Publications

Researchers around the world have demonstrated the effectiveness of titanium dioxide-based photocatalysis for decontaminating water containing hazardous organics and heavy metals. A great advantage of this process is that the organic is completely destroyed, leaving behind only water, carbon dioxide and dilute mineral acids. Also, the process has potential for doing two decontamination jobs at once: oxidizing organics while reducing toxic metals. As part of a program sponsored by the DOE, Sandia National Laboratories is carrying out large-scale tests to study the solar destruction of organics at realistic processing rates in addition to laboratory work aimed at determining the applicability of solar detoxification to the removal of heavy metals. In this paper, we present up-to-date results from Sandia's effort. The large-scale tests illustrate the effectiveness of solar detoxification for a variety of organics and compare measured reaction rates against published values of the rate constants for attack by aqueous hydroxyl radicals. This comparison highlights the importance of hydroxyl radical chemistry in solar detoxification processes. It is concluded that solar detoxification is only feasible for easily destroyed compounds like TCE, and PCE. The chlorinated methanes and ethanes are much more difficult to destroy and require very large solar collectors. In the second part of the paper, laboratory data are presented for a variety of different metals, including Ag, Cd, Cu, Hg, Ni, and Pt. The concentration of dissolved oxygen is one of the variables in the study. It is shown that the presence of dissolved metals can have a profound effect on organic oxidation rate, and that oxygen is not necessarily required for oxidation to occur. It is concluded that solar detoxification would be useful for removing mercury and silver but not for copper, nickel nor cadmium. 38 refs., 7 figs., 2 tabs.

Titanium dioxide (TiO{sub 2}) is a photocatalyst for solar detoxification of water containing organic contaminants such as solvents, PCB's, dioxins, pesticides, and dyes. Unfortunately, the ultraviolet (UV) energy used by TiO{sub 2} ({lambda}<400 nm) only comprises about 4% of the solar spectrum. One way of enhancing the efficiency of solar detoxification technologies is to utilize a larger portion of the solar spectrum to initiate the Tio{sub 2}- catalyzed detoxification chemistry. Metalloporphyrins strongly absorb visible and near infrared radiation. By utilization of a process called photosensitization, adsorption of these dyes onto TiO{sub 2} can enable a much broader portion of the solar spectrum to be used. Photosensitization relies upon the ability of the dye molecule to absorb more of the solar energy than bare TiO{sub 2} and to interact electronically with the TiO{sub 2} surface in such a way as to initiate TiO{sub 2}-based redox photochemistry using the dye-absorbed energy. 16 refs., 7 figs.

This document contains planned actions to correct the deficiencies identified in the Pre-Tiger Team Self-Assessment (PTTSA), January 1991, of Sandia National Laboratories (SNL -- Albuquerque, New Mexico; Tonopah, Nevada; and Kauai, Hawaii). The Self-Assessment was conducted by a Self-Assessment Working Group consisting of 19 department managers, with support from Environment, Safety, and Health (ES H) professionals, from October through December 1990. Findings from other past audits, dating back to 1985, were reviewed and compared with the PTTSA findings to determine if additional findings, key findings, or root causes were warranted. The resulting ES H Action Plan and individual planned actions were prepared by the ES H Action Plan Project Group with assistance from the Program owners/authors during February and March 1991. The plan was reviewed by SNL Management in April 1991. This document serves as a planning instrument for the Laboratories to aid in the scoping and sizing of activities related to ES H compliance for the coming five years. It will be modified as required to ensure a workload/funding balance and to address the findings resulting from the Tiger Team assessment at SNL, Albuquerque. The process of producing this document has served well to prepare SNL, Albuquerque, for the coming task of producing the required post-Tiger Team action plan document. 8 tabs.

The degree of oxidation of drops of aluminum metal was investigated parametrically for a range of melt diameters, relative melt-water velocities, melt temperatures, water temperatures, and ambient pressures using a combined film boiling-metal oxidation model. The model predictions of degree of oxidation were then compared to small-scale experiments involving molten drops of aluminum metal. The conclusions were, first, that for the range of melt temperatures and diameters considered, if an oxide layer forms and blankets the molten aluminum, then no significant oxidation occurs, in agreement with the results of experiments performed under quiescent, steady-state conditions. Second, comparing model results to data from single drop fragmentation experiments indicates that under the transient conditions occurring during rapid fragmentation, the oxide layer is disturbed and oxidation rates are limited primarily by the amount of steam available at the melt surface. Third, for a range of parameters, the heat gain in the melt drop from the oxidation reaction can exceed the heat loss to the surroundings, resulting in thermal runaway and ignition of the melt. This effect is observed experimentally as a threshold temperature effect, predicted to be about 1100 K for the initial single drop study, and between 1500 K and 1600 K for the single drop experiments. 7 refs., 2 tabs.

It is shown that preirradiation channel-mobility and 1/f-noise measurements can reveal a great deal about postirradiation interface- and oxide-trap charge buildup in MOS transistors. A model is developed to explain the observed correlations. 10 refs., 4 figs.

The effectiveness of hardening the SA3300 against SEU using design and design-plus-resistor approaches is presented. The full performance and SEU tolerance requirements are met using R{sub fb} {le} 160 k{Omega}. Lumped-parameter circuit simulations are used to analyze results. 10 refs., 5 figs.

The chemical synthesis of advanced ceramic and glass materials by the sol-gel process has become an area of increasing activity in the field of material science. The sol-gel process provides a means to prepare homogeneous, high purity materials with tailored chemical and physical properties. This paper surveyed the nuclear magnetic resonance (NMR) studies of silicon-based sol-gel kinetics. A review of the various models which have been used to analyze the chemical kinetics of various sol-gel systems was presented. The utility of NMR spectroscopy was demonstrated in investigating the influence that various reaction conditions have on the reaction pathways by which sol-gel derived materials are synthesized. By observing in a direct fashion the chemical pathway of the sol-gel, it is often possible to relate the final properties of the material to the formulation and reaction conditions of the sol-gel. The study of reaction kinetics by NMR is expected to play an increasingly important role in understanding sol-gel processing and material properties. 15 refs. (DP)

The durability of a carbon-carbon composite, Aerolor A05, X-point divertor dump plate to thermal fatigue was evaluated for the Joint European Torus (JET) at Sandia's Plasma Material Test Facility. Of primary interest was the effect of thermal cycling on the carbon-carbon threads of the bolted attachment scheme for the Aerolor X-point divertor. This report describes the testing performed at the Ion Beam Test System and the test and analysis results obtained in support of this effort. After completing 1000 thermal cycles, where the surface temperature of the 8 cm by 8 cm by 2.3 cm Aerolor tile reached 2200{degree}C during a 10 s, 500 W/cm{sup 2} pulse, the tile survived without any noticeable damage. Post test inspection of the carbon-carbon threads showed only minor wear and no signs of significant damage. Thermal modeling of the test article using the ABAQUS finite element code agreed very well with experimental results. The thermal creep experienced by the M-12 stainless steel bolt during ion beam testing will not be expected to occur during normal operations in JET because of the longer cycle times between the thermal events. Finite element analysis indicates that the longer cycle times at the JET will reduce the peak temperatures in the vicinity of the bolt and bolt insert below the level at which thermal creep would occur. An additional margin of safety could be obtained by using Inconel or Nimonic fasteners. Overall, the performance of the bolted divertor design to thermal fatigue was acceptable. 12 figs., 2 tabs.

An electromagnetic measurement system (EMMS) was designed and constructed to provide essential data relating to electromagnetic compatibility (EMC) of modern weapons carried on military aircraft. This system measures the equivalent plane wave electric and magnetic fields impinging on a weapon's exterior surface arising from electromagnetic radiators on board host or nearby aircraft. To relate practical sensor responses to specified equivalent plane wave EMC field levels, a modern weapon shape was used as the primary sensor element which responds with a simple dipole antenna response at the lower frequencies and is instrumented with local skin current sensors. At higher frequencies, the locally induced currents can be related to the incident fields by simple scattering theory. Finally, an error analysis that catalogs all measurement path elements was performed to provide an error bound on the equivalent free electric field measurements reported by the EMMS. 6 refs., 9 figs.

Micromachining is a rapidly growing field which allows for the fabrication of extremely small sensors and actuators using many of the techniques common to microelectronics. Two methods are commonly used: bulk micromachining, which involves the sculpting of single crystal silicon, and surface micromachining, which uses etched thin films that have been deposited on the substrate. Sensors are the primary commercial application, but microactuators are being actively researched at several laboratories and universities. Sandia National Laboratories is pursuing applications of both bulk and surface micromachining for silicon microsensors, microactuators, and high-performance, silicon packages for microelectronics. 3 figs.

This is an extension of two previous analytical studies to investigate a technique for generating high frequency, high amplitude vibration environments. These environments are created using a device attached to a common vibration exciter that permits multiple metal on metal impacts driving a test surface. These analytical studies predicted that test environments with an energy content exceeding 10 kHz could be achieved using sinusoidal and random shaker excitations. The analysis predicted that chaotic vibrations yielding random like test environments could be generated from sinusoidal inputs. In this study, a much simplified version of the proposed system was fabricated and tested in the laboratory. Experimental measurements demonstrate that even this simplified system, utilizing a single impacting object, can generate environments on the test surface with significant frequency content in excess of 40 kHz. Results for sinusoidal shaker inputs tuned to create chaotic impact response are shown along with the responses due to random vibration shaker inputs. The experiments and results are discussed. 4 refs., 5 figs.

Sandia National Laboratories has utilized pool fires for over thirty years to subject military components, weapon mockups and hazardous material shipping containers to postulated transportation accident environments. Most of the tests have been performed in either open pools or wind shielded facilities with little control of visible smoke emissions. Because of the increased sensitivity of environmental issues and because wind generates the biggest uncontrollable effect on the thermal environment in open pool fires, enclosed test facilities with reduced visible emissions have been developed. The facilities are basically water cooled enclosures fitted with controlled air supply systems and high temperature afterburners. The purpose of this paper is to present our experience with both open and enclosed fires. In the first section, a review of the fire test facilities is given. A following section presents a mathematical model behind our approach to characterizing the fire environment. In the last section, data from open and closed fires are compared.

Research programs from Sandia Laboratory in Materials Science are briefly presented. Significant accomplishments include: preparation of Tl superconductors under equilibrium conditions, development of force-feedback sensor for interfacial force microscope, predictive model of hydrogen interactions in silicon dioxide on silicon, layer-by-layer sputtering of Si (001), oscillatory As{sub 4} surface reaction rates during molecular beam epitaxy of AlAs, GaAs and InAs, the effects of interfacial strain on the band offsets of lattice matched III-V semiconductor, a new mechanism for surface diffusion, solid solution effects in Tl-containing superconductors, record high superconducting transitions for organic materials, atomic vibrations in boron carbides and a method for studying radical/surface reactions in chemical vapor deposition (CVD).

Recent government actions to eliminate Chlorofluorocarbons (CFCs) and Chlorinated Hydrocarbons (CHCs) from the industrial environment require the evaluation of new cleaning solvents and processes. High reliability printed wiring board (PWB) assemblies require cleaning to remove process materials which could lead to corrosion or degradation of the electrical performance of the boards. In the past, CFCs have been used extensively for PWB cleaning purposes. Concerns about CFC emissions and their effect on ozone depletion in the atmosphere, greater demands on cleaning systems, and the availability of alternative cleaning methods are requiring manufacturers of electronic assemblies to reconsider the choice of cleaning methods. We will review some of the presently available cleaning solvents and discuss the results of our work using a terpene-based cleaner. 5 refs., 4 figs.

The Recirculating Linear Accelerator (RLA) is returning to operation with a new electron beam injector and a modified accelerating cavity. Upon completion of our experimental program the RLA will capture the injected beam on an IFR guiding plasma channel in either a spiral or a closed racetrack drift tube. The relativistic beam will be efficiently recirculated for up to four passes through two or more accelerating cavities, in phase with the ringing cavity voltage waveforms, and thereby increased in energy to 10 MeV before being extracted. The inductively isolated four-stage injector was designed to produce beam parameters of 4 MeV, 10--20 kA, and 40--55 ns FWHM. The three-line radial cavity is being modified to improve the 1-MV accelerating voltage pulse shape while an advanced cavity design study is in progress. The actual versus predicted pulsed-power performance of the RLA injector and cavity and the associated driving hardware will be discussed in this paper.

Last year at the HP82000 Users Group Meeting, Sandia National Laboratories gave a presentation on I{sub DDQ} testing. This year, we will present some advances on this testing including DUT board fixturing, external DC PMU measurement, and automatic IDD-All circuit calibration. This paper is geared more toward implementation than theory, with results presented from Sandia tests. After a brief summary I{sub DDQ} theory and testing concepts, we will describe how the break (hold state) vector and data formatting present a test vector generation concern for the HP82000. We than discuss fixturing of the DUT board for both types of I{sub DDQ} measurement, and how the continuity test and test vector generation must be taken into account. Results of a test including continuity, IDD-All and I{sub DDQ} Value measurements will be shown. Next, measurement of low current using an external PMU is discussed, including noise considerations, implementation and some test results showing nA-range measurements. We then present a method for automatic calibration of the IDD-All analog comparator circuit using RM BASIC on the HP82000, with implementation and measurement results. Finally, future directions for research in this area will be explored. 14 refs., 16 figs.

CEPXS/ONELD is the only discrete ordinates code capable of modelling the fully-coupled electron-photon cascade at high energies. Quantities that are related to the particle flux such as dose and charge deposition can readily be obtained. This deterministic code is much faster than comparable Monte Carlo codes. The unique adjoint transport capability of CEPXS/ONELD also enables response functions to be readily calculated. Version 2.0 of the CEPXS/ONELD code package has been designed to allow users who are not expert in discrete ordinates methods to fully exploit the code's capabilities. 14 refs., 15 figs.

With the current trends towards miniaturization, high performance, high quality and cost competiveness, the electrodeposition process has become an important manufacturing technology in many new microelectronic applications. Gold electrodeposition plays an increasing role in processes that require this noble metal. Added to these trends is the continuing and increasing emphasis on manufacturing processes which are less damaging to the environment and potentially less hazardous to the operator and personnel in the vicinity of the operation. The present standard gold plating solutions are based on cyanide salts and are considered acutely hazardous solutions. The trend away from their use is gaining momentum as new non-hazardous gold plating solutions and manufacturing processes making use of them are developed. 2 refs.

A performance assessment methodology has been developed for use by the US Nuclear Regulatory Commission in evaluating license applications for low-level waste disposal facilities. This report provides detailed guidance on input and output procedures for the computer codes recommended for use in the methodology. Seven sample problems are provided for various aspects of a performance assessment analysis of a simple hypothetical conceptual model. When combined, these sample problems demonstrate how the methodology is used to produce a dose history for the site under normal conditions, and to demonstrate an analysis of an intruder scenario. 20 refs., 26 figs., 4 tabs.

Results of calculations performed with MELCOR and HECTR in support of the NUREG-1150 study are presented in this report. The analyses examined a wide range of issues. The analyses included integral calculations covering an entire accident sequence, as well as calculations that addressed specific issues that could affect several accident sequences. The results of the analyses for Grand Gulf, Peach Bottom, LaSalle, and Sequoyah are described, and the major conclusions are summarized.

Electromagnetic coupling to electronic components or subsystems is a concern in modern system design. Undesired coupling can cause interference or, in the extreme, system upset. To be able to characterize the coupling is an important step to understanding the limitations on system performance. Often the approach is taken to shield the electronic equipment inside some kind of enclosure. However, there are usually inadvertent cracks or bowing at mechanical interfaces. These gaps are apparent slot apertures. An equivalent antenna/local transmission line model for narrow slot apertures with depth including losses has been developed. It may be applied tortuous paths and hence may be used to model practical situations. This model has been previously verified by measuring the coupling through narrow slot apertures with varying width and depth. These measurements were performed for brass slots radiating into a half-space. The results were in good agreement with the model of Warne and Chen. The models, as well as the measurements showed that for very narrow slots the wall loss becomesdominant -- it has been demonstrated that the inclusion of loss is important in making realistic coupling estimates in practical configurations. This paper presents results showing the effects of varying conductivity and surface preparations for half-space coupling as well as different loadings of the narrow slot apertures. The coupling through narrow slot apertures having depth was measured for a variety of resonant cavity loadings. The loadings were chosen such that the cavity resonant frequencies were above, near and below the resonant peak of the half-space coupling curve. Measurements were made in the 2--4 GHz band with vertical polarization. 3 refs., 6 figs., 1 tab.

The solidification behavior of Custom Age 625 PLUS{reg sign} is examined using an integrated analytical approach. Like its predecessors, Alloys 625 and 718, the solidification behavior of this new alloy is dominated by the presence and segregation of Nb, which gives rise to a {gamma}/Laves terminal solidification constituent. 8 refs., 5 figs., 2 tabs.

Iterative, annual performance-assessment calculations are being performed for the Waste Isolation Pilot Plant (WIPP), a planned underground repository in southeastern New Mexico, USA for the disposal of transuranic waste. The performance-assessment calculations estimate the long-term radionuclide releases from the disposal system to the accessible environment. Because direct experimental data in some areas are presently of insufficient quantity to form the basis for the required distributions. Expert judgment was used to estimate the concentrations of specific radionuclides in a brine exiting a repository room or drift as it migrates up an intruding borehole, and also the distribution coefficients that describe the retardation of radionuclides in the overlying Culebra Dolomite. The variables representing these concentrations and coefficients have been shown by 1990 sensitivity analyses to be among the set of parameters making the greatest contribution to the uncertainty in WIPP performance-assessment predictions. Utilizing available information, the experts (one expert panel addressed concentrations and a second panel addressed retardation) developed an understanding of the problem and were formally elicited to obtain probability distributions that characterize the uncertainty in fixed, but unknown, quantities. The probability distributions developed by the experts are being incorporated into the 1991 performance-assessment calculations. 16 refs., 4 tabs.

