may increase the pressure sufficiently to drive brine and gas into the surrounding Salado Formation. Migration of gas and brine in the Salado is an important factor in evaluating the performance of the repository. The studies summarized in this paper have. been performed to evaluate brine and gas flow processes in the WIPP disposal system and to identify some of the important processes. These studies are done in support of, but are not part of, the formal Performance Assessment (PA) effort. Because of probabilistic and system-scale requirements, the PA effort uses the Sandia-developed BRAGFLO (BRine And Gas FLOw) code for multiphase flow calculations.

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Using TOUGH2 to model the coupled effects of gas generation, repository consolidation, and multiphase brine and gas flow at the Waste Isolation Pilot Plant

Larson, K.W.

The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy facility designed to demonstrate the safe underground disposal of transuranic waste. Following waste emplacement, each room will be backfilled with crushed salt. Due to deviatoric stress introduced by excavation, the walls of the waste disposal rooms in the repository will deform over time, consolidating waste containers and salt backfill, thereby decreasing the void volume of the repository. Long-term repository assessment must consider the processes of gas generation, room closure and expansion due to salt creep, and multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. Stone (1992) used the mechanical creep closure code SANCHO to simulate the closure of a single, perfectly sealed disposal room filled with waste and backfill. The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined by Freeze et al. TOUGH2 was employed to couple the processes of gas generation, room closure/consolidation, and multiphase brine and gas flow. Two empirically-based methods for approximating salt creep and room consolidation were implemented in TOUGH2: the pressure-time-porosity line interpolation approach and the fluid-phase-salt approach. Both approaches utilized links to the SANCHO f-series simulation results to calculate room-void-volume changes with time during a simulation.

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The effect of stratigraphic dip on multiphase flow at the Waste Isolation Pilot Plant

Webb, Stephen W.

The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy research and development facility for the underground disposal of transuranic waste from US defense-related activities. The WIPP repository is located within the Salado Formation, which is comprised of beds of pure and impure halite with thin interbeds of anhydrite and related clay seams. This formation is brine saturated with a pore pressure of approximately 12.5 MPa at the repository horizon. The Salado Formation dips gently southeast, on the average approximately 1{degree}, with steeper dips locally. Elevated repository pressures, caused by gas generated as emplaced waste corrodes and degrades, may drive brine and gas out of the repository into the surrounding formation. Stratigraphic dip may cause increased brine inflow to the repository through countercurrent flow in the interbeds and enhanced gas migration distances in the updip direction due to buoyancy. Two-dimensional simulations of isolated WIPP repository room have been performed using TOUGH2 for horizontal and 1{degree} dipping stratigraphy. The impact of dip on multiphase flow at the WIPP may be significant. With dip, an additional mechanism for brine inflow may occur, namely the formation of a cell of countercurrent brine and gas flow in the interbeds. The additional volume of brine inflow resulting from the countercurrent flow cell may be of similar magnitude to brine inflow without dip. Therefore, dip must be included in any repository model to include the countercurrent brine inflow mechanism. Gas migration may also be significantly influenced due to dip. Gas migration distances may increase dramatically with preferential migration updip.

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Progress in MELCOR development and assessment

Summers, R.M.; Kmetyk, L.N.; Cole Jr., R.K.; Smith, R.C.; Elsbernd, A.E.; Stuart, D.S.; Thompson, S.L.

MELCOR models the progression of severe accidents in light water reactor nuclear power plants. Recent efforts in MELCOR development to incorporate CORCON-Mod3 models for core-concrete interactions, new models for advanced reactors, and improvements to several other existing models have resulted in release of MELCOR 1.8.3. In addition, continuing efforts to expand the code assessment database have filled in many of the gaps in phenomenological coverage. Efforts are now under way to develop models for chemical interactions of fission products with structural surfaces and for reactions of iodine in the presence of water, and work is also in progress to improve models for the scrubbing of fission products by water pools, the chemical reactions of boron carbide with steam, and the coupling of flow blockages with the hydrodynamics. Several code assessment analyses are in progress, and more are planned.

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Vibration control for precision manufacturing at Sandia National Laboratories

Martinez, D.

