Publications

The objective of this project was to determine the savings in utility operating costs that could be obtained by installing a Battery Energy Storage System (BESS). The target utility was Kansas City Power and Light (KCPL), a typical Midwestern utility with a mix of generating plants and many interconnections. The following applications of battery energy storage were modeled using an Electric Power Research Institute (EPRI) developed and supported program called DYNASTORE: (1) Spinning Reserve Only (2) Load Leveling with Spinning Reserve (3) Load Leveling Only (4) Frequency Control DYNASTORE commits energy storage units along with generating units and calculates operating costs with and without energy storage, so that savings can be estimated. Typical weeks of hourly load data are used to make up a yearly load profile. For this study, the BESS power ranged from ``small`` to 300 MW (greater than the spinning reserve requirement). BESS storage time ranged from 1 to 8 hours duration (to cover the time-width of most peaks). Savings in operating costs were calculated for each of many sizes of MW capacity and duration. Graphs were plotted to enable the reader to readily see what size of BESS affords the greatest savings in operating costs.

A sinkhole discovered over the edge of the Strategic Petroleum Reserve storage facility at Weeks Island salt dome, Louisiana, led to decommissioning the site during 1995--1998, following extensive diagnostics in 1994. The sinkhole resulted from mine-induced fractures in the salt which took may years to develop, eventually causing fresh water to leak into the storage chamber and dissolve the overlying salt, thus causing overburden collapse into the void. Prior to initiating the oil removal, a freeze wall was constructed at depth around the sinkhole in 1995 to prevent water inflow; a freeze plug will remain in place until the mine is backfilled with brine in 1997--8, and stability is reached. Residual oil will be removed; environmental monitoring has been initiated and will continue until the facility is completely plugged and abandoned, and environmental surety is achieved.

The technology base for Repetitive High Energy Pulsed Power (RHEPP) was originally developed to support defense program applications. As RHEPP technology matures, its potential for use in commercial applications can be explored based on inherent strengths of high average power, high dose rate, cost efficient scaling with power, and potential for long life performance. The 300 kW, 2 MeV RHEPP II accelerator is now in operation as a designated DOE User Facility, exploring applications where high dose-rate (> 10{sup 8} Gy/s) may be advantageous, or very high average power is needed to meet throughput requirements. Material surface and bulk property modification, food safety, and large-scale timber disinfestation are applications presently under development. Work is also in progress to generate the reliability database required for the design of 2nd generation systems.

We studied whether plasma-etching techniques can use screen printed gridlines as etch masks to form self-aligned, patterned-emitter profiles on multicrystalline silicon (mc-Si) cells from Solarex Our initial results found a statistically significant improvement of about half an absolute percentage point m cell efficiency when the self-aligned emitter etchback was combined with a PECVD-nitride surface passivation treatment. Some additional improvement in bulk diffusion length was observed when a hydrogen passivation treatment was used in the process. We attempted to gain additional benefits from using an extra-heavy phosphorus emitter diffusion before the gridlines were deposited. However, this required a lusher plasma-etch power to etch back the deeper diffusion and keep the etch time reasonably short. The higher power etch may have damaged the surface and the gridlines so that improvement due to surface passive and reduced gridline contact resistance was inhibited.

Sandia National Laboratories has found that the reliability and failure modes of current-generation network technologies can be effectively modeled using fault tree-based probabilistic logic modeling (PLM) techniques. We have developed fault tree models that include various hierarchical networking technologies and classes of components interconnected in a wide variety of typical and atypical configurations. In this paper we discuss the types of results that can be obtained from PLMs and why these results are of great practical value to network designers and analysts. After providing some mathematical background, we describe the `plug-and-play` fault tree analysis methodology that we have developed for modeling connectivity and the provision of network services in several current- generation network architectures. Finally, we demonstrate the flexibility of the method by modeling the reliability of a hybrid example network that contains several interconnected ethernet, FDDI, and token ring segments. 11 refs., 3 figs., 1 tab.

Production of a full-size divertor cassette involves eight major components. All of the components are mounted on the cassette body. Inner divertor channel components for the vertical target design are being provided by the Japan Home Team. Outer divertor channel components for the vertical target design are being provided by the European and United States Home Teams. Gas box liners are being provided by the Russian Home Team. The full-size components manufactured by the four parties will be shipped to the US Home Team for assembly into a full size divertor cassette. The techniques for assembly and maintenance of the cassette will be demonstrated during this process. The assembled cassette will be tested for proper flow distribution and proof of the filling and draining procedures. The testing will include vacuum leak tightness at full temperature and pressure, cyclic heating to 150 {degrees}C, verification of dimensional accuracy of the assembled components, and application of thermal gradients to measure dimensional stability. The development of the divertor for the International Thermonuclear Experimental Reactor (ITER) depends on successful R&D efforts on materials, joining, and plasma materials interactions. Results of the development program are presented. The scale-up of the processes developed in the basic research and development tasks is accomplished by producing and high-heat-flux testing medium and full-scale mock- ups. The design of the mock-ups is discussed.

ITER will be the first tokamak having long pulse operation using deuterium-tritium fuel. The problem of designing heat removal structures for steady state in a neutron environment is a major technical goal for the ITER Engineering Design Activity (EDA). The steady state heat flux specified for divertor components is 5 MW/m{sup 2} for normal operation with transients to 15 MW/m{sup 2} for up to 10 s. The selection of materials for plasma facing components is one of the major research activities. Three materials are being considered for the divertor; carbon fiber composites, beryllium, and tungsten. This paper discusses the relative advantages and disadvantages of these materials. The final section of plasma facing materials for the ITER divertor will not be made until the end of the EDA.

This report summarizes available data on ground motions from underground nuclear explosions recorded on and near the Nevada Test Site, with emphasis on the ground motions recorded at stations on Yucca Mountain, the site of a potential high-level radioactive waste repository. Sandia National Laboratories, through the Weapons Test Seismic Investigations project, collected and analyzed ground motion data from NTS explosions over a 14-year period, from 1977 through 1990. By combining these data with available data from earlier, larger explosions, prediction equations for several ground motion parameters have been developed for the Test Site area for underground nuclear explosion sources. Also presented are available analyses of the relationship between surface and downhole motions and spectra and relevant crustal velocity structure information for Yucca Mountain derived from the explosion data. The data and associated analyses demonstrate that ground motions at Yucca Mountain from nuclear tests have been at levels lower than would be expected from moderate to large earthquakes in the region; thus nuclear explosions, while located relatively close, would not control seismic design criteria for the potential repository.

Sandia National Laboratories is operated for the United States Department of Energy by a subsidiary of Lockheed Martin Corporation. National security programs and defense-related environmental programs for DOE comprise 65 percent of Sandia`s work. We are the DOE Defense Programs laboratory responsible for engineering development of all US nuclear weapons and for systems integration of the nuclear weapons with their delivery vehicles. Our responsibilities include design, certification, and assessment of the nonnuclear subsystems of nuclear weapons; safety, security, reliability, and use control; issues associated with production and dismantlement of nuclear weapons; surveillance and support of weapons in the stockpile; and work in nuclear intelligence, nonproliferation, and treaty verification technologies. Sandia is a multiprogram laboratory. Ten percent of our work supports DOE missions in energy science, research, and development. When appropriate, we also perform work for other government agencies, particularly the Department of Defense, in programs where unique competencies built our mission responsibilities can add value. This report discusses the activities of these responsibilities at the Sandia National Laboratories.

Icarus is a 2D Direct Simulation Monte Carlo (DSMC) code which has been optimized for the parallel computing environment. The code is based on the DSMC method of Bird and models from free-molecular to continuum flowfields in either cartesian (x, y) or axisymmetric (z, r) coordinates. Computational particles, representing a given number of molecules or atoms, are tracked as they have collisions with other particles or surfaces. Multiple species, internal energy modes (rotation and vibration), chemistry, and ion transport are modelled. A new trace species methodology for collisions and chemistry is used to obtain statistics for small species concentrations. Gas phase chemistry is modelled using steric factors derived from Arrhenius reaction rates. Surface chemistry is modelled with surface reaction probabilities. The electron number density is either a fixed external generated field or determined using a local charge neutrality assumption. Ion chemistry is modelled with electron impact chemistry rates and charge exchange reactions. Coulomb collision cross-sections are used instead of Variable Hard Sphere values for ion-ion interactions. The electrostatic fields can either be externally input or internally generated using a Langmuir-Tonks model. The Icarus software package includes the grid generation, parallel processor decomposition, postprocessing, and restart software. The commercial graphics package, Tecplot, is used for graphics display. The majority of the software packages are written in standard Fortran.

Intelligent, agile manufacturing relies on automated programming of digitally controlled processes. Currently, processes such as Computer Numerically Controlled (CNC) machining are difficult to automate because of highly restrictive controllers and poor software environments. It is also difficult to utilize sensors and process models for adaptive control, or to integrate machining processes with other tasks within a factory floor setting. As part of a Laboratory Directed Research and Development (LDRD) program, a CNC machine control system architecture based on object-oriented design and graphical programming has been developed to address some of these problems and to demonstrate automated agile machining applications using platform-independent software.

A growing demand exists for inexpensive and reliable sensors for moisture detection in reduced pressure processing environments. Sandia`s Porous Silicon Capacitor (PSC) sensor appears to be an ideal candidate for this application. This sensor is a solid state device that detects moisture through changes in dielectric constant with water adsorption. Standard microelectronic fabrication techniques are used in its production affording low cost production and ready integration into complex sensor and electronic arrays. This sensor has previously been investigated for moisture detection in fluid streams, however, little effort has been placed on its behavior in a vacuum environment. Sandia`s Sensors in Vacuum (SIV) test facility has been employed to evaluate the performance characteristics of this sensor in vacuum. In addition, a vacuum-based study allows for a more controlled environment in which the intrinsic lower limit for moisture detection and response times to moisture changes can be easily determined quantitatively. This report describes the performance characteristics of a series of sensors from a single production lot. Calibration of these sensors to moisture levels from part per billion to part per hundred concentrations has been performed. The concentration-dependent sensitivity of these sensors is documented. The response time and drift characteristics of these sensors are also discussed. The investigation of a preliminary method for increasing the recovery time of the sensor after moisture exposure is presented. The role of hydrocarbon contamination, a potential problem in some vacuum schemes, is also evaluated. Specific recommendations are made on how to implement this sensor for vacuum applications.

This work was performed jointly by Sandia National Laboratories (Albuquerque, NM) and Siemens Solar Industries (Camarillo, CA) under a Cooperative Research and Development Agreement (CRADA 1248). The work covers the period May 1994 to March 1996. The purpose of the work was to explore the performance potential of commercial, photovoltaic-grade Czochralski (Cz) silicon, and to demonstrate this potential through fabrication of high-efficiency cells and a module. Fabrication of the module was omitted in order to pursue further development of advanced device structures. The work included investigation of response of the material to various fabrication processes, development of advanced cell structures using the commercial material, and investigation of the stability of Cz silicon solar cells. Some important achievements of this work include the following: post-diffusion oxidations were found to be a possible source of material contamination; bulk lifetimes around 75 pts were achieved; efficiencies of 17.6% and 15.7% were achieved for large-area cells using advanced cell structures (back-surface fields and emitter wrap-through); and preliminary investigations into photodegradation in Cz silicon solar cells found that oxygen thermal donors might be involved. Efficiencies around 20% should be possible with commercial, photovoltaic-grade silicon using properly optimized processes and device structures.

Gemini is the coupling of Icarus, the Sandia National Laboratories (SNL) 2-D Direct Simulation Monte Carlo (DMSC) code, to MPRES, the University of Houston 2-D finite element plasma reactor code. Thus, Gemini is not a stand alone code. The primary application of Gemini is the simulation of inductively coupled plasma reactors that operate at low pressures (< 10mtorr) where continuum formulations of the transport equations begin to break down. Plasma parameters (electron density (ne), electron temperature (Te) and electrostatic fields (Er and Ez)) are computed in MPRES and interpolated onto the DSMC grid. This allows transport of the neutrals and ions to be performed using the DSMC method while including electron impact reactions and field transport effects. A sample calculation including appropriate input files is given.

This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

Spotlight synthetic aperture radar images can be formed from the complex phase history data using two main techniques: (1) polar-to-cartesian interpolation followed by two-dimensional inverse Fourier transform (2DFFT), and (2) convolution backprojection (CBP). CBP has been widely used to reconstruct medical images in computer aided tomography, and only recently has been applied to form synthetic aperture radar imagery. It is alleged that CBP yields higher quality images because (1) all the Fourier data are used and (2) the polar formatted data is used directly to form a 2D Cartesian image and therefore 2D interpolation is not required. This report compares the quality of images formed by CBP and several modified versions of the 2DFFT method. We show from an image quality point of view that CBP is equivalent to first windowing the phase history data and then interpolating to an exscribed rectangle. From a mathematical perspective, we should expect this conclusion since the same Fourier data are used to form the SAR image. We next address the issue of parallel implementation of each algorithm. We dispute previous claims that CBP is more readily parallelizable than the 2DFFT method. Our conclusions are supported by comparing execution times between massively parallel implementations of both algorithms, showing that both experience similar decreases in computation time, but that CBP takes significantly longer to form an image.

The increased power of computers and computer codes makes the use of nonlinear dynamic finite element analyses attractive for use as a tool used in the design and certification of radioactive material transportation packages. For this analysis technique to be acceptable it must be demonstrated. The technique has the ability to accurately capture the response of the packages to accident environments required by the regulations. The best method of demonstrating this ability is via a series of benchmark analyses. In this paper three benchmark problems involving significant inelastic deformations will be discussed. One of the problems has been analyzed using many different finite element codes. The other two problems involve comparison of finite element calculations to the results form physical tests. The ability of the finite element method to accurately capture the response in these three problems indicates the method should be acceptable for radioactive material transportation package design and certification.

An acoustic emission tester for aircraft Halon bottles has been developed. The necessary load is applied by heating the bottles. Acoustic emission is monitored during the heating by six sensors held in position by a special fixture. This fixture was designed to fit spheres with diameters between 5 and 16 inches. A prototype has been undergoing testing in two commercial Halon bottle repair and test facilities. Results to date indicate that about 97 percent of the bottles tested show no indications of any flaws. The other three percent have had indications of flaws in non-critical areas of the bottles. All bottles tested to date have passed the hydrostatic test required by the Department of Transportation (DOT).

The development of smaller circuit volumes in microelectronic applications, particularly Multichip Module (MCM) technology, entails deposition of minute quantities of solder, with volumes on the order of nanoliters. We propose a system for fluxless solder deposition which uses on-demand solder jetting for deposition of 200 micrometer diameter solder droplets onto aluminum pads. This work details the computational modeling performed to provide design parameters for a magneto-hydrodynamic solder jetter (MHD). A dimensionless analysis was used to relate the fluid properties, the orifice length and width, and the droplet size to the amplitude and duration of the pressure pulse. These results were used as the initial inputs for the fluid dynamics model, and subsequent iterations were performed to determine the operational parameters that lead to the formation of stable, single droplets. Results show that a maximum pulse amplitude on the order of 0.5 Mdynes/cm[sup 2] is necessary to dispense molten solder from a 200 micrometer diameter orifice. The size of the droplet was found to vary linearly with the applied pressure pulse. The duration of the pulse ranged from approximately 0.6 to 0.9 milliseconds. A theoretical description of the relationship between the orifice diameter, surface tension, and `Pinch-off` time is given, and is in agreement with the results of the computational model.

Field sampling and rapid gas analysis techniques were used to survey near-surface soil gases for geotechnical diagnostic purposes at the Weeks Island Strategic Petroleum Reserve (SPR) site and other salt dome locations in southern Louisiana. This report presents the complete data, results and interpretations obtained during 1995. Weeks Island 1994 gas survey results are also briefly summarized; this earlier study did not find a definitive correlation between sinkhole No. 1 and soil gases. During 1995, several hundred soil gas samples were obtained and analyzed in the field by gas chromatography, for profiling low concentrations and gas anomalies at ppm to percent levels. The target gases included hydrogen, methane, ethane and ethylene. To supplement the field data, additional gas samples were collected at various site locations for laboratory analysis of target gases at ppb levels. Gases in the near-surface soil originate predominantly from the oil, from petrogenic sources within the salt, or from surface microbial activity. Surveys were conducted across two Weeks Island sinkholes, several mapped anomalous zones in the salt, and over the SPR repository site and its perimeter. Samples were also taken at other south Louisiana salt dome locations for comparative purposes. Notable results from these studies are that elevated levels of hydrogen and methane (1) were positively associated with anomalous gassy or shear zones in the salt dome(s) and (2) are also associated with suspected salt fracture (dilatant) zones over the edges of the SPR repository. Significantly elevated areas of hydrogen, methane, plus some ethane, were found over anomalous shear zones in the salt, particularly in a location over high pressure gas pockets in the salt, identified in the mine prior to SPR operations. Limited stable isotope ratio analyses, SIRA, were also conducted and determined that methane samples were of petrogenic origin, not biogenic.

Three issues concerning phonon-assisted hopping in molecularly doped polymers are considered. The first issue is whether Arrhenius jump rates in the vicinity of room temperature arise from single- phonon or small-polaronic hopping. It is concluded that Arrhenius hopping only occurs above low temperatures through small-polaronic hopping. Second, hopping in molecularly doped polymers is compared with small- polaronic hopping of other systems. Small-polaronic hopping typically occurs between similar chemical structures whose energies are relatively insensitive to their surroundings. Thus, disorder energies experienced by carriers are often modest, values of several hundredths of an eV are common. Nonetheless, the effects of large electric fields on carrier mobilities differ significantly among disordered systems. Data reported for molecularly doped polymers is unlike that for either transition- metal-oxide or chalcogenide glasses. In no case is high-field transport well understood. Finally, I stress that steady-state flow is driven by differences in sites` quasielectrochemical potentials (QECPs). With disorder, differences of QECPs are not simply related to the driving emf. Solution of the (nonlinear) stochastic equations for the QECPs shows that bottlenecks produced by disorder result in nonohmic conduction. Solving the linearized stochastic (disordered resistor network) equations underestimates bottleneck effects. Linearization is inappropriate when interest differences in the QECPs exceed [kappa]T.

Chemometric multivariate calibration methods are rapidly impacting quantitative infrared spectroscopy in many positive ways. The combination of vibrational spectroscopy and chemometrics has been used by industry for quality control and process monitoring. The growth of these methods has been phenomenal in the past decade. Yet, as with any new technology, there are growing pains. The methods are so powerful at finding correlations in the data, that when used without great care they can readily yield results that are not valid for the analysis of future unknown samples. In this paper, the power of the multivariate calibration methods is discussed while pointing out common pitfalls and some remaining challenges that may slow the implementation of chemometrics in research and industry.

An Electrorheological fluid is normally a low-viscosity colloidal suspension, but when an electric field is applied, the fluid undergoes a reversible transition to a solid, being able to support considerable stress without yield. Commercial possibilities for such fluids are enormous, including clutches, brakes, valves,shock absorbers, and stepper motors. However, performance of current fluids is inadequate for many proposed applications. Our goal was to engineer improved fluids by investigating the key technical issues underlying the solid-phase yield stress and the liquid to solid switching time. Our studies focused on field-induced interactions between colloidal particles that lead to solidification, the relation between fluid structure and performance (viscosity, yield stress), and the time evolution of structure in the fluid as the field is switched on or off.