Segmentation is a process of separating objects of interest from their background or from other objects in an image. Without a suitable segmentation scheme, it is very difficult to detect contraband in X-rays images. In this paper, a Probabilistic Relaxation Labeling (PRL) segmentation scheme is presented and compared with other segmentation methods. PRL segmentation is an interative algorithm that labels each pixel in an image by cooperative use of two information sources: the pixel probability and the degree of certainty of its probability supported by the neighboring pixels. The practical implementation and results of the PRL segmentation on X-ray baggage images are also discussed and compared with other segmentation methods. 13 refs., 12 figs.

This investigation describes how a statistically designed experiment can be useful to characterize the relationship between a fundamental material property such as the glass transition temperature, Tg, and various processing parameters, e.g. composition, cure time, and temperature. To illustrate, formulation weighing errors can have a dramatic affect on material properties such as thermal, mechanical, and electrical properties. The glass transition temperature was selected for monitoring because it represents the materials state of cure and it is relatively easy to determine. Specifically, EPON 828 systems cured with diethanolamine and Shell Z, respectively, were investigated plus a mixture of the latter that employed aluminum oxide as a filler. This investigation showed that Tg changed very little with cure temperature in the DEA system compared to Shell Z, whereas the latter system appeared to display synergistic effects contrary to the DEA system. In the filled formulation, loading level had very little effect on Tg. The significance of this study is that the relationship between Tg, the composition and processing factors can be used to help diagnose the cause of misprocessed material. 2 refs., 11 figs., 3 tabs.

The detonability of hydrogen-air-diluent mixtures was investigated experimentally in the 0.43 m diameter, 13.1 m long Heated Detonation Tube (HDT) for the effects of variations in hydrogen and diluent concentration, initial pressure, and initial temperature. The data were correlated using a ZND chemical kinetics model. The detonation limits in the HDT were obtained experimentally for lean and rich hydrogen-air mixtures and stoichiometric hydrogen-air-steam mixtures. The addition of a diluent, such as steam or carbon dioxide, increases the detonation cell width for all mixtures. In general, an increase in the initial pressure or temperature produces a decrease in the cell width. In the HDT, the detonable range of hydrogen in a hydrogen-air mixture initially at 1 atm pressure is between 11.6 percent and 74.9 percent for mixtures at 20°C, and 9.4 percent and 76.9 percent for mixtures at 100°C. The detonation limit is between 38.8 percent and 40.5 percent steam for a stoichiometric hydrogen-air-steam mixture initially at 100°C and 1 atm. The detonation limit is between 29.6 percent and 31.9 percent steam for a stoichiometric hydrogen-air-steam mixture for the case where hydrogen and steam are added to air initially at 20{degree}C and 1 atm resulting in a final predetonation mixture temperature and pressure of approximately 100°C and 2.6 atm, respectively.

Currently, over 90% of the world's large-scale solar electric energy is generated with concentrating solar thermal power plants. Such plants have the potential to meet many of the world's future energy needs. Research efforts are generally focused on generating electricity, though a variety of other applications are being pursued. Today, the technology for using solar thermal energy is well developed, cost competitive, and in many cases, ready for widespread application. The current state of each of the solar thermal technologies and their applications is reviewed, and recommendations for increasing their use are presented. The technologies reviewed in detail are: parabolic trough systems, central tower systems, and parabolic dish systems. 20 refs., 1 fig., 1 tab.

TRANSNET is a compilation of risk and systems analysis codes, routing and cost models and related data that address hazardous and radioactive materials transportation. TRANSNET is the acronym assigned to this system of models and associated data which reside on a dedicated MicroVAX 3800. After obtaining a password, users may access TRANSNET with a modem-equipped personal computer. TRANSNET was developed by Sandia National Laboratories (SNL) under the sponsorship of the United States Department of Energy (DOE) Office of Defense Programs (subsequently reorganized to the Office of Environmental Restoration and Waste Management). The goals of the TRANSNET system are to speed transfer of technology and data to qualified users by permitting access to the most comprehensive and up-to-date transportation risk and systems analysis models and associated databases. 13 refs.

Relational databases have many advantages over former hierarchical and network systems -- the most important advantage is their ease of modification. This leads designers to a new approach, which we at our company are finding very useful in building an information system of corporate-wide shared data. This approach is a phased bottom-up design and application development which is supported by an information modeling method called NIAM (Nijssen's Information Analysis Method). NIAM is not well known in the USA, but is widely used in Europe. An introduction to the NIAM approach and its advantages will be followed by examples of models and their corresponding relational database designs that have been developed in step-wise fashion at our company. Since NIAM algorithms yield tables in fifth normal form, our relational systems are implemented for optimum update capabilities and enforceable referential integrity. 4 refs., 6 figs.

In FY90 important milestones from past Administrative Information Systems (AIS) plans were realized. The first phase of the Payroll migration was implemented early in the year. This event signified the completion of a major migration milestone and the transition of the Laboratory Information Systems (LIS) machine to a production environment. The Access Clearance System (A CS) system and several early deliverables from other migration projects were also implemented during the year. FY91 promises to be another challenging year for those involved with administrative information systems. Aggressive schedules are in effect for the migration projects; the Financial Migration, Human Resources (HR) Migration, and Integrated Procurement System Replacement (IPS/R) efforts will deliver major system components this year. The administrative computing consolidation is underway and will be completed early in FY91. Consolidating computing hardware resources will provide adequate resources and better systems support for the entire AIS community.

In this paper, we review correlation filters as an approach to pattern recognition with a special emphasis on the consequences of normalizing the correlation to achieve intensity invariance. Intensity invariance is effected using the Cauchy-Schwarz inequality to normalize the correlation integral. We discuss the implications of this criterion for the application of correlation filters to the pattern recognition problem. It is shown that normalized phase-only and synthetic discriminate functions do not provide the recognition/discrimination obtained with the classical matched filter. 34 refs., 5 figs.

In keeping with the philosophy of the external events analyses for NUREG-1150, which are intended to be smart probabilistic risk assessments (PRAs) making full use of all insights gained during the past 10 years of development in risk assessment methodologies, the Savannah River K-Reactor fire analysis was performed using newly developed and simplified methods. These methods have been under development at Sandia National Laboratories under sponsorship of the Nuclear Regulatory Commission (NRC) Division of Risk Assessment as part of the Dependent Failure Methodology Development Program. A detailed screening analysis was performed which showed most plant areas had a negligible contribution to fire-induced core damage frequency. Detailed analysis of the fire risk resulted in a total (mean) core damage frequency of 1.35E-7 per year. 18 refs., 12 figs., 17 tabs.

The project comprises the development of concentrating solar collectors, heliostats and dishes, and the development of optical materials. Because the solar concentrator represents from 40 to 60% of the cost of a solar thermal electric system, the continued development of high-performance concentrators is very important to the commercial viability of these systems. The project is currently testing two large area heliostats, the SPECO 200 m{sup 2} heliostat and the ATS 150 m{sup 2} heliostat and also trying to reduce the cost of the heliostats through the development of stretched-membrane heliostats. Stretched-membrane heliostats are made by attaching thin metal membranes to the two sides of a circular, metal ring. A slight vacuum in the plenum between the two membranes is used to focus the heliostat. The optical surface is provided by a silver-acrylic film, ECP 305. A prototype 100 m{sup 2} commercial unit has been built and is currently being tested. Parabolic dish concentrators are under development for use on dish-Stirling electric systems. The state-of-the-art dish is the McDAC/SCE faceted glass concentrator. Because of the success of stretched-membrane technology for heliostats, the project applied the technology to parabolic dish development and is currently designing a near-term, faceted, stretched-membrane dish. The current thrust of the program in optical materials development is the development of a low-cost, high-performance, silver-acrylic film. 3M's ECP 305 has demonstrated substantial improvement over previous films in its resistance to corrosion, longer life. An experimental film, developed at SERI, has promise for further improving the lifetime of the ECP 305. The project is currently investigating solutions to the problem of separation between the silver and acrylic layers of the film in the presence of water.

Double-Layer Capacitors (DLCs) have been used mainly for computer memory backup in consumer applications during the last ten years. Their high capacitance density, along with maintenance-free operation, makes them suited for these applications. In recent years users, mostly in military applications, have expressed interest in using DLCs in high reliability applications both for backup power and pulse power applications. To meet this need, developers have pursued technologies that use carbon and mixed metal oxides as the electrode material to produce high reliability double-layer capacitors. In this paper, a carbon-based DLC that was manufactured by Evans Company, and a mixed metal oxide (MMO) DLC by Pinnacle Research Inc. were evaluated. There is little published data on their reliability and aging characteristics. In addition, questions have arisen as to their environmental stability as a function of temperature, shock, vibration, and linear acceleration. The purpose of this paper is to review the available test data for both types of DLCs under these stress conditions. The data for this paper was generated by Sandia National Laboratories, General Electric Neutron Devices Department, Motorola Company, and Evans Company.

A technique to localize errors between two modal models is presented. Mode shape difference are calculated from each model. A global comparison of the ratios of these corresponding differences is used to identify the physical locations on the structure where stiffness differences exist between the two models. Some of the strengths and limitations of the technique are illustrated using the mode shapes of two similar finite element models with a known stiffness difference. The technique is then applied to a two link robot arm for which a finite element model exists and a modal test has been conducted. The results of the error localization aid the selection of physical parameters to be updated in the finite element model. Sensitivity methods are used to correlate the finite element model to the modal test. The results of the correlation are presented. 5 refs., 3 figs., 3 tabs.

This paper will provide an overview of cleaning qualifications used in a variety of industries: from small-scale manufacturer's of precision-machined products to large-scale manufacturer's of electronics (printed wiring boards and surface mount technology) and microelectronics. Cleanliness testing techniques used in the production of precision-machined products, will be described. The on-going DOD program to obtain high-reliability electronics, through the use of military specifications for cleaning and cleanliness levels, will be reviewed. In addition, the continually changing cleanroom/materials standards of the microelectronics industry will be discussed. Finally, we will speculate on the role that new and improved analytical techniques and sensor technologies will play in the factories of the future. 4 refs., 1 tab.

Ray paths and focal lengths are derived to fourth order for a nuclear-reactor wall-pumped gas laser. Ray paths in the laser gain cell are shown to be nearly random for a long gain region. Focal lengths calculated from the ray paths exiting the laser are shown to oscillate between {plus minus} {infinity} during pumping. The use of stimulated Brillouin scattering as a means for beam clean-up is discussed with the conclusion that the phase conjugated beam would cycle on and off as the ray paths and focal lengths oscillate between extremes. The parameters determining this cycling effect and its characteristics are also derived. 17 refs., 11 figs., 1 tab.

MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. MELCOR is being developed at Sandia National Laboratories for the US Nuclear Regulatory Commission as a second-generation plant risk assessment tool and the successor to the Source Term Code Package. The entire spectrum of severe accident phenomena, including reactor coolant system and containment thermal-hydraulic response, core heatup, degradation and relocation, and fission product release and transport, is treated in MELCOR in a unified framework for both boiling water reactors and pressurized water reactors. MELCOR has been especially designed to facilitate sensitivity and uncertainty analyses. Its current uses include estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications. This report is a summary of MELCOR 1.8.0, the code version released in March 1989. Condensed information is presented on its developmental history, structure, modeling features and capabilities, verification and validation, and quality assurance. Detailed documentation on these aspects of MELCOR, including users' guides, reference manuals, programmers' guides, and assessment and application reports, is available in draft form and is distributed to MELCOR users.

Experimental tests on the Annular Core Research Reactor have confirmed that the Three-Bean-Salad'' control algorithm based on the Pontryagin maximum principle can change the power of a nuclear reactor many decades with a very fast startup rate and minimal overshoot. The paper describes the results of simulations and operations up to 25 MW and 87 decades per minute. 3 refs., 4 figs., 1 tab.

The spherical element computer code DMC (Distinct Motion Code) used to model rock motion resulting from blasting has been enhanced to allow routine computer simulations of bench blasting. The enhancements required for bench blast simulation include: (1) modifying the gas flow portion of DMC, (2) adding a new explosive gas equation of state capability, (3) modifying the porosity calculation, and (4) accounting for blastwell spacing parallel to the face. A parametric study performed with DMC shows logical variation of the face velocity as burden, spacing, blastwell diameter and explosive type are varied. These additions represent a significant advance in the capability of DMC which will not only aid in understanding the physics involved in blasting but will also become a blast design tool. 8 refs., 7 figs., 1 tab.

Nd:YAG laser cleaning of metal oxides from 304L stainless steel surfaces has been characterized. Thin chromium oxide films can be completely removed from the surface using a single 10 nsec pulse of laser radiation with an average surface irradiance greater than 120 MW/cm{sup 2}. Laser etching of thicker iron oxide films exhibit a self-limiting effect that prevents overetching into the stainless steel substrate. 8 figs.

Electron-Beam (EBeam) melting furnaces are routine used to minimize the occurrence of second-phase particles in the processing of segregation-sensitive alloys. As one part of the process, a circulating electron beam impinges the surface of a crucible melt pool to help control the shape of the solidification front below. By modeling melt pool hydrodynamics, heat transfer, and the shape of solidification boundaries, we plan to optimize the dwell pattern of the beam so that the material solidifies with a composition as spatially homogeneous as possible. Both two- and three-dimensional models are being pursued with FIDAP 5.02, the former serving as a test bed for various degrees of model sophistication. A heat flux distribution is specified on the top of the domain to simulate the EBeam dwell pattern. In two dimensions it is found that an inertially-driven recirculation in the melt pool interacts with a counter-rotating buoyancy-driven recirculation, and that both recirculations are influenced heavily by surface tension gradients on the melt-pool surface. In three dimensions the inertial cell decays quickly with distance from the position of the inlet stream, causing the fluid to precess the crucible. Ingot macrosegregation patterns for a U-6 wt. % Nb alloy are calculated with the Flemings-Mehrabian equation of solute redistribution; the sensitivity of these patterns to EBeam dwell pattern is explored.

The LIFE2 computer code is a fatique/fracture analysis code that is specialized to the analysis of wind turbine components. The numerical formulation of the code uses a series of cycle count matrices to describe the cyclic stress states imposed upon the turbine. In this formulation, each stress cycle is counted or binsed'' according to the magnitude of its mean stress and alternating stress components and by the operating condition of the turbine. A set of numerical algorithms has been incorporated into the LIFE2 code. These algorithms determine the cycle count matrices for a turbine component using stress-time histories of the imposed stress states. This paper describes the design decisions that were made and explains the implementation of these algorithms using Fortran 77. 7 refs., 7 figs.

The CONTAIN quality assurance program follows a strict set of procedures designed to ensure the integrity of the code, to avoid errors in the code, and to prolong the life of the code. The code itself is maintained under a code-configuration control system that provides a historical record of changes. All changes are incorporated using an update processor that allows separate identification of improvements made to each successive code version. Code modifications and improvements are formally reviewed and checked. An exhaustive, multilevel test program validates the theory and implementation of all codes changes through assessment calculations that compare the code-predicted results to standard handbooks of idealized test cases. A document trail and archive establish the problems solved by the software, the verification and validation of the software, software changes and subsequent reverification and revalidation, and the tracking of software problems and actions taken to resolve those problems. This document describes in detail the CONTAIN quality assurance procedures.

The 10-MW{sub e} Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top a of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the US Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the US utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

The results of the first year of an evaluation of charge controllers for stand-alone photovoltaic (PV) systems are presented. The objectives of the test program are to positively influence the development of battery charge controllers for stand-alone PV applications and to develop design and application criteria that will improve PV system reliability and battery performance. Future goals are to expand the evaluation program to include various battery technologies and controller algorithms. Also, the information is being communicated to manufacturers to aid in the design of more effective and reliable charge controllers for PV systems. Eight different models of small (nominal 10 amp) charge controllers are being subjected to a comprehensive evaluation. These evaluations include operational tests in identical stand-alone PV systems and environmental and electrical cycling tests. Selected custom tests are also performed on the controllers to determine the response to transients, installation requirements and system design compatibilities. Data presented in this paper include measured electrical characteristics of the controllers, temperature effects on set points, and operational performance in PV systems both in the lab and in the field. A comparison is presented for four different charge controller algorithms which include array-shunt, series-interrupting, series-linear constant-voltage and series-linear-multistep constant-current. 9 refs., 11 figs., 2 tabs.

SAS software is being used to analyze product test data stored in an INGRES relational database. The database has been implemented at Allied-Signal in Kansas City on a Digital Equipment Corporation (DEC) VAX computer. The INGRES application development has been a joint project between Sandia National Laboratories and Allied-Signal. Application screens have been developed so that the user can query the database for selected data. Fourth generation language procedures are used to retrieve all data requested. FORTRAN and VAX/VMS DCL (DIGITAL Control Language) procedures are invoked from the application to create SAS data sets and dynamically build SAS programs that are executed to build custom reports or graphically display the retrieved test data along with control and specification limits. A retrieval screen has also been developed which invokes SAS software to calculate the mean and standard deviation of the retrieved data. These parameters are passed back into the application for display and may then be used as an aid in setting new control limits for future test runs. Screens have been developed to provide an interface for the user to select from a library of SAS programs, edit the selected program, and run the program with a user-defined SAS data set as input. This paper will give a brief description of the application screens and provide details of how information is passed between the application and SAS programs.

