Publications

This paper describes several different types of constraints that can be placed on multilayered feedforward neural networks which are used for automatic target recognition (ATR). We show how unconstrained networks are likely to give poor generalization on the ATR problem. We also show how the ATR problem requires a special type of classifier called a one-class classifier. The network constraints come in two forms: architectural constraints and learning constraints. Some of the constraints are used to improve generalization, while others are incorporated so that the network will be forced to perform one-class classification. 14 refs

Foams, like most highly structured fluids, exhibiting rheological behavior that is both fascinating and complex. We have developed microrheological models for uniaxial extension and simple shearing flow of a `dry`, perfectly ordered, three-dimensional foam composed of thin films with uniform surface tension T and negligible liquid content. We neglect viscous flow in the thin films and examine large elastic-plastic deformations of the foam. The primitive undeformed foam structure is composed of regular space-filling tetrakaidecahedra, which have six square and eight hexagonal surfaces. This structure possesses the film-network topology that is necessary to satisfy equilibrium: three films meet at each edge, which corresponds to a Plateau border, and four edges meet at vertex. However, to minimize surface energy, the films must meet at equal angles of 120{degrees} and the edges must join at equal tetrahedral angles of cos{sup {minus}1}({minus}1/3) {approx} 10.947{degree}. No film in an equilibrium foam structure can be a planar polygon because no planar polygon has all angles equal to the tetrahedral edge. In the equilibrium foam structure known as Kelvin`s minimal tetrakaidecahedron, the `squares` are planar quadrilateral surfaces with curved edges and the `hexagons` are non-planar saddle surfaces with zero mean curvature. As the foam structure evolves with the macroscopic flow, each film maintains zero mean curvature because the pressure is the same in every bubble. In general, the shape of each thin film, defined by z = h(x,y), satisfies R{sub 1}/1 + R{sub 2}/1 = {del}{center_dot} (1 + {vert_bar}{del}h{vert_bar}){sup {1/2}} = O where R{sub 1}{sup {minus}1} and A{sub 2}{sup {minus}1} are the principal curvatures. The appropriate boundary conditions correspond to three films meeting at equal angles. For the homogeneous deformations under consideration, the center of each film moves affinely with the flow. 5 refs

We have measured the atmospheric isoplanatic angle in the near infrared by correlating widely separated time-resolved stellar images.

We have grown Zn{sub 1-x}Mn{sub x}Te alloys by molecular beam epitaxy and characterized them using x-ray diffraction and low temperature magnetoluminescence. Zn{sub 1-x}Mn{sub x}Te is a dilute magnetic semiconductor (DMS) whose bandgap ranges from the green through the blue part of the spectrum and is therefore of interest for blue LEDs.

Renewable energy technologies convert naturally occurring phenomena into useful energy forms. These technologies use resources that generally are not depleted, such as the direct energy (heat and light) from the sun and the indirect results of its impact on the earth (wind, falling water, heating effects, plant growth), gravitational forces (the tides), and the heat of the Earth`s core (geothermal), as the sources from which they produce useful energy. These very large stores of natural energy represent a resource potential that is incredibly massive -- dwarfing that of equivalent fossil energy resources. The magnitude of these resources is, therefore, not a key constraint on energy production. However, they are generally diffuse and not fully accessible, some are intermittent, and all have distinct regional and local variability. It is these aspects of their character that give rise to difficult, but generally solvable, technical, institutional, and economic challenges inherent in development and use of renewable energy resources. This report discusses the technologies and their associated energy source.

Theoretical models have been formulated describing the dynamic behavior of the swelling and contracting of polyelectrolyte gels. This paper presents a method of weighted residuals approach to solving the governing system of equations by finite element analysis. The modulation of the imbibition of solvent by a spherical gel is studied.

There is considerable interest in the use of chemically vapor deposited (CVD) polycrystalline diamond films in advanced materials technology. However, most of the potential applications of CVD diamond films require well-controlled properties which depend on the film structure, and in turn, on the conditions under which the films are synthesized. The structure of the vapor-deposited diamond films is frequently characterized by Raman spectroscopy. Despite extensive research, much work still needs to be completed to understand the various features of the Raman spectra and to understand how the processing variables affect the spectral features. This paper examines the Raman spectra of diamond films prepared by a hot-filament-assisted CVD process as a function of substrate processing and deposition parameters.