A suite of MATLAB-based code modules has been developed to provide optimal weld schedules, regulating weld process parameters for C0[sub 2] and pulse ND:YAG laser welding methods, and arc welding in support of the Smartweld manufacturing initiative. The optimization methodology consists of mixed genetic and gradient-based algorithms to query semi-empirical, nonlinear algebraic models. The optimization output provides heat-input-efficient welds for user-specified weld dimensions. User querying of all weld models is available to examine sub-optimal schedules. In addition, a heat conduction equation solver for 2-D heat flow is available to provide the user with an additional check of weld thermal effects. The inclusion of thermodynamic properties allows the extension of the empirical models to include materials other than those tested. All solution methods are provided with graphical user interfaces and display pertinent results in two and three-dimensional form. The code architecture provides an extensible framework to add an arbitrary number of modules.

Drill hole USW SD-9 is one of several holes drilled under Site Characterization Plan Study as part of the characterization program at Yucca Mountain, Nevada, which has been proposed as the potential location of a repository for high-level nuclear waste. The SD-9 drill hole is located in the northern part of the potential repository area. Quantitative and semiquantitative data are included in this report for cover recovery, rock-quality designation (RQD), lithophysal cavity abundance, and fracturing. These data are spatially variable, both within and among the major formational-level stratigraphic units. Nonwelded intervals in general exhibit higher recoveries and more intact (higher) RQD values than welded intervals. The most intact, highest-RQD materials encountered within the Topopah Spring belong to the lower 33.3 ft of the middle nonlithophysal zone. This report includes quantitative data for the framework material properties of porosity, bulk and particle density, and saturated hydraulic conductivity. Graphical analysis of variations in these laboratory hydrologic properties indicates first-order control of material properties by the degree of welding and the presence of zeolite minerals. Many major lithostratigraphic contacts are not well expressed in the material-property profiles; contacts of material-property units are related more to changes in the intensity of welding. Approximate in-situ saturation data of samples preserved immediately upon recovery from the hole are included in the data tabulation.

By predicting the total life-cycle cost of owning and operating production equipment, it becomes possible for processors to make accurate and intelligent decisions regarding major capitol equipment investments as well as determining the most cost effective manufacturing processes and environments. Cost of Ownership (COO) is a decision making technique based on inputting the total costs of acquiring, operating and maintaining production equipment. All quantitative economic and production data can be modeled and processed using COO software programs such as the Cost of Ownership Luminator program TWO COOL{trademark}. This report investigated the Cost of Ownership differences between the current state-of-the-art solder ball attachment process and a prototype solder jetting process developed by Sandia National Laboratories. The prototype jetting process is a novel and unique approach to address the anticipated high rate ball grid array (BGA) production requirements currently forecasted for the next decade. The jetting process, which is both economically and environmentally attractive eliminates the solder sphere fabrication step, the solder flux application step as well as the furnace reflow and post cleaning operations.

A comprehensive collection of scenarios is presented that connect initiating tectonic events with radionuclide releases by logical and physically possible combinations or sequences of features, events and processes. The initiating tectonic events include both discrete faulting and distributed rock deformation developed through the repository and adjacent to it, as well as earthquake-induced ground motion and changes in tectonic stress at the site. The effects of these tectonic events include impacts on the engineered-barrier system, such as container rupture and failure of repository tunnels. These effects also include a wide range of hydrologic effects such as changes in pathways and flow rates in the unsaturated and saturated zones, changes in the water-table configuration, and in the development of perched-water systems. These scenarios are intended go guide performance-assessment analyses and to assist principal investigators in how essential field, laboratory, and calculational studies are used. This suite of scenarios will help ensure that all important aspects of the system disturbance related to a tectonic scenario are captured in numerical analyses. It also provides a record of all options considered by project analysts to provide documentation required for licensing agreement. The final portion of this report discusses issues remaining to be addressed with respect to tectonic activity. 105 refs.

Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO{sub 2} as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.

Findings from a four-year study by an international benchmarking group in the comparison of computational methods for evaluating burnup credit in criticality safety analyses are presented in this paper. Approximately 20 participants from 11 countries have provided results for most problems. Four detailed benchmark problems for Pressurized Water Reactor (PWR) fuel have been completed and are summarized in this paper. Preliminary results from current work addressing burnup credit for Boiling Water Reactor (BWR) fuel will also be discussed as well as planned activities for additional benchmarks including Mixed-Oxide (MOX) fuels, subcritical benchmarks, international databases, and other activities.

No abstract available.

The U.S. Department of Energy`s (DOE) Yucca Mountain Site Characterization Project (YMP) is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization will be facilitated by the construction of an Exploratory Studies Facility (ESF). The ESF and potential repository will be excavated from both nonwelded and welded ashflow tuff with varying rock quality (degree of welding, rock mass strength, etc.) and fault and fracture characteristics. Design concerns for the construction of these facilities include the integrity of the structure during underground testing operations and, if it occurs, the emplacement and storage of high-level nuclear waste which could increase the local temperatures in the underground rock mass to as high as 300{degrees}C. Because of the associated issues regarding personnel and long-term environmental safety, sophisticated jointed rock mass models will be required to provide a high degree of confidence for decisions regarding the design, site characterization, and licensing of such facilities. The objective of the work documented in this report is to perform code validation calculations for three rock-mass computer models. The three rock-mass computer models used for this report are the discrete element code UDEC, Version 1.82; and the finite element continuum joint models JAC2D Version 5.10 and JAS3D Version 1.1. The rock mass behavior predicted by the models are compared to the results of laboratory experiments on layered polycarbonate (Lexan) and granite plate experiments. These experiments examine the rock mass behavior of well-defined jointed rock structures or models of jointed structures under uniaxial and biaxial loading. The laboratory environment allows control over the boundary conditions, material properties, and quality and quantity of the data obtained.

This report describes activities completed in August 1996 under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories and General Motors which began in April 1993 and was later expanded in January 1994 to include Ford and Chrysler under the Low Emission Partnership (LEP). The tasks within this effort (CRADA SC93/01155) included the evaluation of hydrous metal oxide materials as catalyst supports for the abatement of nitrogen oxides in lean-burn automotive exhaust catalyst applications.

Fracture and matrix properties in a sequence of unsaturated, welded tuffs at Yucca Mountain, Nevada, are modeled in two-dimensional cross-sections through geostatistical simulation. In the absence of large amounts of sample data, an n interpretive, deterministic, stratigraphic model is coupled with a gaussian simulation algorithm to constrain realizations of both matrix porosity and fracture frequency. Use of the deterministic, stratigraphic model imposes scientific judgment, in the form of a conceptual geologic model, onto the property realizations. Linear coregionalization and a regression relationship between matrix porosity and matrix hydraulic conductivity are used to generate realizations of matrix hydraulic conductivity. Fracture-frequency simulations conditioned on the stratigraphic model represent one class of fractures (cooling fractures) in the conceptual model of the geology. A second class of fractures (tectonic fractures) is conceptualized as fractures that cut across strata vertically and includes discrete features such as fault zones. Indicator geostatistical simulation provides locations of this second class of fractures. The indicator realizations are combined with the realizations of fracture spacing to create realizations of fracture frequency that are a combination of both classes of fractures. Evaluations of the resulting realizations include comparing vertical profiles of rock properties within the model to those observed in boreholes and checking intra-unit property distributions against collected data. Geostatistical simulation provides an efficient means of addressing spatial uncertainty in dual continuum rock properties.

Advantages in transient ionizing and single-event upset (SEU) radiation hardness of silicon-on-insulator (SOI) technology spurred much of its early development. Both of these advantages are a direct result of the reduced charge collection volume inherent to SOI technology. The fact that SOI transistor structures do not include parasitic n-p-n-p paths makes them immune to latchup. Even though considerable improvement in transient and single-event radiation hardness can be obtained by using SOI technology, there are some attributes of SOI devices and circuits that tend to limit their overall hardness. These attributes include the bipolar effect that can ultimately reduce the hardness of SOI ICs to SEU and transient ionizing radiation, and charge buildup in buried and sidewall oxides that can degrade the total-dose hardness of SOI devices. Nevertheless, high-performance SOI circuits can be fabricated that are hardened to both space and nuclear radiation environments, and radiation-hardened systems remain an active market for SOI devices. The effects of radiation on SOI MOS devices are reviewed.

In 1991, the Department of Energy initiated the Advanced Liquefaction Concepts Program to promote the development of new and emerging technology that has potential to reduce the cost of producing liquid fuels by direct coal liquefaction. Laboratory research performed by researchers at CAER, CONSOL, Sandia, and LDP Associates in Phase I is being developed further and tested at the bench scale at HTI. HTI Run ALC-1, conducted in the spring of 1996, was the first of four planned tests. In Run ALC-1, feed coal ash reduction (coal cleaning) by oil agglomeration, and recycle solvent quality improvement through dewaxing and hydrotreatment of the recycle distillate were evaluated. HTI`s bench liquefaction Run ALC-1 consisted of 25 days of operation. Major accomplishments were: 1) oil agglomeration reduced the ash content of Black Thunder Mine coal by 40%, from 5.5% to 3.3%; 2) excellent coal conversion of 98% was obtained with oil agglomerated coal, about 3% higher than the raw Black Thunder Mine coal, increasing the potential product yield by 2-3% on an MAF coal basis; 3) agglomerates were liquefied with no handling problems; 4) fresh catalyst make-up rate was decreased by 30%, with no apparent detrimental operating characteristics, both when agglomerates were fed and when raw coal was fed (with solvent dewaxing and hydrotreating); 5) recycle solvent treatment by dewaxing and hydrotreating was demonstrated, but steady-state operation was not achieved; and 6) there was some success in achieving extinction recycle of the heaviest liquid products. Performance data have not been finalized; they will be available for full evaluation in the new future.

Systems and devices that are controlled remotely are becoming more common in security systems in the US Air Force and other government agencies to provide protection of valuable assets. These systems reduce the number of needed personnel while still providing a high level of protection. However, each remotely controlled device usually has its own communication protocol. This limits the ability to change devices without changing the system that provides the communications control to the device. Sandia is pursuing a standard protocol that can be used to communicate with the different devices currently in use, or may be used in the future, in the US Air Force and other government agencies throughout the security community. Devices to be controlled include intelligent pan/tilt mounts, day/night video cameras., thermal imaging cameras, and remote data processors. Important features of this protocol include the ability to send messages of varying length, identify the sender, and more importantly, control remote data processors. As camera and digital signal processor (DSP) use expands, the DSP will begin to reside in the camera itself. The DSP can be used to provide auto-focus, frame-to- frame image registration, video motion detection (VMD), target detection, tracking, image compression, and many other functions. With the serial data control link, the actual DSP software can be updated or changed as required. Coaxial video cables may become obsolete once a compression algorithm is established in the DSP. This paper describes the proposed public domain protocol, features, and examples of use. The authors hope to elicit comments from security technology developers regarding format and use of remotely controlled automated assessment devices. 2 figs., 1 tab.

A {ital q}-vector of responses, y, is related to a {ital p}-vector of explanatory variables, x, through a causal linear model. In analytical chemistry, y and x might represent the spectrum and associated set of constituent concentrations of a multicomponent sample which are related through Beer`s law. The model parameters are estimated during a calibration process in which both x and y are available for a number of observations (samples/specimens) which are collectively referred to as the calibration set. For new observations, the fitted calibration model is then used as the basis for predicting the unknown values of the new x`s (concentrations) form the associated new y`s (spectra) in the prediction set. This prediction procedure can be viewed as parameter estimation in an errors-in-variables (EIV) framework. In addition to providing a basis for simultaneous inference about the new x`s, consideration of the EIV framework yields a number of insights relating to the design and execution of calibration studies. A particularly interesting result is that predictions of the new x`s for individual samples can be improved by using seemingly unrelated information contained in the y`s from the other members of the prediction set. Furthermore, motivated by this EIV analysis, this result can be extended beyond the causal modeling context to a broader range of applications of multivariate calibration which involve the use of principal components regression.

We have developed a two-dimensional Shack-Hartman wavefront sensor that uses binary optic lenslet arrays to directly measure the wavefront slope (phase gradient) and amplitude of the laser beam. This sensor uses an array of lenslets that dissects the beam into a number of samples. The focal spot location of each of these lenslets (measured by a CCD camera) is related to the incoming wavefront slope over the lenslet. By integrating these measurements over the laser aperture, the wavefront or phase distribution can be determined. Since the power focused by each lenslet is also easily determined, this allows a complete measurement of the intensity and phase distribution of the laser beam. Furthermore, all the information is obtained in a single measurement. Knowing the complete scalar field of the beam allows the detailed prediction of the actual beam`s characteristics along its propagation path. In particular, the space- beamwidth product M{sup 2}, can be obtained in a single measurement. The intensity and phase information can be used in concert with information about other elements in the optical train to predict the beam size, shape, phase and other characteristics anywhere in the optical train. We present preliminary measurements of an Ar{sup +} laser beam and associated M{sup 2} calculations.

The quest for fabricating complex metal parts rapidly and with minimal cost has brought rapid prototyping (RP) processes to the forefront of the investment casting industry. Relatively recent advances in DTM Corporation`s selective laser sintering (SLS) and 3D Systems stereolithography (SL) processes have had a significant impact on the overall quality of patterns produced using these rapid prototyping processes. Sandia National Laboratories uses patterns generated from rapid prototyping processes to reduce the cycle time and cost of fabricating prototype and small lot production parts in support of a program called FASTCAST. The SLS process is used to fabricate patterns from materials such as investment casting wax, polycarbonate, and a new material called TrueForm PM{trademark}. With the timely introduction of each of these materials, the quality of patterns fabricated has improved. The development and implementation of SL QuickCast{trademark} software has enabled this process to produce highly accurate patterns for use in investment casting. This paper focuses on the successes with these new pattern materials and the infrastructure required to cast rapid prototyping patterns successfully. In addition, a brief overview of other applications of rapid prototyping at Sandia will be discussed.

Resistance degradation in PZT thin-film capacitors has been studied as a function of applied voltage, temperature, and film composition. It is found that the mean-time-to-failure (life-time or t{sub f}) of the capacitors shows a power law dependence on applied voltage of he form t{sub f} {proportional_to} V{sup {minus}n} (n {approximately} 4--5). The capacitor life-time also exhibits a temperature dependence of the form t{sub f} {proportional_to} exp(E{sub a}/kT), with an activation energy of {approximately} 0.8 eV. The steady-state leakage current in these samples appears to be bulk controlled. The voltage, temperature, and polarity dependence of the leakage current collectively suggest a leakage current mechanism most similar to a Frenkel-Poole process. The life-time and leakage current of the Nb-doped PZT films are superior to the undoped PZT films. This result can be explained based on the point-defect chemistry of the PZT system. Finally, the results indicate that the Nb-doped PZT films meet the essential requirements for decoupling capacitor applications.

First-principles density functional calculations and corresponding experimental results underline the importance of basic chemical concepts, such as coordination, valence saturation and promotion-hybridization energetics, in understanding bonding and diffusion of atoms at and on metal surfaces. Several examples are reviewed, including outer-layer relaxations of clean hcp(0001) surfaces, liquid-metal-embrittlement energetics, separation energies of metal-adatom dimers, concerted substitutional self-diffusion on fcc(001) surfaces, and adsorption and diffusion barrier sites for adatoms near steps.

The Department of Defense (DoD) operates hundreds of test, evaluation, and training facilities across the US and abroad. Due to the nature of their missions, these facilities are often remote and isolated from the utility grid. The preferred choice for power at these facilities has historically been manned diesel generators. The DoD Photovoltaic Review Committee, estimates that on the order of 350 million gallons of diesel fuel is burned each year to generate the 2000 GWh of electricity required to operate these remote military facilities. Other federal agencies, including the National Park Service and the USDA Forest Service use diesel generators for remote power needs as well. The generation of power diesel generators is both expensive and detrimental to the environment. The augmentation of power from diesel generators with power processing and battery energy storage enhances the efficiency and utilization of the generator resulting in lower fuel consumption and lower generator run- time in proportion to the amount of renewables added. The hybrid technology can both reduce the cost of power and reduce environmental degradation at remote DoD facilities. This paper describes the expected performance and economics of photovoltaic/diesel hybrid systems. Capabilities and status of systems now being installed at DoD facilities are presented along with financing mechanisms available within DoD.

Sandia National Laboratories developed a process to identify and remove the hazardous sub-components from dismantled weapons components utilizing real-time radiography and abrasive water-jet cutting. The components were then crushed, granulated, screened, and separated into an aluminium and a precious-and-base-metals fraction using air-tables. Plastics were further cleaned for disposal as non- hazardous waste.

Solid free form fabrication is one of the fastest growing automated manufacturing technologies that has significantly impacted the length of time between initial concept and actual part fabrication. Starting with CAD renditions of new components, several techniques such as stereolithography and selective laser sintering are being used to fabricate highly accurate complex three-dimensional concept models using polymeric materials. Coupled with investment casting techniques, sacrificial polymeric objects are used to minimize costs and time to fabricate tooling used to make complex metal castings. This paper will describe recent developments in a new technology, known as LENS{sup {trademark}} (Laser Engineered Net Shaping), to fabricate metal components directly from CAD solid models and thus further reduce the lead times for metal part fabrication. In a manner analogous to stereolithography or selective sintering, the LENS{sup {trademark}} process builds metal parts line by line and layer by layer. Metal particles are injected into a laser beam, where they are melted and deposited onto a substrate as a miniature weld pool. The trace of the laser beam on the substrate is driven by the definition of CAD models until the desired net-shaped densified metal component is produced.

The international scientific community has long had an interest in determining methods by which information regarding nuclear waste repositories, and the inherent danger to humanity, could be passed from generation to generation and society to society. Because nuclear waste will remain radioactive for thousands of years future generations must be warned of the dangers thus eliminating intentional or inadvertent intrusion. Member States of the IAEA have determined that the principle safety of such sites must not rely solely on long term institutional arrangements for the retention of information. It is believed that repository siting, design, operation and postoperation information should be gathered, managed and retained so that this information remains accessible to future societies over a very long period of time. The radionuclide life is 10,000 years; thus the retention of information continues beyond current societies, cultures and languages, and must be continually migrated to new retrieval technologies to assure access.

A great deal has been written about the history of science in America since World War II. Much of that work has explored the government`s research and development establishment, focusing on the scientific community immediately after the war. It is generally argued that the apparent triumphs of the huge and expensive wartime research and development projects gave rise to a belief that scientific resources should be nurtured and kept on hand - ready to provide service in an emergency. The Cold War drive for more and better weapons further fed this belief, leading to a massive system of national laboratories, military laboratories, and defense industries. The science of this complex is built on extensive financial support, the central strategy of which is that by steadily, and occasionally even lavishly funding large research programs, you will have a constant stream of scientific ideas that can be applied to national security purposes. What is true of science, is also true, in slightly modified form, of postwar engineering. The story I want to tell you today is, I think, an example of the way Cold War engineering r&d for national security worked. This report describes aspects of the Sandia National Laboratories.