I was asked to write a database application that would be user friendly to the extent that a minimum amount of learning would be required of the user to run the application, yet it would be flexible enough to gather the data in various combinations. Writing SELECT'' or RETRIEVE'' queries required to much initial training. Hard coding queries into the application meant the users could not pick columns or create contraints. I decided to compromise somewhat, requiring my users to learn how to manipulate VIFRED menus and by doing so they could pick any combination of columns for output, select any column variable to sort on, and impose simple, yet practical constaints on the data, all this possible at run time. This handout contains copies of the VIFRED menus, the help message for imposing constraints, output from sample retrievals, descriptions of the relational tables needed to implement the methodology, and the computer coding of the actual retrieval construction.

Burnup credit is the application of the effects of fuel burnup to nuclear criticality design. When burnup credit is considered in the design of storage facilities and transportation casks for spent fuel, the objectives are to reduce the requirements for storage space and to increase the payload of casks with acceptable nuclear criticality safety margins. The spent-fuel carrying capacities of previous-generation transport casks have been limited primarily by requirements to remove heat and/or to provide shielding. Shielding and heat transfer requirements for casks designed to transport older spent fuel with longer decay times are reduced significantly. Thus a considerable weight margin is available to the designer for increasing the payload capacity. One method to achieve an increase in capacity is to reduce fuel assembly spacing. The amount of reduction in assembly spacing is limited by criticality and fuel support structural concerns. The optimum fuel assembly spacing provides the maximum cask loading within a basket that has adequate criticality control and sufficient structural integrity for regulatory accident scenarios. The incorporation of burnup credit in cask designs could result in considerable benefits in the transport of spent fuel. The acceptance of burnup credit for the design of transport casks depends on the resolution of system safety issues and the uncertainties that affect the determination of criticality safety margins. The remainder of this report will examine these issues and the integrated approach under way to resolve them. 20 refs., 2 figs.

Dip coating is the primary means of depositing sol-gel films for precision optical coatings. Sols are typically multicomponent systems consisting of an inorganic phase dispersed in a solvent mixture, with each component differing in volatility and surface tension. This, together with slow coating speeds (<1cm/s), makes analysis of the coating process complicated; unlike most high-speed coating methods, solvent evaporation, evolving rheology, and surface tension gradients alter significantly the fluid mechanics of the deposition stage. We set out to understand these phenomena with computer-aided predictions of the flow and species transport fields. The underlying theory involves mass, momentum, and species transport on a domain of unknown shape, with models and constitutive equations for vapor-liquid equilibria and surface tension. Due accounting is made for the unknown position of the free surface, which locates according to the capillary hydrodynamic forces and solvent loss by evaporation. Predictions of the effects of mass transfer, hydrodynamics, and surface tension gradients on final film thickness are compared with ellipsometry measurements of film thickness on a laboratory pilot coater. Although quantitative agreement is still lacking, both experiment and theory reveal that the film profile near the drying line takes on a parabolic shape. 2 refs., 2 figs.

Sandia National Laboratories is a multiprogram engineering laboratory that serves the nation through the Department of Energy (DOE), both in its programs and those of other agencies. Major research and development responsibilities cover nuclear weapons, arms control, energy, environment and other areas of strategic importance to national security. The principal mission is to support national defense policies by ensuring that the nuclear weapon stockpile meets the highest standards of safety, security, control and military performance. In May of 1968, the Albuquerque Office of DOE (then AEC) assigned the Quality Assurance function to Sandia Laboratories on all products for which Sandia has design responsibility. The Sandia Quality Improvement Plan presents a Quality Management System that integrates the Sandia quality policies and several independent improvement processes into a cohesive structure. This structure guides day-to-day operations toward strategic objectives. The Sandia Quality Policy provides the underlying principles for the management of our research and engineering efforts and establishes our customers as the central focus of our Sandia quality improvement efforts. Operationally, these efforts are centered around quality improvement processes based on good management practices developed by AT T, and progress is measured against the Malcolm Baldridge National Quality Award criteria. Developing a comprehensive plan based on these processes requires that we determine where we are, where we want to be, and how we measure our progress. 1 fig. (JF)

A review of the objectives and accomplishments of the Computational Benchmark Problem Committee (CBPC) of the American Nuclear Society Mathematics and Computation Division is presented. A list of the benchmark problems compiled by the CBPC and published by the Argonne Code Center is included, along with a list of the problems currently under review. A brief discussion of the challenge of benchmarking in the current environment of rapidly evolving computing technology is given. 20 refs., 3 tabs.

The Distant Light Program sponsored by the Defense Nuclear Agency (RAEE) is directed toward understanding the response of electronic systems to Source Region EMP (SREMP) and will result in the development of proven system hardening and validation techniques for SREMP. This program relies very strongly on testing in above ground test (AGT) simulators such as the HERMES III gamma ray simulator at Sandia National Laboratories in Albuquerque, New Mexico. This paper describes theoretical and experimental efforts aimed at understanding the gamma ray flux produced by HERMES III in terms of its time dependence, spatial variation and spectrum. As part of this characterization, the calibration of various measuring devices must be considered. This paper describes the progress made in characterizing the HERMES III radiation output through December of 1990.

Lithium batteries have been used in a variety of applications for a number of years. As their use continues to grow, particularly in the consumer market, a greater emphasis needs to be placed on safety and reliability. There is a useful technique which can help to design cells and batteries having a greater degree of safety and higher reliability. This technique, known as fault tree analysis, can also be useful in determining the cause of unsafe behavior and poor reliability in existing designs.

During 1990, Sandia National Laboratories initiated an advanced lead-acid battery development program supported by the US Department of Energy's Office of Energy Management. The goal is to develop a low maintenance, cost effective battery by the mid- to late 1990's that is tailored to a variety of electric utility applications. Several parallel activities are being pursued to achieve this goal. One activity seeks to quantify the economic benefits of battery storage for specific cases in candidate utility systems and identify opportunities for field demonstration of battery systems at electric utility and utility customer sites. Such demonstrations will not only generate valuable operating experience data, but will also help in building user confidence in battery storage systems. Other activities concentrate on cell- and battery-level research and development aimed at overcoming shortcomings in existing technologies, such as Valve-Regulated Lead-Acid (VRLA), or, sealed lead-acid batteries.

This study was undertaken in order to document and analyze the unique set of data on subsurface fracture characteristics, especially spacing, provided by the US Department of Energy's Slant Hole Completion Test well (SHCT-1) in the Piceance Basin, Colorado. Two hundred thirty-six (236) ft (71.9 m) of slant core and 115 ft (35.1 m) of horizontal core show irregular, but remarkably close, spacings for 72 natural fractures cored in sandstone reservoirs of the Mesaverde Group. Over 4200 ft (1280 m) of vertical core (containing 275 fractures) from the vertical Multiwell Experiment wells at the same location provide valuable information on fracture orientation, termination, and height, but only data from the SHCT-1 core allow calculations of relative fracture spacing. Within the 162-ft (49-m) thick zone of overlapping core from the vertical and deviated wellbores, only one fracture is present in vertical core whereas 52 fractures occur in the equivalent SHCT-1 core. The irregular distribution of regional-type fractures in these heterogeneous reservoirs suggests that measurements of average fracture spacing'' are of questionable value as direct input parameters into reservoir engineering models. Rather, deviated core provides data on the relative degree of fracturing, and confirms that cross fractures can be rare in the subsurface. 13 refs., 11 figs.

Current computer network protocols are very robust and capable of being used in a variety of different environments. Typically, the implementations of these protocols come to the user with preset parameters that provide reasonable performance for low delay- bandwidth product environments with low error rates, but these defaults do not necessarily provide optimal performance for high delay-bandwidth, high error rate environments. To provide optimal performance from the user's perspective, which is application to application, all equivalent layers of the protocol must be tuned. The key to tuning protocols is reducing idle time on the links caused by various protocol layers waiting for acknowledgments. The circuit bandwidth, propagation delay, error rate, number of outstanding packets, buffer length, number of buffers, and buffer size can all affect the observed idle time. Experiments have been conducted on test bed systems, and on live satellite and terrestrial circuits. Observations from these experiments led the authors to draw conclusions about the locations of common bottlenecks. Various aspects of network tuning and certain specific issues relating to the tuning of three protocols (DECnet, TCP/IP, NETEX) over various media types (point-to-point and broadcast) under several different conditions (terrestrial and satellite) are examined in this paper. Also described are the lessons learned about protocol and network tuning. 3 refs., 2 tabs.

A comparison of the short-transverse SCC behavior of 2090 in pH 5.5 Cl{sup {minus}} and alkaline CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} solutions using a static load smooth bar SCC technique was made. In the alkaline CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} solutions, E{sub br} for the {alpha}-Al matrix phase was 0.130 V more positive than the E{sub br} of the subgrain boundary T{sub 1} phase. In this environment, stress corrosion cracking test specimens subjected to potentials in the window defined by the two breakaway potentials failed along an intersubgranular path in less than an hour. In the Cl{sup {minus}} environment, the E{sub br} values for the two phases were nearly equal and this rapid SCC condition could not be satisfied; accordingly SCC failures were not observed. Rapid SCC failure of 2090 in CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} in our static load, constant immersion experiments appear to be related to recently reported pre-exposure embrittlement'' failures induced by immersing stressed specimens removed into ambient laboratory air after immersion in aerated NaCl solution for 7 days. In those experiments, specimens failed in less than 24 hours after removal from solution. Our polarization experiments have shown that the corrosion behavior of T{sub 1}, CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} environments, but the {alpha}-Al phase crack walls, is rapidly passivated. X-ray diffraction of the films which formed in simulated crevices suggests that this passivating film belongs to a class of compounds known as hydrotalcites.

Vertical axis wind turbine (VAWT) technology in the United States started in the early 1970s directly from the original work in Canada. The close, and very productive relationships among laboratories, universities and industry have continued since that time. This paper briefly discusses the significant technical progress and rather dramatic programmatic changes that have occurred in the past 18 to 24 months on the US side of the border. 20 refs., 14 figs.

Numerous small-scale in situ seal experiments have been emplaced in boreholes up to 38 in. in diameter at the WIPP. Seal materials include expansive salt concrete, bentonite, and crushed salt. Emplacement techniques stressed conventional technology and the use of available site personnel. Preliminary evaluation of the performance of these seals has been completed by using structural data from embedded instrumentation and fluid flow data from gas and brine flow measurements. Preliminary results suggest that submicrodarcy permeabilities can be obtained using these materials and that structural performance is satisfactory. 17 refs., 3 figs., 1 tab.

This paper describes a formal process for selecting, from a diverse set of proposed waste minimization activities, those activities that provide the greatest benefit to DOE. A methodology for evaluating and prioritizing proposals was developed to illustrate how the selection process works and what types of data are required to characterize waste minimization activities. It is clearly impossible to remove all aspects of subjective judgment from the proposal selection process. With this important consideration in mind, the methodology presented is put forth to enhance, not replace, the traditional DOE decision-making process. With relatively minor refinements, this methodology can be immediately useful to DOE Environmental Restoration and Waste Management and Defense Program organizations in preparing, evaluating, and prioritizing waste minimization proposals. 7 refs., 1 tab., 2 figs.

Our primary purpose in this test is to provide a brief general description of a few applications of various electrophoretic systems which have been investigated and have found use in various coating applications at Sandia National Laboratories. Both organic and inorganic suspensions in aqueous and non-aqueous media have been considered in these studies. Applications include high voltage insulating dielectrics, thermally conductive/electrically insulating films, adherent lubricating films, uniform photoresist films, glass coatings, and fissile uranium oxide/carbon composite films for studies of nuclear powered lasers. More recently, we have become interested in the beneficial environmental aspects of being able to provide protective polymer coatings which reduce or minimize the use of organic solvents required by traditional spray coat processes. Important practical factors which relate to film uniformity, adhesion, and composition are related to unique coating or plating capabilities and applications. 6 refs., 2 figs., 1 tab.

System dynamicists frequently encounter signals they interpret as realizations of normal random processes. To simulate these analytically and in the laboratory they use methods that yield approximately normal random signals. The traditional digital methods for generating such signals have been developed during the past 25 years. During the same period of time much development has been done in the theory of chaotic processes. The conditions under which chaos occurs have been studied, and several measures of the nature of chaotic processes have been developed. Some of the measures used to characterize the nature of dynamic system motions are common to the study of both random vibrations and chaotic processes. This paper considers chaotic processes and random vibrations. It shows contrasts between the two and situations where they are indistinguishable. The applicability of the Central Limit Theorem to chaotic processes is demonstrated. 12 refs., 8 figs.

A knowledge of the short term creep rupture behavior of Tantalum alloy T-111 is necessary to predict device integrity in the heat source section of Radioisotope Thermoelectric Generators (RTG's) at the end of service life, in the event of a fuel fire. High pressures exist in RTG's near the end of service life, these are caused by gas generation resulting from radioactive decay of the nuclear fuel. The internal pressure exerts a significant hoop stress on the T-111 alloy structural containment member. This paper analyses the short term creep behavior (rupture times up to {approximately}2 {times} 10{sup 3} hrs.) of cold worked (CW) T-111 alloy, using the existing data of Stephenson (1967). Corellations for the time to rupture, time to 1% strain and minimum creep rate have been obtained from this data using multivariable linear regression analysis. These results are compared to other short term rupture data for T-111 alloy. Finally, at the stress/temperature levels relevant to the RTG fuel fire scenario near the end of service life, the rupture time correlation for T-111 alloy predicts a rupture time of approximately 100 hrs. 10 refs., 3 figs., 1 tab.

Before the Waste Isolation Pilot Plant (WIPP) may begin service as the United States' first repository for the permanent disposal of transuranic (TRU) radioactive waste, the Department of Energy (DOE) must establish compliance with applicable environmental and safety regulations. This paper addresses one major regulation, the United States Environmental Protection Agency's (EPA) Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, hereafter referred to as the Standard. The paper does not address compliance with other regulations. This paper summarizes Sandia National Laboratories' (SNL) early-1990 understanding of the WIPP Project's ability to comply with the long-term performance requirements set by Subpart B of the Standard, the Environmental Standards for Disposal. It also reviews the current understanding of questions critically affecting compliance and outlines the options available to assure that radionuclide releases will remain within regulatory limits. 10 refs., 3 figs.

An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.

We are studying the kinetics of singlet oxygen ({sup 1}{Delta}{sub g}O{sub 2}) in solid polymers by monitoring its phosphorescence in time-resolved experiments. In macromolecular matrices where {sup 1}{Delta}{sub g}O{sub 2} is produced by energy transfer from a photosensitizer, {sup 1}{Delta}{sub g}O{sub 2} lifetimes can be obtained by deconvoluting the {sup 1}{Delta}{sub g}O{sub 2} sensitizer kinetics from the {sup 1}{Delta}{sub g}O{sub 2} phosphorescence signal. The sensitizer kinetics can be obtained in a flash absorption experiment. These time-resolved techniques have been utilized to examine the interaction of {sup 1}{Delta}{sub g}O{sub 2} in polymers with two types of additives: (1) molecules capable of undergoing chemical reactions with {sup 1}{Delta}{sub g}O{sub 2} (reactive quenchers) and (2) molecules capable of quenching {sup 1}{Delta}{sub g}O{sub 2} to its ground triplet state (physical quenchers). From this study we have determined directly that significant reactive and physical quenching of {sup 1}{Delta}{sub g}O{sub 2} are possible in a solid polymer. The polymer matrix greatly reduces the quenching rate of a very efficient quencher and slightly elevates the quenching rate of inefficient quenchers, as compared with rates determined in analogous liquids. This compressed range of quenching efficiencies has implications for understanding photodegradation and stabilization of polymers. 12 refs., 3 figs., 1 tab.

Neutron spin-echo spectroscopy is used to study the topology of aerogels. Topology or connectivity is varied through precursor chemistry and thermal annealing. Topology is characterized using the concept of fractons (the vibrational excitations of a fractal network). A qualitative difference is observed in the spectrum of polymeric vs colloidal aerogels, the latter showing a peak in the density of vibrational states. For colloidal aerogels whose structure appears to arise from phase separation in the solution precursor, low-energy excitations were only observed in the lowest density material studied. Finally, a transition from fractal to colloidal microstructure was observed during the sintering of polymeric aerogels. This transformation revealed itself as a transition from a fracton-like to a peaked density of states function. 23 refs., 7 figs.

Detailed geometric models have been used within a graphical simulation environment to study transportation cask facility design and to perform design and analyses of robotic systems for handling of nuclear waste. The models form the basis for a robot control environment which provides safety, flexibility, and reliability for operations which span the spectrum from autonomous control to tasks requiring direct human intervention.

This paper provides a summary and status report for two ongoing experimental programs. The purpose of each program is to determine the behavior of certain components of the containment pressure boundary when subjected to severe accident conditions. The first program is investigating the effect of various parameters on tearing of the steel liner in reinforced concrete containments. The second will attempt to determine if worst-case containment loading conditions are capable of causing leakage through piping penetration bellows. The liner test program is almost complete; however, the bellows tests have not yet begun. Therefore, the emphasis of the paper is on the liner experiments. The research activities described herein are a part of the Containment Integrity Programs, which are managed by Sandia National Laboratories for the US Nuclear Regulatory Commission.