Sandia National Laboratories performs R and D in structural dynamics and vibration suppression for precision applications in weapon systems, space, underwater, transportation and civil structures. Over the last decade these efforts have expanded into the areas of active vibration control and ``smart`` structures and material systems. In addition, Sandia has focused major resources towards technology to support weapon product development and agile manufacturing capability for defense and industrial applications. This paper will briefly describe the structural dynamics modeling and verification process currently in place at Sandia that supports vibration control and some specific applications of these techniques to manufacturing in the areas of lithography, machine tools and flexible robotics.

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GCMS and FTIR studies of by-product inhibited growth and the rate-limiting step in TEOS-based SiO{sub 2} CVD

Bartram, M.E.

To improve process reliability and deposition methods, it is essential to identify the rate-limiting step in TEOS-based SiO{sub 2} CVD and its dependence on process conditions. For this purpose, experiments designed to evaluate by-product inhibition effects and to identify the rate-limiting step in TEOS decomposition have been carried out in a research reactor using GCMS and FTIR. By repetitively sampling a series of reactions in which TEOS was first mixed with ethylene, ethanol, and water in the gas-phase, GCMS was used to show clearly that these reaction by-products do not inhibit the heterogeneous reaction step on SiO{sub 2} at 1,000K. FTIR was used to determine that ethoxy groups from TEOS dissociative chemisorption have a significant lifetime on the SiO{sub 2} surface at CVD temperatures and have an activation energy for decomposition of 16kcal/mol{+-}4kcal/mol. This is much higher than the activation energy of 6 kcal/mol reported for the initial chemisorption step and is near the 22 kcal/mol reported for the overall activation energy for SiO{sub 2} deposition in a cold-wall reactor. These results suggest that, whether or not surface ethoxy groups inhibit TEOS reactions, their decomposition may be directly related to the rate-limiting step in SiO{sub 2} deposition.

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Preliminary design for Arctic atmospheric radiative transfer experiments

Zak, Bernard D.

If current plans are realized, within the next few years, an extraordinary set of coordinated research efforts focusing on energy flows in the Arctic will be implemented. All are motivated by the prospect of global climate change. SHEBA (Surface Energy Budget of the Arctic Ocean), led by the National Science Foundation (NSF) and the Office of Naval Research (ONR), involves instrumenting an ice camp in the perennial Arctic ice pack, and taking data for 12--18 months. The ARM (Atmospheric Radiation Measurement) North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) Cloud and Radiation Testbed (CART) focuses on atmospheric radiative transport, especially in the presence of clouds. The NSA/AAO CART involves instrumenting a sizeable area on the North Slope of Alaska and adjacent waters in the vicinity of Barrow, and acquiring data over a period of about 10 years. FIRE (First ISCCP [International Satellite Cloud Climatology Program] Regional Experiment) Phase 3 is a program led by the National Aeronautics and Space Administration (NASA) which focuses on Arctic clouds, and which is coordinated with SHEBA and ARM. FIRE has historically emphasized data from airborne and satellite platforms. All three program anticipate initiating Arctic data acquisition during spring, 1997. In light of his historic opportunity, the authors discuss a strawman atmospheric radiative transfer experimental plan that identifies which features of the radiative transport models they think should be tested, what experimental data are required for each type of test, the platforms and instrumentation necessary to acquire those data, and in general terms, how the experiments could be conducted. Aspects of the plan are applicable to all three programs.

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A collision avoidance system for workpiece protection

Schmitt, D.J.

This paper describes an application of Sandia`s non-contact capacitive sensing technology for collision avoidance during the manufacturing of rocket engine thrust chambers. The collision avoidance system consists of an octagon shaped collar with a capacitive proximity sensor mounted on each face. The sensors produced electric fields which extend several inches from the face of the collar and detect potential collisions between the robot and the workpiece. A signal conditioning system processes the sensor output and provides varying voltage signals to the robot controller for stopping the robot.

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Intermetallic compound layer growth kinetics in non-lead bearing solders

Vianco, Paul T.