A strategic surety roadmap for high consequence software systems under the High Integrity Software (HIS) Program at Sandia National Laboratories guides research in identifying methodologies to improve software surety. Selected research tracks within this roadmap are identified and described detailing current technology and outlining advancements to be pursued over the coming decade to reach HIS goals. The tracks discussed herein focus on Correctness by Design, and System Immunology{trademark}. Specific projects are discussed with greater detail given on projects involving Correct Specification via Visualization, Synthesis, & Analysis; Visualization of Abstract Objects; and Correct Implementation of Components.

Computational modeling has been performed to determine optimum operational parameters for a piston-driven molten solder jetting device used to create array interconnects for BGA applications. The device is capable of delivering a 20 x 20 array of 600-800 {mu}m diameter molten 60Sn40Pb solder droplets onto an array of copper pads and primarily consists of an electromechanically driven piston, a heated reservoir, and an orifice plate. computer simulations were performed to determine the relationship between the amplitude and the rate of piston displacement, the onset of fluid ``pinch off``, and the production of satellite droplets. Results show that stable droplets are generated when the volume of the displaced fluid has a spherical diameter that is approximately equal to the orifice diameter.

This document, after giving a summary of Sandia`s mission, describes technology transfer efforts and accomplishments at Sandia. This includes information on their user facilities: the combustion research facility, the national solar thermal test facility, and the electronics quality and reliability center.

NASA-Ames Research Center, in collaboration with Sandia National Laboratories, is developing a Scannerless Terrain Mapper (STM) for autonomous vehicle guidance through the use of virtual reality. The STM sensor is based on an innovative imaging optical radar technology that is being developed by Sandia National Laboratories. The sensor uses active flood-light scene illumination and an image intensified CCD camera receiver to rapidly produce and record very high quality range imagery of observed scenes. The STM is an all solid-state device (containing no moving parts) and offers significant size, performance, reliability, simplicity, and affordability advantages over other types of 3-D sensor technologies, such as scanned laser radar, stereo vision, and structured lighting. The sensor is based on low cost, commercially available hardware, and is very well suited for affordable application to a wide variety of military and commercial uses, including: munition guidance, target recognition, robotic vision, automated inspection, driver enhanced vision, collision avoidance, site security and monitoring, and facility surveying. This paper reviews the sensor technology, discusses NASA`s terrain mapping applications, and presents results from the initial testing of the sensor at NASA`s planetary landscape simulator.

SrCo{sub 0.5}FeO{sub x} (SCF) is an attractive material for oxygen separation membranes and for use in catalytic membrane reactors. While tubes of this material have been prepared by extrusion, further improvements in oxygen transport performance may be gained by preparing thinner membranes on porous supports. In this paper, we will discuss the deposition of thick films by spray deposition and centrifugal casting, and thin films by pyrolysis of chemical precursors. For the chemically derived thin films, porous MgO supports were used as membrane supports. Three types of precursor solutions were employed for dipcoating: a Pechini type solution, a nitrate-based solution, and a citrate-based solution. To prevent the infiltration of the precursor into the support, the support was backfilled with a material that decomposed at higher temperatures than the precursors. Cracking due to the volume changes during drying and pyrolysis of the precursors is discussed. Thick films were prepared by spray coating and centrifugal casting. Spray deposition of thick film membranes was accomplished by air brushing SCF from a water-based suspension onto the surface of a porous MgO support. Films on the interior surface of the supports were prepared by centrifugal casting using a xylene/butanol-based SCF suspension. Unlike extruded tubes, thick films undergo constrained sintering due to the presence of the support, which greatly reduces the densification rate. For membranes prepared by both approaches, we will discuss the effects of heating schedules on membrane microstructure, densification behavior, and cracking.

Plasma-induced-damage often degrades the electrical and optical properties of compound semiconductor devices. Despite the fact that the binding energy of GaN is larger than that for more conventional III--V compounds, etch damage is still a concern. Photoluminescence measurements and atomic force microscopy have been used to determine the damage induced in GaN by exposure to both electron cyclotron resonance (ECR) and inductively coupled plasmas (ICP) generated Ar plasmas.

This paper presents a portion of the work on specification, design, and implementation of safety-critical systems such as reactor control systems. A natural approach to this problem, once all the requirements are captured, would be to state the requirements formally and then either to prove (preferably via automated tools) that the system conforms to spec (program verification), or to try to simultaneously generate the system and a mathematical proof that the requirements are being met (program derivation). An obstacle to this is frequent presence of partially defined operations within the software and its specifications. Indeed, the usual proofs via first order logic presuppose everywhere defined operations. Recognizing this problem, David Gries, in ``The Science of Programming,`` 1981, introduced the concept of partial functions into the mainstream of program correctness and gave hints how his treatment of partial functions could be formalized. Still, however, existing theorem provers and software verifiers have difficulties in checking software with partial functions, because of absence of uniform first order treatment of partial functions within classical 2-valued logic. Several rigorous mechanisms that took partiality into account were introduced [Wirsing 1990, Breu 1991, VDM 1986, 1990, etc.]. However, they either did not discuss correctness proofs or departed from first order logic. To fill this gap, the authors provide a semantics for software correctness proofs with partial functions within classical 2-valued 1st order logic. They formalize the Gries treatment of partial functions and also cover computations of functions whose argument lists may be only partially available. An example is nuclear reactor control relying on sensors which may fail to deliver sense data. This approach is sufficiently general to cover correctness proofs in various implementation languages.

The US Department of Energy (DOE) uses sensitive or classified parts and material that must be protected and accounted for. The authors believe there is a need for an automated system that can help protect and monitor these parts and material. In response to this need Sandia National Laboratories (SNL) has developed a real-time personnel and material tracking system called PAMTRAK that has been installed at selected DOE facilities. PAMTRAK safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. This paper describes the goals when designing PAMTRAK, the PAMTRAK system components, the current installations, and the benefits a site can expect when using PAMTRAK.

Planar, surface micromachined pressure sensors have been fabricated by an extension of the chemical-mechanical polishing (CMP) process. CMP eliminates many of the fabrication problems associated with the photolithography, dry etch, and metallization of non-planar devices. Furthermore, CMP adds additional design flexibility. The sensors are based upon deformable, silicon nitride diaphragms with polysilicon piezoresistors. Absolute pressure is detected by virtue of reference pressure cavities underneath the diaphragms. Process details are discussed and characteristics from many devices are presented.

Phosphorus diffusions are used in the fabrication process for nearly all crystalline-silicon (c-Si) photovoltaic solar cells to form the emitter of the solar cell. These phosphorous diffusions are also well known to have beneficial gettering benefits, i.e., deleterious metallic impurities are gettered from the bulk of the c-Si substrate into the phosphorous doped layer. In this study, we examined the effect of oxidations performed after the phosphorus diffusion. We were particularly interested in using the oxidation to passivate the surface of the phosphorus diffusion. Post-diffusion oxidations or moderate temperature steps in oxidizing ambients are also commonly found in commercial fabrication sequences of c-Si solar cells. we found that the bulk lifetime was degraded in Czochralski (Cz) silicon due to the post-diffusion oxidation unless there was a gettering agent present during the oxidation. Possible explanations for these results are presented at the end of the paper.

The dehydrogenation of propane and isobutane was studied in hydrogen permselective packed bed membrane reactors and conventional packed bed reactors. Two different types of developmental membranes were investigated: sol-gel derived silica-based membranes and a pure palladium thin film supported by a porous ceramic substrate. The palladium membranes deactivated and eventually failed when exposed to both isobutane and propane dehydrogenation temperatures above 773 K. Moderate improvements in propylene and isobutylene yields were obtained with the silica-based membrane reactors. An isobutylene yield of 48 mole percent was obtained at a liquid hourly space velocity (LHSV) of 1.8 and temperature of 798 K compared to a yield of 39 percent in a conventional reactor operated with the same flow rate. Similar improvements in propylene yield were obtained when the silica-based membranes were tested in propane dehydrogenation experiments. There was no significant difference in the reaction selectivities for the desired olefin products when the membrane and conventional reactors were operated with the scone LHSV However, for a constant value of the olefin yield, the membrane reactors had a higher reaction selectivity since the desired yield was achieved at a higher LHSV where there was less time for side products to form. Catalyst deactivation rates were generally greater in the membrane reactors, especially when the reactors were operated with high hydrogen removal rates at temperatures of 773 K and above.

GaAs Junction Field Effect Transistors (JFETs) have attracted renewed attention for low-power, low-voltage electronics. JFETs have a significant advantage over MESFETs for low-power operation due to their higher gate barrier to current flow resulting from p/n junction gate. This paper reports recent advances in an all ion implanted self-aligned GaAs JFET with a gate length down to 0.3 {mu}m. By employing shallopw SiF implants next to the gate, dielectric sidewall spacers, and 50 keV source and drain implants, JFETs with a f{sub t} up to 49 GHz with good pinchoff and subthreshold characteristics have been realized. In addition, the JFET benefits from the use of shallow Zn or Cd implantation to form abrupt p{sup +}/n gate profiles.

Deep etching of GaAs is a critical process step required for many device applications including fabrication of through-substrate via holes for monolithic microwave integrated circuits (MMICs). Use of high-density plasmas, including inductively coupled plasmas (ICP), offers an alternative approach to etching vias as compared to more conventional parallel plate reactive ion etch systems. This paper reports ICP etching of GaAs vias at etch rates of about 5.3 {mu}m/min with via profiles ranging from highly anistropic to conical.

In this study, 33 different conversion coatings were applied to 5 different Al alloy substrates. Salt spray exposure testing and EIS (electrochemical impedance spectroscopy) were conducted for comparison. A relation was developed.

With the demonstration of implant doping of GaN and the resulting need to perform the activation anneal at 1100 C, details of thermal stability of the GaN surface needs to be understood. This work reports on the use of a sputtered AlN encapsulant to preserve the surface of GaN during such annealing. The surface was characterized by formation of Pt/Au Schottky contacts and by AES. Schottky contacts deposited an GaN annealed wtih the AlN encapsulant displayed good rectification properties while those formed on GaN annealed uncapped approached ohmic behavior. AES analysis supports the hypothesis that the uncapped sample has lost N from the very near surface which creates N-vacancies that act as donors and thereby form an n{sup +}-surface layer.

This paper presents design, analysis, and first results of the high brightness electron beam experiments currently under investigation at Sandia. Anticipated beam parameters are: energy 12 MeV, current 35-40 kA, rms radius 0.5 mm, pulse duration 40 ns FWHM. The accelerator is SABRE, a pulsed LIVA modified to higher impedance, and the electron source is a magnetically immersed foilless electron diode. 20 to 30 Tesla solenoidal magnets are required to insulate the diode and contain the beam to its extremely small sized (1 mm) envelope. These experiments are designed to push the technology to produce the highest possible electron current in a submillimeter radius beam. Design, numercial simulations, and first experimental results are presented.

Development of a complementary heterostructure field effect transistor (CHFET) technology for low-power, mixed-mode digital-microwave applications is presented. Digital CHFET technology with independently optimizable transistors has been shown to operate with 319 ps loaded gate delays at 8.9 fJ. Power consumption is dominated by leakage currents of the p-channel FET, while performance is determined by the characteristics of 0.7 {mu}m gate length devices. As a microwave technology, the nJFET forms the basis of low-power cirucitry without any modification to the digital process. Narrow band amplification with a 0.7x100 {mu}m nJFET has been demonstrated at 2.1-2.4 GHz with gains of 8-10 dB at 1 mW power. These amplifiers showed a minimum noise figure of 2.5 dB. Next generation CHFET transistors with sub 0.5 {mu}m gate lengths have also been developed. Cutoff frequencies of 49 and 11.5 GHz were achieved for n- and p-channel FETs with 0.3 and 0.4 {mu}m gates, respectively. These FETs will enable enhancements in both digital and microwave circuits.

Extracting information from unstructured text has become an important research area in recent years due to the large amount of text now electronically available. This status report describes the findings and work done during the second year of a two-year Laboratory Directed Research and Development Project. Building on the first-year`s work of identifying important entities, this report details techniques used to group words into semantic categories and to output templates containing selective document content. Using word profiles and category clustering derived during a training run, the time-consuming knowledge-building task can be avoided. Though the output still lacks in completeness when compared to systems with domain-specific knowledge bases, the results do look promising. The two approaches are compatible and could complement each other within the same system. Domain-independent approaches retain appeal as a system that adapts and learns will soon outpace a system with any amount of a priori knowledge.

This paper provides an overview of the history and process of establishing a cooperative research and development agreement (CRADA) between Sandia National Laboratories and Magnavox Electronic Systems Company for the design, development, and testing of a 360-degree scanning, imaging, intrusion detection sensor. The subject of the CRADA is the Advanced Exterior Sensor (AES). It is intended for exterior use at ranges from 50 to 1,500 meters and uses a combination of three sensing technologies (infrared, visible, and radar) and a new data processing method to provide low false-alarm intrusion detection and tracking combined with immediate visual assessment. The establishment of this CRADA represents a new paradigm in the cooperation between the Department of Defense, the Department of Energy, the National Laboratories and Private Industry. Although a formal document has now been executed, a CRADA is, nonetheless, primarily an agreement to work with each other to achieve goals that might otherwise be unattainable.

In this paper, the authors explore the feasibility of using the distributed Bragg reflector, grown on the substrate for a VCSEL (Vertical Cavity Surface Emitting Laser), to provide waveguiding within the substrate. This waveguiding could serve as an interconnection among VCSELs in an array. Before determining the feasibility of waveguide interconnected VCSELs, two analysis methods are presented and evaluated for their applicability to this problem. The implementations in Mathematica of both these methods are included. Results of the analysis show that waveguiding in VCSEL structures is feasible. Some of the many possible uses of waveguide interconnected VCSELs are also briefly discussed. The tools and analysis presented in this report can be used to evaluate such system concepts and to do detailed design calculations.

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). If a beam-chopping system could be developed for the Los Alamos Meson Physics Facility low-energy beam line, there would be potential to operate the Los Alamos Neutron Scattering Center (LANSCE) at much higher power and duty factor and enable such operation with a radio-frequency quadrapole (RFQ) injector. This would greatly extend the capability of the facility. To accommodate LANSCE operation in the new configuration, a chopped beam must be created in the low-energy transport line before the RFQ. Chopping in this region has never been demonstrated and constitutes the major uncertainty of the proposal and determines the critical path for project completion. This study produces a better understanding of the physics involved in chopping an H-beam in a dilute plasma background, and in transporting a chopped H-beam through a neutralized or partially neutralized plasma channel, as well as an estimate for the optimum neutralization strategy for the beam chopping and transport between the ion source and the RFQ.

This 1995 report contains data from routine radiological and non-radiological environmental monitoring activities. Summaries of significant environmental compliance programs in progress, such as National Environmental Policy Act documentation, environmental permits, environmental restoration and various waste management programs at Sandia National Laboratories in Albuquerque, New Mexico, are included.

DOE installations possessing sufficient quantities of fissile material to potentially constitute a critical mass, such that the excessive exposure of personnel to radiation from a nuclear accident is possible, are required to provide nuclear accident dosimetry services. This document describes the personal nuclear accident dosimeter (PNAD) used by SNL and prescribes methodologies to initially screen, and to process PNAD results. In addition, this report describes PNAD dosimetry results obtained during the Nuclear Accident Dosimeter Intercomparison Study (NAD23), held during 12-16 June 1995, at Los Alamos National Laboratories. Biases for reported neutron doses ranged from -6% to +36% with an average bias of +12%.

Ten commercial MgO powders were evaluated for their suitability to act as a binder in the separator of thermal batteries to immobilize the electrolyte when it is molten. One brand in particular, Maglite S from Calgon, outperformed all the others. This report describes the results of a characterization study of this MgO as well as similar materials from other commercial vendors. The study objective was to define the critical properties of Maglite S MgO that are responsible for its superior performance in thermal-battery separators. Separator mixes were prepared with the various MgO powders and the resulting powders and pellets were characterized, to correlate key physical properties of these materials to select physical and chemical properties of the MgO powders used in their preparation. The MgO pore-size distribution was the only parameter that could be related to the deformation and electrolyte-leakage behavior of separator pellets. A potential replacement for the Maglite S is currently being qualified, since Maglite S MgO is no longer available.

This report summarizes the environmental surveillance activities conducted by Sandia National Laboratories. Sandia National Laboratories` responsibility for environmental surveillance results extends to those activities performed by Sandia National Laboratories or under its direction. Results from other organizations environmental surveillance activities are included to provide a measure of completeness. Other environmental compliance programs such as the National Environmental Policy Act of 1969, environmental permits, and environmental restoration and waste management programs are also included in this report, prepared for the U.S. Department of Energy (DOE) in compliance with DOE Order 5400.1.

Capillary barriers consisting of tilted fine-over-coarse layers have been suggested as landfill covers as a means to divert water infiltration away from sensitive underground regions under unsaturated flow conditions, especially for arid and semi-arid regions. Typically, the HELP code is used to evaluate landfill cover performance and design. Unfortunately, due to its simplified treatment of unsaturated flow and its essentially one-dimensional nature, HELP is not adequate to treat the complex multidimensional unsaturated flow processes occurring in a tilted capillary barrier. In order to develop the necessary mechanistic code for the performance evaluation of tilted capillary barriers, an efficient and comprehensive unsaturated flow code needs to be selected for further use and modification. The present study evaluates a number of candidate mechanistic unsaturated flow codes for application to tilted capillary barriers. Factors considered included unsaturated flow modeling, inclusion of evapotranspiration, nodalization flexibility, ease of modification, and numerical efficiency. A number of unsaturated flow codes are available for use with different features and assumptions. The codes chosen for this evaluation are TOUGH2, FEHM, and SWMS{_}2D. All three codes chosen for this evaluation successfully simulated the capillary barrier problem chosen for the code comparison, although FEHM used a reduced grid. The numerical results are a strong function of the numerical weighting scheme. For the same weighting scheme, similar results were obtained from the various codes. Based on the CPU time of the various codes and the code capabilities, the TOUGH2 code has been selected as the appropriate code for tilted capillary barrier performance evaluation, possibly in conjunction with the infiltration, runoff, and evapotranspiration models of HELP. 44 refs.

An oblique penetration modeling procedure is evaluated by correlation with onboard acceleration data from a series of six penetration tests into Antelope Dry Lake soil at Tonopah Test Range, Nevada. The modeling represents both the loading which is coupled to the penetrator bending and the penetrator structure including connections between the major subsections. Model results show reasonable agreement with the data which validates the modeling procedure within a modest uncertainty related to accelerometer clipping and rattling of the telemetry package. The experimental and analytical results provide design guidance for the location and lateral restraint of components to reduce their shock environment.

CHEM{_}MACCS has been developed from the radiological accident consequence code, MACCS, to perform probabilistic calculations of potential off-site consequences of the accidental atmospheric release of hazardous chemicals. The principal phenomena considered in CHEM{_}MACCS are atmospheric transport, mitigative actions based on dose projection, dose accumulation by a number of pathways, and early and latent health effects. CHEM{_}MACCS provides the following capabilities: (1) statistical weather sampling data (8,760 hourly data points per year), (2) population dose and health effect risk calculations based on site-specific population data, (3) health effects calculations including the consideration of potential site specific mitigative actions (evacuation and shielding), and (4) modeling of multiple release segments. Three different sample problems are contained in this report to show how to use CHEM{_}MACCS. Three test problems are run to compare CHEM{_}MACCS and D2PC. The doses versus the downwind centerline distances from the source for the given doses are in very close agreement.