A Science Advisor Program has been established at Sandia National Laboratories (SNL) for the long term augmentation of math and science instruction in New Mexico schools. Volunteer SNL engineers and scientists team with the faculty of participating schools to enhance the teachers' abilities to capture and hold the student's scientific imagination and develop their scientific skills. This is done primarily through providing laboratory resources, training the teachers how to use those resources, and advising how to obtain them in the future. In its first year, over 140 advisors teamed with 132 schools, for average weekly contact with 500 teachers and 10,000 students. Surveys indicate a general rise in frequency and quality of hands-on science instruction, as well as teacher and student attitudes. An expanded evaluation is planned for subsequent years.

The mechanical strength of silicon, in combination with the sophisticated silicon wafer processing techniques developed to produce silicon integrated circuits, makes it an ideal candidate for the development of a microelectromechanical device technology. We describe a new electrochemical processing technique based on porous silicon that can produce surface and buried insulators, conductors, and sacrificial layers required for sensor, micromotor, and membrane fabrication. 4 refs., 2 figs.

This paper discusses the development of the software for Source Term Analyses for Containment Evaluations (STACE). This software is being developed for the Source Term Technical Issue Resolution Program at Sandia National Laboratories (SNL) in support of the Cask Systems Development Program (CSDP) that is sponsored by the US Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM). STACE is a system of computer codes operating under a graphics-based controller that performs source term analysis of spent fuel transport casks. Output from STACE includes the cladding breach probability, the releasable radionuclide concentrations, and maximum permissible gas flow rates past the closure seals. STACE is anticipated being used for on- and off-site situations related to the handling and transport of spent fuel casks.

A methodology for determining the probability spent-fuel cladding breach due to normal and accident class B cask transport conditions is introduced. This technique uses deterministic stress analysis results as well as probabilistic cladding material properties, initial flaws, and breach criteria. Best estimates are presented for the probability distributions of irradiated Zircaloy properties such as ductility and fracture toughness, and for fuel rod initial conditions such as manufacturing flaws and PCI part-wall cracks. Example analyses are used to illustrate the implementation of this methodology for a BWR (GE 7 {times} 7) and a PWR (B W 15 {times} 15) assembly. The cladding breach probabilities for each assembly are tabulated for regulatory normal and accident transport conditions including fire.

Residual stress states that are a direct result of fabrication and processing are known to exist inside wound capacitors. Considerable insights into the nature of these mechanical and thermomechanical stress states have been gained through the application of analytical prediction capabilities that have been developed for that purpose. For example, analysis shows where roll slip may occur in the capacitor due to steep wound tension gradients or low radial pressures, and how the tension loss of individual plies is distributed throughout the capacitor. Significant tension loss differences between dielectric and conducting plies has also been predicted, with conducting plies not only losing their initial winding tension, but actually experiencing a net compressive value of wound tension. While the results of these predictions are both quantitative and qualitative, only qualitative verification has been obtained thus far, such as visual observation of wrinkled conducting plies discovered in unwrapped capacitors. The purpose of this paper is to describe two experimental activities that were undertaken to support the analytical modeling effort and provide quantitative, experimental verification of some of the analysis predictions.

Fourier transform-infrared spectroscopy (FT-IR) was used to investigate the adsorption and thermally-induced decomposition of copper (I) {beta}-diketonate precursors of the type (hfac)CuL, where hfac is the hexafluoroacetylacetonate bidentate ligand and L is trimethylphosphine or 1,5-cyclooctadiene. The (hfac)CuPMe{sub 3} precursor desorbs from the surface at very low temperatures whereas the (hfac)Cu(1,5-COD) dissociates on adsorption, liberating 1,5-COD and leaving a surface(hfac)Cu complex which can subsequently disproportionate. Evidence is provided for hydrogen-bonding between the hfac ligand and the surface silanols for (hfac)CuPMe{sub 3}, but not for (hfac)Cu(1,5-COD). These results are consistent with the selective behavior of these precursors for copper deposition and suggest that the selectivity of the (hfac)CuPMe{sub 3} and (hfac)Cu(1, 5-COD) precursors may be due to the ability of the hfac ligand to hydrogen bond to the surface silanol groups.

The concept of allowing reactivity credit for the transmuted state of spent fuel offers both economic and risk incentives. This paper presents a general overview of the technical work being performed in support of the US Department of Energy (DOE) program to resolve issues related to the implementation of burnup credit. An analysis methodology is presented along with information representing the validation of the method against available experimental data. The experimental data that are applicable to burnup credit include chemical assay data for the validation of the isotopic prediction models, fresh fuel critical experiments for the validation of criticality calculations for various casks geometries, and reactor restart critical data to validate criticality calculations with spent fuel. The methodology has been specifically developed to be simple and generally applicable, therefore giving rise to uncertainties or sensitivities which are identified and quantified in terms of a percent bias in k{sub eff}. Implementation issues affecting licensing requirements and operational procedures are discussed briefly.

The US Department of Energy is sponsoring a research effort through Sandia National Laboratories and the University of Missour-Rolla to test a correlation for the upper shelf energy (USE) values obtained from the impact testing of subsize Charpy V-notch specimens to those obtained from the testing of full size samples. The program involves the impact testing of unirradiated and irradiated full, half, and third size Charpy V-notch specimens. To verify the applicability of the correlation on LWR materials unirradiated and irradiated full, half, and third size Charpy V-notch specimens of a commercial pressure vessel steel (ASTM A533 Grade B) will be tested. This paper will provide details of the program and present results obtained from the application of the developed correlation methodology to the impact testing of the unirradiated full, half, and third size A533 Grade B Charpy V-notch specimens.

Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is tested for the ability to track step commands, and for the amount of coupling impurity. Both controllers are developed via a linear-quadratic-regulator synthesis procedure, which is motivated by the multi-input/multi-output nature of second controller. Time responses and a singular value analysis are used to evaluate controller performance. This paper describes the development and comparison of two controllers that are designed to provide attitude control of a spinning rocket that is equipped with thrust vector control. 12 refs., 13 figs., 2 tabs.

The theoretical basis for the relationship between moisture content and light transmission (FFM) is developed, and shown to correspond well to the observed behavior. A calibration procedure for FFM based on the relationship between moisture content and matric potential is presented and tested. Means of expanding the range of sensitivity of the FFM are discussed.

We report dramatic improvements to the implanted-planar buried-heterostructure graded-index separate confinement heterostructure (IPBH-GRINSCH) laser in (AlGa)As/GaAs which produces low threshold current, continuous-wave operation. Our process features significantly reduced fabrication complexity of high quality, index-guided laser diodes compared to regrowth techniques and, in contrast to diffusion-induced disordering, allows creation of self-aligned, buried, blocking junctions by ion implantation. The improved single-stripe IPBH-GRINSCH lasers exhibit 39 mA threshold current, cw operation.

Thermomechanical fatigue tests were performed on two near-eutectic Sn-Pb solder alloys, 60Sn-40Pb and 62Sn-36Pb-2Ag, to examine the effect silver additions have on solder joints. The cyclic load was found to have consistent trends between the two silver alloys (for given amounts of total strain and strain rates). It was found that a decreasing strain rate increased the life of both alloys equally in thermomechanical fatigue. At slower strain rates, the dislocation substructure recovers faster than it work-hardens, which tends to minimize subsequent recrystallization and heterogeneous coarsening of the solder joint. The microstructure of 62Sn-36Pb-2Ag contained large whisker-like Ag3Sn precipitates that nucleate and grow out from the Cu6Sn5 interfacial intermetallics. At this size, the Ag3Sn precipitates have little effect on the deformation behavior of the solder. The intermetallics are not detrimental in that they do not prematurely crack, nor are they beneficial because they are too large to stabilize the microstructure. It does not appear, from a microstructural viewpoint, that adding silver to near-eutectic Sn-Pb has any significant effect on improving the thermomechanical fatigue behavior.

Shock and unloading experiments on quartz and silicate rocks indicate that the release adiabats lie below the Hugoniot. The hysteresis and energy dissipation inherent in this situation have important wave propagation implications. On loading, there is a pressure-induced transition to the stishovite phase which does not occur under conditions of thermodynamic equilibrium, in that the Hugoniot passes through a metastable mixed-phase region for several tens of GPa. One interpretation of the unloading data is that the transition is not reversible, and the phase mixture remains frozen on unloading. However, material strength may also play a role. A complete thermodynamically consistent equation of state which includes phase transitions and strength effects has been developed and used to examine shock and release data on quartz and silicate rocks in order to quantify the kinetics of the reverse transition and to separate the hysteretic effects due to reverse phase transition kinetics from those due to material strength. The model allows quantitative determination of the effect of reverse transition kinetics on ground shock propagation in silicate materials.

Severe nuclear reactor accidents - accidents involving the melting of the reactor core - dominate the residual risk associated with the use of nuclear power. The uninterrupted progression of a severe reactor accident is expected to lead to the expulsion of core debris into the reactor containment. Many safety-significant phenomena may be hypothesized to occur when core debris is expelled from the reactor coolant system. The exact nature of these events depends on whether or not the coolant system is pressurized at the time of melt expulsion and whether or not expulsion is into water. Regardless of what transient events are associated with the initial expulsion of core debris from the reactor coolant system, a protracted period of core debris interactions with the structural concrete of the reactor is expected in most analyses of severe reactor accidents.

Results for Cr/Fe/Ni films are reported, showing that the simulation of electron scattering in solids by Monte Carlo techniques is well suited to parallel computation. Significant gains in computation time are realized and make explicit calculation of convoluted composition profiles possible. Computation time is sufficiently shortened to enable such simulations to be used in a real-time experimental environment. Because such simulations break naturally into independent computational pieces that require little intercommunication, they are ideal candidates for fast parallel implementation on a MIMD machine such as the NCUBE 2. Similar performance gains should be possible for other kinds of Monte Carlo transport simulations.

The history and current status of dish-Stirling receiver development are presented and discussed. The technical challenges to be addressed by the dish-Stirling community and the future plans at Sandia National Laboratories are outlined. Stirling tube and reflux solar receiver technologies are discussed. Pool-boiler receiver technology has been successfully tested and a number of promising heat-pipe receiver designs are very close to hardware demonstrations. The high-efficiency potential of reflux receivers has been demonstrated. However, many of the technical challenges that led to the change from tube to reflux receivers-especially life and reliability, systems integration, and hybridization-are just beginning to be addressed by the dish-Stirling community.

Superconducting crystals of La2CuO4+x prepared by high-pressure oxygenation have been analyzed by Raman spectroscopy. A direct comparison of the role of excess oxygen was made by examining the same crystals with and without excess oxygen. La2CuO4+x, like non-superconducting La2CuO4.0, is found to have a soft phonon that derives an orthorhombic to tetragonal phase transition. In both its tetragonal and orthorhombic forms, La2CuO4+x has a phonon peak at 630 cm-1 that is absent in La2CuO4.0. The frequency of this peak is suggestive of a peroxide-like species in La2CuO4+x. Surprisingly, the Ag phonons of La2CuO4.0 and La2CuO4+x occur at essentially the same frequency. While La2CuO4.0 has a well-defined peak from double-magnon scattering, no well-defined double-magnon scattering is observed in La2CuO4+x, even in its phase-separated form.

A procedure for updating estimates of an object's pose using information from one or more monocular images is presented. Features in monocular images are assigned correspondence with modeled three-dimensional (3-D) features based on estimated object position. An improved position estimate is computed based on the feature correspondence. The method accommodates partial occlusion or contact among objects. Features need not appear in multiple views to be used for estimation. Results from this system are presented which demonstrate the location of multiple objects within approximately 0.1 in. in translation and 2° in rotation.

A general-purpose robotic grasping system for use in unstructured environments is described. Using computer vision and a compact set of heuristics, the system automatically generates the robot arm and hand motions required for grasping an unmodeled object. The utility of such a system is most evident in environments where the robot will have to grasp and manipulate a variety of unknown objects, but where many of the manipulation tasks may be relatively simple. Examples of such domains are planetary exploration and astronaut assistance, undersea salvage and rescue, and nuclear waste site clean-up. A two-stage model of grasping is described. Stage one is an orientation of the hand and wrist and a ballistic reach toward the object; stage two is hand preshaping and adjustment. Visual features are first extracted from the unmodeled object. These features and their relations are used by an expert system to generate a set of valid reaches/grasps for the object. These grasps are then used in driving the robot hand and arm to bring the fingers into contact with the object in the desired configuration.

A method is described for obtaining the boundary equations of configuration obstacles for stick-figure manipulators in three-dimensional environments. Polyhedral obstacles are represented as a collection of planar triangular patches, and the intersection conditions between a line segment and a triangular patch are used to derive boundary equations. It is shown that the boundary equation for the nth joint variable can be solved explicitly in terms of the 0th, 1st, ..., (n-1)th joint variables. The expressions can be used to compute configuration obstacles or to analyze the geometry of contacts between manipulators and obstacles.

We are investigating direct laser-produced plasmas as an ion source for the PBFA II pulsed power accelerator. Laser-generated plasmas have several potential advantages for this application, including the ability to generate a pre-formed anode plasma, simplicity, and flexibility. Previous experiments have shown that a high-density lithium plasma can be produced by direct laser irradiation of a solid lithium surface with a pulsed dye laser tuned to the Li 1s-2p resonance line at 670.8 nm (Laser Ionization Based On Resonant Saturation - LIBORS). We are also investigating a two-step approach, which uses a short-pulse Nd:YAG laser to efficiently vaporize the lithium-bearing source material, followed by LIBORS ionization of the evolving vapor to produce plasmas of mid-1016/cm3 densities. © 1990 World Scientific.

The experimental results of model-based and sensor-based control strategies for a two-link, flexible, planar robot arm are analyzed. Off-line optimization determines a minimum-time, straight-line tip trajectory which stays within the torque constraints of the motors and ends in a quiescent state, i.e., no vibrational transients. An efficient finite-element model is used in the optimization to approximate the flexible arm dynamics. Control schemes tested include an open-loop torque profile, a closed-loop proportional-derivative (PD) joint controller, and a feedforward controller. This last scheme uses the torque profile created from the optimization, along with PD feedback of the joint angles and proportional feedback of the strain gages, to correct for errors in the model. The results show that the best performance is achieved with this feedforward approach.

The use of one or more monocular images to estimate the three-dimensional position of objects is investigated. The identities of the objects are known, and geometric models are assumed to be available. Linear features extracted from sensor data are interpreted as corresponding with model features by search of an interpretation tree built using prior position estimates. Object positions are updated by maximum-likelihood estimation. Position estimation results from an implemented system are presented, demonstrating the location of partially occluded objects in a cluttered scene.

On-line chemical monitoring systems can help ensure safe, environmentally sound operation of industrial processes using hazardous chemicals. Using polymer-coated surface acoustic wave (SAW) sensors, we have demonstrated monitors that are capable of detecting dilute concentrations of volatile organic species. Using changes in both wave velocity and wave attenuation, the identity and concentration of an isolated chemical species can be determined. A polysiloxane coating has been found to provide unique properties for monitoring chlorinated hydrocarbons (CHCs) such as trichloroethylene: good discrimination of CHCs from most other organic species, rapid and reversible sensor response, and low detection limits. Using this technology, a portable acoustic wave sensor (PAWS) system has been constructed.

Quantitative analysis routines based on the Bence-Albee, the ZAF, and the {Phi}({rho}Z) techniques are available for the TASK8 microprobe operating system. All of the routines are able to be run from within TASK8 or as stand alone programs. For quick analyses, energy dispersive x-ray data can be collected and processed by running the Tracor standardless quantitative (SQ) routine from within TASK8. For normal analyses, data are collected via the wavelength spectrometers. The procedures and routines described in this document permit the interactive collection and processing of data via joystick control or the automatic collection and processing of data from up to seven line traces or an essentially unlimited number of preselected points. 7 refs., 5 figs., 1 tab.

Sandia National Laboratories operates the Primary Standards Laboratory (PSL) for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the first half of 1990 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.

Sandia National Laboratories, Albuquerque, has been designated as Lead Center for the Exploratory Battery Technology Development and Testing Project, which is sponsored by the US Department of Energy's Office of Energy Storage and Distribution. In this capacity, Sandia is responsible for the engineering development of advanced rechargeable batteries for both mobile and stationary energy storage applications. This report details the technical achievements realized in pursuit of the Lead Center's goals during calendar year 1989. 4 refs., 84 figs., 18 tabs.

This report describes some field tests of the CUBIC CR-100 distance measuring equipment. The distance measurements depend on the refractivity of the atmospheric. The CR-100 uses 320 for the refractivity. For the Albuquerque area on a clear spring day, 220 is a more realistic value for refractivity. This difference of 100 between the actual and assumed refractivities causes the range error to accumulate at the rate of 1 meter per 10,000 meters of range. For example, a difference of 100 in refractivity forces the measured range to contain an error of 5 meters for a 50,000 meter baseline. 12 figs.

The Explosive Components Facility (ECF) is to be a new major facility in the Sandia National Laboratories (SNL) Weapons Program. The ECF is a self-contained, secure site on SNL property and is surrounded by Kirtland Air Force Base which is located 6-1/2 miles east of downtown Albuquerque, New Mexico. The ECF will be dedicated to research, development, and testing of detonators, neutron generators, batteries, explosives, and other weapon components. It will have capabilities for conducting explosive test fires, gas gun testing, physical analyses, chemical analyses, electrical testing and ancillary explosive storage in magazines. The ECF complex is composed of a building covering an area of approximately 91,000 square feet, six exterior explosive service magazines and a remote test cell. Approximately 50% of the building space will be devoted to highly specialized laboratory and test areas, the other 50% of the building is considered nonhazardous. Critical to the laboratory and test areas are the blast-structural design consideration and operational considerations, particularly those concerning personnel access control, safety and environmental protection. This area will be decoupled from the rest of the building to the extent that routine tests will not be heard or felt in the administrative area of the building. While the ECF is designed in accordance with the DOE Explosives Safety Manual to mitigate any off-site blast effects, potential injuries or death to the ECF staff may result from an accidental detonation of explosive material within the facility. Therefore, reducing the risk of exposing operation personnel to hazardous and energetic material is paramount in the design of the ECF.