Many applications of national importance require the design, analysis, and simulation of complex electromagnetic phenomena. These applications range from the simulation of synthetic aperture radar to the design and analysis of low-observable platforms, antenna design, and automatic target recognition. In general, the modeling of complex electromagnetic phenomena requires significant amounts of computer time and capacity on conventional vector supercomputers but takes far less on massively parallel computers. Sandia National Laboratories is currently developing massively parallel methods and algorithms for the characterization of complex electromagnetic phenomena. The goal of on going research at Sandia is to understand the characteristics, limitations, and trade-offs associated with complex electromagnetic systems including: modeling the seeker response to complex targets in clutter, calculating the radiation and scattering from conformal communication and radar system antennas, and the analysis and design of high speed circuitry. By understanding the theoretical underpinnings of complex electromagnetic systems it is possible to achieve realistic models of system performance. The first objective is the development of computationally practical, high fidelity, systems models targeted for massively parallel computers. Research to achieve this objective is conducted in such areas as mathematical algorithms, problem decomposition, inter-processor communication schemes, and load balancing. The work in mathematical algorithms includes both the development of new methods and the parallel implementation of existing techniques. The second objective is the application of these high fidelity models to facilitate a better understanding of systems level performance for many C{sup 3}I platforms. This presentation describes applications of much current interest and novel solution techniques for these applications utilizing massively parallel processing techniques.

A neighboring external control problem is formulated for a hypersonic glider to execute a maximum-terminal-velocity descent to a stationary target. The resulting two-part, feedback control scheme initially solves a nonlinear algebraic problem to generate a nominal trajectory to the target altitude. Secondly, a neighboring optimal path computation about the nominal provides a lift and side-force perturbations necessary to achieve the target downrange and crossrange. On-line feedback simulations of the proposed scheme and a form of proportional navigation are compared with an off-line parameter optimization method. The neighboring optimal terminal velocity compares very well with the parameter optimization solution and is far superior to proportional navigation. 8 refs.

A camera with 3-ns time resolution -- and a continuous (> 100-ns) record length -- has been developed to image a 10{sup 12}-10{sup 13} W/cm{sup 2} ion beam for inertial-confinement-fusion experiments. A thin gold Rutherford-scattering foil placed in the path of the beam scatters ions into the camera. The foil is in a near-optimized scattering geometry and reduces the beam intensity seven orders of magnitude. The scattered ions are pinhole imaged onto a 2-D array of 39 p-i-n diode detectors. The output of each detector is recorded on a LeCroy 6880 transient-waveform digitizer. The waveforms are analyzed and combined to produce a 39-pixel movie which can be displayed on an image processor to provide, for example, time-resolved horizontal- and vertical-focusing information.

A survivable debris shield is necessary if very high levels of cleanliness are to be achieved on samples exposed to soft x rays from laboratory simulation sources. These samples, often of optical quality, require a low or zero debris environment in order to distinguish low levels of soft x-ray damage from debris-induced effects. We will describe the development of survivable debris shield technology on the Sandia National Laboratories` Saturn x-ray simulation facility, which permits ultraclean exposure over sample areas of 58 cm{sup 2} {at} {approximately}0.35 cal/cm{sup 2}, 5 cm{sup 2}{at} {approximately}0.8 cal/cm{sup 2}, cm{sup 2}, 2.8 cm{sup 2} {at} {approximately}1.2 cal/cm{sup 2}, and 0.8 cm{sup 2} {at} {approximately}1.5 cal/cm{sup 2} with 3-keV argon K-shell photons. These new fluence-area produce test capabilities represent an order-of-magnitude improvement in the state of the art (previously 0.25 cm{sup 2} {at} {approximately} 1 cal/cm{sup 2} or 1.0 cm{sup 2} {at} {approximately}0.35 cal/cm{sup 2}) for soft x-ray simulators.