An autonomous gas chromatograph system was designed and built to support the Thermal Enhanced Vapor Extraction System (TEVES) demonstration. TEVES is a remediation demonstration that seeks to enhance an existing technology (vacuum extraction) by adding a new technology (soil heating). A pilot scale unit was set up at one of the organic waste disposal pits at the Sandia National Laboratories Chemical Waste Landfill (CWL) in Tech Area 3. The responsibility for engineering a major part of the process instrumentation for TEVES belonged to the Manufacturing Control Subsystems Department. The primary mission of the one-of-a-kind hardware/software system is to perform on-site gas sampling and analysis to quantify a variety of volatile organic compounds (VOCs) from various sources during TEVES operations. The secondary mission is to monitor a variety of TEVES process physical parameters such as extraction manifold temperature, pressure, humidity, and flow rate, and various subsurface pressures. The system began operation in September 1994 and was still in use on follow-on projects when this report was published.

In support of the Motorola CRADA, the capabilities of the computational fluid dynamics code FIDAP (Fluid Dynamics International) for simulating problems involving fluid flow, heat transport, and chemical reactions have been assessed and enhanced as needed for semiconductor-processing applications (e.g. chemical vapor deposition). A novel method of treating surface chemical species that uses only pre-existing FIDAP commands is described and illustrated with test problems. A full-Jacobian treatment of the chemical reaction rate expressions during formation of the stiffness matrix has been implemented in FIDAP for both the Arrhenius-parameter and user-subroutine methods of specifying chemical reactions, where the Jacobian terms can be calculated analytically or numerically. This formulation is needed to obtain convergence when reaction rates become large compared to transport rates (stiff chemistry). Several test problems are analyzed, and in all cases this approach yields good convergence behavior, even for extremely stiff fluid-phase and surface reactions. A stiff segregated algorithm has been developed and implemented in FIDAP. Analysis of test problems indicates that this algorithm yields improved convergence behavior compared with the original segregated algorithm. This improved behavior enables segregated techniques to be applied to problems with stiff chemistry, as required for large three-dimensional multi-species problems.

The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

Transient dynamics simulations are commonly used to model phenomena such as car crashes, underwater explosions, and the response of shipping containers to high-speed impacts. Physical objects in such a simulation are typically represented by Lagrangian meshes because the meshes can move and deform with the objects as they undergo stress. Fluids (gasoline, water) or fluid-like materials (earth) in the simulation can be modeled using the techniques of smoothed particle hydrodynamics. Implementing a hybrid mesh/particle model on a massively parallel computer poses several difficult challenges. One challenge is to simultaneously parallelize and load-balance both the mesh and particle portions of the computation. A second challenge is to efficiently detect the contacts that occur within the deforming mesh and between mesh elements and particles as the simulation proceeds. These contacts impart forces to the mesh elements and particles which must be computed at each timestep to accurately capture the physics of interest. In this paper we describe new parallel algorithms for smoothed particle hydrodynamics and contact detection which turn out to have several key features in common. Additionally, we describe how to join the new algorithms with traditional parallel finite element techniques to create an integrated particle/mesh transient dynamics simulation. Our approach to this problem differs from previous work in that we use three different parallel decompositions, a static one for the finite element analysis and dynamic ones for particles and for contact detection. We have implemented our ideas in a parallel version of the transient dynamics code PRONTO-3D and present results for the code running on a large Intel Paragon.

Sandia National Laboratories and Oceania, Inc. entered into a Cooperative Research and Development Agreement (CRADA) in November 1993 to provide ``Information Integrity and Privacy for Computerized Medical Patient Records`` (CRADA No. SC93/01183). The main objective of the project was to develop information protection methods that are appropriate for databases of patient records in health information systems. This document describes the findings and alternative solutions that resulted from this CRADA.

PHASER (Probabilistic Hybrid Analytical System Evaluation Routine) is a software tool that has the capability of incorporating subjective expert judgment into probabilistic safety analysis (PSA) along with conventional data inputs. An earlier report described the PHASER methodology, but only gave a cursory explanation about how dependence was incorporated in Version 1.10 and about how ``Importance`` and ``Sensitivity`` measures were to be incorporated in Version 2.00. A more detailed description is given in this report. The basic concepts involve scale factors and confidence factors that are associated with the stochastic variability and subjective uncertainty (which are common adjuncts used in PSA), and the safety risk extremes that are crucial to safety assessment. These are all utilized to illustrate methodology for incorporating dependence among analysis variables in generating PSA results, and for Importance and Sensitivity measures associated with the results that help point out where any major sources of safety concern arise and where any major sources of uncertainty reside, respectively.

This work addresses a new kind of silicon based chemical sensor that combines the reliability and stability of silicon microelectronic field effect devices with the highly selective and sensitive immunoassay. The sensor works on the principle that thin SiN layers on lightly doped Si can detect pH changes rapidly and reversibly. The pH changes affect the surface potential, and that can be quickly determined by pulsed photovoltage measurements. To detect other species, chemically sensitive films were deposited on the SiN where the presence of the chosen analyte results in pH changes through chemical reactions. A invention of a cell sorting device based on these principles is also described. A new method of immobilizing enzymes using Sandia`s sol-gel glasses is documented and biosensors based on the silicon wafer and an amperometric technique are detailed.

Microsensors do not have the selectivity to chemical species available in large laboratory instruments. This project employed arrays of catalytically gated silicon microsensors with different catalysts to create data streams which can be analyzed by pattern recognition programs. One of the most significant accomplishments of the program was the demonstration of that mixtures of H{sub 2} with the oxidants NO{sub x} and O{sub 2} could distinguished from one another by the use of different catalytic metals on the Sandia Robust Hydrogen (SRH) sensors and the newly developed pattern recognition algorithm. This sensor system could be used to identify explosive gas mixtures and analyze exhaust streams for pollution control.

This manual describes the use of MPSalsa, an unstructured finite element (FE) code for solving chemically reacting flow problems on massively parallel computers. MPSalsa has been written to enable the rigorous modeling of the complex geometry and physics found in engineering systems that exhibit coupled fluid flow, heat transfer, mass transfer, and detailed reactions. In addition, considerable effort has been made to ensure that the code makes efficient use of the computational resources of massively parallel (MP), distributed memory architectures in a way that is nearly transparent to the user. The result is the ability to simultaneously model both three-dimensional geometries and flow as well as detailed reaction chemistry in a timely manner on MT computers, an ability we believe to be unique. MPSalsa has been designed to allow the experienced researcher considerable flexibility in modeling a system. Any combination of the momentum equations, energy balance, and an arbitrary number of species mass balances can be solved. The physical and transport properties can be specified as constants, as functions, or taken from the Chemkin library and associated database. Any of the standard set of boundary conditions and source terms can be adapted by writing user functions, for which templates and examples exist.

The USW SD-7 drill hole is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the Systematic Drilling Program, as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada. The Yucca Mountain site has been proposed as the potential location of a repository for high-level nuclear waste. The SD-7 drill hole is located near the southern end of the potential repository area and immediately to the west of the Main Test Level drift of the Exploratory Studies Facility. The hole is not far from the junction of the Main Test Level drift and the proposed South Ramp decline. Drill hole USW SD-7 is 2675.1 ft (815.3 m) deep, and the core recovered nearly complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. Core was recovered from much of the underlying Calico Hills Formation, and core was virtually continuous in the Prow Pass Tuff and the Bullfrog Tuff. The SD-7 drill hole penetrated the top several tens of feet into the Tram Tuff, which underlies the Prow Pass and Bullfrog Tuffs. These latter three units are all formations of the Crater Flat Group, The drill hole was collared in welded materials assigned to the crystal-poor middle nonlithophysal zone of the Tiva Canyon Tuff; approximately 280 ft (85 m) of this ash-flow sheet was penetrated by the hole. The Yucca Mountain Tuff appears to be missing from the section at the USW SD-7 location, and the Pah Canyon Tuff is only 14.5 ft thick. The Pah Canyon Tuff was not recovered in core because of drilling difficulties, suggesting that the unit is entirely nonwelded. The presence of this unit is inferred through interpretation of down-hole geophysical logs.

This LDRD program No. 3505.230 explored a new approach to monolithic integration of active waveguides and rare-earth solid state lasers directly onto III-V substrates. It involved selectively incorporating rare-earth ions into spin-on glasses (SOGs) that could be solvent cast and then patterned with conventional microelectronic processing. The patterned, rare-earth spin-on glasses (RESOGs) were to be photopumped by laser diodes prefabricated on the wafer and would serve as directly integrated active waveguides and/or rare-earth solid state lasers.

Under the auspices of the {open_quotes}Government/Industry Wind Technology Applications Project{close_quotes} [{open_quotes}Letter of Interest{close_quotes} (LOI) Number RC-1-11101], Flo Wind Corp. has successfully developed, tested, and delivered a high-energy rotor upgrade candidate for their 19-meter Vertical Axis Wind Turbine. The project included the demonstration of the innovative extended height-to-diameter ratio concept, the development of a continuous span single-piece composite blade, the demonstration of a continuous blade manufacturing technique, the utilization of the Sandia National Laboratories developed SNLA 2150 natural laminar flow airfoil and the reuse of existing wind turbine and wind power plant infrastructure.

PHASER (Probabilistic Hybrid Analytical System Evaluation Routine) is a computer code for solving the top event probability of a system fault tree. It has the capability for easy migration of individual basic event probabilities from a zero-{open_quotes}scale{close_quotes}-factor (completely subjective) state to one in which the analyst has total knowledge (completely stochastic) about each basic event. The code implements a fuzzy algebra solution for subjective data, a probabilistic solution for stochastic data, and a hybrid mathematics solution for data that are partly subjective and partly stochastic. Events that are not completely subjective or completely stochastic are hybrid events and are internally handled as such. The stochastic and fuzzy ranges of uncertainty in the top event probability are also computed for the analyst. These are provided in the form of a fuzzy function for the subjective uncertainty, a probability density function (PDF) for the stochastic variability, and the overall {open_quotes}confidence{close_quotes} factors for the two constituents of uncertainty, giving a complete hybrid result. PHASER interfaces with other Sandia codes (SABLE, LHS and LHSPOST) to assist the user in determining cutsets, and to compute probability density functions.

In 1983, high-level radioactive waste repository performance requirements related to groundwater travel time were defined by NRC subsystem regulation 10 CFR 60.113. Although DOE is not presently attempting to demonstrate compliance with that regulation, understanding of the prevalence of fast paths in the groundwater flow system remains a critical element of any safety analyses for a potential repository system at Yucca Mountain, Nevada. Therefore, this analysis was performed to allow comparison of fast-path flow against the criteria set forth in the regulation. Models developed to describe the conditions for initiation, propagation, and sustainability of rapid groundwater movement in both the unsaturated and saturated zones will form part of the technical basis for total- system analyses to assess site viability and site licensability. One of the most significant findings is that the fastest travel times in both unsaturated and saturated zones are in the southern portion of the potential repository, so it is recommended that site characterization studies concentrate on this area. Results support the assumptions regarding the importance of an appropriate conceptual model of groundwater flow and the incorporation of heterogeneous material properties into the analyses. Groundwater travel times are sensitive to variation/uncertainty in hydrologic parameters and in infiltration flux at upper boundary of the problem domain. Simulated travel times are also sensitive to poorly constrained parameters of the interaction between flow in fractures and in the matrix.

This report provides a users` guide for parallel processing ITS on a UNIX workstation network, a shared-memory multiprocessor or a massively-parallel processor. The parallelized version of ITS is based on a master/slave model with message passing. Parallel issues such as random number generation, load balancing, and communication software are briefly discussed. Timing results for example problems are presented for demonstration purposes.

The work is part of the rock mechanics effort for the Yucca Mountain Site Characterization Program. The laboratory-scale experiments are intended to provide high quality data on the mechanical behavior of jointed structures that can be used to validate complex numerical models for rock-mass behavior. Frictional sliding between simulated rock joints was studied using phase shifting moire interferometry. A model, constructed from stacks of machined and sandblasted granite plates, contained a central hole bore normal to the place so that frictional slip would be induced between the plates near the hole under compressive loading. Results show a clear evolution of slip with increasing load. Since the rock was not cycled through loading- unloading, the quantitative differences between the three data sets are probably due to a ``wearing-in`` effect. The highly variable spatial frequency of the data is probably due to the large grain size of the granite and the stochastic frictional processes. An unusual feature of the evolution of slip with increasing load is that as the load gets larger, some plates seem to return to a null position. Figs, 6 refs.

The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity model for the uppermost 350m of the mountain. This model is useful for prediction of repository-level ground motions for potential large nearby earthquakes.

The Do-It-Now (DIN) building maintenance system is proposed to reduce the cost of routine building maintenance and repairs and to improve customer satisfaction with maintenance services. DIN uses a team approach to periodically inspect buildings and provide maintenance services on the spot. It emphasizes communications between the customers and the craftspeople performing the work. The system was designed using a reengineering approach that characterized the existing maintenance work control system, analyzed comparable systems in other DOE laboratories, envisioned an ideal system, and proposed a workable, testable system for initial implementation. At each stage, input was solicited from customer representatives and Facilities management to ensure meeting customer requirements with an implementable system.

This report describes the analysis and conclusion of an investigation of the carbon monoxide emissions resulting from Sandia National Laboratories and Department of Energy (DOE) commuter and on-base traffic for the Clean Air Act (CAA) Conformity Determination. Albuquerque/Bernalillo County was classified as a nonattainment area by the Environmental Protection Agency. Nonattainment area is an area which is shown by monitored data or which is calculated by air quality modeling to exceed any National Ambient Air Quality Standard (NAAQS) for the pollutant. Albuquerque/Bernalillo County exceeds the NAAQS for carbon monoxide and ozone. The Conformity Determination was needed to complete the CAA Title V Permitting process for SNL and the DOE. The analysis used the EPA approved MOBILE5a Carbon Monoxide (CO) emissions modeling program. This analysis will provide a baseline for mobile sources to allow Sandia to estimate any future activity and how that activity will impact CO emissions. The General Conformity Rule (AQCR 43) requires that operations which will increase CO emissions in nonattaimnent or maintenance areas such as Bernalillo County undergo conformity analyses to determine whether or not they will impact ambient air quality in the area.

The US DOE has amassed over 555,000 metric tons of depleted uranium from its uranium enrichment operations. Rather than dispose of this depleted uranium as waste, this study explores a beneficial use of depleted uranium as metal shielding in casks designed to contain canisters of vitrified high-level waste. Two high-level waste storage, transport, and disposal shielded cask systems are analyzed. The first system employs a shielded storage and disposal cask having a separate reusable transportation overpack. The second system employs a shielded combined storage, transport, and disposal cask. Conceptual cask designs that hold 1, 3, 4 and 7 high-level waste canisters are described for both systems. In all cases, cask design feasibility was established and analyses indicate that these casks meet applicable thermal, structural, shielding, and contact-handled requirements. Depleted uranium metal casting, fabrication, environmental, and radiation compatibility considerations are discussed and found to pose no serious implementation problems. About one-fourth of the depleted uranium inventory would be used to produce the casks required to store and dispose of the nearly 15,400 high-level waste canisters that would be produced. This study estimates the total-system cost for the preferred 7-canister storage and disposal configuration having a separate transportation overpack would be $6.3 billion. When credits are taken for depleted uranium disposal cost, a cost that would be avoided if depleted uranium were used as cask shielding material rather than disposed of as waste, total system net costs are between $3.8 billion and $5.5 billion.

An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada, involves characterization 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 boreholes UE25 NRG-2, 2A, 2B, and 3 drilled in support of the Exploratory Studies Facility (ESF) at Yucca Mountain. The holes penetrated the Timber Mountain tuff and two thermal/mechanical units of the Paintbrush tuff. The thermal/mechanical stratigraphy was defined by Ortiz 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 for each borehole is presented. The tuff samples in this study have a wide range of welding characteristics (usually reflected in sample porosity), 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.

Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from boreholes UE25 NRG-4 and -5, at Yucca Mountain, Nevada. Measurements have been performed on three thermal/mechanical units, PTn, TSwl, and TSw2. On each specimen the following bulk properties have been reported: dry bulk density, saturated bulk density, average grain density, and porosity. Unconfined compression to failure, confined compression to failure, and indirect tensile strength tests were performed on selected specimens recovered from the boreholes. In addition, compressional and shear wave velocities were measured on specimens designated for unconfined compression and confined compression experiments. Measurements were conducted at room temperature on nominally water-saturated specimens. The nominal rate for the fracture experiments was 10{sup -5}s{sup -1}.

Sandia National Laboratories, New Mexico (SNL/NM) is managed and operated by Sandia Corporation, a Lockheed Martin Company. SNL/NM is located on land owned by the U.S. Department of Energy (DOE) within the boundaries of the Kirtland Air Force Base (KAFB) in Albuquerque, New Mexico. The major responsibilities of SNL/NM are the support of national security and energy projects. Low-level radioactive waste (LLW) is generated by some of the activities performed at SNL/NM in support of the DOE. This report describes potential environmental effects of the shipments of low-level radioactive wastes to other sites.

Ambient air samples were taken at two locations in the East Mountain Area in conjunction with thermal testing at the Lurance Canyon Burn Site (LCBS). The samples were taken to provide measurements of particulate matter with a diameter less than or equal to 10 micrometers (PM{sub 10}) and volatile organic compounds (VOCs). This report summarizes the results of the sampling performed in 1995. The results from small-scale testing performed to determine the potentially produced air pollutants in the thermal tests are included in this report. Analytical results indicate few samples produced measurable concentrations of pollutants believed to be produced by thermal testing. Recommendations for future air sampling in the East Mountain Area are also noted.

One of the most common oil-field treatments is hot oiling to remove paraffin from wells. Even though the practice is common, the thermal effectiveness of the process is not commonly understood. In order for producers to easily understand the thermodynamics of hot oiling, a simple tool is needed for estimating downhole temperatures. Such a tool has been developed that was distributed as a compiled, public-domain-software spreadsheet. That spreadsheet has evolved into an interactive from on the World Wide Web and has been adapted into a Windows{trademark} program by Petrolite, St. Louis MO. The development of such a tools was facilitated by expressing downhole temperatures in terms of analytic formulas. Considerable algebraic work is required to develop such formulas. Also, the data describing hot oiling is customarily a mixture of practical units that must be converted to a consistent set of units. To facilitate the algebraic manipulations and to assure unit conversions are correct, during development parallel calculations were made using the spreadsheet and a symbolic mathematics program. Derivation of the formulas considered falling film flow in the annulus and started from the transient differential equations so that the effects of the heat capacity of the tubing and casing could be included. While this approach to developing a software product does not have the power and sophistication of a finite element or difference code, it produces a user friendly product that implements the equations solved with a minimum potential for bugs. This allows emphasis in development of the product to be placed on the physics.