This report describes the Phase 1 drilling operations for the Magma Energy Exploratory Well near Mammoth Lakes, California. An important part of the Department of Energy's Magma Energy Program, this well is designed to reach an ultimate depth of 20,000 feet or a bottomhole temperature of 500{degree}C, whichever comes first. There will be four drilling phases, at least a year apart, with scientific investigations in the borehole between the drilling intervals. Phase 1 of this project resulted in a 20 inch cased hole to 2558 feet, with 185 feet of coring beyond that. This document comprises a narrative of the daily activities, copies of the daily mud and lithologic reports, time breakdowns of rig activities, inventories of lost circulation materials, temperature logs of the cored hole, and a strip chart mud log. 2 figs.

The validity of scale model impact evaluation of the SST Transportation System is acceptable based on Dimensional Analysis (Buckingham Pi Theorem) and the work of numerous programs that have evaluated the agreement among dimensional analysis, several different reduced-size models and full-scale impact test data. Excellent accuracy has been demonstrated between scale models and full-scale impact data when collected in conformance with the Buckingham Pi Theorem. 20 refs., 4 figs.

A five-step procedure was used in the 1990 performance simulations to construct probability distributions of the uncertain variables appearing in the mathematical models used to simulate the Waste Isolation Pilot Plant's (WIPP's) performance. This procedure provides a consistent approach to the construction of probability distributions in cases where empirical data concerning a variable are sparse or absent and minimizes the amount of spurious information that is often introduced into a distribution by assumptions of nonspecialist. The procedure gives first priority to the professional judgment of subject-matter experts and emphasizes the use of site-specific empirical data for the construction of the probability distributions when such data are available. In the absence of sufficient empirical data, the procedure employs the Maximum Entropy Formalism and the subject-matter experts' subjective estimates of the parameters of the distribution to construct a distribution that can be used in a performance simulation. 23 refs., 4 figs., 1 tab.

This report documents the data available as of August 1990 and used by the Performance Assessment Division of Sandia National Laboratories in its December 1990 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Parameter values are presented in table form for the geologic subsystem, engineered barriers, borehole flow properties, climate variability, and intrusion characteristics. Sources for the data and a brief discussion of each parameter are provided. 101 refs., 72 figs., 21 tabs.

A theoretical model was developed for the minimum charge to trigger a gaseous detonation in spherical geometry as a generalization of the Zeldovich model. Careful comparisons were made between the theoretical predictions and experimental data on the minimum charge to trigger detonations in propane-air mixtures. The predictions are an order of magnitude too high, and there is no apparent resolution to the discrepancy. A dynamic model, which takes into account the experimentally observed oscillations in the detonation zone, may be necessary for reliable predictions. 27 refs., 9 figs.

The Salado Formation is a thick evaporite sequence located in the Permian Delaware Basin of southeastern New Mexico. This study focuses on the intense diagenetic alteration that has affected the small amounts of clay, feldspar, and quartz washed into the basin during salt deposition. These changes are of more than academic interest since this formation also houses the WIPP (Waste Isolation Pilot Plant). Site characterization concerns warrant compiling a detailed data base describing the clays in and around the facility horizon. An extensive sampling effort was undertaken to address these programmatic issues as well as to provide additional insight regarding diagenetic mechanisms in the Salado. Seventy-five samples were collected from argillaceous partings in halite at the stratigraphic level of the Waste Isolation Pilot Plant (WIPP). These were compared with twenty-eight samples from cores of the Vaca Triste member of the Salado, a thin clastic unit at the top of the McNutt potash zone, and with a clay-rich sample from the lower contact of the Culebra Dolomite (in the overlying Rustler Formation). These settings were compared to assess the influence of differences in brine chemistry (i.e., halite and potash facies, normal to hypersaline marine conditions) and sediment composition (clays, sandy silt, dolomitized limestone) on diagenetic processes. 44 refs., 11 figs., 5 tabs.

The Waste Isolation Pilot Plant (WIPP) is planned as the first mined geologic repository for transuranic (TRU) wastes generated by defense programs of the United States Department of Energy (DOE). Before disposing of waste at the WIPP, the DOE must evaluate compliance with the United states Environmental Protection Agency's (EPA) Standard, Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR Part 191, US EPA, 1985). Sandia National Laboratories (SNL) is evaluating long-term performance against criteria in Subpart B of the Standard. Performance assessment'' as used in this report includes analyses for the Containment Requirements ({section} 191.13(a)) and the Individual Protection Requirements ({section} 191.15). Because proving predictions about future human actions or natural events is not possible, the EPA expects compliance to be determined on the basis of specified quantitative analyses and informed, qualitative judgment. The goal of the WIPP performance-assessment team at SNL is to provide as detailed and thorough a basis as practical for the quantitative aspects of that decision. This report summarizes SNL's late-1990 understanding of the WIPP Project's ability to evaluate compliance with Subpart B. 245 refs., 88 figs., 23 tabs.

Calculations were performed with CTH (a finite difference hydrodynamics code) to evaluate computational capabilities for predicting residual projectile length and position in high velocity penetration events. The calculations simulated selected tests in a set of armor penetration experiments conducted and reported by Los Alamos National Laboratory. The tests and simulations involved penetration of armor ranging from 6.4 to 50.8 mm in thickness by long rod projectiles over a range of velocities from 1.0 to 1.29 km/sec. Comparisons are made between the calculated and measured final projectile lengths and positions, and the sensitivity of the predicted results to target and projectile property variations is investigated. 8 refs., 11 figs., 8 tabs.

This study supports the Waste Isolation Pilot Plant (WIPP) Final Supplemental Environmental Impact Statement and has two main objectives. First, it describes current ideas about the characteristics and potential impacts of the disturbed-rock zone (DRZ) known to develop with time around excavations at the WIPP horizon. Second, it presents new calculations of radionuclide migration within and from the WIPP repository for steady-state undisturbed conditions and for two cases that consider human intrusion into the repository. At the WIPP, the presence of a DRZ has been confirmed by geophysical studies, gas-flow tests, and direct observations. The DRZ will allow gas or brine from waste-emplacement panels to bypass panel seals and flow into adjacent portions of the underground workings unless preventive measures are taken. Revised calculations of the undisturbed performance of the repository indicate that no radionuclides will be released into the Culebra Dolomite within the regulatory period of 10,000 years. The human-intrusion calculations included here assume a connection between the WIPP repository, an occurrence of pressurized brine within the underlying Castile Formation, and the overlying Culebra Dolomite. 61 refs., 40 figs., 16 tabs.

The problem of calculating the vibrations of rotating structures has challenged analysts since the observation that use of traditional modal coordinates in such problems leads to the prediction of instability involving infinite deformation when rotation rates exceed the first natural frequency. Much recent published work on beams has shown that such predictions are artifacts of incorporating incomplete kinematics into the analysis, but that work addresses analysis of only simple structures such as individual beams and plates. The authors present a new approach to analyzing rotating flexible structures that applies to the rotation of general linear (unjointed) structures, using a system of nonlinearly coupled deformation modes. This technique is called a Method of Quadratic Modes. 37 refs., 5 figs., 1 tab.

The geochemical modeling codes EQ3NR/EQ6 were used to model the interaction of cementitious materials with ground water from the Yucca Mountain proposed nuclear waste repository site in Nevada. This paper presents a preliminary estimate of the compositional changes caused by these interactions in the ground water and in the cement-based compounds proposed for use as sealing and shaft liner materials at the Yucca Mountain site. The geochemical speciation/solubility/reaction path codes EQ3NR/EQ6 were used to model the interaction of cementitious materials and water. Interaction of water with a cementitious material will result in dissolution of certain cement phases and changes in the water chemistry. These changes in the water chemistry may further lead to the precipitation of minerals either in the concrete or in the surrounding tuff at the Yucca Mountain Site (YMS). As part of a larger scoping study, a range of water, cement, and tuff compositions, temperatures, and reaction path modes were used. This paper presents a subset of that study by considering the interaction of three different cement formulations at 25{degree}C with J-13 water using the ``closed`` reaction path mode. This subset was chosen as a base case to answer important questions in selecting the compositions of cementitious materials for use in the proposed repository. 8 refs., 1 fig., 3 tabs.

American Samoa has no indigenous fossil fuels and is almost totally dependent for energy on seaborne petroleum. However, the seven Pacific Islands located at 14 degrees south latitude that constitute American Samoa have a wide variety of renewable resources with the potential for substituting for imported oil. Included as possible renewable energy conversion technologies are solar thermal, photovoltaics, wind, geothermal, ocean thermal, and waste-to-energy recovery. This report evaluates the potential of each of these renewable energy alternatives and establishes recommended priorities for their development in American Samoa. Rough cost estimates are also included. Although renewable energy planning is highly site specific, information in this report should find some general application to other tropical insular areas.

In this report, we provide a detailed discussion of methodology of predicting cable degradation versus dose rate, temperature, and exposure time and its application to data obtained on a number of additional nuclear power plant cable insulation (a hypalon, a silicon rubber and two ethylenetetrafluoroethylenes) and jacket (a hypalon) materials. We then show that the predicted, low-dose-rate results for our materials are in excellent agreement with long-term (7 to 9 years), low dose-rate results recently obtained for the same material types actually aged under nuclear power plant conditions. Based on a combination of the modelling and long-term results, we find indications of reasonably similar degradation responses among several different commercial formulations for each of the following generic'' materials: hypalon, ethylenetetrafluoroethylene, silicone rubber and PVC. If such generic'' behavior can be further substantiated through modelling and long-term results on additional formulations, predictions of cable life for other commercial materials of the same generic types would be greatly facilitated. Finally, to aid utilities in their cable life extension decisions, we utilize our modelling results to generate lifetime prediction curves for the materials modelled to data. These curves plot expected material lifetime versus dose rate and temperature down to the levels of interest to nuclear power plant aging. 18 refs., 30 figs., 3 tabs.

PRONTO 2D and PRONTO 3D are two- and three-dimensional transient solid dynamics codes for analyzing large deformations of highly nonlinear materials subjected to high strain rates. This newsletter is issued to document changes to these codes. As of this writing, the latest version of PRONTO 2D is Version 4.5.6, and the latest version of PRONTO 3D is Version 4.5.6. This update of the two codes discusses two major modifications to the numerical formulations, three new constitutive models, and the additions and improvements of contact surfaces. Changes in file formats, other miscellaneous revisions, and the availability of PRONTO 2D and PRONTO 3D are also discussed. In addition, updated commands for PRONTO 2D are provided in Appendix A of this newsletter. 29 refs., 12 figs., 2 tabs.

This report analyzes the effects of finite-precision arithmetic on discrete Fourier transforms (DFTs) calculated using the chirp-z transform algorithm. An introduction to the chirp-z transform is given together with a description of how the chirp-z transform is implemented in hardware. Equations for the effects of chirp rate errors, starting frequency errors, and starting phase errors on the frequency spectrum of the chirp-z transform are derived. Finally, the maximum possible errors in the chirp rate, the starting frequencies, and starting phases are calculated and used to compute the worst case effects on the amplitude and phase spectrums of the chirp-z transform. 1 ref., 6 figs.

Numerous gas flow measurements have been made at the Waste Isolation Pilot Plant (WIPP) Facility horizon during 1988. All tests have been pressure decay or constant pressure tests from single boreholes drilled from the underground excavations. The test fluid has been nitrogen. The data have been interpreted as permeabilities and porosities by means of a transient numerical solution method. A closed-form steady-state approximation provides a reasonable order-of-magnitude permeability estimate. The effective resolution of the measurement system is less than 10{sup {minus}20} m{sup 2}. Results indicate that beyond 1 to 5 m from an excavation, the gas flow is very small and the corresponding permeability is below the system resolution. Within the first meter of an excavation, the interpreted permeabilities can be 5 orders of magnitude greater than the undisturbed or far-field permeability. The interpreted permeabilities in the region between the undisturbed region and the first meter from an excavation are in the range of 10{sup {minus}16} to 10{sup {minus}20} m{sup 2}. Measurable gas flow occurs to a greater depth into the roof above WIPP excavations of different sizes and ages than into the ribs and floor. The gas flows into the formation surrounding the smallest excavation tested are consistently lower than those at similar locations surrounding larger excavations of comparable age. Gas flow measured in the interbed layers near the WIPP excavations is highly variable. Generally, immediately above and below excavations, relatively large gas flow is measured in the interbed layers. These results are consistent with previous measurements and indicate a limited disturbed zone surrounding WIPP excavations. 31 refs., 99 figs., 5 tabs.

A workstation manufactured by International Business Machines Corporation (IBM) was loaned to the Simulation Technology Research Division for evaluation. We have found that these new UNIX workstations from IBM have superior cost to performance ratios compared to the CRAY supercomputers and Digital's VAX machines. Our appraisal of this workstation included floating-point performance, system and environment functionality, and cost effectiveness. Our assessment was based on a suite of radiation transport codes developed at Sandia that constitute the bulk of our division's computing workload. In this report, we also discuss our experience with features that are unique to this machine such as the AIX operating system and the XLF Fortran Compiler. The interoperability of the RS/6000 workstation with Sandia's network of CRAYs and VAXs was also assessed.

A pilot plant project was undertaken to develop a central refrigeration compressor station capable of providing the necessary cooling to a network of nine independently-controlled environmental test chambers operating at temperatures of {minus}85{degree}F to 350{degree}F. Design features of the central two-stage (cascade) vapor compression refrigeration system are described. Computer control of the central refrigeration station is a major contribution to the improved efficiency of the overall system. A second computer-control system was developed to perform the task of environmental chamber control, test management, and chamber performance monitoring. Data on performance of the Climatic Central Refrigeration System (CCRS) are presented. 7 refs., 18 figs.

A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

Automated entry control has become an increasingly important issue at facilities where budget constraints are limiting options for manned entry control points. Three questions are immediately raised when automated entry control is considered: What hardware is available How much does it cost How effective is it in maintaining security Ongoing work at Sandia National Labs is attempting to answer these questions and establish a data base for use by facility security managers working the problem of how to maintain security on a limited budget. 14 refs.

A wide variety of physical phenomena arising within many scientific disciplines can be described by systems of coupled partial differential equations (PDEs). The numerical approximation of these PDEs often involves the solution of a system of algebraic equations (possibly nonlinear) which are typically large, sparse and nonsymmetric. The increasing computational demands required by the solution of such complex scientific applications has motivated the current direction toward large-scale parallel computers. We, therefore, consider solution techniques of representative systems of equations on large scale MIMD machines. Our primary emphasis in this study is the evaluation of iterative methods for the solution of nonsymmetric systems. In particular, we discuss two Krylov subspace methods, the conjugate gradient squared algorithm (CGS) and the generalized minimum residual method (GMRES), along with the multigrid algorithm (MG) on massively parallel MIMD architectures. The focus of this evaluation considers the performance of various algorithm and implementation variations over a broad selection of problems using a parallel machine.

The corrosion behavior of a rapidly solidified Al-Fe-Gd alloy glass was studied in aqueous chloride environments of varying pH using potentiodynamic polarization. The corrosion behavior of a rapidly solidified pure Al glass, crystalline Al-Fe-Gd alloy and crystalline Al were measured for comparison. Due to lattice disorder, the dissolution rate of the glasses in the passive region was greater than that of their crystalline counterparts. The breakaway potentials measured for the glasses were more positive than those of the crystalline metals because film breakdown initiation sites like second phase particles and internal boundaries were not present in the glass. Alloy glass specimens exposed to alkaline solutions exhibited lower passive current densities and higher breakaway potentials than expected. This appeared to be a result of an enrichment of oxidized Fe at the specimen surface. This Fe-rich protective film also appeared to form in pits which developed on crystallized specimens tested in neutral chloride solutions.

There are tremendous resources of natural gas in tight fissured rocks, but these formations require special care for hydraulic fracturing to be successful. Serious problems include leakoff, damage and complex fracturing. Leakoff may be constant, pressure-sensitive, or accelerating. Leakoff becomes most severe when fissures begin to dilate and accept large volumes of fracture fluid, which may rapidly dehydrate a sandladen slurry. Determining values of pressure-sensitive and accelerated leakoff coefficients is difficult, and generally requires both a pressure-decline analysis (after a minifrac) and an analysis of the injection pressure. Fine-mesh sand, often used in fissured reservoirs, will help control leakoff. Damage to the natural fractures, due to leakoff of the fluid and gels and to mechanical types of damage, must be avoided, since the fissures are the production mechanism. It is particularly important to minimize the amount of liquid and gels, since the fissures are narrow and easily blocked. These concepts are also applicable to oil reservoirs.

This document contains the steady-state and loss-of-pumping accident analysis of the representative design for the Savannah River heavy water new production reactor. A description of the reactor system and computer input model, the results of the steady-state analysis, and the results of four loss-of-pumping accident calculations are presented. 5 refs., 37 figs., 4 tabs.

This report lists the measurement capabilities of the Department of Energy Contractors' Standard Laboratories within the Nuclear Weapon Complex. It is intended to foster cross-utilization of measurements between laboratories and provides a guide for survey and audit activities. Although this report was prepared by Sandia Primary Standards Laboratory (PSL), the PSL was intentionally omitted. Capabilities of the PSL are documented in SAND88-3402.UC-700.