Methods which report an ability to determine interstitial oxygen (O{sub i}) in heavily doped silicon include the short baseline (SBL) and the curved baseline (CBL) techniques. Both the SBL and CBL methods are similar with the exception of the calibration. We developed a FORTRAN software package to provide separate methods for calculating O{sub i}. The strength of the software is its ability to rapidly compare methods. We report on a comparison of calculation methods including the ASTM standard test F1188-88 which is used in a calibration, and the SBL and the CBL methods, which are used for the heavily doped silicon to provide reliable results. The O{sub i} values calculated for both virgin and thermally processed silicon are reported.

This paper describes the design of an inverse adaptive filter, using the Least-Mean-Square (LMS) algorithm, the correct data taken with an analog filter. The gradient estimate used in the LMS algorithm is based upon the instantaneous error, e{sup 2}(n). Minimizing the mean-squared-error does not provide an optimal solution in this specific case. Therefore, another performance criterion, error power, was developed to calculate the optimal inverse model. Despite using a different performance criterion, the inverse filter converges rapidly and gives a small mean-squared-error. Computer simulations of this filter are also shown in this paper.

Intense light ion beams are being developed to drive inertial confinement fusion (ICF) targets. Recently, intense proton beams have been used to drive two different types of targets in experiments on the Particle Beam Fusion Accelerator. The experiments focused separately on ion deposition physics and on implosion hydrodynamics. In the ion deposition physics experiments, a 3--4 TW/cm{sup 2} proton beam heated a low-density foam contained within a gold cylinder with a specific power deposition exceeding 100 TW/gm for investigating ion deposition, foam heating, and generation of x-rays. The significant results from these experiments included the following: the foam provided an optically thin radiating region, the uniformity of radiation across the foam was good, and the foam tamped the gold case, holding it in its original position for the 15 ns beam pulse width.

This paper identifies some of the sources of resistance to change that face Sandia National Laboratories` management, and examines the mechanisms that are being used to minimize the effects of that resistance. The rapid and radical nature of many of the changes now being demanded of Sandia make them all the more likely to meet stiff resistance from within the organization. Sandia`s management has attempted to anticipate some of the sources of resistance to the changes planned for its operating procedures and has taken action to minimize their effects. Within this paper, particular attention is given to those individuals who will not only be most effected by, by may also be required to implement the changes. The change process at Sandia is currently ongoing. It is not complete. No claim is made that all of the changes that will be necessary at Sandia National Laboratories have been recognized, nor that all sources of resistance have been anticipated.

A production vacuum arc remelt (VAR) furnace was modified to enable direct viewing of the metal vapor arc and molten electrode tip during melting of 432 mm dia. alloy 718 electrodes into 508 mm dia. ingots. Diffuse and constricted arcing conditions were characterized using high speed cinematography, standard video format, and monochromatic imaging. Constricted arcing was observed while melting electrodes contaminated with oxide slag of the type used for refractory linings in vacuum induction furnaces. Monochromatic imaging was used in visualize the ion distribution in the arc plasma; these images clearly showed whether the arc operated in a diffuse or constricted model. Diffuse arc melting conditions were very similar to those previously reported in the literature for smaller laboratory sized melts.

In November of 1989, technology transfer became a mission for Sandia National Laboratories, (SNL), with the passage of the National Competitiveness Technology Transfer Act. In order to address the specialized technology transfer needs of small businesses, SNL created and implemented the Technology-Based Regional Economic Development (TRED) program. The TRED model has two major components -- technology assistance (or teaming), and `` widget transfer.`` In the technology assistance component, SNL`s technology resources (expertise, services, and equipment) are made available to companies developing commercial products. In the ``widget transfer`` component, SNL`s intellectual property (patents, copyrights) is placed with private sector firms through various partnership intermediaries

This manual is intended to aid operators of the pressure controller in the Transducer Calibration Laboratory. We include discussions of automated control, data acquisition, and data analysis techniques that improve the quality and thoroughness of transducer pressure calibration procedures.

This memorandum is a synopsis of the description and operation of the equipment used and the events occurring during the calibration of an accelerometer on the 5000 g centrifuge.