This paper considers the protein structure prediction problem for lattice and off-lattice protein folding models that explicitly represent side chains. Lattice models of proteins have proven extremely useful tools for reasoning about protein folding in unrestricted continuous space through analogy. This paper provides the first illustration of how rigorous algorithmic analyses of lattice models can lead to rigorous algorithmic analyses of off-lattice models. The authors consider two side chain models: a lattice model that generalizes the HP model (Dill 85) to explicitly represent side chains on the cubic lattice, and a new off-lattice model, the HP Tangent Spheres Side Chain model (HP-TSSC), that generalizes this model further by representing the backbone and side chains of proteins with tangent spheres. They describe algorithms for both of these models with mathematically guaranteed error bounds. In particular, the authors describe a linear time performance guaranteed approximation algorithm for the HP side chain model that constructs conformations whose energy is better than 865 of optimal in a face centered cubic lattice, and they demonstrate how this provides a 70% performance guarantee for the HP-TSSC model. This is the first algorithm in the literature for off-lattice protein structure prediction that has a rigorous performance guarantee. The analysis of the HP-TSSC model builds off of the work of Dancik and Hannenhalli who have developed a 16/30 approximation algorithm for the HP model on the hexagonal close packed lattice. Further, the analysis provides a mathematical methodology for transferring performance guarantees on lattices to off-lattice models. These results partially answer the open question of Karplus et al. concerning the complexity of protein folding models that include side chains.

A formal program of cooperation between the US Department of Energy and the Belarusian regulatory agency Promatomnazdor (PAN) began in 1994. A visit to the Belarusian Sosny Science and Technology Center (SSTC) by representatives from the United States, Sweden, Japan, and the International Atomic Energy Agency resulted in a multinational program of cooperation to enhance the existing material protection, control, and accounting systems in place at Sosny. Specific physical-protection-related recommendations included upgrades to the physical protection systems at Buildings 33 and 40 at Sosny and the security systems in the SSTC central alarm station. US experts, in conjunction with the multinational team and Belarus representatives, have reviewed initial designs for physical protection upgrades at Sosny. Subsequently, the United States assumed an essential role for funding and technical oversight for enhancements at the SSTC, aspects of its emergency communication systems, and the upgrade of the SSTC site access control system. This paper addresses the status of physical protection enhancements at the Sosny site.

AIBN-iniliated functionalization of polyphenylsilane with allyl(ethoxy) silanes generates (elhoxysilylpropyl)polysilanes in good yield. Amorphous polysilane-polysiloxane hybrid nanocomposites can be prepared by the mild, acid-catalyzed sol-gel hydrolysis-condensation of polysilane-based precursors 2a-c at the pendant alkoxysilane residues. UV-Vis and multinuclear NMR spectroscopies establish the mention of the polysilane chromophore and attached organic residues; NMR also reflects the degree of condenstion at the siloxane silicon nuclei. The bulk morphology of the resulting dried gels can be influenced by the choice of solvent removal from the wet gel Aqueous extraction of solvent results in ponporous xerogels. while solvent removal by supercritical CO2 yields mesoporous aerogels with retention of the wet gel surface area. In hybrid materials 3a-c the polysilane chromophore is homogeneously dispersed in. and covalently bound to, a highly crosslinked siloxane matrix. The demonstrated ability to homogeneously entrain polysilanes within glass matrices holds great potential for fabricating sohisticated electronic, NLO and photoconducting devices.

The post cold war security environment poses both difficult challenges and encouraging opportunities. Some of the most difficult challenges are related to regional conflict and the proliferation of weapons of mass destruction. New and innovative approaches to prevent the proliferation of weapons of mass destruction are essential. More effort must be focused on underlying factors that motivate countries to seek weapons of mass destruction. Historically the emphasis has been on denial: denying information, denying technology, and denying materials necessary to build such weapons. Though still important, those efforts are increasingly perceived to be insufficient, and initiatives that address underlying motivational factors are needed. On the opportunity side, efforts to establish regional dialogue and confidence-building measures are increasing in many areas. Such efforts can result in cooperative agreements on security issues such as border control, demilitarized zones, weapons delivery systems, weapons of mass destruction free zones, environmental agreements, and resource sharing. In some cases, implementing such cooperative agreements will mean acquiring, analyzing, and sharing large quantities of data and sensitive information. These arrangements for ``cooperative monitoring`` are becoming increasingly important to the security of individual countries, regions, and international institutions. However, many countries lack sufficient technical and institutional infrastructure to take full advantage of these opportunities. Constructing a peaceful twenty-first century will require that technology is brought to bear in the most productive and innovative ways to meet the challenges of proliferation and to maximize the opportunities for cooperation.

The MELCOR Accident Consequence Code System (MACCS), publicly distributed since 1987, was developed to estimate the potential impacts to the surrounding public of severe accidents at nuclear power plants. The principal phenomena considered in MACCS are atmospheric transport and deposition under time-variant meteorology, short-term and long-term mitigative actions and exposure pathways, deterministic and stochastic health effects, and economic costs of mitigative actions. At this time, no other publicly available code in the US offers all these capabilities. MACCS2 represents a major enhancement of the capabilities of its predecessor MACCS. MACCS2 was developed as a general-purpose analytical tool applicable to diverse reactor and nonreactor Department of Energy (DOE) facilities. The MACCS2 package includes three primary enhancements: (1) a more flexible emergency response model, (2) an expanded library of radionuclides, and (3) a semidynamic food-chain model. The new code features allow detailed evaluations of risks to workers at nearby facilities on large DOE reservations and allow the user to assess the potential impacts of over 700 radionuclides that cannot be considered with MACCS.

Batch-fabricated silicon seismic transducers could revolutionize the discipline of seismic monitoring by providing inexpensive, easily deployable sensor arrays. Our ultimate goal is to fabricate seismic sensors with sensitivity and noise performance comparable to short-period seismometers in common use. We expect several phases of development will be required to accomplish that level of performance. Traditional silicon micromachining techniques are not ideally suited to the simultaneous fabrication of a large proof mass and soft suspension, such as one needs to achieve the extreme sensitivities required for seismic measurements. We have therefore developed a novel {open_quotes}mold{close_quotes} micromachining technology that promises to make larger proof masses (in the 1-10 mg range) possible. We have successfully integrated this micromolding capability with our surface-micromachining process, which enables the formation of soft suspension springs. Our calculations indicate that devices made in this new integrated technology will resolve down to at least sub-{mu}G signals, and may even approach the 10{sup -10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

The goal of the Waveform Correlation Event Detection System (WCEDS) Project at Sandia Labs has been to develop a prototype of a full-waveform correlation based seismic event detection system which could be used to assess potential usefulness for CTBT monitoring. The current seismic event detection system in use at the IDC is very sophisticated and provides good results but there is still significant room for improvement, particularly in reducing the number of false events (currently being nearly equal to the number of real events). Our first prototype was developed last year and since then we have used it for extensive testing from which we have gained considerable insight. The original prototype was based on a long-period detector designed by Shearer (1994), but it has been heavily modified to address problems encountered in application to a data set from the Incorporated Research Institutes for Seismology (IRIS) broadband global network. Important modifications include capabilities for event masking and iterative event detection, continuous near-real time execution, improved Master Image creation, and individualized station pre-processing. All have been shown to improve bulletin quality. In some cases the system has detected marginal events which may not be detectable by traditional detection systems, but definitive conclusions cannot be made without direct comparisons. For this reason future work will focus on using the system to process GSETT3 data for comparison with current event detection systems at the IDC.

An initial security evaluation of the proposed International Monitoring System (IMS) suggests safeguards at various points in the IMS to provide reliable information to the user community. Modeling the IMS as a network of information processing nodes provides a suitable architecture for assessing data surety needs of the system. The recommendations in this paper include the use of public-key authentication for data from monitoring stations and for commands issued to monitoring stations. Other monitoring station safeguards include tamper protection of sensor subsystems, preservation of data (i.e. short-term archival), and limiting the station`s network services. The recommendations for NDCs focus on the need to provide a backup to the IDC for data archival and data routing. Safeguards suggested for the IDC center on issues of reliability. The production of event bulletins should employ {open_quotes}two-man{close_quotes} procedures. As long as the data maintains its integrity, event bulletins can be produced by NDCs as well. The effective use of data authentication requires a sound key management system. Key management systems must be developed for the authentication of data, commands, and event bulletins if necessary. It is recommended that the trust placed in key management be distributed among multiple parties. The recommendations found in this paper offer safeguards for identified vulnerabilities in the IMS with regard to data surety. However, several outstanding security issues still exist. These issues include the need to formalize and obtain a consensus on a threat model and a trust model for the IMS. The final outstanding security issue that requires in-depth analysis concerns the IDC as a potential single point of failure in the current IMS design.

This paper summarizes the requirements for the interpolation scheme needed for the CTBT Knowledge Base and discusses interpolation issues relative to the requirements. Based on these requirements, a methodology for providing an accurate and robust interpolation scheme for the CTBT Knowledge Base is proposed. The method utilizes a Delaunay triangle tessellation to mesh the Earth`s surface and employs the natural-neighbor interpolation technique to provide accurate evaluation of geophysical data that is important for CTBT verification. The natural-neighbor interpolation method is a local weighted average technique capable of modeling sparse irregular data sets as is commonly found in the geophysical sciences. This is particularly true of the data to be contained in the CTBT Knowledge Base. Furthermore, natural neighbor interpolation is first order continuous everywhere except at the data points. The non-linear form of the natural-neighbor interpolation method can provide continuous first and second order derivatives throughout the entire data domain. Since one of the primary support functions of the Knowledge Base is to provide event location capabilities, and the seismic event location algorithms typically require first and second order continuity, this is a prime requirement of any interpolation methodology chosen for use by the CTBT Knowledge Base.

It is recognized that some dynamic and noise environments are characterized by time histories which are not Gaussian. An example is high intensity acoustic noise. Another example is some transportation vibration. A better simulation of these environments can be generated if a zero mean non-Gaussian time history can be reproduced with a specified auto (or power) spectral density (ASD or PSD) and a specified probability density function (pdf). After the required time history is synthesized, the waveform can be used for simulation purposes. For example, modem waveform reproduction techniques can be used to reproduce the waveform on electrodynamic or electrohydraulic shakers. Or the waveforms can be used in digital simulations. A method is presented for the generation of realizations of zero mean non-Gaussian random time histories with a specified ASD, and pdf. First a Gaussian time history with the specified auto (or power) spectral density (ASD) is generated. A monotonic nonlinear function relating the Gaussian waveform to the desired realization is then established based on the Cumulative Distribution Function (CDF) of the desired waveform and the known CDF of a Gaussian waveform. The established function is used to transform the Gaussian waveform to a realization of the desired waveform. Since the transformation preserves the zero-crossings and peaks of the original Gaussian waveform, and does not introduce any substantial discontinuities, the ASD is not substantially changed. Several methods are available to generate a realization of a Gaussian distributed waveform with a known ASD. The method of Smallwood and Paez (1993) is an example. However, the generation of random noise with a specified ASD but with a non-Gaussian distribution is less well known.

One of the major thrusts established under the FAA`s National Aging Aircraft Research Program is to foster new technologies associated with civil aircraft maintenance. Recent DOD and other government developments in the use of bonded composite patches on metal structures has supported the need for research and validation of such doubler applications on U.S. certificated airplanes. Composite patching is a rapidly maturing technology which shows promise of cost savings on aging aircraft. Sandia Labs is conducting a proof-of-concept project with Delta Air Lines, Lockheed Martin, Textron, and the FAA which seeks to remove any remaining obstacles to the approved use of composite doublers. By focusing on a specific commercial aircraft application - reinforcement of the L-1011 door frame - and encompassing all {open_quotes}cradle-to-grave{close_quotes} tasks such as design, analysis, installation, and inspection, this program is designed to prove the capabilities of composite doublers. This paper reports on a series of structural tests which have been conducted on coupons and subsize test articles. Tension-tension fatigue and residual strength tests attempted to grow engineered flaws in coupons with composite doublers bonded to aluminum skin. Also, structures which modeled key aspects of the door corner installation were subjected to extreme tension, shear, and bending loads. In this manner it was possible to study strain fields in and around the Lockheed-designed composite doubler using realistic aircraft load scenarios and to assess the potential for interply delaminations and disbonds between the aluminum and the laminate. The data acquired was also used to validate finite element models (FEM) and associated Damage Tolerance Analyses.

The purpose of the Data Visualization Project at Sandia Labs is to prototype and evaluate new approaches to the presentation of data for CTBT monitoring applications. The great amount of data expected to be available, and the complex interrelationships in that data, make this a promising area for scientific data visualization techniques. We are developing a powerful and flexible prototyping environment with which to explore these possibilities. A user-friendly graphical user interface (GUI) should be an integral part of any data visualization tools developed. The GUI is necessary to select which data to visualize, and to modify and explore the displays that are the result of data visualization. Using our prototyping environment, we have produced data visualization displays of various kinds of data and have also experimented with different GUIs for controlling the visualization process. We present here an overview of that work, including promising results, lessons learned, and work in progress. To better understand what is needed, we have identified several data processing/analysis scenarios which we think will be important in CTBT monitoring. These scenarios help us identify what types of information we should display (together or in sequence), and help us focus on isolating the underlying goals. Each display we have produced is put in the context of one or more processing scenarios to help explain why and how it could be useful.

The uses of the LON, `Local Operating Network,` developed by Echelon Corporation, Palo Alto, California, has been expanded to handle a number of safeguards applications. A magnetic and vibration sensor pack has been developed to monitor for magnetic fields and vibration. This sensor pack can be attached to any source that generates a magnetic field, such as electrical solenoids or motors, to detect when the source is activated. New network nodes that interface directly with the raw data of Sandia developed radiation sensors, for detecting the presence of radiation sources, have been developed. The capacity of the network has been expanded to allow the transmission of large data sets, specifically the transmission of digital video images from the Sandia-developed-Image Compression and Authentication Module (ICAM).

For the past two years Sandia National Laboratories (SNL) has been involved in developing and installing Remote Monitoring Systems (RMS) at a number of sites around the world. Through the cooperation of the various countries and facilities, it has been possible to collect data on the requirements and performance of these systems that are for monitoring the movement of spent nuclear fuel. The data collected shows that the front end detection method can be a very useful concept to reduce the amount of data that has to be collected and, more importantly, reviewed by inspectors. Spent fuel storage monitoring is a major part of the non-proliferation monitoring that must be done since spent fuel is the by-product of all the power and research reactors worldwide. The movement of spent fuel is easier in many respects to monitor since it always requires protective shielding. This paper will describe a number of the Remote Monitoring Systems that have been installed to monitor spent fuel movement and the resulting decrease in data from the use of a sensor-driven front detection system. The reduction of the data collected and stored is also important to remote monitoring since it decreases the time required to transmit the data to a review site.

The accurate analytical determination of the response of radioactive material transportation packages to the hypothetical puncture accident requires inelastic analysis techniques. Use of this improved analysis method recudes the reliance on empirical and approximate methods to determine the safety for puncture accidents. This paper will discuss how inelastic analysis techniques can be used to determine the stresses, strains and deformations resulting from puncture accidents for thin skin materials with different backing materials. A method will be discussed to assure safety for all of these types of packages.

The safety of the transportation of radioactive materials by road and rail has been well studied and documented. However, the safety of waterborne transportation has received much less attention. Recent highly visible waterborne transportation campaigns have led to DOE and IAEA to focus attention on the safety of this transportation mode. In response, Sandia National Laboratories is conducting a program to establish a method to determine the safety of these shipments. As part of that program the mechanics involved in ship-to-ship collisions are being evaluated to determine the loadings imparted to radioactive material transportation packages during these collisions. This paper will report on the results of these evaluations.

This paper describes the results of an International Monitoring System synergy study using Sandia National Laboratory`s IVSEM (Integrated Verification System Evaluation Model). The study compares individual subsystem performance (seismic, infrasound, radionuclide, and hydroacoustic) with integrated system performance. The integrated system exhibits synergy because different sensor technologies cover different locations; thus, the integrated system covers more locations than can any individual subsystem. Energy and system performance can be further enhanced by allowing mixed technology detection and location.

An enhanced version of NetSim and an expanded supporting database were used to predict the detection and location performances of the International Seismic Monitoring System (ISMS) proposed in Working Paper 330 by the Ad Hoc Committee on a Nuclear Test Ban Treaty who supported the Conference on Disarmament in formulating the system monitoring requirements. The primary goals of this effort were to estimate the levels of 9 performance of the proposed ISMS and to predict the enhancements in location accuracy as would be provided by station and regional calibrations. An estimate of the detection threshold indicates that the primary network alone and in its mature state is capable of detecting a fully coupled 1 kiloton nuclear shot contained in consolidated rock anywhere on the earth. Further, the best detection thresholds appear in central Eurasia and range from 3.25 to 3.5 magnitude units. The threshold estimates were based on a 3P at 99% network detection criterion. Location performance estimates indicated that conventional location methods using regional and station calibrations are capable of achieving location accuracies better than 1000 square kilometers with 90% confidence largely everywhere for events with magnitudes at or above the detection threshold of the primary network. The poorest accuracies primarily appear on islands in the southern oceans and in portions of Antarctica. For events having a magnitude of 4.25 the location accuracy exceeds 100 square kilometers in almost the entire northern hemisphere, over a large portion of Africa, and a small portion of South America. Better accuracies than these are possible at larger event magnitudes. Regional and station calibrations yield net reductions in the elliptical areas of uncertainty by factors better than 6.0 using conventional location methods.

The United States Department of Energy (DOE) uses sensitive or classified parts and material that must be protected and accounted for. We believe there is a need for an automated system that can help protect and monitor these parts and material. In response to this need Sandia National Laboratories (SNL) has developed a real-time personnel and material tracking system called PAMTRAK that has been installed at selected DOE facilities. PAMTRAK safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. This paper describes our goals when designing PAMTRAK, the PAMTRAK system components, our current installations, and the benefits a site can expect when using PAMTRAK. So far PAMTRAK has been installed exclusively at government facilities; however, it is also applicable to private industries that need to protect high value assets. Through government programs such as CRADAs, SBIRs, and other mechanisms, the DOE often works with private industry to promote further development and commercialization of national laboratory developed technologies. SNL supports and welcomes partners and new users of PAMTRAK.

A remote monitoring system (RMS) field trial will be conducted for the International Atomic Energy Agency (IAEA) on highly enriched uranium materials in a vault at the Oak Ridge Y-12 Plant. Remote monitoring technologies are being evaluated to verify their capability to enhance the effectiveness and timeliness of IAEA safeguards in storage facilities while reducing the costs of inspections and burdens on the operator. Phase one of the field trial, which involved proving the satellite transmission of sensor data and safeguards images from a video camera activated by seals and motion sensors installed in the vault, was completed in September 1995. Phase two involves formal testing of the RMS as a tool for use by the IAEA during their tasks of monitoring the storage of nuclear material. The field trial to be completed during early 1997 includes access and item monitoring of nuclear materials in two storage trays. The RMS includes a variety of Sandia, Oak Ridge, and Aquila sensor technologies that provide video monitoring, radiation attribute measurements, and container identification to the on-site data acquisition system (DAS) by way of radio-frequency and Echelon LONWorks networks. The accumulated safeguards information will be transmitted to the IAEA via satellite (COMSAT/RSI) and international telephone lines.

The capture and storage of video images have been major engineering challenges for safeguard and security applications since the video camera provided a method to observe remote operations. The problems of designing reliable video cameras were solved in the early 1980`s with the introduction of the CCD (charged couple device) camera. The first CCD cameras cost in the thousands of dollars but have now been replaced by cameras costing in the hundreds. The remaining problem of storing and viewing video images in both attended and unattended video surveillance systems and remote monitoring systems is being solved by sophisticated digital compression systems. One such system is the PC-104 three card set which is literally a ``video engine`` that can provide power for video storage systems. The use of digital images in surveillance systems makes it possible to develop remote monitoring systems, portable video surveillance units, image review stations, and authenticated camera modules. This paper discusses the video card set and how it can be used in many applications.