The introduction of alternative, non-lead bearing solders into electronic assemblies requires a thorough investigation of product manufacturability and reliability. Both of these attributes can be impacted by the excessive growth of intermetallic compound (IMC) layers at the solder/substrate interface. An extensive study has documented the stoichiometry and solid state growth kinetics of IMC layers formed between copper and the lead-free solders: 96.5Sn-3.5Ag (wt.%), 95Sn-5Sb, 100Sn, and 58Bi-42Sn. Aging temperatures were 70--205 C for the Sn-based solders and 55--120 C for the Bi-rich solder. Time periods were 1--400 days for all of the alloys. The Sn/Cu, Sn-Ag/Cu, and Sn-Sb/Cu IMC layers exhibited sub-layers of Cu{sub 6}Sn{sub 5} and Cu{sub 3}Sn; the latter composition was present only following prolonged aging times or higher temperatures. The total layer growth exhibited a time exponent of n = 0.5 at low temperatures and a value of n = 0.42 at higher temperatures in each of the solder/Cu systems. Similar growth kinetics were observed with the low temperature 58Bi-42Sn solder; however, a considerably more complex sub-layer structure was observed. The kinetic data will be discussed with respect to predicting IMC layer growth based upon solder composition.

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Current trends in the packaging of photonic devices

Carson, R.F.

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Sandia National Lab`s precision laser tracking systems

Patrick, D.L.

Sandia Labs` mobile tracking systems have only one moving part. The double gimballed 18 inch diameter beryllium mirror is capable of constant tracking velocities up to 5 rads/sec in both axes, and accelerations to 150 rads/sec/sec in both axes. Orthogonality is <10 microradians. The mirror directs the 488 and 514 nm wavelength CW laser beams to adhesive-backed reflective material applied to the test unit. The mirror catches the return beam and visual image, directing the visual image to three camera bays, and the return beam to an image dissector behind an 80 inch gathering telescope. The image dissector or image position sensor is a photomultiplier with amplifying drift tube and electron aperture and its associated electronics. During the test, the image dissector scan senses the change in position of the reflective material and produces signals to operate the azimuth and elevation torque motors in the gimbal assembly. With the help of 1 1/8 inch diameter azimuth and elevation galvonometer steering mirrors in the optical path, the laser beam is kept on the target at extremely high velocities. To maintain a constant return signal strength, the outgoing beam is run through a microprocessor controlled beam focusing telescope.

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Geologic site characterization requirements for storage and mining in salt

Neal, J.T.

Geologic Site Characterization should be a dynamic, continuing process, not an event. Its successes and failures are legion and can make or break an operator. A balanced approach must be sought to provide adequate information for safety of operations, neither slighting nor overdoing the effort. The evolving nature of study methods and geologic knowledge essentially mandates that characterization efforts be reviewed periodically. However, indifference, nonchallance, and even outright disdain describe attitudes witnessed in some circles regarding this subject. Unawareness may also be a factor. Unfortunately, several unanticipated events have led to severe economic consequences for the operators. The hard-learned lessons involving several unanticipated geotechnical occurrences at several Gulf Coast salt domes are discussed. The ultimate benefit of valuing site characterization efforts may be more than just enhanced safety and health--costs not expended in lost facilities and litigation can become profit.

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Scalable ATM encryption

Pierson, Lyndon G.

In order to provide needed security assurances for traffic carried in Asynchronous Transfer Mode (ATM) networks, methods of protecting the integrity and privacy of traffic must be employed. Cryptographic methods can be used to assure authenticity and privacy, but are hard to scale and the incorporation of these methods into computer networks can severely impact functionality, reliability, and performance. To study these trade-offs, a research prototype encryptor/decryptor is under development. This prototype is to demonstrate the viability of implementing certain encryption techniques in high speed networks by processing Asynchronous Transfer Mode (ATM) cells in a SONET OC-3 payload. This paper describes the objectives and design trade-offs intended to be investigated with the prototype. User requirements for high performance computing and communication have driven Sandia to do work in the areas of functionality, reliability, security, and performance of high speed communication networks. Adherence to standards (including emerging standards) achieves greater functionality of high speed computer networks by providing wide interoperability of applications, network hardware, and network software.

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Assessment of ALWR passive safety system reliability. Phase 1: Methodology development and component failure quantification

Hake, T.M.