Many MoS{sub 2} lubricant film formulations exhibit tribological performance degradation after extended storage in high humidity ambient environments. As a part of an extensive study of the effects of high humidity storage on a wide variety of MoS{sub 2} lubricant film formulations, the effects of high humidity storage on sputtered MoS{sub 2} films have been examined. The surface chemistries of a series of ten different commercially deposited MoS{sub 2} lubricant film formulations on 440C stainless steel have been examined before and after 1 month of storage at 98% relative humidity. While the films varied greatly in film chemistry prior to high humidity storage, many smaller differences were observed after high humidity storage. Addition of Ni to the films affects the film chemistry far more dramatically than the addition of AuPd or SbO{sub x}, facilitating oxidation of the MoS{sub 2} and enhancing formation of sulfate species. All of the films are adequately characterized by considering only MoS{sub 2} and MoO{sub 3} species, with the exception of the films co-sputtered with Ni and ion implanted with N{sup +}, where some MoO{sub 2} or MoS{sub 2-x}O{sub x} must also be present.

This bibliography contains 64 references concerning the management of business and industry. Books and articles are both cited. Methods for gathering and utilizing information are emphasized. (GHH)

A power MOSFET macro-model for use with the circuit simulator SPICE has been developed suitable for use over the temperature range of {minus}55 to 125{degrees}C. The model is comprised of a single parameter set with the temperature dependence accessed through the SPICE TEMP card. This report describes in detail the development of the model and the extraction algorithms used to obtain model parameters. The extraction algorithms are described in sufficient detail to allow for automated measurements which in turn allows for rapid and cost effective development of an accurate SPICE model for any power MOSFET. 22 refs.

The analytical procedures for establishing the fragment hazard zone for explosive test facilities are presented. Environment, safety and health regulations require that a hazard zone analysis be conducted for every explosive test facility. Analyses are presented for explosively driven missile fragment trajectories resultant from cased explosive configurations. Fragment trajectory parameter data are presented in graphical form for three different fragment materials (aluminum, steel and tantalum), initial velocities between 0.6mm/{mu}s (2000 ft/sec) to 4.3mm/{mu}s (14,000 ft/sec), and for various geometries. This trajectory information is used, as an example, to determine the safe distance or hazard zone for the Area 2 explosive test facility at Sandia National Laboratories.

The equations of motion of beam and channel particles are analyzed in the ion focused regime. Using the paraxial approximation and assuming only transverse electro-magnetostatic interactions between beam and channel particles for the equations of motion (the same equations solved in the BUCKSHOT code) are written in non-dimensional form and scaling relations are derived for propagation parameters, magnetic erosion, and evaporation. These relations are very useful in doing parameter studies with a limited number of computer simulations.

Methods of mechanical and thermal testing specifically directed toward evaluation of impact-limiting materials for radioactive material transportation containers are presented. Associated figures of merit and procedures for rank-ordering the materials are also developed. Based on testing and evaluation procedures developed herein, thermal and mechanical results are presented for high- and low-density aluminum honeycombs, polyurethane foams, and aluminum foams. On a minimum mass basis, the high-density aluminum honeycomb is found to be a superior impact energy absorber up to the point of lock up. On a minimum volume basis, the high-density polyurethane foam is far superior, however. Based on the thermal figures of merit, the high-density polyurethane foam was found to be the most favorable material.

The energy-absorbing capability of impact limiters is an important part of radioactive waste transportation system. This document presents the results of the Basic Impact Limiter Study (BILS). The objective of this design development program was to increase the energy-absorbing capabilities of an external impact limiter for both axial and off-axis response. The impact limiter that was evaluated was made of stainless steel and was a right circular cylinder. The evaluation included computer analysis complemented by static and dynamic testing of quater-scale and half-scale models. The design development, analysis, and testing were conducted at Sandia National Laboratories.