There are important differences between the safety principles for nuclear weapons and for nuclear reactors. For example, a principal concern for nuclear weapons is to prevent electrical energy from reaching the nuclear package during accidents produced by crashes, fires, and other hazards, whereas the foremost concern for nuclear reactors is to maintain coolant around the core in the event of certain system failures. Not surprisingly, new methods have had to be developed to assess the risk from nuclear weapons. These include fault tree transformations that accommodate time dependencies, thermal and structural analysis techniques that are fast and unconditionally stable, and parameter sampling methods that incorporate intelligent searching. This paper provides an overview of the new methods for nuclear weapons and compares them with existing methods for nuclear reactors. It also presents a new intelligent searching process for identifying potential nuclear detonation vulnerabilities. The new searching technique runs very rapidly on a workstation and shows promise for providing an accurate assessment of potential vulnerabilities with far fewer physical response calculations than would be required using a standard Monte Carlo sampling procedure.

The US Nuclear Regulatory Commission (USNRC) and the European Commission (EC) have conducted a formal expert judgment elicitation jointly to systematically collect the quantitative information needed to perform consequence uncertainty analyses on a broad set of commercial nuclear power plants. Information from three sets of joint US/European expert panels was collected and processed. Information from the three sets of panels was collected in the following areas: in the phenomenological areas of atmospheric dispersion and deposition, in the areas of ingestion pathways and external dosimetry, and in the areas of health effects and internal dosimetry. This exercise has demonstrated that the uncertainty for particular issues as measured by the ratio of the 95th percentile to the 5th percentile can be extremely large (orders of magnitude), or rather small (factor of two). This information has already been used by many of the experts that were involved in this process in areas other than the consequence uncertainty field. The benefit to the field of radiological consequences is just beginning as the results of this study are published and made available to the consequence community.

Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure. Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.

The Cassini spacecraft is a deep space probe whose mission is to explore the planet Saturn and its moons. Since the spacecraft`s electrical requirements will be supplied by radioisotope thermoelectric generators (RTGs), the spacecraft designers and mission planners must assure that potential accidents involving the spacecraft do not pose significant human risk. The Cassini risk analysis team is seeking to perform a quantitative uncertainty analysis as a part of the overall mission risk assessment program. This paper describes the uncertainty analysis methodology to be used for the Cassini mission and compares it to the methods that were originally developed for evaluation of commercial nuclear power reactors.

Sandia National Laboratories has assembled an interdisciplinary team to explore the applicability of probabilistic logic modeling (PLM) techniques to model network reliability for a wide variety of communications network architectures. The authors have found that the reliability and failure modes of current generation network technologies can be effectively modeled using fault tree PLM techniques. They have developed a ``plug-and-play`` fault tree analysis methodology that can be used to model connectivity and the provision of network services in a wide variety of current generation network architectures. They have also developed an efficient search algorithm that can be used to determine the minimal cut sets of an arbitrarily-interconnected (non-hierarchical) network without the construction of a fault tree model. This paper provides an overview of these modeling techniques and describes how they are applied to networks that exhibit hybrid network structures (i.e., a network in which some areas are hierarchical and some areas are not hierarchical).

In November 1988, the US Nuclear Regulatory Commission (NRC) issued Generic Letter 88-20 requesting that all licensees perform an individual Plant Examination (IPE) to identify any plant-specific vulnerability to severe accidents and report the results to the Commission. This paper provides perspectives gained from reviewing 75 Individual Plant Examination (IPE) submittals covering 108 nuclear power plant units. Variability both within and among reactor types is examined to provide perspectives regarding plant-specific design and operational features, and modeling assumptions that play a significant role in the estimates of core damage frequencies in the IPEs.

This paper provides perspectives on human actions gained from reviewing 76 individual plant examination (IPE) submittals. Human actions found to be important in boiling water reactors (BWRs) and in pressurized water reactors (PWRs) are presented and the events most frequently found important are discussed. Since there are numerous factors that can influence the quantification of human error probabilities (HEPs) and introduce significant variability in the resulting HEPs (which in turn can influence which events are found to be important), the variability in HEPs for similar events across IPEs is examined to assess the extent to which variability in results is due to real versus artifactual differences. Finally, similarities and differences in human action observations across BWRs and PWRs are examined.

Arylamine-containing diblock copolymers were prepared via ring- opening metathesis polymerization (ROMP) to afford well-defined phase- separated materials. Alteration of the functionaity in a block, as well as the size of the blocks, allowed for the synthesis of self- assembled monolayers on a copper surface. The arylamine-containing block exhibited a strong binding affinity for the copper surface as seen by neutron reflectivity experiments. In addition, neutron reflectivity data verifies the self-assembly of block copolymer monolayers normal to the copper surface. Block copolymers prepared in this manner allow for the preparation of a wide range of adhesives and corrosion resistant materials. The use of ring-opening metathesis polymerization is important because it permits the synthesis of a variety of functionalized block copolymers.

The Agreement Between the Department of Defense of the United States and The Ministry of the Russian Federation for Atomic Energy (MINATOM) Concerning Control, Accounting, and Physical Protection of Nuclear Material, as well as a subsequent amendment to that agreement and a joint statement signed by the Department of Energy (DOE) and MINATOM, resulted in the selection of the Mayak Production Association (MPA) as one of the Russian enterprises that would participate with DOE Laboratories in expanded cooperation aimed at enhancing Material protection, Control and Accounting (MPC&A) systems in both countries. This paper describes the nature and scope of the expanded cooperation involving MPA and six DOE laboratories at an operating civilian, spent-nuclear-fuel reprocessing plant designated RT-1. RT-1 produces, among other materials, reactor-grade plutonium dioxide, a direct-use material that is stored within the boundaries of this plant. Initial efforts at expanded cooperation will focus on enhancements to the existing MPC&A systems at MPA`s RT-1 plant.

This paper describes an evolutionary development process that will lead to spent fuel measurements that directly measure fissile reactivity. First, the Fork measurement system has been used to verify the burnup of pressurized water reactor (PWR) spent-fuel assemblies at U.S. nuclear utilities. Fork measurements have demonstrated the utility of the passive Fork system to verify reactor records with a single 100-second measurement on each assembly. Second, an Advanced Fork system incorporating collimated gamma-ray spectroscopy has been designed to permit advanced calibration techniques that are independent of reactor burnup records and to allow rapid axial scanning of spent fuel assemblies. Third, an Active Fork system incorporating a neutron source to interrogate spent fuel is proposed to provide the capability to measure fissile reactivity, when compared to measurements on fresh fuel assemblies of the same design. The Advanced and Active Fork systems have wide applicability to spent fuel verification for PWR, boiling water reactor (BWR), and U.S. Department of Energy (DOE) spent fuel.

Since 1994, the U.S. Department of Energy (DOE) has provided cooperative assistance to the non-nuclear weapons states of the Former Soviet Union. This effort, within DOE`s program of Material Protection, Control, and Accounting (MPC&A), identified the Institute of Nuclear Physics (INP) in Uzbekistan and the Ignalina Nuclear Power Plant (INPP) in Lithuania as sites for cooperative MPC&A projects. The INP, located just outside of Tashkent, is the site of a 10-megawatt WWR-SM research reactor. This reactor is expected to remain operational as a major nuclear research and isotope production reactor for Central Asia. The INPP, located 100 kilometers northeast of the capital city of Vilnius, consists of two Russian-made RBMK reactors with a combined power output of 3,000 megawatts (electric). This power plant has been the subject of international safety and security concerns, which prompted DOE`s cooperative assistance effort. This paper describes U.S. progress in a multi-national effort directed at implementing physical protection upgrades in Lithuania and Uzbekistan. The upgrades agreed upon between DOE and the INP and between DOE and the INPP have been designed to interface with upgrades being implemented by other donor countries. DOE/INPP upgrade projects include providing training on U.S. approaches to physical protection, access control through the main vehicle portal, a hardened central alarm station, and improved guard force communications. DOE/INP upgrade projects in Uzbekistan include an access control system, a hardened fresh fuel storage vault, an interior intrusion detection and assessment system, and an integrated alarm display and assessment system.

The optical correlator described in this report is intended to serve as an attention-focusing processor. The objective is to narrowly bracket the range of a parameter value that characterizes the correlator input. The input is a waveform collected by a satellite-borne receiver. In the correlator, this waveform is simultaneously correlated with an ensemble of ionosphere impulse-response functions, each corresponding to a different total-electron-count (TEC) value. We have found that correlation is an effective method of bracketing the range of TEC values likely to be represented by the input waveform. High accuracy in a computational sense is not required of the correlator. Binarization of the impulse-response functions and the input waveforms prior to correlation results in a lower correlation-peak-to-background-fluctuation (signal-to-noise) ratio than the peak that is obtained when all waveforms retain their grayscale values. The results presented in this report were obtained by means of an acousto-optic correlator previously developed at SNL as well as by simulation. An optical-processor architecture optimized for 1D correlation of long waveforms characteristic of this application is described. Discussions of correlator components, such as optics, acousto-optic cells, digital micromirror devices, laser diodes, and VCSELs are included.

The simplest general kinetic schemes applicable to the oxidation of polymers are presented, discussed and analyzed in terms of the underlying kinetic assumptions. For the classic basic autoxidation scheme (BAS), which involves three bimolecular termination steps and is applicable mainly to unstabilized polymers, typical assumptions used singly or in groups include (1) long kinetic chain length, (2) a specific ratio of the termination rate constants and (3) insensitivity to the oxygen concentration (e.g., domination by a single termination step). Steady-state solutions for the rate of oxidation are given in terms of one, two, three, or four parameters, corresponding respectively to three, two, one, or zero kinetic assumptions. The recently derived four-parameter solution predicts conditions yielding unusual dependencies of the oxidation rate on oxygen concentration and on initiation rate, as well as conditions leading to some unusual diffusion-limited oxidation profile shapes. For stabilized polymers, unimolecular termination schemes are typically more appropriate than bimolecular. Kinetics incorporating unimolecular termination reactions are shown to result in very simple oxidation expressions which have been experimentally verified for both radiation-initiated oxidation of an EPDM and thermoxidative degradation of nitrile and chloroprene elastomers.

One emphasis of weapon surety (safety and security) at Sandia National Laboratories is the assessment of fire-related risk to weapon systems. New developments in computing hardware and software make possible the application of a new generation of very powerful analysis tools for surety assessment. This paper illustrates the application of some of these computational tools to assess the robustness of a conceptual firing set design in severe thermal environments. With these assessment tools, systematic interrogation of the parameter space governing the thermal robustness of the firing set has revealed much greater vulnerability than traditional ad hoc techniques had indicated. These newer techniques should be routinely applied in weapon design and assessment to produce more fully characterized and robust systems where weapon surety is paramount. As well as helping expose and quantify vulnerabilities in systems, these tools can be used in design and resource allocation processes to build safer, more reliable, more optimal systems.

A massively-parallel ab initio computer code, which uses Gaussian bases, pseudopotentials, and the local density approximation, permits the study of transition-metal systems with literally hundreds of atoms. We present total energies and relaxed geometries for Ru, Pd, and Ag clusters with N = 55, 135, and 140 atoms; we also used the DMOL code to study 13-atom Pd and Cu clusters, with and without hydrogen. The N = 55 and 135 clusters were chosen because of simultaneous cubo-octahedral (fcc) and icosahedral (icos) sub-shell closings, and we find icos geometries are preferred. Remarkably large compressions of the central atoms are observed for the icos structures (up to 6% compared with bulk interatomic spacings), while small core compressions ({approx} 1 %) are found for the fcc geometry. In contrast, large surface compressive relaxations are found for the fcc clusters ({approx} 2-3% in average nearest neighbor spacing), while the icos surface displays small compressions ({approx} 1%). Energy differences between icos and fcc are smallest for Pd, and for all systems the single-particle densities of states closely resembles bulk results. Calculations with N = 134 suggest slow changes in relative energy with N. Noting that the 135-atom fcc has a much more open surface than the icos, we also compare N = 140 icos and fcc, the latter forming an octahedron with close packed facets. These icos and fcc clusters have identical average coordinations and the octahedron is found to be preferred for Ru and Pd but not for Ag. Finally, we compare Harris functional and LDA energy differences on the N = 140 clusters, and find fair agreement only for Ag.

A prototype sensor fusion framework called the {open_quotes}Knowledge Assistant{close_quotes} has been developed and tested on a gantry robot at Sandia National Laboratories. This Knowledge Assistant guides the robot operator during the planning, execution, and post analysis stages of the characterization process. During the planning stage, the Knowledge Assistant suggests robot paths and speeds based on knowledge of sensors available and their physical characteristics. During execution, the Knowledge Assistant coordinates the collection of data through a data acquisition {open_quotes}specialist.{close_quotes} During execution and postanalysis, the Knowledge Assistant sends raw data to other {open_quotes}specialists,{close_quotes} which include statistical pattern recognition software, a neural network, and model-based search software. After the specialists return their results, the Knowledge Assistant consolidates the information and returns a report to the robot control system where the sensed objects and their attributes (e.g., estimated dimensions, weight, material composition, etc.) are displayed in the world model. This report highlights the major components of this system.

Nuclear cooperation between Argentina and Brazil has been growing since the early 1980`s and as it grew, so did cooperation with the US Department of Energy (DOE). The Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) was formed in December 1991 to operate the Common System of Accounting and Control of Nuclear Materials (SCCC). In April 1994, ABACC and the DOE signed an Agreement of Cooperation in nuclear material safeguards. This cooperation has included training safeguards inspectors, exchanging nuclear material measurement and containment and surveillance technology, characterizing reference materials, and studying enrichment plant safeguards. The goal of the collaboration is to exchange technology, evaluate new technology in Latin American nuclear facilities, and strengthen regional safeguards. This paper describes the history of the cooperation, its recent activities, and future projects. The cooperation is strongly supported by all three governments: the Republics of Argentina and Brazil and the United States.

With increased awareness of the significant changes of the past several years and their effect on the expectations to international safeguards, it is necessary to reflect on the direction for development of nuclear safeguards in a new era and the resulting implications. The time proven monitoring techniques, based on quantitative factors and demonstrated universal application, have shown their merit. However, the new expectations suggest a possibility that a future IAEA safeguards system could rely more heavily on the value of a comprehensive, transparent, and open implementation regime. With the establishment of such a regime, it is highly likely that remote monitoring will play a significant role. Several states have seen value in cooperating with each other to address the many problems associated with the remote interrogation of integrated monitoring systems. As a consequence the International Remote Monitoring Project was organized to examine the future of remote monitoring in International Safeguards. This paper provides an update on the technical issues, the future plans, and the safeguards implications of cooperative programs relating to remote monitoring. Without providing answers to the policy questions involved, it suggests that it is timely to begin addressing these issues.

To support the signal processing and data visualization needs of CTBT related projects at SNL, a MATLAB based GUI was developed. This program is known as MatSeis. MatSeis was developed quickly using the available MATLAB functionality. It provides a time-distance profile plot integrating origin, waveform, travel-time, and arrival data. Graphical plot controls, data manipulation, and signal processing functions provide a user friendly seismic analysis package. In addition, the full power of MATLAB (the premier tool for general numeric processing and visualization) is available for prototyping new functions by end users. This package is being made available to the seismic community in the hope that it will aid CTBT research and will facilitate cooperative signal processing development. 2 refs., 5 figs.

In the field of explosives detection there is currently a need for a calibrated source of explosives vapor. Such a source could be used to test and calibrate explosives detection systems which identify explosives via the collection of vapor or air borne particulate matter. This paper describes the principles of operation and evaluation of one such explosives vapor generator. This generator is based on the diffusion of vapor from a condensed phase (i.e., solid or liquid) in a source reservoir, and the output has been tied to a National Institute of Standards and Technology (NIST) mass standard. We discuss results of the calibration of this generator using the explosives 2,4,6-trinitrotoluene (TNT) and cyclonite (RDX). The mass output of this generator is stable over hundreds of hours of continuous operation, and is adjustable from the low picograms(pg)/sec range to at least 10 nanograms(ng)/sec. In the case of TNT, the mass output correlates well with predictions based on gas phase diffusion theory. In the case of RDX, the agreement with theory is less good. This may be attributable to a variety of factors, possibly including inaccuracies in the published data on RDX vapor pressure as a function of temperature.

A previously-developed approximation to the first integral of the Poisson equation enables one to 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 reproduced the time-dependent voltage-current characteristics of the two extreme cases corresponding to the Lieberman rf sheath theory and the Metze-Ernie-Oskam theory. In this paper the sheath model is connected to the plasma bulk description, and a prescription is given for the ion relaxation time constant, which determines the time-dependent ion impact energy on the electrode surface. It appears that this connected model should be applicable to those high density, low pressure plasmas in which the Debye length is a small fraction of the ion mean free path, which itself is a small fraction of the plasma dimension.

Edge finishing processes have seemed like ideal candidates for automation. Most edge finishing processes are unpleasant, dangerous, tedious, expensive, not repeatable and labor intensive. Estimates place the cost of manual edge finishing processes at 12% of the total cost of fabricating precision parts. For small, high precision parts, the cost of hand finishing may be as high as 305 of the total part cost. Up to 50% of this cost could be saved through automation. This cost estimate includes the direct costs of edge finishing: the machining hours required and the 30% scrap and rework rate after manual finishing. Not included in these estimates are the indirect costs resulting from cumulative trauma disorders and retraining costs caused by the high turnover rate for finishing jobs.. Despite the apparent economic advantages, edge finishing has proven difficult to automate except in low precision and/or high volume production environments. Finishing automation systems have not been deployed successfully in Department of Energy defense programs (DOE/DP) production, A few systems have been attempted but have been subsequently abandoned for traditional edge finishing approaches: scraping, grinding, and filing the edges using modified dental tools and hand held power tools. Edge finishing automation has been an elusive but potentially lucrative production enhancement. The amount of time required for reconfiguring workcells for new parts, the time required to reprogram the workcells to finish new parts, and automation equipment to respond to fixturing errors and part tolerances are the most common reasons cited for eliminating automation as an option for DOE/DP edge finishing applications. Existing automated finishing systems have proven to be economically viable only where setup and reprogramming costs are a negligible fraction of overall production costs.

The US Department of Energy (DOE) and Gosatomnadzor (GAN) of Russia are engaged in a program of cooperation to enhance the nonproliferation of nuclear weapons by developing a strong national system of nuclear material protection, control and accounting (MPC&A). The purpose of this system is to prevent the theft, diversion or unauthorized use of nuclear materials. DOE and GAN signed an agreement to this effect in June 1995. DOE and GAN have since agreed to cooperate in several important areas including: developing regulatory documents; designing a federal material control and accounting (MC&A) information; providing MPC&A equipment for GAN inspectors and assistance in developing Russian equipment; designing an MPC&A oversight information system for GAN; training inspectors and operators; and upgrading MPC&A at six non-Minatom facilities that operate with highly enriched uranium. In order to assist GAN in its ongoing efforts to enhance its national system of nuclear MPC&A, DOE provides GAN with technical assistance in the form of equipment, supplies, training and other services. This paper will describe the program of cooperation between DOE and GAN to further the national security interests of both the United States and Russia. Specifically, it will focus on those mutually beneficial, technically oriented projects that are encompassed in the program. This cooperative effort represents a vital aspect of DOE`s government-to-government program to support Russia`s nonproliferation efforts.