Many advanced light water reactor (ALWR) concepts proposed for the next generation of nuclear power plants rely on passive systems to perform safety functions, rather than active systems as in current reactor designs. These passive systems depend to a great extent on physical processes such as natural circulation for their driving force, and not on active components, such as pumps. An NRC-sponsored study was begun at Sandia National Laboratories to develop and implement a methodology for evaluating ALWR passive system reliability in the context of probabilistic risk assessment (PRA). This report documents the first of three phases of this study, including methodology development, system-level qualitative analysis, and sequence-level component failure quantification. The methodology developed addresses both the component (e.g. valve) failure aspect of passive system failure, and uncertainties in system success criteria arising from uncertainties in the system`s underlying physical processes. Traditional PRA methods, such as fault and event tree modeling, are applied to the component failure aspect. Thermal-hydraulic calculations are incorporated into a formal expert judgment process to address uncertainties in selected natural processes and success criteria. The first phase of the program has emphasized the component failure element of passive system reliability, rather than the natural process uncertainties. Although cursory evaluation of the natural processes has been performed as part of Phase 1, detailed assessment of these processes will take place during Phases 2 and 3 of the program.

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Thermal measurements to characterize large fires

Gritzo, Louis A.

Full-scale fire characterization tests are becoming less frequent due to cost restrictions and environmental concerns. This trend, combined with significant advances in fire field modeling, has resulted in an increased effort to perform well-designed experiments which support the development and validation of numerical tools. In pursuit of improved fire characterization, large-fire measurement techniques in large-scale (D > 2m) fires are reviewed in this work. Primary attention is focused on the measurement of temperature and heat flux. Additional measurements of quantities such as soot volume fraction, soot emission temperature, and gas species are also addressed. Issues relating to the use of existing techniques, and methods for improving and interpreting the results from existing measurement techniques are presented. Alternate techniques for fire characterization and needs for development of advanced measurement technology are also briefly discussed.

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Dynamic pulse buckling of cylindrical shells under axial impact: A benchmark study of 2D and 3D finite element calculations

Hoffman, Edward L.

A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. During the pulse buckling tests, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. Numerical simulations of the test were performed using PRONTO, a Sandia developed transient dynamics analysis code, and ABAQUS/Explicit with both shell and continuum elements. The calculations are compared to the tests with respect to deformed shape and impact load history.

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Models of transport, gas-phase and surface chemistry in diamond chemical vapor deposition

Coltrin, Michael E.

This paper presents an analysis of the Chemical Vapor Deposition of diamond thin films in a direct-current (dc) arc-jet reactor. The analysis discussed here includes a model of the performance of the arc-jet hydrogen excitation source, chemistry in the free-stream region, diffusive transport and chemistry in the boundary layer and at the surface. The surface chemistry model includes pathways for deposition of diamond, as well as creation of defects in the diamond lattice.

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Growth and characterization of heterostructures and infrared emitters with compressed InAsSb layers

Kurtz, S.R.

An overview is presented of work on strained InAsSb heterostructures and infrared emitters. InAsSb/InGaAs strained-layer superlattices (SLS) and InAsSb quantum wells were grown by metal-organic chemical vapor deposition and characterized using magneto-photoluminescence. LEDs and lasers with InAsSb heterostructure active regions are described.

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The design life affects system design

Dean, F.F.

When a system is being designed, one of the system requirements will specify the intended life for the system, which is called the design life, the system life, the expected operational lifetime, or the service life. This specification is an important driver of the total life cycle cost. This paper suggests how specifying this design life affects the design and the cost of the system.

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A hazard separation system for dismantlement of nuclear weapon components

Lutz, J.D.

Over the next decade, the US Department of Energy (DOE) must retire and dismantle many nuclear weapon systems. In support of this effort, Sandia National Laboratories (SNL) has developed the Hazard Separation System (HSS). The HSS combines abrasive waterjet cutting technology and real-time radiography. Using the HSS, operators determine the exact location of interior, hazardous sub-components and remove them through precision cutting. The system minimizes waste and maximizes the recovery of recyclable materials. During 1994, the HSS was completed and demonstrated. Weapon components processed during the demonstration period included arming, fusing, and firing units; preflight control units; neutron generator subassemblies; and x-units. Hazards removed included radioactive krytron tubes and gap tubes, thermal batteries, neutron generator tubes, and oil-filled capacitors. Currently, the HSS is being operated at SNL in a research and development mode to facilitate the transfer of the technology to other DOE facilities for support of their dismantlement operations.

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Results 93201–93400 of 96,771
Results 93201–93400 of 96,771