Analyses have shown that early rupture of the Mark-I boiling water reactor containment-by the direct action of core debris depends strongly on the time that core debris is superheated above its liquidus. The analyses of the duration of superheat in the core debris are compared to predictions obtained with the CORCON-MOD 3 computer code. The predicitons of this computer code as functions of the core debris mass, composition, and initial superheat are used to create a polynomial response surface. This response surface is used in a Monte Carlo analysis to produce probability distributions for the duration of superheat in core debris in the drywell of a Mark-I containment. It is concluded that to a high level of confidence (>90%) the duration of superheating predicted with the CORCON-MOD 3 code is less than what has been used in the analyses of the threats to the Mark-I containment liner. Based on these results, to the extent superheat duration dictates the threat to the liner, analyses in NUREG/CR-5423 would appear to overestimate the threat to the liner in comparison to threats estimated using the predictions of the duration of superheating obtained with CORCON-MOD 3.

A postnotification record is required for all Highway Route Controlled Quantities of radioactive materials that are shipped in the United States. These reports, which are required by 49 CFR 172.203(d), are compiled in the Radioactive Materials Routing Report (RAMRT) database at the US Department of Transportation (DOT). Sandia National Laboratories` has developed an expanded version of the RAMRT which is entitled the Radioactive Materials Postnotification (RAMPOST) database. This paper provides the summary detail on the following topics: major carriers of highway route controlled quantities, major US Department of Energy (DOE) shippers, major US Nuclear Regulatory Commission (NRC) shippers and a breakdown of the types of Highway Route Controlled Quantities that have been shipped for the time period 1985--1990.

We describe the design and operation of an optical fiber accelerometer intended for environments inhospitable to electronic components. An overview of the device is presented along with descriptions of the optical, electronic, and mechanical components. The performance of the current prototype is equivalent to state of the art piezoelectric accelerometers. Improvements to the current design are discussed.

The possibility of formulating and validating a multi-site, multi- solute model for prediction of contaminant transport in groundwaters is being evaluated through experiments with simple analog systems. These systems consist of mixtures of well-characterized synthetic and natural materials in which the effects of sorption by ion exchange and amphoteric sites are isolated. Initial results are reported for studies of lead sorption by mixtures of goethite and montmorillonite, and Ni-Sr and Pb-Sr ion exchange by montmorillonite. The results of studies of simple clay-oxide mixtures indicate that the pH-dependent sorption behavior of Ni by mixtures of minerals containing amphoteric sites can be predicted from the properties of the component minerals.

Site characterization is an integral component of any environmental assessment or restoration project. However, it is often difficult to know how to prioritize site characterization activities. In the absence of a preliminary analysis, site characterization decisions are sometimes guided by little more than intuition. The objective of this paper is to show that a Performance Assessment Methodology, used very early in a project, can be a useful tool for guiding site characterization activities. As an example, a ``preliminary`` performance assessment for the Greater Confinement Disposal project is used to demonstrate implementation of the methodology.

We present results that correlate microstructure and mechanical evolution to variations of deformation rate, hold time and environmental effects on the thermomechanical fatigue (TMF) behavior of 60Sn-40Pb solder. The results are used to define valid conditions for performing accelerated TMF tests. TMF tests at deformation rates of 5.6{times}10{sup {minus}4}s{sup {minus}1}, 2.8{times}10{sup {minus}4}s{sup {minus}1} and 2.1{times}10{sup {minus}4}s{sup {minus}1} were performed. Deformation rates greater than 2.8{times}10{sup {minus}4}s{sup {minus}1} result in fewer cycles to failure. At low deformation rates, the microstructure heterogeneously coarsens at cell boundaries. At higher rates, the deformation mechanism changes, and heterogeneous coarsening occurs at a strain concentration in the joint, independent of the microstructure. TMF tests with hold times of 0, 3 and 6 min. at the temperature extremes were performed. At hold times 3 min. or longer the damage at cell boundaries is annealed, resulting in heterogeneous coarsening. With no hold times the TMF life was greatly enhanced as a result of limited coarsening. The effect of the oxygen environment was explored. The TMF life in the presence of oxygen was found to be extended. Valid acceleration conditions for a TMF test of solder are: a deformation rate of 2.8{times}10{sup {minus}4}s{sup {minus}1} or lower, with hold times of 3 mn. or longer.