The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the United States without compromising the national security to the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct- use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring system, and discuss the impacts that remote monitoring will have on the national security of participating countries.

Thermal desorption/gas chromatography (TD/GC) was used to screen soil samples on site for total petroleum hydrocarbon (TPH) content during a RCRA Facility Investigation (RFI). It proved to be a rapid, cost- effective tool for detecting non-aromatic mineral oil in soil. The on- site TD/GC results correlated well with those generated at an off- site laboratory for samples analyzed in accordance with EPA Method 418.1.

Photovoltaic (PV) power systems offer the prospect of allowing a utility company to meet part of the daily peak system load using a renewable resource. Unfortunately, some utilities have peak system- load periods that do not match the peak production hours of a PV system. Adding a battery energy storage system to a grid-connected PV power system will allow dispatching the stored solar energy to the grid at the desired times. Batteries, however, pose system limitations in terms of energy efficiency, maintenance, and cycle life. A new control system has been developed, based on available PV equipment and a data acquisition system, that seeks to minimize the limitations imposed by the battery system while maximizing the use of PV energy. Maintenance requirements for the flooded batteries are reduced, cycle life is maximized, and the battery is operated over an efficient range of states of charge. This paper presents design details and initial performance results on one of the first installed control systems of this type.

This report presents the results of laboratory tests conducted on soil core samples obtained prior to an instantaneous profile test conducted west of the Mixed Waste Landfill in Technical Area III. The instantaneous profile test was conducted to measure in situ hydrologic parameters controlling unsaturated flow and contaminant transport in the near - surface vadose zone. Soil core samples from the instantaneous profile test plot were tested in the Sandia National Laboratory`s Environmental Restoration Project Hydrology Laboratory to measure saturated hydraulic conductivity and the relationships between moisture content and soil water tension. Data from laboratory tests and the instantaneous profile field test were then modeled using the computer code RETC to quantify moisture content, soil water tension, and unsaturated hydraulic conductivity relationships. Results content, soil verified that a combination of laboratory and field data yielded a more complete definition of hydrologic properties than either laboratory or field data alone. Results also indicated that at native moisture contents, the potential for significant unsaturated aqueous flow is limited, while at saturated or near - saturated conditions, preferential flow may occur.

Over an extended period of time station noise spectra were collected from various sources for use in estimating the detection and location performance of global networks of seismic stations. As the database of noise spectra enlarged and duplicate entries became available, an effort was mounted to more carefully select station noise spectra while discarding others. This report discusses the methodology and criteria by which the noise spectra were selected. It also identifies and illustrates the station noise spectra which survived the selection process and which currently contribute to the modeling efforts. The resulting catalog of noise statistics not only benefits those who model network performance but also those who wish to select stations on the basis of their noise level as may occur in designing networks or in selecting seismological data for analysis on the basis of station noise level. In view of the various ways by which station noise were estimated by the different contributors, it is advisable that future efforts which predict network performance have available station noise data and spectral estimation methods which are compatible with the statistics underlying seismic noise. This appropriately requires (1) averaging noise over seasonal and/or diurnal cycles, (2) averaging noise over time intervals comparable to those employed by actual detectors, and (3) using logarithmic measures of the noise.

The Explosive Components Facility (ECF) is a major, low-hazard, non-nuclear, research and development facility of the Sandia National Laboratories/Albuquerque (SNL). Sandia Corporation, a subsidiary of Lockheed-Martin, operates this designated User Facility for the Department of Energy (DOE). The ECF consolidates many SNL energetic-materials activities and provides a unique combination of explosive-technologies, neutronic-components, batteries, and weapons-evaluation capabilities. This paper describes the project objectives, the basic building features, programmatic capabilities, and the processes used to beneficially occupy and assess readiness to operate.

The Precision Linear Shaped Charge (PLSC) design concept involves the independent fabrication and assembly of the liner (wedge of PLSC), the tamper/confinement, and explosive. The liner is the most important part of a linear shaped charge (LSC) and should be fabricated by a more quality controlled, precise process than the tamper material. Also, this concept allows the liner material to be different from the tamper material. The explosive can be loaded between the liner and tamper as the last step in the assembly process rather than the first step as in conventional LSC designs. PLSC designs have been shown to produce increased jet penetrations in given targets, more reproducible jet penetration, and more efficient explosive cross-section geometries using a minimum amount of explosive. The Linear Explosive Shaped Charge Analysis (LESCA) code developed at Sandia National Laboratories has been used to assist in the design of PLSCs. LESCA predictions for PLSC jet tip velocities, jet-target impact angles, and jet penetration in aluminum and steel targets are compared to measured data. The advantages of PLSC over conventional LSC are presented. As an example problem, the LESCA code was used to analytically develop a conceptual design for a PLSC component to sever a three-inch thick 1018 steel plate at a water depth of 500 feet (15 atmospheres).

This paper describes high reliability radiation hardened computers built by Sandia for application aboard DOE satellite programs requiring 32 bit processing. The computers highlight a radiation hardened (10 kGy(Si)) R3000 executing up to 10 million reduced instruction set instructions (RISC) per second (MIPS), a dual purpose module control bus used for real-time default and power management which allows for extended mission operation on as little as 1.2 watts, and a local area network capable of 480 Mbits/s. The central processing unit (CPU) is the NASA Goddard R3000 nicknamed the ``Mongoose or Mongoose 1``. The Sandia Satellite Computer (SSC) uses Rational`s Ada compiler, debugger, operating system kernel, and enhanced floating point emulation library targeted at the Mongoose. The SSC gives Sandia the capability of processing complex types of spacecraft attitude determination and control algorithms and of modifying programmed control laws via ground command. And in general, SSC offers end users the ability to process data onboard the spacecraft that would normally have been sent to the ground which allows reconsideration of traditional space-grounded partitioning options.

The continued exploration of Mars is a high priority item with NASA`s interplanetary science community. It has long been a desire of this group to define an experiment that would investigate the possible presence and location of water/ice beneath the Martian surface. Until recently, however, there has not been a flight experiment dedicated to achieving this goal. This paper describes a concept design effort conducted at Sandia National Labs in collaboration with JPL and CalTech that has produced a feasible flight system to investigate this question.

Under acidic sol-gel polymerization conditions, 1,3-bis(triethoxysilyl)-propane (1) and 1,4-bis(triethoxysilyl)butane (2) were shown to preferentially form cyclic disilsesquioxanes 3 and 4 rather than the expected 1,3-propylene- and 1,4-butylene-bridged polysilsesquioxane gels. Formation of 3 and 4 is driven by a combination of an intramolecular cyclization to six and seven membered rings, and a pronounced reduction in reactivity under acidic conditions as a function of increasing degree of condensation. The ease with which these relatively unreactive cyclic monomers and dimers are formed (under acidic conditions) helps to explain the difficulties in forming gels from 1 and 2. The stability of cyclic disilsesquioxanes was confirmed withe the synthesis of 3 and 4 in gram quantities; the cyclic disilsesquioxanes react slowly to give tricyclic dimers containing a thermodynamically stable eight membered siloxane ring. Continued reactions were shown to perserve the cyclic structure, opening up the possibility of utilizing cyclic disilsesquioxanes as sol-gel monomers. Preliminary polymerization studies with these new, carbohydrate-like monomers revealed the formation of network poly(cyclic disilsesquioxanes) under acidic conditions and polymerization with ring-opening under basic conditions.

The goal of this laboratory-directed research and development (LDRD) project was to develop a new and efficient electronic structure algorithm that would scale linearly with system size. Since the start of the program this field has received much attention in the literature as well as in terms of focused symposia and at least one dedicated international workshop. The major success of this program is the development of a unique algorithm for minimization of the density functional energy which replaces the diagonalization of the Kohn-Sham hamiltonian with block diagonalization into explicit occupied and partially occupied (in metals) subspaces and an implicit unoccupied subspace. The progress reported here represents an important step toward the simultaneous goals of linear scaling, controlled accuracy, efficiency and transferability. The method is specifically designed to deal with localized, non-orthogonal basis sets to maximize transferability and state by state iteration to minimize any charge-sloshing instabilities and accelerate convergence. The computational demands of the algorithm do scale as the particle number, permitting applications to problems involving many inequivalent atoms. Our targeted goal is at least 10,000 inequivalent atoms on a teraflop computer. This report describes our algorithm, some proof-of-principle examples and a state of the field at the conclusion of this LDRD.

Accident source terms, source term probabilities, consequences, and risks are developed for ship collisions that might occur in U.S. ports during the shipment of spent fuel from foreign research reactors to the United States in break-bulk freighters.

This paper presents a comparison of calculations of severe accident progression for several postulated accident sequences for representative Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR) nuclear power plants performed with the MELCOR 1.8.3 and the MAAP4 computer codes. The PWR system examined in this study is a 1100 MWe system similar in design to a Westinghouse 3-loop plant with a large dry containment; the BWR is a 1100 MWe system similar in design to General Electric BWR/4 with a Mark I containment. A total of nine accident sequences were studied with both codes. Results of these calculations are compared to identify major differences in the timing of key events in the calculated accident progression or other important aspects of severe accident behavior, and to identify specific sources of the observed differences.

The topics covered in this session include: slimhole testing and data acquisition, theoretical and numerical models for slimholes, and an overview of the analysis of slimhole data acquired by the Japanese. The fundamental issues discussed are concerned with assessing the efficacy of slimhole testing for the evaluation of geothermal reservoirs. the term reservoir evaluation is here taken to mean the assessment of the potential of the geothermal reservoir for the profitable production of electrical power. As an introduction to the subsequent presentations and discussions, a brief summary of the more important aspects of the use of slimholes in reservoir evaluation is given.

Converting a large, heterogeneous, networked, environment to ATM (Asynchronous Transfer Mode) can yield many benefits. Before these benefits can be reaped, however, numerous decisions must be made and implemented. This paper presents a case study which describes the steps that were necessary to convert a backbone network at Sandia National Laboratories in Albuquerque, New Mexico to ATM. It presents each step by explaining its importance and what options were considered along with their tradeoffs. It is hoped that organizations contemplating converting to ATM will have a better understanding of how the transition is implemented after reading this paper.

A study using long-period seismic data showed that seismic events can be detected and located based on correlations of processed waveform profiles with the profile expected for an event. In this technique both time and space are discretized and events are found by forming profiles and calculating correlations for all time-distance points. events are declared at points with large correlations. In the first phase of the Waveform Correlation Event Detection System (WCEDS) Project at Sandia Labs we have developed a prototype automatic event detection system based on Shearer`s work which shows promise for treaty monitoring applications. Many modifications have been made to meet the requirements of the monitoring environment. A new full matrix multiplication has been developed which can reduce the number of computations needed for the data correlation by as much as two orders of magnitude for large grids. New methodology has also been developed to deal with the problems caused by false correlations (sidelobes) generated during the correlation process. When an event has been detected, masking matrices are set up which will mask all correlation sidelobes due to the event, allowing other events with intermingled phases to be found. This process is repeated until a detection threshold is reached. The system was tested on one hour of Incorporated Research Institutions for Seismology (IRIS) broadband data and built all 4 of the events listed in the National Earthquake Information Center (NEIC) Preliminary Determination of Epicenters (PDE) which were observable by the IRIS network. A continuous execution scheme has been developed for the system but has not yet been implemented. Improvements to the efficiency of the code are in various stages of development. Many refinements would have to be made to the system before it could be used as part of an actual monitoring system, but at this stage we know of no clear barriers which would prevent an eventual implementation of the system.

For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

A set of model interface guidelines, called MIG, is presented as a means by which any compliant numerical material model can be rapidly installed into any parent code without having to modify the model subroutines. Here, {open_quotes}model{close_quotes} usually means a material model such as one that computes stress as a function of strain, though the term may be extended to any numerical operation. {open_quotes}Parent code{close_quotes} means a hydrocode, finite element code, etc. which uses the model and enforces, say, the fundamental laws of motion and thermodynamics. MIG requires the model developer (who creates the model package) to specify model needs in a standardized but flexible way. MIG includes a dictionary of technical terms that allows developers and parent code architects to share a common vocabulary when specifying field variables. For portability, database management is the responsibility of the parent code. Input/output occurs via structured calling arguments. As much model information as possible (such as the lists of required inputs, as well as lists of precharacterized material data and special needs) is supplied by the model developer in an ASCII text file. Every MIG-compliant model also has three required subroutines to check data, to request extra field variables, and to perform model physics. To date, the MIG scheme has proven flexible in beta installations of a simple yield model, plus a more complicated viscodamage yield model, three electromechanical models, and a complicated anisotropic microcrack constitutive model. The MIG yield model has been successfully installed using identical subroutines in three vectorized parent codes and one parallel C++ code, all predicting comparable results. By maintaining one model for many codes, MIG facilitates code-to-code comparisons and reduces duplication of effort, thereby reducing the cost of installing and sharing models in diverse new codes.

This report provides a study of gases in microporous solids using molecular modeling. The theory of gas transport in porous materials as well as the molecular modeling literature is briefly reviewed. Work complete is described and analyzed with retard to the prevailing theory. The work covers two simple subjects, construction of porous solid models and diffusion of He, H{sub 2}, Ar and CH{sub 4} down a pressure gradient across the material models as in typical membrane permeation experiments. The broader objective is to enhance our capability to efficiently and accurately develop, produce and apply microporous materials.

A new class of inorganic ion exchange material called crystalline silicotitanates (CST) has been developed for radioactive waste treatment in a collaborative effort between Sandia National Laboratories and Texas A&M University. The Sandia National Laboratories Laboratory Directed Research and Development program provided the initial funding for this effort and this report summarizes the rapid progress that was achieved. A wide range of compositions were synthesized, evaluated for cesium (Cs) removal efficiency, and a composition called TAM-5 was developed that exhibits high selectivity and affinity for Cs and strontium (Sr). Tests show it can remove parts per million concentrations of Cs{sup +} from highly alkaline, high-sodium, simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. In experiments with solutions that simulate highly alkaline Hanford defense wastes, the crystalline silicotitanates exhibit distribution coefficients for Cs{sup +} of greater than 2,000 ml/g, and distribution coefficients greater than 10,000 ml/g for solutions adjusted to a pH between 1 and 10. In addition, the CSTs were found to exhibit distribution coefficients for Sr{sup +} greater than 100,000 ml/g and for plutonium of 2,000 ml/g from simulated Hanford waste. The CST crystal structure was determined and positions of individual atoms identified using x-ray and neutron diffraction. The structural information has permitted identification of the ion exchange sites and provided insights into the strong effect of pH on Cs ion exchange. Information on the synthesis, composition, and structure of CST is considered proprietary and is not discussed in this report.

Groundwater in and around underground radioactive waste repositories has several potential effects on repository performance. Repository excavation produces conditions where the repository is underpressured relative to the surrounding host rock, resulting in groundwater inflow to the repository. The presence of groundwater has been shown to enhance gas generation from emplaced waste forms, which expedites repository pressurization. Repository pressurization results in an increased driving force for dissolved radionuclide movement away from the repository. Repository excavation also produces a zone surrounding the repository having disturbed hydrologic and geochemical properties. Within the disturbed rock zone (DRZ), intrinsic permeability and porosity change over time due to the formation of microfractures and grain boundary dilation. Additionally, elastic and inelastic changes in pore volume may cause variation in the near-field fluid pressure and fluid saturation distributions that influence groundwater flow toward the repository excavation. Increased permeability, decreased pore-fluid pressure, and partially saturated conditions in the DRZ contribute to enhancing potential release pathways away from the repository. It is important for a repository performance assessment to consider chemical processes, hydrologic processes, as well as the complex coupling between these processes.

We have investigated tailoring damage effects of explosive devices by addition of unconventional materials, specifically combustible metals. Initial small-scale as well as full-scale testing has been performed. The explosives functioned to disperse and ignite these materials. Incendiary, enhanced-blast, and fragment-damage effect have been identified. These types of effects can be used to extend the damage done to hardened facilities. In other cases it is desirable to disable the target with minimal collateral damage. Use of unconventional materials allows the capability to tailor the damage and effects of explosive devices for these and other applications. Current work includes testing of an incendiary warhead for a penetrator.

This paper outlines the use of a failure modes and effects analysis for the safety assessment of a robotic system being developed at Sandia National Laboratories. The robotic system, the weigh and leak check system, is to replace a manual process for weight and leakage of nuclear materials at the DOE Pantex facility. Failure modes and effects analyses were completed for the robotics process to ensure that safety goals for the systems have been met. Due to the flexible nature of the robot configuration, traditional failure modes and effects analysis (FMEA) were not applicable. In addition, the primary focus of safety assessments of robotics systems has been the protection of personnel in the immediate area. In this application, the safety analysis must account for the sensitivities of the payload as well as traditional issues. A unique variation on the classical FMEA was developed that permits an organized and quite effective tool to be used to assure that safety was adequately considered during the development of the robotic system. The fundamental aspects of the approach are outlined in the paper.

Since 1978, Sandia National Laboratories has provided training courses in the systematic design of Physical Protection Systems (PPS). One such course, the International Training Course (TC) on the Physical Protection of Nuclear Facilities and Materials, is sponsored by the Department of Energy`s International Safeguards Division , the International Atomic Energy Agency, and the Department of State. Since 1978, twelve 3- and 4-week classes have been conducted by Sandia for these sponsors. One- and two-week adaptations of this course have been developed for other customers, and, since 1994, nine of these abbreviated courses have been presented in the Russian language to participants from the Former Soviet Union (SU). These courses have been performed in support of the Department of Energy`s program on Material Protection, Control and Accounting (MPC&A) for the Russian Federation and the Newly Independent States. MPC&A physical protection training assumes participants have more narrowly defined backgrounds. In using affective approaches, the overall goal of training in the context of the MPC&A Program is to develop modern and effective, indigenous capabilities for physical protection system design and analysis within the SU. This paper contrasts the cognitive and affective approaches to training and indicates why different approaches are required for the ITC and the MPC&A Programs.

A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.

One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs.

Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Sandia National Laboratories Environmental Restoration Technologies Department is developing environmental restoration technologies through funding form the US Department of Energy`s (DOE`s) Office of Science and Technology. Initially, this technology development has been through the Mixed Waste Landfill Integrated Demonstration (MWLID). It is currently being developed through the Contaminant Plume containment and Remediation Focus Area, the Landfill Stabilization Focus Area, and the Characterization, Monitoring, and Sensor Cross-Cutting Program. This Technology Integration Project (TIP) was responsible for transferring MWLID-developed technologies for routine use by environmental restoration groups throughout the DOE complex and commercializing these technologies to the private sector. The MWLID`s technology transfer/commercialization successes were achieved by involving private industry in development, demonstration, and technology transfer/commercialization activities; gathering and disseminating information about MWLID activities and technologies; and promoting stakeholder and regulatory involvement. From FY91 through FY95, 30 Technical Task Plans (TTPs) were funded. From these TTPs, the MWLID can claim 15 technology transfer/commercialization successes. Another seven technology transfer/commercialization successes are expected. With the changeover to the focus areas, the TIP continued the technology transfer/commercialization efforts begun under the MWLID.