Early attempts at estimation of stress wave damage due to blasting by use of finite element calculations met with limited success due to numerical instabilities that prevented calculations from being carried to late times. An improved damage model allows finite element calculations which remain stable at late times. Reasonable agreement between crater profiles calculated with this model using the PRONTO finite element program and excavated crater profiles from blasting experiments in granite demonstrate a successful application of this model. Detailed instructions for use of this new damage model with the PRONTO finite element programs are included. 18 refs., 16 figs.

The DEBRIS module was developed to deal with the analysis of core melt processes in Light Water Reactors (LWR's). It was designed to address the important processes associated with the late phase'' of a core meltdown. This phase encompasses the period following the loss of intact rod geometry and ending with vessel head failure. It is characterized by the melting and relocation of ceramic rich materials through a rubblized medium composed primarily of fuel pellet and oxidized cladding fragments. Of particular interest are the dynamics of the melting process, the relocation of the components, the formation of crusts, retention of molten materials by the crust, and remelting of crusts. The DEBRIS module treats these processes in a two-dimensional (r,z) geometry solving the continuity, momentum, and energy equations to describe the dynamics of meltdown. The DEBRIS models are described together with some of the analyses to which the module has been applied. In particular, a description is given of the DEBRIS module analysis of the MP-1 experiment. The DEBRIS module appears to have significant potential for the analysis of late phase'' meltdown processes and can be effectively used both in a stand-alone mode or in conjunction with the severe accident analysis codes (MELCOR,SCDAP). In addition, the module may prove effective for treatment of the early phase processes as well. 19 refs., 16 figs.

Position location is a fundamental requirement in autonomous mobile robots which record and subsequently follow x,y paths. The Dept. of Energy, Office of Safeguards and Security, Robotic Security Vehicle (RSV) program involves the development of an autonomous mobile robot for patrolling a structured exterior environment. A straight-forward method for autonomous path-following has been adopted and requires digitizing'' the desired road network by storing x,y coordinates every 2m along the roads. The position location system used to define the locations consists of a radio beacon system which triangulates position off two known transponders, and dead reckoning with compass and odometer. This paper addresses the problem of combining these two measurements to arrive at a best estimate of position. Two algorithms are proposed: the optimal'' algorithm treats the measurements as random variables and minimizes the estimate variance, while the average error'' algorithm considers the bias in dead reckoning and attempts to guarantee an average error. Data collected on the algorithms indicate that both work well in practice. 2 refs., 7 figs.

The MC4039 Unique Signal Override Plug (USOP) provides the unique signal for the B90 when fielded on aircraft that are not equipped with unique signal capability. Since the USOP is field installed, the concern is that it might be susceptible to electromagnetic radiation prior to installation on the weapon. This report documents a characterization of the USOP, evaluates various techniques for attaching electromagnetic shields, and evaluates the susceptibility of a fully assembled passive-USOP. Tests conducted evaluated the electromagnetic susceptibility of the passive, unconnected USOP. During normal operation the USOP is powered directly from the weapon. During the course of this test program two prototypes were developed. The prototype 1 USOP internal circuitry contains one SA3727 chip, five diodes, three resistors, and two capacitors; these are mounted on a circular circuit board and contained inside a metal back shell cover, which serves as an electromagnetic shield. The prototype 2 design incorporated four changes. The manufacturer of the SA3727 chip was changed from Lasarray to LSI Logic, the circuit board ground was tied to the case ground through a straight wire, Cl was changed from 1 microfarad to 0.1 microfarads. and the circuit board was changed, as required. 2 refs., 17 figs., 3 tabs. (JF)

Using Sequoyah as a representative plant, calculations have been performed with a developmental version of the CONTAIN computer code to assess the effectiveness of various possible improvements to ice condenser containments in mitigating severe accident scenarios involving direct containment heating (DCH) and/or hydrogen combustion. Mitigation strategies considered included backup power for igniters and/or air return fans, augmented igniter systems, containment venting, containment inerting, subatmospheric containment operation, reduced ice condenser bypass, and primary system depressurization. Various combinations of these improvements were also considered. Only inerting the containment or primary system depressurization combined with backup power supplies for the igniter systems resulted in large decreases in the peak pressures calculated to result from DCH events. Potential hydrogen detonation threats were also assessed; providing backup power for both the igniter systems and the air return fans would significantly reduce the potential for detonations but might not totally eliminate it. Sensitivity studies using the NUREG-1150 PRA methodology indicated that primary system depressurization combined with backup power for both igniters and fans could reduce the contribution to the mean risk potential of the class of events considered by about a factor of three. 7 refs., 6 figs., 6 tabs.

Finding new and improved means of cooling small electronic packages are of great importance to today's electronic packaging engineer. Thermal absorption through the use of a material which changes phase is an attractive alternative. Taking advantage of the heat capacity of a material's latent heat of fusion is shown to absorb heat away from the electronics, thus decreasing the overall temperature rise of the system. The energy equation is formulated in terms of enthalpy and discretized using a finite-difference method. A FORTRAN program to solve the discretized equations is presented which can be used to analyze heat conduction in a rectangular region undergoing an isothermal phase change. An analysis of heat transfer through a miniature radar electronic module cooled by a phase-change reservoir is presented, illustrating the method's advantages over conventional heat sinks. 41 refs., 11 figs., 2 tabs.

This report gives an annotated bibliography of reports published in 1989 by the Nuclear Energy Technology Directorate. A listing is also given of reports published by the staff in the nuclear energy field since 1972.

Remote automated cask handling has the potential to reduce both the occupational exposure and the time required to process a nuclear waste transport cask at a handling facility. The ongoing Advanced Handling Technologies Project (AHTP) at Sandia National Laboratories is described. AHTP was initiated to explore the use of advanced robotic systems to perform cask handling operations at handling facilities for radioactive waste, and to provide guidance to cask designers regarding the impact of robotic handling on cask design. The proof-of-concept robotic systems developed in AHTP are intended to extrapolate from currently available commercial systems to the systems that will be available by the time that a repository would be open for operation. The project investigates those cask handling operations that would be performed at a nuclear waste repository facility during cask receiving and handling. The ongoing AHTP indicates that design guidance, rather than design specification, is appropriate, since the requirements for robotic handling do not place severe restrictions on cask design but rather focus on attention to detail and design for limited dexterity. The cask system design features that facilitate robotic handling operations are discussed, and results obtained from AHTP design and operation experience are summarized. The application of these design considerations is illustrated by discussion of the robot systems and their operation on cask feature mock-ups used in the AHTP project. 11 refs., 11 figs.

This report describes the clutter model developed at Sandia National Laboratories for the SRIM code version 2.2s. The SNL clutter model is a fully polarimetric model that includes both coherent and incoherent scattering effects. The input parameters to the SNL clutter model are chosen so that an acceptable match is obtained between the model predicted data and the appropriate experimental data. These input parameters are then used in the SRIM code to simulated the desired clutter type. 12 refs., 13 figs., 2 tabs.

The DF-4 in-pile fuel damage experiment investigated the behavior of boiling water reactor (BWR) fuel canisters and control blades in the high temperature environment of an unrecovered reactor accident. This experiment, which was carried out in the Annular Core Research Reactor (ACRR) at Sandia National Laboratories, was performed under the USNRC's internationally sponsored severe fuel damage (SFD) program. The DF-4 test is described herein and results from the experiment are presented. Important findings from the DF-4 test include the low temperature melting of the stainless steel control blade caused by reaction with the B{sub 4}C, and the subsequent low temperature attack of the Zr-4 channel box by the relocating molten blade components. Hydrogen generation was found to continue throughout the experiment, diminishing slightly following the relocation of molten oxidizing zircaloy to the lower extreme of the test bundle. A large blockage which was formed from this material continued to oxidize while steam was being fed into the the test bundle. The results of this test have provided information on the initial stages of core melt progression in BWR geometry involving the heatup and cladding oxidation stages of a severe accident and terminating at the point of melting and relocation of the metallic core components. The information is useful in modeling melt progression in BWR core geometry, and provides engineering insight into the key phenomena controlling these processes. 12 refs., 12 figs.

The Hydrologic Code Intercomparison Project (HYDROCOIN) was formed to evaluate hydrogeologic models and computer codes and their use in performance assessment for high-level radioactive-waste repositories. This report describes the results of a study for HYDROCOIN of model sensitivity for isothermal, unsaturated flow through layered, fractured tuffs. We investigated both the types of flow behavior that dominate the performance measures and the conditions and model parameters that control flow behavior. We also examined the effect of different conceptual models and modeling approaches on our understanding of system behavior. The analyses included single- and multiple-parameter variations about base cases in one-dimensional steady and transient flow and in two-dimensional steady flow. The flow behavior is complex even for the highly simplified and constrained system modeled here. The response of the performance measures is both nonlinear and nonmonotonic. System behavior is dominated by abrupt transitions from matrix to fracture flow and by lateral diversion of flow. The observed behaviors are strongly influenced by the imposed boundary conditions and model constraints. Applied flux plays a critical role in determining the flow type but interacts strongly with the composite-conductivity curves of individual hydrologic units and with the stratigraphy. One-dimensional modeling yields conservative estimates of distributions of groundwater travel time only under very limited conditions. This study demonstrates that it is wrong to equate the shortest possible water-travel path with the fastest path from the repository to the water table. 20 refs., 234 figs., 10 tabs.

The US Department of Energy is responsible for the design, construction, operation, and decommission of a site for the deep geologic disposal of high-level radioactive waste (HLW). This involves site characterization and the use of performance assessment to demonstrate compliance with regulations for HLW disposal from the US Environmental Protection Agency (EPA) and the US Nuclear Regulatory Commission. The EPA standard states that a performance assessment should consider the associated uncertainties involved in estimating cumulative release of radionuclides to the accessible environment. To date, the majority of the efforts in uncertainty analysis have been directed toward data and parameter uncertainty, whereas little effort has been made to treat model uncertainty. Model uncertainty includes conceptual model uncertainty, mathematical model uncertainty, and any uncertainties derived from implementing the mathematical model in a computer code. Currently there is no systematic approach that is designed to address the uncertainty in conceptual models. The purpose of this investigation is to take a first step at addressing conceptual model uncertainty. This will be accomplished by assessing the relative impact of alternative conceptual models on the integrated release of radionuclides to the accessible environment for an HLW repository site located in unsaturated, fractured tuff. 4 refs., 2 figs.

An intermediate step in the development of inertial confinement fusion (ICF) for power production will be the development and testing of a high-gain facility. One concept being considered for this facility is the Laboratory Microfusion Facility (LMF). Other projected applications of the LMF include high-energy-density physics experiments and nuclear effects testing. At the Air Force Institute of Technology (AFIT), Lawrence Livermore National Laboratory (LLNL), and Sandia National Laboratories Albuquerque (SNLA), we have been studying the use of the LMF for nuclear effects experiments. Because of the amount of energy that will be released in a high-gain ICF test and the size of the LMF, test objects could be any size from very small electronic components to large systems; and nuclear effects in the LMF may include thermal radiation, x-rays, electromagnetic pulse, gamma rays, neutrons, or others. At AFIT, LLNL, and SNLA we have been investigating a test to expose systems to high-energy x-ray pulses, and have completed predictions of x-ray fluence, dose, etc. in various conceptual LMF reactors. However, comparison of our results is more meaningful if our prediction methods produce the same results for the same design. To establish a basis for comparison, we set up a simple benchmark problem and we each computed x-ray and neutron transport. The model and codes are described and the results are compared and discussed.

Partial least squares multivariate calibration methods were applied to the infrared spectra of a new set of borophosphosilicate glass (BPSG) thin films on silicon wafers. The calibration samples were prepared by a low pressure chemical vapor deposition (LPCVD) process. The statistically designed calibration set included data from nearly 400 coated Si wafers. Calibrations were attempted for properties such as dopant concentrations, thickness, etch rate, film stress, and electrical parameters. It was found that annealed films were predicted more precisely than unannealed films. B, P, and thickness measurements yielded the most precise results by these techniques. Multivariate calibration methods applied to etch rate for annealed films and unannealed film stress provided some limited predictive ability. The detection and removal of outliers greatly improved the analysis precisions. Finally, within wafer and between wafer dopant uniformity may be responsible for degrading the precision of these analytical methods.

Particle Impact Noise Detection (PIND) testing is widely used to test electronic devices for the presence of conductive particles which can cause catastrophic failure. This paper develops a statistical model based on the rate of particles contaminating the part, the rate of particles induced by the test vibration, the escape rate, and the false alarm rate. Based on data from a large number of PIND tests for a canned transistor, the model is shown to fit the observed results closely. Knowledge of the parameters for which this fit is made is important in evaluating the effectiveness of the PIND test procedure and for developing background judgment about the performance of the PIND test. Furthermore, by varying the input parameters to the model, the resulting yield, failure rate and percent fallout can be examined and used to plan and implement PIND test programs.

The proposed high-level nuclear waste repository at Yucca Mountain, Nevada will have many miles of underground openings. Because of the long-term nature of this project it is important to gain a high level of understanding of the dynamic behavior of its underground openings. The site, located on and adjacent to the Nevada Test Site (NTS), is subject to seismic loading from both natural events and underground nuclear explosions (UNEs). While ground motions from both of these seismic sources are of interest to the Yucca Mountain Project, those resulting from earthquakes are expected to be the larger of the two and, therefore, more significant in design. It would be difficult, however, to collect underground data from earthquakes because of their unpredictable nature. In contrast, UNEs have been conducted on a regular basis at the NTS and present an opportunity to obtain data useful in understanding the seismic behavior of underground openings. To this end, the Tunnel Dynamics Experiment (TDE) was fielded adjacent to a recent UNE in a pre-existing tunnel. The objective of this experiment was to document tunnel damage corresponding to measured and observed ground motions.

This report contains the full papers submitted to the Committee on the Safety of Nuclear Installations (CSNI) Workshop on Probabilistic Safety Assessment (PSA) Applications and Limitations held in Santa Fe, New Mexico, USA, on September 4 through 6, 1990. The purpose of the Workshop was to provide an avenue for discussions in the following areas: (1) current PSA result, (2) current uses of PSA, (3) views on current limitations, (4) expert opinion, and (5) low probability numbers. The papers contained herein address these issues, along with several other related topics.

The success of probabilistic risk assessment (PRA) has led to numerous improvements to the safety of commercial nuclear power plants. Those very successes, however, have led to situation where the events that PRAs have traditionally modeled are extremely rare. As a result, current PRAs have the potential to be misleading because events previously considered to be unimportant and, thus, not included in the scope of the analyses may now be dominant. This paper provides an assessment of the current status of accident sequence analysis methods and identifies particular limitations that should be addressed in future studies.

Level 2 PRA analysis can be extremely costly. There are several options that can be used to avoid the high expenditures of time and money to obtain Level 2 insights. With reduced expenditure comes reduced insight into the behavior of specific parameters that contribute to containment failure and large source terms. If the primary objective of a study is quantitative, and does not require insights concerning the complex interactions among physical parameters and system parameters, a reduced scope method can be acceptable. If primary objectives require the understanding of the relative importance of specific physical processes and the complex interactions among the processes, reduced scope methods should not be used.

This report summarizes the advanced development of the Spectrum Sciences Model 5005-TF, Single-Event Test Fixture. The Model 5005-TF uses a Californium-252 (Cf-252) fission-fragment source to test integrated circuits and other devices for the effects of single-event phenomena. Particle identification methods commonly used in high-energy physics research and nuclear engineering have been incorporated into the Model 5005-TF for estimating the particle charge, mass, and energy parameters. All single-event phenomena observed in a device under test (DUT) are correlated with an identified fission fragment, and its linear energy transfer (LET) and range in the semiconductor material of the DUT.

This report describes the features and use of the Sandia National Laboratories Assembly Test Chip Ver. 01 (ATC01). This chip contains a variety of Al conductor features which are intended for use in corrosion testing. These include triple tracks with a variety of line and gap widths, ladder structures, straight line structures, and van der Pauw sheet resistance structures. The chip is square, approximately 0.250 in. on a side, with a minimum Al feature size of 1.25 {mu}m. The various test structures on the die are described in detail and bonding layout data are given. Finally, we give an example of measurements made on ATC01 when packaged in a 40 lead CERDIP. 15 refs., 7 figs., 7 tabs.

Sub-gridding techniques enable finite-difference time-domain (FDTD) electromagnetic codes to model apertures that are much narrower than the spatial resolution of the FDTD mesh. Previous thin-slot methods have assumed that the slot walls are perfectly conducting. As the slot depth-to-width ratio becomes large, interior wall losses for realistic materials can significantly affect the coupling through the slot, and therefore these loss effects should not be neglected. This paper presents two methods for incorporating loss for walls with good, but not perfect conductivity, into the FDTD calculations. The first method modifies an FDTD equation internal to the slot to include a surface-impedance contribution. This method is appropriate for the usual FDTD thin-slot formalisms. The second method includes the losses into a half-space'' integral equation that can be used by the recently introduced Hybrid Thin-Slot Algorithm. Results based on the two methods are compared for a variety of slot parameters and wall conductivities.