The discrete Fourier transform and power spectral density are often used in analyzing data from analog-to-digital converters. These analyses normally apply a window to the data to alleviate the effects of leakage. This paper describes how windows modify the magnitude of a discrete Fourier transform and the level of a power spectral density computed by Welch`s method. For white noise, the magnitude of the discrete Fourier transform at a fixed frequency has a Rayleigh probability distribution. For sine waves with an integer number of cycles and quantization noise, the theoretical values of the amplitude of the discrete Fourier transform and power spectral density are calculated. We show how the signal-to-noise ratio in a single discrete Fourier transform or power spectral density frequency bin is related to the normal time-domain definition of the signal-to-noise ratio. The answer depends on the discrete Fourier transform length, the window type and the function averaged.

A new, laser-based system has been developed for rapid evaluation of monolithic thermoluminescence dosimetry (TLD) arrays. A precision controlled CO{sub 2} laser is used to sequentially heat 1.5 mm diameter, {approx} 0.04 mm thick TLDs deposited on a .125 mm thick polymer substrate in a 3 mm {times} 3 mm grid. Array areas up to 30 cm {times} 30 cm are used (> 10,000 TLD elements), with evaluation times of 45--90 minutes. Isodose contours and various analysis functions are available on the system-operating PC. This system allows for greatly expanded dosimetry compared to standard TLDs, simultaneously decreasing effort and record keeping. We compared the dosimetric characteristics of this system with standard techniques, using near Si-equivalent CaF{sub 2}:Mn TLD elements, in a test with 19 MeV end-point X radiation. The results show the laser system performs as well as the standard system. 4 refs.

The Chemical Waste Landfill (CWL) was used by Sandia National Laboratories (SNL), Albuquerque for disposal of hazardous chemicals from the years 1962 to 1985. Prompted by the detection of low levels of trichlorethylene (TCE) in groundwater samples from a water table aquifer approximately 146 meters below ground surface, a RCRA Site Investigation (RSI) and remediation of organic contaminants will be performed at the CWL prior to closure of this landfill. The RSI is focused on optimal characterization of the VOC and dense non-aqueous phase liquid (DNAPL) contamination at this site which will be possible through application of innovative strategies for characterization and promising new technologies. This paper provides a discussion of conceptual models of contaminant transport at the CWL, and an overview of our investigative strategy which is focused on characterizing transport of VOC and DNAPLS. Each stage of the RSI has been developed to gather information which will reduce the uncertainty in the design of each subsequent phase of the investigation. Three stages are described; a source characterization stage, unsaturated zone characterization stage, and a saturated zone characterization stage. The unsaturated zone characterization must provide all data necessary to make decisions concerning the necessity of a saturated zone characterization phase.

This paper summarizes the results of aging, condition monitoring, and accident testing of Class 1E cables used in nuclear power generating stations. Three sets of cables were aged for up to 9 months under simultaneous thermal ({approximately}100{degrees}C) and radiation ({approximately}0.10 kGy/hr) conditions. After the aging, the cables were exposed to a simulated accident consisting of high dose rate irradiation ({approximately}6 kGy/hr) followed by a high temperature steam (up to 400{degrees}C) exposure. A fourth set of cables, which were unaged, was also exposed to the accident conditions. The cables that were aged for 3 months and then accident tested were subsequently exposed to a high temperature steam fragility test (up to 400{degrees}C), while the cables that were aged for 6 months and then accident tested were subsequently exposed to a 1000-hour submergence test in a chemical solution. The results of these tests do not indicate any reason to believe that many popular nuclear power plant cable products cannot inherently be qualified for 60 years of operation for conditions simulated by this testing. Mechanical measurements (primarily elongation, modulus, and density) are more effective than electrical measurements for monitoring age-related degradation. In the high temperature steam test, ethylene propylene rubber (EPR) cable materials generally survived to higher temperatures than crosslinked polyolefin (XLPO) cable materials. In dielectric testing after the submergence testing, the XLPO materials performed better than the EPR materials.