The analysis of component fatigue lifetime for a wind energy conversion system (WECS) requires that the component load spectrum be formulated in terms of stress cycles. Typically, these stress cycles are obtained from time series data using a cycle identification scheme. As discussed by many authors, the matrix or matrices of cycle counts that describe the stresses on a turbine are constructed from relatively short, representative samples of time series data. The ability to correctly represent the long-term behavior of the distribution of stress cycles from these representative samples is critical to the analysis of service lifetimes. Several techniques are currently used to convert representative samples to the lifetime cyclic loads on the turbine. There has been recently developed a set of fitting algorithms that is particularly useful for matching the body of the distribution of fatigue stress cycles on a turbine component. Fitting techniques are now incorporated into the LIFE2 fatigue/fracture analysis code for wind turbines. In this paper, the authors provide an overview of the fitting algorithms and describe the pre- and post-count algorithms developed to permit their use in the LIFE2 code. Typical case studies are used to illustrate the use of the technique.

A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log{sub 10} saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs.

A folded compact range configuration has been developed ant the Sandia National Laboratories` compact range antenna and radar-cross- section measurement facility as a means of performing indoor, environmentally-controlled, far-field simulations of synthetic aperture radar (SAR) measurements of distributed target samples (i.e. gravel, sand, etc.). The folded compact range configuration has previously been used to perform coherent-change-detection (CCD) measurements, which allow disturbances to distributed targets on the order of fractions of a wavelength to be detected. This report describes follow-on CCD measurements of other distributed target samples, and also investigates the sensitivity of the CCD measurement process to changes in the relative spatial location of the SAR sensor between observations of the target. Additionally, this report describes the theoretical and practical aspects of performing interferometric inverse-synthetic-aperture-radar (IFISAR) measurements in the folded compact range environment. IFISAR measurements provide resolution of the relative heights of targets with accuracies on the order of a wavelength. Several examples are given of digital height maps that have been generated from measurements performed at the folded compact range facility.

In the manufacture of printed wiring boards (PWB), plasma etchback and desmear processes facilitate the making of good mechanical and electrical bonds of copper inner layers to copper plating. Without sufficient plasma treatment, internal layer copper features receive inadequate polymer removal which results in circuit discontinuity during the plating process. Additionally, the plasma serves to roughen the polymer wall of drilled holes which improves copper adhesion. To ensure proper plasma treatment, careful adherence to strict production guidelines is essential. These guidelines include attention to several critical criteria in placement, pretreatment and treatment of the PWBs during the plasma process; process verification via post plasma testing; and careful process monitoring throughout. In this brief, some guidelines for process monitoring and control will be discussed. A description of a new plasma monitor utilizing optical emission spectroscopy (OES), developed cooperatively between Sandia National Laboratories, National Consortium for Manufacturing Sciences (NCMS) and Texas Instruments Inc., will be discussed along with possible benefits derived from in situ monitoring of plasma systems.

This information package was prepared for both new and experienced users of the SPHINX (Short Pulse High Intensity Nanosecond X-radiator) flash X-Ray facility. It was compiled to help facilitate experiment design and preparation for both the experimenter(s) and the SPHINX operational staff. The major areas covered include: Recording Systems Capabilities,Recording System Cable Plant, Physical Dimensions of SPHINX and the SPHINX Test cell, SPHINX Operating Parameters and Modes, Dose Rate Map, Experiment Safety Approval Form, and a Feedback Questionnaire. This package will be updated as the SPHINX facilities and capabilities are enhanced.

This paper is the first step in the resolution of the direct containment heating (DCH) issue for the Zion nuclear power plant using the risk oriented accident analysis methodology (ROAAM). This paper includes the definition of a probabilistic framework that decomposes the DCH problem into three probability density functions that reflect the most uncertain initial conditions (UO2 mass, zirconium oxidation fraction, and steel mass). Uncertainties in the initial conditions are significant, but our quantification approach is based on establishing reasonable bounds that are not unnecessarily conservative. To this end, we also make use of the ROAAM ideas of enveloping scenarios and 'splintering'. Two causal relations (CRs) are used in this framework: CR1 is a model that calculates the peak pressure in the containment as a function of the initial conditions, and CR2 is a model that returns the frequency of containment failure as a function of pressure within the containment. Uncertainty in CR1 is accounted for by the use of two independently developed phenomenological models, the convection-limited containment heating model and the two-cell equilibrium model, and by probabilistically distributing the key parameter in both, which is the ratio of the melt entrainment time to the system blowdown time constant. The two phenomenological models have been compared with an extensive database including recent integral simulations at two different physical scales (1:10-scale in the Surtsey facility at Sandia National Laboratories and 1:40-scale in the COREXIT facility at Argonne National Laboratory). The loads predicted by these models were significantly lower than those from previous parametric calculations. The containment load distributions do not intersect the containment strength (fragility) curve in any significant way, resulting in containment failure probabilities less than 10-3 for all scenarios considered. Sensitivity analyses did not show any areas of large sensitivity. The feasibility of extrapolating containment loads distributions to most other pressurized water reactors is explored.

The use of hydrous titanium oxide (HTO) ion-exchange materials as supports for iron and chromium based dehydrogenation catalysts is compared to current commercial catalyst systems in order to determine the potential of HTO technology for impacting this important chemical processing area. The best Fe/HTO catalysts synthesized to date achieve ethylbenzene conversions to styrene approaching those of commercial catalysts, even though the Fe/HTO catalysts contain no promoters while the commercial catalysts contain several different promoters, including K, Cr, and Ce. Addition of promoters to Fe/HTO catalyst is expected to result in further conversion improvements such that the activity of the commercial catalysts may be equaled or exceeded. Fe/HTO and Cr/HTO catalysts achieve only modest conversions of isobutane to isobutene that are far below available commercial catalysts. With the Cr/HTO catalysts, however, activity normalized to Cr loading far exceeds that of the commercial catalyst. Since optimum Cr loading conditions have not yet been identified, there is ample room for increases in both Cr loading and catalyst activity. Even if Cr/HTO and Fe/HTO catalysts do not ultimately exceed the performance obtained with commercial catalysts, the ability to cast HTO materials in the form of thin films may present important advantages for catalytic membrane reactor systems. These potential advantages are discussed and evaluated.

The Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan and the US Department of Energy (DOE) are cooperating on the development of a remote monitoring system for nuclear nonproliferation efforts. This cooperation is part of a broader safeguards agreement between PNC and DOE. A remote monitoring system is being installed in a spent fuel storage area at PNC`s experimental reactor facility Joyo in Oarai. The system has been designed by Sandia National Laboratories (SNL) and is closely related to those used in other SNL remote monitoring projects. The Joyo project will particularly study the unique aspects of remote monitoring in contribution to nuclear nonproliferation. The project will also test and evaluate the fundamental design and implementation of the remote monitoring system in its application to regional and international safeguards efficiency. This paper will present a short history of the cooperation, the details of the monitoring system and a general schedule of activities.

A double quantum well (QW) subject to in-plane magnetic fields B∥ has the dispersion curves of its two QWs shifted in k-space. When the QWs are strongly coupled, an anticrossing and partial energy gap occur, yielding a tunable multi-component Fermi surface. We report measurements of the resultant features in the conductance, the capacitive density of states and giant deviations in the cyclotron effective masses.

As a part of the International Remote Monitoring Project, during March 1995, a Remote Monitoring System (RMS) was installed at the Embalse Nuclear Power Station in Embalse, Argentina. This system monitors the status of four typical Candu spent fuel dry storage silos. The monitoring equipment for each silo consists of analog sensors for temperature and gamma radiation measurement; digital sensors for motion detection; and electronic fiber-optic seals. The monitoring system for each silo is connected to a wireless Authenticate Item Monitoring System (AIMS). This paper describes the operation of the RMS during the first year of the trial and presents the results of the signals reported by the system compared with the on site inspections conducted by the regulatory bodies, ABACC, IAEA, ENREN. As an additional security feature, each sensor periodically transmits authenticated State-of-Health (SOH) messages. This feature provides assurance that all sensors are operational and have not been tampered with. The details of the transmitted information and the incidents of loss of SOH, referred to as Missing SOH Event, and the possible causes which produced the MSOHE are described. The RMS at the embalse facility uses gamma radiation detectors in a strong radiation field of spent fuel dry storage silos. The detectors are Geiger Muller tubes and Silicon solid state diodes. The study of the thermal drift of electronics in GM detectors and the possible radiation damage in silicon detectors is shown. Since the initial installation, the system has been successfully interrogated from Buenos Aires and Albuquerque. The experience gained, and the small changes made in the hardware in order to improve the performance of the system is presented.

In applications where multiple magnetic modulators are used to drive a single Linear Induction Voltage Adder (LIVA) or Linear Accelerator (LINAC), it is essential that the outputs of the modulators be synchronized. Output rise times are typically in the 10 ns to 20 ns range, often making it necessary to synchronize to within less than 1 ns. Microprocessor and electronic feedback schemes have been developed and demonstrated that achieve the required level of synchronization, however, they are sophisticated and potentially complex. In a quest for simplicity, this work seeks to determine the achievable level of modulator to modulator timing jitter that can be obtained with simple design practices and passive techniques. Sources of output pulse time jitter in magnetic modulators are reviewed and some basic modulator design principles that can be used to minimize the intrinsic time jitter between modulators are discussed. A novel technique for passive synchronization is presented.

Pulsed power offers and efficient, high energy, economical source of x-rays for inertial confinement fusion (ICF) research. We are pursuing two main approaches to ICF driven with pulsed power accelerators: intense light ion beams and z-pinches. This paper describes recent progress in each approach and plans for future development.

Risks in software systems arise from many directions. There are risks that the software is faulty, that the system may be attacked, that safety hazards exist, that the system may be inoperable or untimely, that an abnormal event may cause unexpected actions, etc. Risk analysis tools should support and document risk-mitigation decisions and facilitate understanding of residual risks. These tools must be based on a sound theory of risk, which does not exist today. Probabilistic risk assessment techniques apply to physically-based systems where failure modes and event dependence are fairly well understood. But they cannot be blindly applied to software systems, which do not share these characteristics. Moreover, we need to meld many diverse aspects of risk for software systems. This presentation will explore some thought-provoking ideas about modeling, problem spaces, solution approaches, math, decision friendly output, and the role of risk analysis in the software lifecycle.

The purpose of the Programmatic Risk Management System (PRMS) is to evaluate and manage potential risks associated with proposed projects (i.e., new products or processes, or possible research and technological development projects). Although the PRMS considers some technical aspects of risk, the primary focus of the methodology is programmatic risk. That is, the methodology permits an assessment of risks associated with such issues as the ability to successfully produce a product that performs in accordance with all customer requirements, and the availability and allocation of resources (money, equipment, facilities, skilled personnel). The PRMS process consists of five formalized activities that are essential for effective management of risks associated with proposed projects. These activities include risk assessment, development of appropriate risk mitigation strategies, estimating strategy implementation cost, ranking of risk mitigation strategies for resource allocation, and scheduling of strategy implementing. The PRMS utilizes a ranking system that allows the user to identify the most cost-effective investment of resources of minimizing risk.

Cl{sub 2}+Ar Reactive-Ion-Beam Etching is demonstrated for anisotropic, low-damage etching of InAlGaAs semiconductor alloys for use as optical transmission modulators at 1.32 {mu}m wavelength.

Two thin-walled Al tubes were filled with epoxy which were cured isothermally; one tube was instrumented with strain gauges, and the other with thermocouples. Finite element codes were used. Predicted and measured centerline hoop strains are shown; predictions and measurements agree. This is being applied to encapsulated components.

The primary research objective of the work described here is to design, synthesize, and characterize new materials for use as chemical sensor interfaces, integrate these materials, using appropriate transducers, into sensor arrays, and then develop appropriate mathematical algorithms for interpreting the array response. In this paper, we will discuss two new types of materials we have developed that are ideally suited for use as chemically sensitive interfaces for array-based chemical sensing applications, since they: (1) provide general specificity towards classes of functional groups rather than individual compounds; (2) are intermediate in structure between monolayers and polymers; (3) exhibit both endo- and exo-recognition. The first class of materials is surface-confined dendrimers and the second is hyperbranched polymers.

We have studied the different driving forces behind syneresis in MTES/TEOS gels by aging them in different H{sub 2}O/EtOH pore fluids. We show using shrinkage, density, contact angle, and N{sub 2} sorption measurements, the influence of gel/solvent interactions on the microstructural evolution during drying. Competing effects of syneresis (that occurs during aging) and drying shrinkage resulted in the overall linear shrinkage of the organically modified gels to be constant at {approximately}50%. Increasing the hydrophobicity of the gels caused the driving force for syneresis to change from primarily condensation reactions to a combination of condensation and solid/liquid interfacial energy. In addition the condensation driven shrinkage was observed to be irreversible, whereas the interfacial free energy driven shrinkage was observed to be partially reversible. Nitrogen sorption experiments show that xerogels with the same overall extent of shrinkage can have vastly different microstructures due to the effects of microphase separation.

Solar dish/Stirling systems using sodium heat pipe receivers are being developed by industry and government laboratories here and abroad. The unique demands of this application lead to heat pipe wicks with very large surface areas and complex three-dimensional flow patterns. These characteristics can enhance the mass transport and concentration of constituents of the wick material, resulting in wick corrosion and plugging. As the test times for heat pipe receivers lengthen, we are beginning to see these effects both indirectly, as they affect performance, and directly in post-test examinations. We are also beginning to develop corrective measures. In this paper, we report on our test experiences, our post-test examinations, and on our initial effort to ameliorate various problems.

A unifying framework is developed for the analysis of brittle materials. Heretofore diverse classes of models result from different choices for unspecified coefficient and distribution functions in the unified theory. Material response is described in terms of expectation integrals of transverse symmetry tensors. First, a canonical body containing cracks of all the same orientation is argued to possess macroscopic transverse isotropy. An orthogonal basis for the linear subspace consisting of all double-symmetric transversely-isotropic fourth-order tensors associated with a given material vector is introduced and applied to deduce the explicit functional dependence of the compliance of such contrived materials on the shared crack orientation. A principle of superposition of strain rates is used to write the compliance for a more realistic material consisting of cracks of random size and orientation as an expectation integral of the transverse compliance for each orientation times the joint distribution function for the size and orientation. Utilizing an evolving (initially exponential) size- dependence in the joint distribution, the general theory gives unprecedented agreement with measurements of the dynamic response of alumina to impact loading, especially upon release where the calculations predict the development of considerable deformation- induced anisotropy, challenging the conventional notion of shocks as isotropic phenomena.

This paper describes the design, implementation and performance of a port of the Argonne National Laboratory/Mississippi State University MPICH implementation of the Message Passing Interface standard to the Cray T3D massively parallel processing system. A description of the factors influencing the design and the various stages of implementation are presented. Performance results revealing superior bandwidth and comparable latency as compared to other full message passing systems on the T3D are shown. Further planned improvements and optimizations, including an analysis of a port to the T3E, are mentioned.

Development of this pyrotechnic occurred because of the need for a static insensitive material to meet personnel safety requirements and related system safety issues in nuclear weapon energetic material component designs. Ti subhydride materials are made by the thermal dehydrding of commercial Ti hydride powder to the desired equivalent hydrogen composition in the Ti lattice. These Ti subhydrides, when blended with K perchlorate, meet the static insensitivity requirement of not being initiated from an equivalent human body electrostatic discharge. Individual material and blend qualification requirements provide a reproducible material from lot to lot. These pyrotechnic formulations meet the high reliability requirements (0.9995) for initiation and performance parameters and have the necessary stability and compatibility to meet long lived requirements of more than 25 years. Various experiences and problems are also discussed that have led to a mature technology for Ti subhydride/K perchlorate during its use in energetic material component designs.

SmartWeld is a concurrent engineering system that integrates product design and processing decisions within an electronic desktop engineering environment. It is being developed to provide designers, process engineers, researchers and manufacturing technologists with transparent access to the right process information, process models, process experience and process experts, to realize``right the first time`` manufacturing. Empirical understanding along with process models are synthesized within a knowledge-based system to identify robust fabrication procedures based on cost, schedule, and performance. Integration of process simulation tools with design tools enables the designer to assess a number of design and process options on the computer rather than on the manufacturing floor. Task models and generic process models are being embedded within user friendly GUI`s to more readily enable the customer to use the SmartWeld system and its software tool set without extensive training. The integrated system architecture under development provides interactive communications and shared application capabilities across a variety of workstation and PC-type platforms either locally or at remote sites.

Compared to other metrology approaches, electrical test structures for the measurement of dimensional characteristics such as linewidth and overlay directly relate to the electrical performance of the circuits being fabricated. The inherent disadvantage of electrical techniques is that they can be applied only to the extraction of the dimensions of features patterned in electrically-conducting materials. They can not be directly applied to patterned resist films or dielectric material layers. In the case of narrow on-wafer features patterned in resist, for example, linewidths are preferably extracted by electron-beam methods. These methods are sufficiently repeatable for monitoring fabrication-process variations. However, the traceability of the units in which linewidth is expressed is thwarted by the unavailability of suitable calibration artifacts. In the case of overlay metrology, the same limitations as regards electrical conduction apply. However, similar advantages accrue in principle to electrical overlay methods when they can be utilized. It is the electrical quality of the overlay of a conducting via relative to underlying or overlying conducting material which is of driving importance for circuit functionality. This may differ from the overlay values extracted from the same patterns by commonly-used optical overlay tools. Further refinements in the state of the art in both electrical linewidth and electrical overlay metrologies are desirable as feature sizes and spacings continue to shrink in emerging generations of devices. This paper discusses some recent innovations which have been recently introduced and indicates new roles for electrical metrology in low-cost certification of reference materials for both linewidth and overlay applications.

Dynamic compaction of mine-run salt is being investigated for the Waste Isolation Pilot Plant (WIPP), where compacted salt is being considered for repository sealing applications. One large-scale and two intermediate-scale dynamic compaction demonstrations were conducted. Initial fractional densities of the compacted salt range form 0.85 to 0.90, and permeabilities vary. Dynamically-compacted specimens were further consolidated in the laboratory by application of hydrostatic pressure. Permeability as a function of density was determined, and consolidation microprocesses were studied. Experimental results, in conjunction with modeling results, indicate that the compacted salt will function as a viable seal material.

As part of the demonstration of compliance with federal regulations, a shaft seal system has been designed for the Waste Isolation Pilot Plant. The system completely fills the 650 m shafts with components consisting of the common engineering materials, each of which possesses low permeability, longevity, and can be constructed using available technology. Design investigations couple rock mechanics and fluid flow analysis and tests of these materials within the natural geological setting, and demonstrate the effectiveness of the design.

Because many of the phenomenologically based codes used to support risk assessments require lone execution times, it is important to have a rationally based means for optimizing the choice of parameter values that are input to the code calculations. For this reason, we have developed a method for intelligently searching the space of parameter values to deduce, with as few computations as possible, the values that are most likely to lead to high risk. We have applied the method to a problem involving electrical initiation of an explosive due to the response of the system to fires. We have shown that our method can locate potential risk vulnerabilities with far fewer time-consuming physical response computations than would be necessary using standard sampling approaches.