The establishment of a database for the materials that are used in production Li(Si)/FeS{sub 2} thermal batteries designed at Sandia National Laboratories is described. The database is a Hewlett-Packard (HP) network type (IMAGE) designed to run on an HP3000 computer. Heavy emphasis is placed on the use of screen forms for entry, editing, and retrieval of data. Custom screen forms were used for the various materials in the battery. For the purposes of the materials database, each battery is composed of four mixes: cathode, separator, anode, and heat (pyrotechnic) powders. A consistent lot-numbering system was adopted for both the mixes and the discrete components that make up the mixes. Each serial number of a particular battery is linked to the lot numbers of the four mixes used in the battery. Each mix, in turn, is linked to the lot numbers of the discrete components that are contained within the mix. This allows traceability of each of the components used in any given serial number of a particular battery. The materials database provides the necessary traceability, as required by the Department of Energy, for the lifetime of the program associated with the battery. 3 refs., 23 figs.

A method which is capable of efficient calculation of the axisymmetric flow field produced by a large system of ring vortices is presented in this report. The system of ring vortices can, in turn, be used to model body surfaces and wakes in incompressible unsteady axisymmetric flow fields. This method takes advantage of source point and field point series expansions which enables one to make calculations for interactions between groups of vortices which are in well separated spatial domains rather than having to consider interactions between every pair of vortices. In this work, series expansions for the stream function of the ring vortex system are obtained. Such expansions explicitly contain the radial and axial velocity components. A Fortran computer code RSOLV has been written to execute the fast solution technique to calculate the stream function and the axial and radial velocity components at points in the flow field. Test cases have been run to optimize the code and to benchmark the truncation errors and CPU time savings associated with the method. Non-dimensional truncation errors for the stream function and total velocity field are on the order of 5 {times} 10{sup {minus}5} and 3 {times} 10{sup {minus}3} respectively. Single precision accuracy produces errors in these quantities up to about 1 {times} 10{sup {minus}5}. For 100 vortices in the field, there is virtually no CPU time savings with the fast solver. For 10,000 vortices in the flow, the fast solver obtains solutions in about 1% to 3% of the time required for the direct solution technique. Simulations of vortices with square and circular cores were run in order to obtain expressions for the self-induced velocities of such vortices. 8 refs., 26 figs.

A balloon-borne integrating nephelometer has been successfully developed and flown by Sandia National Laboratories and Radiance Research. This report details instrument design, calibration and data conversion procedure. Free and tethered balloon transport and telemetry systems are described. Data taken during March 1989 South-Central New Mexico free flight ascents are presented as vertical profiles of atmospheric particle scattering coefficient, temperature and balloon heading. Data taken during December 1989 Albuquerque, New Mexico tethered flights are also presented as vertical profiles. Data analysis shows superior instrument performance. 5 refs., 22 figs.

This report describes the computer program used at the Tonopah Test Range to maintain the explosive inventory. The program, which uses dBASE III or dBASE III Plus and runs on an IBM PC or compatible, has the capabilities to update (add or subtract) items, edit or delete, append, and generate various reports.

Mass measurements may be greatly enhanced by an understanding of the operation of balances, the effects of buoyancy, practices encountered in weighing and the impacts and meanings of revelant mass standards. Beginning with the basic forces acting on weights, the equations brought to equality in balances are developed. These give explanation of the weighing process and an appreciation for some balance characteristics. The requirements of relevant mass standards are also reviewed. Recommendations are made for operation of practical mass calibration. An appendix is attached which gives computation examples using apparent mass'' and also gives a method for determining the density of mass artifacts or unknown materials. 2 tabs.

This project is a collaboration between Sandia National Laboratories and Harvey E. Yates Company being conducted under the auspices of the Oil Recovery Technology Partnership. The project seeks to apply perspectives related to the effects of natural fractures, stress, and sedimentology to the simulation and production of low-permeability gas reservoirs to low-permeability oil reservoirs as typified by the Bone Spring sandstones of the Permian Basin, southeast New Mexico. This report presents the results and analysis obtained in 1989 from 233 ft of oriented core, comprehensive suite of logs, various in situ stress measurements, and detailed well tests conducted in conjunction with the drilling of two development wells. Natural fractures were observed in core and logs in the interbed carbonates, but there was no direct evidence of fractures in the sandstones. However, production tests of the sandstones indicated permeabilities and behavior typical of a dual porosity reservoir. A general northeast trend for the maximum principal horizontal stress was observed in an elastic strain recovery measurements and in strikes of drilling-induced fractures; this direction is subparallel to the principal fracture trend observed in the interbed carbonates. Many of the results presented are believed to be new information for the Bone Spring sandstones. 57 figs., 18 tabs.

This report addresses the need for commercially available lighting design computer programs and evaluates several of these programs. Sandia National Laboratories uses these programs to provide lighting designs for exterior closed-circuit television camera intrusion detection assessment for high-security perimeters.

This report summarizes the role of performance assessment in assessing compliance with the containment requirements in 40 CFR Part 191, the Environmental Protection Agency's Standard for the disposal of spent nuclear fuel, high-level and transuranic radioactive wastes. In 1986, Hunter et al. prepared a similar report (NUREG/CR-4510, SAND86-0121) which provided an overview of the approach to assess compliance with this standard. The present report builds on its predecessor in that it incorporates advances in performance assessment subsequent to Hunter et al.'s report. The main purpose of this report is to serve as a mechanism for transferring to the Nuclear Regulatory Commission (NRC) and its contractors the performance assessment methodologies (PAMs) developed by Sandia National Laboratories (SNL) for high-level radioactive waste repositories. The report starts with a discussion of the requirements in 40 CFR Part 191 and focuses on the containment requirements (Section 191.13). It follows with a discussion of the role of performance assessment and its use in regulatory compliance. The report concludes with a discussion of sources of uncertainty, treatment of uncertainties, and the construction of the complementary cumulative distribution function of summed normalized total releases to the accessible environment for one or more scenarios. Examples are presented of the demonstration of performance assessment methodologies for high-level waste disposal at two hypothetical sites. Consistent with the technology transfer objective, numerous references are made throughout this report to publications related to the SNL PAMs. As such, this is not a stand-alone report and the reader is encouraged to consult those references. 30 refs., 9 figs., 1 tab.

NIRVANA is an effort to standardize electrical computer-aided design workstations at Sandia National Laboratories in Albuquerque, New Mexico. The early effect of this project will be the introduction of at least 60 new engineering workstations at Sandia National Laboratories, Albuquerque, and at Allied Signal, Kansas City Division. These workstations are expected to begin arriving in September 1990. This paper outlines the requirements that a NIRVANA Network must satisfy to comply with the Government Open Systems Interconnect Profile (GOSIP). The author also identifies several issues involved in achieving GOSIP compliance. 4 refs., 1 fig.

Response to interrupts within a certain time frame is an important issue for all software operating in real-time environment. A knowledge-based system (KBS) is no exception. Prior work on real-time knowledge-based systems either concentrated on improving the performance of the KBS in order to meet these constraints or focused on producing a better solution as more time was allowed. However, a problem with much of the latter research was that it required inference-time costs to be hardcoded into the different branches of reasoning. This limited the type of reasoning possible and the size of the KBS. Furthermore, performing the analysis required to derive those numbers is very difficult in knowledge based systems. This research explored a model for overcoming these drawbacks. It is based on integrating conventional programming techniques used to control task processing with knowledge-based techniques used to actually produce task results. The C-Language Integrated Production System (CLIPS) was used for the inference engine in the KBS; using CLIPS for the inference engine simplified the rapid context switching required. Thus, the KBS could respond in a timely manner while maintaining the fullest spectrum of KBS functionality.

Welcome to this first issue of Manufacturing Technology, one of three new technology bulletins published at Sandia National Laboratories in which we seek to share information with US industry about applications of technology. Inside this issue: industry/DOE/Sandia agreement to strengthen specialty metals competitiveness; silicon micromachining produces microscopic parts; Sandia develops state-of-the-art capacitor winding machine; new robotic system spells finis to manual edge finishing; and milling assistant speeds numerically controlled machine programming.

This paper discusses several methods to detect the presence of and track the frequency of a chirping signal in broadband noise. The dynamic behavior of each of the methods is described and tracking error bounds are investigated in terms of the chirp rate. Frequency tracking and behavior in the presence of varying levels of noise are illustrated in examples. 11 refs., 29 figs.

The authors have developed and applied a methodology to evaluate and prioritize proposed waste minimization activities affecting Department of Energy (DOE) programs. The approach provides a systematic and defensible method for selecting a set of waste minimization proposals that maximizes the benefits to DOE while maintaining costs within a specified budget. The report discusses the development of a structured set of evaluation criteria to characterize waste minimization issues; techniques for documenting the anticipated and potential costs, risks, and benefits of waste minimization proposals; and a method of translating disparate data into a figure of merit for each proposal. A test case demonstration of this prioritization approach was applied to proposals currently being considered at two DOE weapons production facilities. Recommendations are provided for combining this approach with the existing DOE proposal selection process. 9 refs., 9 figs., 3 tabs.

NIRVANA is an effort to standardize electrical computer-aided design workstations at Sandia National Laboratories in Albuquerque, New Mexico. The early effect of this project will be the introduction of at least 60 new engineering workstations at Sandia National Laboratories. Albuquerque, and at Allied Signal, Kansas City Division. These workstations are expected to begin arriving in September 1990. This paper proposes a design and outlines the requirements for a network to support the NIRVANA project. The author proposes a near-term network design, describes the security profile and caveats of this design, and proposes a long-term networking strategy for NIRVANA. 6 refs., 7 figs.

This WIPP Bin-Scale CH TRU Waste Test program described herein will provide relevant composition and kinetic rate data on gas generation and consumption resulting from TRU waste degradation, as impacted by synergistic interactions due to multiple degradation modes, waste form preparation, long-term repository environmental effects, engineered barrier materials, and, possibly, engineered modifications to be developed. Similar data on waste-brine leachate compositions and potentially hazardous volatile organic compounds released by the wastes will also be provided. The quantitative data output from these tests and associated technical expertise are required by the WIPP Performance Assessment (PA) program studies, and for the scientific benefit of the overall WIPP project. This Test Plan describes the necessary scientific and technical aspects, justifications, and rational for successfully initiating and conducting the WIPP Bin-Scale CH TRU Waste Test program. This Test Plan is the controlling scientific design definition and overall requirements document for this WIPP in situ test, as defined by Sandia National Laboratories (SNL), scientific advisor to the US Department of Energy, WIPP Project Office (DOE/WPO). 55 refs., 16 figs., 19 tabs.

Calculations have been performed with the HULL hydrocode to study ground shock effects for multiple earth penetrator weapon (EPW) bursts in hexagonal-close-packed (HCP) arrays. Several different calculational approaches were used to treat this problem. The first simulations involved two-dimensional (2D) calculations, where the hexagonal cross-section of a unit-cell in an effectively-infinite HCP array was approximated by an inscribed cylinder. Those calculations showed substantial ground shock enhancement below the center of the array. To refine the analysis, 3D unit-cell calculations were done where the actual hexagonal cross-section of the HCP array was modelled. Results of those calculations also suggested that the multiburst array would enhance ground shock effects over those for a single burst of comparable yield. Finally, 3D calculations were run in which an HCP array of seven bursts was modelled explicitly. In addition, the effects of non-simultaneity were investigated. Results of the seven-burst HCP array calculations were consistent with the unit-cell results and, in addition, provided information on the 3D lethal contour produced by such an array.

Analyses of the internal argon gas concentrations monitored on surveillance units of the W84 indicates that field aging of this weapon for times up to {approximately}4 years does not lead to important increases in the rate at which water leaks into the interior of the weapon. This implies that the EPDM environmental seals used on the W84 do not age significantly over this time period. By comparing the percentages of oxygen and argon in the internal atmosphere, an estimate of the oxygen consumption rate is made for a typical W84 unit. The argon gas analysis approach is then applied to the W88, which is sealed with a new EPDM material. Predictive expressions are derived which relate the anticipated argon gas concentrations of future, field-returned units to their water leakage rates. The predictions are summarized in convenient plots, which can be immediately and easily applied to surveillance data as reported. Since the argon approach is sensitive enough to be useful over the entire lifetime of the W88, it can be used to point out leaking units and to determine whether long-term aging has any significant effect on the new EPDM material. 11 refs., 10 figs., 3 tabs.

The Robotic Edge Finishing Laboratory at Sandia National Laboratories is developing four areas of technology required for automated deburring, chamfering, and blending of machined edges: (1) the automatic programming of robot trajectories and deburring processes using information derived from a CAD database, (2) the use of machine vision for locating the workpiece coupled with force control to ensure proper tool contact, (3) robotic deburring, blending, and machining of precision chamfered edges, and (4) in-process automated inspection of the formed edge. The Laboratory, its components, integration, and results from edge finishing experiments to date are described here. Also included is a discussion of the issues regarding implementation of the technology in a production environment. 24 refs., 17 figs.

A series of impact experiments on a composite propellant, an energetic propellant, and their simulants was recently completed using a light-gas gun. Previous experiments were done to obtain Hugoniot data, to investigate the pressure threshold at which a reaction occurs, and to measure spall damage at various impact velocities. The present studies measured the attenuation of shock waves in these materials, completing the shock characterization needed for material modeling. An initial impulse of 2.0 GPa magnitude and {approximately}0.6 {mu}s duration was imposed upon samples of various thicknesses. VISAR was used to measure the free-surface velocity at the back of the samples; these data were used to generate a curve of shock-wave attenuation versus sample thickness for each material. Results showed that all four materials attenuated the shock wave very similarly. Material thicknesses of 3.0, 7.62, 12.7, and 19.0 mm attenuated the shock wave {approximately}16%, 33%, 50%, and 66% respectively. 14 refs., 12 figs., 4 tabs.

This report concerns the evaluation of the Stellar Systems Inc. E-Field intrusion detection system Series 800 control unit and the 5000 Series hardware components. Included are functional descriptions, installation procedures, testing procedures, and testing/operational results. 35 figs.

The WhiteStar project provides design engineers with needed part design data. WhiteStar encourages the use of preferred parts by providing a user-convenient parts database. This report shows selections the user makes in order to obtain information on a particular part. 15 figs.

This report investigates the behavior of a family of finite element error estimators based on projected stresses, i.e., continuous stresses that are a least squared error fit to the conventional Gauss point stresses. An error estimate based on element force equilibrium appears to be quite effective. Examples of adaptive mesh refinement for a one-dimensional problem are presented. Plans for two-dimensional adaptivity are discussed. 12 refs., 82 figs.

This report describes the design intent, design considerations, system use, development, product characteristics, and early production history of the MC3714 Thermal Battery. This battery has a required operating life of 146 s above 24.0 V with a constant current load of 0.5 A. It is activated when the MC3830 Actuator initiates the WW42C1 Percussion Primer in the battery. The MC3714 employs the Li(Si)/LiCl-CCl/lithiated FeS{sub 2} electrochemical system. The battery is a hermetically sealed right-circular cylinder with an antirotation ring brazed to the base of the cylinder. The battery is 50 mm long and 38.1 mm in diameter. The mass of the battery is 165 g. The battery was designed and developed to provide the power for the W82 JTA Telemetry System. 8 refs., 12 figs., 11 tabs.

Infrared video thermograms of a portion of the surface of graphite limiters in Textor were taken during several disruptions. Estimates of the deposition power density were made by comparison of the observed temperature histories with those calculated from a numerical thermal conduction model. It was found that the heat flux, at the observed locations, often occurred in sharp submillisecond bursts, the magnitudes of which were much larger than the heat flux density averaged over the whole disruption. 5 refs., 4 figs.

The mechanical properties of a coring from the bottom of the MOSAIK KfK cask were determined as a function of through wall position for the 21 cm thick section. The elastic moduli were determined from ultrasonic velocity measurements. The standard tensile properties were determined as a function of strain rate at {minus}29{degree}C. The Charpy impact behavior was measured as a function of temperature from {minus}100 to {plus}100{degree}C. The fracture toughness was determined for both static and elevated loading rates (at {minus}29{degree}C). In addition to these mechanical properties, the variation in microstructure and composition with position in the coring is reported. The mechanical properties provide the essential information for the stress analysis modeling of the behavior of the cask during a drop test which will be conducted to simulate a very severe accident condition. The results from the elevated loading rate fracture toughness tests are used to suggest the severity of the flaws that should be introduced into the cask for the sequential series of drops which are scheduled to begin in March 1990. 24 refs., 16 figs., 6 tabs.

Recently an appreciable number of continuous release profiles have been measured from dynamic experiments with geological materials. For each material an empirical generalization of the available release curves may be constructed to allow easy application of the experimental data to problems in much the same way as a linear shock velocity -- particle velocity fit allows easy application of Hugoniot data. This generalization is made in two steps. The first is to compute the Eulerian axial modulus at the Hugoniot pressure and its first three pressure derivatives along the release for each test. This corresponds to a partial Taylor series of the axial modulus, which integrates to give a very close match to the original release. An alternative formulation, which takes volume as the independent variable, fails because that Taylor series does not converge with the rapidity needed for these calculations. The second step is to plot each of these quantities against the Hugoniot pressure for the suite of tests, and fit these data. A release from an arbitrary pressure within the general range of the experimental data may be computed by using the interpolated modulus and its interpolated derivatives. This generalization, which allows volume to be computed as a function of pressure, reproduces the experimental curves fairly well. We present the results of applying this technique to release data for Mini Jade 2 grout, and briefly compare these results with those from several Nevada Test Site tuffs, saturated and dry Indiana Limestone, and aluminum. Finally, we use the generalized Mini Jade 2 data to solve a sample problem, that of estimating the error produced by making the release = Hugoniot'' assumption in the analysis of ground motion gauges in an underground test. 12 refs., 14 figs., 5 tabs.