Numerous investigations have studied the potential for chaotic vibrations of nonlinear systems. It has been shown for many simple nonlinear systems, that when they are excited severely enough, or with the appropriate parametric combinations, that they will execute chaotic vibrations. The present investigation considers the potential for the occurrence of chaos in a practical nonlinear system -- the isolated accelerometer. A simple, first order model is proposed for the isolated accelerometer, and it is shown that chaos can occur in the isolated accelerometer. A preliminary investigation into the bearing that this chaos potential has on the measurement of shock response is summarized. 7 refs.

Carrier-driven photochemical reactions require direct participation of free carriers for the chemical reaction to proceed. Therefore, they can be selectively suppressed by increasing the carrier recombination rate through creation of defects using ion implantation. The residual defect concentration following ion implantation should correlate with etching suppression. Changes in the Raman LO-phonon lineshape correlate well with the degree of etching suppression and predict etching behavior better than defect concentrations calculated with the Monte Carlo code, TRIM. Raman spectroscopy may be a useful pre-etch diagnostic to predict the degree of etching suppression resulting from a given implantation treatment. 11 refs.

Direct containment heating (DCH) has recently been studied at Sandia National Laboratory`s Surtsey facility in a number of experiments in which high-temperature thermite melts are ejected by pressurized steam from a melt generator into scaled reactor cavities. Steam blowdown from the melt generator disperses at least part of the melt into the Surtsey vessel. Efficient team-metal chemical reaction was observed in many of the experiments. Analysis of the results suggests that hydrogen generation occurs primarily in the cavity can actually reduce hydrogen generation by separating the debris from the blowdown steam. Debris-gas heat transfer appears to include both a component that takes place in the cavity in proportion to the hydrogen generation, and a second component that takes place in the Surtsey vessel itself. The magnitude of the latter depends upon the amount of debris dispersed and the length of the unobstructed flight path in the Surtsey vessel. Some possible implications of these results are discussed.

A Senate Committee requested assistance from Sandia in determining the adequacy of the investigation of the incident aboard the USS IOWA. This currently unexplained explosion occurred in Turret 2 of the battleship on April 19, 1989, killing 47 crewmen. The investigation included material characterization of debris found after the explosion, ignition experiments to characterize the propellant, and analytic modeling of the mechanics, interior ballistics and ignition. The analytic modeling is described in this paper. The modeling of the incident was concerned with the mechanics of the ramming equipment used to load the 16 inch guns, and the interior ballistic and ignition of the propellant. Many separate analyses were performed to explain the crushing of the propellant grains, the dynamics and location of ignition of the propellant train, and the presence of damage after the incident. The goal of this modeling was to assess the feasibility of the various events in the turret, and to identify the cause of the incident. An item of particular interest was damage to the rammer control handle quadrant. The US Navy conjectured that the blast propelled the rammermans seat into the quadrant in such a way as to suggest low speed ram during the incident. The speed of the ram was discovered to be very important in determining the probability of ignition during an overram, and an analysis of the rammermans seat motion was completed. In order to understand how the seat impacts the quadrant, a three-dimensional finite element analysis was completed using ABAQUS/Explicit. The loading of the seat was due to two-phase gas and propellant flow through the bag train and into the turret volume. The results showed that impact onto the quadrant probably first occurred at the rear, dislodging it from its mount. This analysis was pivotal in the examination of the incident, and was the final evidence that the cause of the explosion could not be conclusively determined.

High spatial resolution x-ray microanalysis in the analytical electron microscope (AEM) describes a technique by which chemical composition can be determined on spatial scales of less than 50 nm. Dependent upon the size of the incident probe, the energy (voltage) of the beam, the average atomic number of the material being analyzed, and the thickness of the specimens at the point of analysis it is possible to measure uniquely the composition of a region 2--20 nm in diameter. Conventional thermionic (tungsten or LaB{sub 6}) AEMs can attain direct spatial resolutions as small as 20 nm, while field emission (FEG) AEM`s can attain direct spatial resolutions approaching 2 nm. Recently, efforts have been underway to extract compositional information on a finer spatial scale by using massively parallel Monte Carlo electron trajectory simulations coupled with AEM measurements. By deconvolving the measured concentration profile with the calculated x-ray generation profile it is possible to extract compositional information at near atomic resolution.