The tests described in this report were conducted to obtain information on the effects target characteristics have on portal type metal detector response. A second purpose of the tests was to determine the effect of detector type and settings on the detection of the targets. Although in some cases comparison performance of different types and makes of metal detectors is found herein, that is not the primary purpose of the report. Further, because of the many variables that affect metal detector performance, the information presented can be used only in a general way. The results of these tests can show general trends in metal detection, but do little for making accurate predictions as to metal detector response to a target with a complex shape such as a handgun. The shape of an object and its specific metal content (both type and treatment) can have a significant influence on detection. Thus it should not be surprising that levels of detection for a small 100g stainless steel handgun are considerably different than for detection of the 100g stainless steel right circular cylinder that was used in these tests. 7 figs., 1 tab.

A steam blowdown test was performed at the Surtsey Direct Heating Test Facility to test the steam supply system and burst diaphragm arrangement that will be used in subsequent Surtsey Direct Containment Heating (DCH) experiments. Following successful completion of the steam blowdown test, the HIPS-10S (High-Pressure Melt Streaming) experiment was conducted to demonstrate that the technology to perform steam-driven, high-pressure melt ejection (HPME) experiments has been successfully developed. In addition, the HIPS-10S experiment was used to assess techniques and instrumentation design to create the proper timing of events in HPME experiments. This document discusses the results of this test.

Sandia is committed to a policy of adherence to all US export control laws and regulations. The export of technical data, software, or hardware will be accomplished in accordance with Federal agencies` export control regulations. Sandia employees at all levels are responsible to ensure that exports are accomplished in compliance with export control laws and regulations. This booklet explains these export control laws and regulations.

High pressure Hugoniot and release equation of state data are provided for samples from three Nevada Test Site rock units. These are the MC-2 and MC-3 members of the P-Tunnel (Paintbrush) Tuff and the N-Tunnel (Tunnel Bed) Tuff. The technique used provides continuous release trajectories from the Hugoniot pressure down to approximately half of the Hugoniot pressure. Hugoniot and release results for the MC-2 and MC-3 members are very similar, while the Hugoniot of the N-Tunnel Tuff is somewhat stiffer, consistent with the higher density of this tuff as tested. The materials were tested at less than full saturation; correcting for this tends to narrow the difference in the properties of the two rock types sufficiently that the data do not provide a basis for predicting significantly different groundshock properties of the three units, leaving unexplained the anomalously high groundshock attenuation observed in the Mission Cyber event (performed in the MC-2 unit of the Paintbrush tuff). 26 refs., 61 figs., 9 tabs.

During rapid solidification, nonequilibrium interface kinetics alter the predictions of the Mullins-Sekerka theory for the stability of a planar interface against cellular breakdown. The velocity-dependence of the partition coefficient and of the Sn concentration at the onset of cellular breakdown have been measured during pulsed laser melting of Si--Sn alloys. The Mullins-Sekerka theory is modified by inserting a velocity-dependent partition coefficient and a velocity-dependent slope of the kinetic liquids,'' both of which are extracted from the Continuous Growth Model for interface kinetics. These nonequilibrium interface kinetic effects increase the predicted critical concentration for cellular breakdown by two orders of magnitude for Sn in Si, and account fairly well for the experimental results. 34 refs., 3 figs.

Several models of runaway electron generation during a disruption are described and applied to the problem of determining the radiation loss and energy limit of runaway electrons. In particular the prediction of orbits and energy limits for proposed ITER design are discussed. It was found that resonance between the electron gyrofrequency and the fundamental ripple frequency can lead to large synchrotron radiation losses and create an upper bound on runaway energy. Interactions with the second harmonic of the ripple field are very sensitive to ripple amplitude and may lead to a further reduction in runaway energy. In ITER this effect can limit the runaway energy to values of 270 MeV. A lump circuit model of the plasma can be used to determine the coupled interactions of the runaway currents with the plasma and control circuit currents. Depending on what is assumed about the perpendicular energy of the runaway electrons. Maximum values of runaway energy predicted for ITER are in the range of 35 to 120 MeV. 4 refs., 15 figs.

A bilateral teleoperation system consists of a local master manipulator and a remotely located slave manuipulator. Generalized velocity commands are sent forward from the master to the slave, and generalized force/torque information is reflected'' back from the slave to the master. Often there is a transmission delay incurred when communicating between the two subsystems which causes instability in the bilateral teleoperator. Recently, a solution for this instability problem was found, based on mimicking the behavior of a lossless transmission line. Although this solution provides steady-state force and velocity tracking, it does not provide steady-state force and position tracking, as is desired for bilateral teleoperation. In this paper a modification is given to the basic control law which overcomes this difficulty. 13 refs., 6 figs., 1 tab.

This document serves as the proceedings for the annual project review meeting held by Sandia's Photovoltaic Cell Research Division and Photovoltaic Technology Division. It contains information supplied by each organization making a presentation at the meeting, which was held August 7 through 9, 1990 at the Sheraton Hotel in Albuquerque, New Mexico. Sessions were held to discuss national photovoltaic programs, one-sun crystalline silicon cell research, concentrator silicon cell research, concentrator 3-5 cell research, and concentrating collector development.

The Center for Compound Semiconductor-Technology (CCST)at Sandia National Laboratories encompasses the full range of required activities--theoretical and experimental solid-state physics, materials science, crystal growth, device design, and fabrication--to develop the next generation of electronic and optoelectronic devices. Semiconductor electronics are vital to the communications and computer industries and to the nation's defense. Compound semiconductors offer very high-speed electronics and integrated optical and electronic capabilities not available with silicon, and will underlie future electronic, optoelectronic, and photonic technologies. The purpose of the CCST is to perform collaborative research generic to electronic and optoelectronic technologies in compound semiconductors. The CCST also includes related research in high-temperature superconducting electronics and hybrid superconductor-semiconductor devices. Facilities in the CCST include extensive molecular-beam epitaxy and metal-organic chemical vapor deposition crystal growth capabilities, a 400-keV ion implanter, and a new 3700 net square foot, class 1000/100 clean room with state-of-the-art processing equipment. Addition of an electron-beam lithography system to permit fabrication of devices with feature sizes below 100 nm is planned for the near future.

The near-field, explosive dispersal of a liquid into air has been explored using a combination of analytical and numerical models. The near-field flow regime is transient, existing only as long as the explosive forces produced by the detonation of the burster charge dominate or are approximately equal in magnitude to the aerodynamic drag forces on the liquid. The near-field model provides reasonable initial conditions for the far-field model, which is described in a separate report. The near-field model consists of the CTH hydrodynamics code and a film instability model. In particular, the CTH hydrodynamics code is used to provide initial temperature, pressure, and velocity fields, and bulk material distribution for the far-field model. The film instability model is a linear stability model for a radially expanding fluid film, and is used to provide a lower bound on the breakup time and an upper and lower bound on the initial average drop diameter for the liquid following breakup. Predictions of the liquid breakup time and the initial arithmetic average drop diameter from the model compare favorably with the sparse experimental data. 26 refs., 20 figs., 8 tabs.

This report highlights Sandia National Laboratories' work in the following areas: photometrics and optical development; still and time-lapse photography; real-time motion photography; high-speed photography; image-motion photography; schlieren photography; ultra-high-speed photography; electronic imaging; shuttered video and high-speed video; infrared imaging radiometry; exoatmospheric photography and videography; microdensitometry and image analysis; and optical system design and development.

This report describes reference concepts for a hydrogen-oxygen combustion, turboalternator power system that supplies power during battle engagement to a space-based, ballistic missile defense platform. All of the concepts are open''; that is, they exhaust hydrogen or a mixture of hydrogen and water vapor into space. We considered the situation where hydrogen is presumed to be free to the power system because it is also needed to cool the platform's weapon and the situation where hydrogen is not free and its mass must be added to that of the power system. We also considered the situation where water vapor is an acceptable exhaust and the situation where it is not. The combination of these two sets of situations required four different power generation systems, and this report describes each, suggests parameter values, and estimates masses for each of the four. These reference concepts are expected to serve as a baseline'' to which other types of power systems can be compared, and they are expected to help guide technology development efforts in that they suggest parameter value ranges that will lead to optimum system designs. 7 refs., 18 figs., 5 tabs.

This report covers the development of improved assembly processes for the Quartz Digital Accelerometer cantilever. In this report we discuss improved single-assembly tooling, the development of tooling and processes for precision application of polyimide adhesive, the development of the wafer scale assembly procedure, and the application of eutectic bonding to cantilever assembly. 2 refs., 17 figs.

A computer code, PREGO, has been developed to perform calculations for three related problems: reflection of an acoustic wave against a layered viscoelastic medium: (water/medium); transmission of an acoustic wave through such a medium (water/medium/water); and radiation of an acoustic wave through such a medium: (medium/water). This code draws an experience gained in writing and using a predecessor code, IMPEDE, which was devised to calculate the steady state reflection of an acoustic wave impinging on a layered substrate of elastic or viscoelastic materials. That code employed a finite element formulation to discretize the complex-valued, second order ordinary differential equations for monochromatic steady state acoustics. The principles of numerical analysis that underlie PREGO are different and less subject to discretization error than those used in IMPEDE. The formulation used in PREGO is similar to that of higher dimensional boundary integral formulations in that it uses closed form expressions for the complex velocity fields in each layer, given in terms of the velocities at the boundary of that layer. The solutions for each layer are coupled together by requiring that stresses and velocities be continuous across interfaces. 5 refs., 4 figs.

A performance assessment methodology has been developed for use by the US Nuclear Regulatory Commission in evaluating license applications for low-level waste disposal facilities. This report provides a summary of background reports on the development of the methodology and an overview of the models and codes selected for the methodology. The overview includes discussions of the philosophy and structure of the methodology and a sequential procedure for applying the methodology. Discussions are provided of models and associated assumptions that are appropriate for each phase of the methodology, the goals of each phase, data required to implement the models, significant sources of uncertainty associated with each phase, and the computer codes used to implement the appropriate models. In addition, a sample demonstration of the methodology is presented for a simple conceptual model. 64 refs., 12 figs., 15 tabs.

Glass-to-metal seals are an integral part of many electronic components. When seals are formed at elevated temperatures and cooled to room temperature, residual stresses are generated by the unequal thermal contractions of the constituent materials. The combination of high stress and low fracture resistance of glass makes it extremely difficult to design and build hermetic glass-to-metal seals. Rigorous and robust stress analyses must incorporate the complex and coupled changes in volumetric strain and stress relaxation which occur as glass passes through the liquid/solid temperature regime. The phenomenological behavior of glass can be modeled viscoelastically. The theory and numerical discretization of the viscoelastic equations is presented for use in finite element programs. Vectorizable integration schemes are derived for both the traditional hereditary integrals of viscoelasticity and the equivalent rate forms of the equations. The general behavior of glass is discussed and related to the viscoelastic model. Solutions to discretized viscoelastic equations are applied to an example problem and compared to results obtained from experimental data. The viscoelastic model of glass provides a new capability to analyze and design actual manufacturing processes by predicting, a priori, the effects of temperature history on the residual stress state.

Kerberos is a network user authentication system that was recently developed at the Massachusetts Institute of Technology (MIT). It has been adopted by Sandia National Laboratories, Albuquerque, for use in the Secure Supercomputing Network (SSN) which is currently under development. FTP and TELNET are two of the most important network applications for the SSN, which is to use the TCP/IP protocol suite. FTP provides capabilities for bulk file transfer between nodes and TELNET provides a remote interactive login capability across the network. This design describes how authentication is currently performed in FTP and TELNET using clear text passwords and proposes a method for modifying them to use Kerberos authentication.

When the boundary integral equation method is applied to exterior acoustics problems, singularities occur in the resulting algebraic equations at various frequencies associated with the eigenvalues of an interior problem. These frequencies are referred to as forbidden,'' and various methods have been devised to overcome the computational difficulties presented at these frequencies. The work presented here is an extension to the CHIEF method in that higher derivatives, in addition to the function itself, are constrained to be zero at selected points in the interior domain. Whereas the relative success of either method depends on the quantity and selection of interior points, the SuperCHIEF method requires fewer interior points and is less sensitive to point selection, resulting in improved robustness without significant increase in computational complexity. 3 refs., 14 refs.

Massively parallel computers and computer networks are beginning to appear as an integral part of the scientific computing workplace. This report documents the goals and the corresponding development plan of the massively parallel project of Departments 1530 and 1420. The main goal of the project is to provide a clear understanding of the issues and difficulties involved in bringing the current production hydrocode CTH to the state of being portable to a number of currently available parallel computing architectures. In the process of this research, various working versions of the code will be produced. 6 refs., 6 figs.

This report examines effects of aging on cables, connections, and containment electrical penetration assemblies (EPAs). Aging is defined as the cumulative effects that occur to a component with the passage of time. If unchecked, these effects can lead to a loss of function and a potential impairment of plant safety. This study includes a review of component usage in nuclear power plants; a review of some commonly used components and their materials of construction; a review of the stressors that the components might be exposed to in both normal and accident environments; a compilation and evaluation of industry failure data; a discussion of component failure modes and causes; and a brief description of current industry testing and maintenance practices. 51 refs., 12 figs., 12 tabs.

CEPXS/ONELD is a discrete ordinates code package for one-dimensional coupled electron-photon transport over the energy range of 100 MeV to 1.0 keV. In this Results Guide, CEPXS/ONELD predictions are compared to the predictions of Monte Carlo codes and to experiment. These comparisons are made for a variety of quantities, including energy deposition, charge deposition and electron current spatial profiles as well as electron and photon spectra. Sensitivity studies are presented that show how the numerical approximations of CEPXS/ONELD can affect the accuracy of predictions. Guidelines for the efficient and accurate use of the code package are given. All examples involve one-dimensional planar geometry and non-adjoint transport. 35 refs.

Charge exchange results in the transfer of momentum from an ion to a neutral atom, thus it is equivalent to a slowing down mechanism for ions. This might be helpful in IFR propagation of relativistic electron beams. The effect of charge exchange on the ion hose instability and channel expansion after beam passage is investigated in this report. For parameters of interest to current experiments, it is found that the effect on growth of the ion hose instability is insignificant, but there is significant reduction in the energy of the expanding ions after passage of the electron beam. 5 refs., 5 figs.

The nickel/hydrogen battery was developed in the 1970s as an energy storage subsystem for commercial communication satellites. The advantages offered by nickel/hydrogen batteries, including long life, low maintenance and high reliability, make it very attractive for terrestrial applications such as stand-alone photovoltaic systems. The major drawback to the wider use of the nickel/hydrogen battery is its high initial cost. Sandia National Laboratories has directed cost-shared contracts at Comsat Laboratories and Johnson Controls, Inc. to reduce the cost, and a battery consisting of prismatic cells in a common pressure vessel has evolved. Contract deliverables include cells and batteries that are evaluated at Sandia. This report summarizes the results over the past two years of both cycle and solar testing. 6 refs., 12 figs., 5 tabs.

This report will present the development history, characterization data and the qualification activities for the SA3646. This device is manufactured by SEEQ Technology Inc., with part number LM28C256-250/B and is a 256K Electricity Erasable Programmable Read Only Memory (EEPROM). 14 refs., 25 figs.

A computational fluids dynamics scheme is presented to solve the unsteady Thin-Layer Navier-Stokes (TLNS) equations over a blunt body at high altitude, high Mach number atmospheric reentry flow conditions. This continuum approach is directed to low density hypersonic flows by accounting for non-zero bulk viscosity effects in near frozen flow conditions. The TLNS equations are solved over an axisymmetric body at zero incidence relative to the free stream. The time dependent axisymmetric governing equations are transformed into a computational plane, then cast into weak conservative form and solved using a first-order fully implicit scheme in time with second-order flux vector splitting for spatial derivatives. The physical domain is defined over representative sphere and sphere/cone geometries using a body-fitted clustered algebraic grid within a fixed domain (i.e., shock capturing). At the present time, nonequilibrium thermo-chemistry effects are not modeled. Catalytic wall, ionization and radiation effects are also excluded from the current analysis. However, the significant difference from previous studies is the inclusion of the capability to model non-zero bulk viscosity effects. The importance of bulk viscosity is reviewed and blunt body flow field solutions are presented to illustrate the potential contribution of this phenomena at high altitude hypersonic conditions. The current technique is compared with experimental data and other approximate continuum solutions. A variety of test cases are also presented for a wide range of free stream Mach conditions.

This report documents the development and testing of the 375492, a Schottky barrier diode die, similar to the Hewlett-Packard 5082-0094. 18 figs., 4 tabs.

This document contains the technical specifications and implementation details for the Product Evaluation Management Information System (PREMIS) Version 1.1.2. This document does not include the requirements analysis or design information and is not intended as a user's guide. The INGRES Applications-by-Forms (ABF) software development tool was used to specify and define the modules and screens which comprise the PREMIS application. Several external procedures are called by the ABF procedures; these have been written in VAX/VMS DCL (Digital Command Language) and SQL (Standard Query Language). These specifications together with the PREMIS information model and corresponding database definition constitute the PREMIS Version 1.1.2 technical specification and implementation description presented herein.

The feasibility of performing, numerous spent fuel cask operations using fully integrated robotic systems is under evaluation. Using existing technology, operational and descriptive software and hardware in the form of robotic end effectors are being designed in conjunction with interfacing cask components. A robotic radiation and contamination survey system has been developed and used on mock-up cask hardware to evaluate the impact of such fully automated operations on cask design features and productivity. Based on experience gained from the survey system, numerous health physics operations can be reliably performed with little human intervention using a fully automated system. Such operations can also significantly reduce time requirements for cask-receiving operations. 7 refs., 51 figs., 6 tabs.