Chemical and physical transformations involved in ion implantation processes in glasses determine changes in mechanical. and tribological properties, in network dilatation, in induced optical absorption and luminescence and in the composition and chemical behavior as a function of different experimental conditions (ion, energy, dose, target temperature). Variations of chemical etch rate in HF are related to radiation damages and formation of compounds. A systematic study of the etch rate changes in silica due to Ar, N, Si plus N implants has been performed. Structure modifications at depths greater than the corresponding implanted ion ranges are evidenced for nuclear deposited energy greater than 10{sup 22} keV cm{sup {minus}3}. Formation of silicon oxynitrides reduces the etch rate values.

Archimedes is a prototype mechanical assembly system which generates and executes robot assembly programs from a CAD model input. The system seeks to increase flexibility in robotic mechanical assembly applications by automating the programming task. Input is a solid model of the finished assembly, augmented by additional design information such as weld specifications. Parts relationships and geometric constraints are deduced from the solid model. A rule-based planner generates a ``generic`` assembly plan that satisfies the geometric constraints, as well as other constraints embodied in the rules. A plan compiler then converts the generic plan into code specific to an application environment. Other outputs include fixture designs, workcell layout information, object-recognition (vision) routines, grasp plans, and executable code for controlling the robot and workcell accessories. Lessons from operating and demonstrating the system are presented, with a particular emphasis on the implications for future systems. 12 refs.

Isolated accelerometer measurement systems are used to measure environments composed of a wide spectrum of frequencies including the natural frequency of the isolated accelerometer. Because the isolated accelerometer measurement system is a nonlinear system, it is subject to the potential for chaotic vibrations. it is clear that this potential if realized, affects the response of the measurement system to vibration input and perhaps to shock input also. This paper explores the effects that the potential for chaotic vibrations and nonlinear response, in general, has on the random vibration response of the isolated accelerometer measurement system. Specifically, the system response to white noise is investigated and assessed in terms of response histogram and response spectral density. 6 refs.

In the Federal Register, Volume 51, Number 168, NRC has intended the use of IMPACTS-BRC to evaluate petitions for evaluating radioactive waste streams as below regulatory concern. IMPACTS-BRC is a generic radiological assessment code that allows calculation of potential impacts to maximum individuals, waste disposal workers, and the general population resulting from exemption of very low-level radioactive waste from regulatory control. The code allows calculations to be made of human exposure to the waste by many pathways and exposure scenarios. This document describes the code history and the quality assurance work that has been carried out on IMPACTS-BRC. The report includes a summary of all the literature reviews pertaining to IMPACTS-BRC up to Version 2.0. The new code and data verification work necessary to produce IMPACTS-BRC, Version 2.1 is presented. General comments about the models and treatment of uncertainty in IMPACTS-BRC are also given.

This work describes the collection, handling, transportation, thermal desorption, and analysis of explosive vapors using quartz collection tubes. A description of the sampling system is presented, along with the collection efficiency of the quartz tubes and some of the precautions necessary to maintain the sample integrity. The design and performance characteristics of the thermal desorption system are also discussed. Collection of explosive vapor using empty, 0.25 inch O.D. by 5.25 inch long quartz tubes at a flow rate of 200 mL min-1 is quite different. Thermal desorption of the explosive vapor molecules using a furnace that allows control of the gas phase chemistry in the IMS has been shown to provide a reliable, reproducible means of analysis. Empty quartz tubes provide a sharper desorption profile than packed collection tubes, resulting in a better signal-to-noise ratio, and perhaps, a lower detection limit than packed quartz tubes. Both the ion drift time of the explosive and its desorption characteristics can provide a means of identification. Sample handling, packaging, and transportation methods which minimize sample loss and contamination have been developed and evaluated.

This report contains the purchasing and materials management operating highlights for Fiscal Year 1991. Included in the report are compiled data on: personnel; type of procurement; small business procurements; disadvantaged business procurements; woman-owned business procurements; New Mexico commercial business procurements; Bay Area commercial business procurements; commitments by states and foreign countries to commercial suppliers; and, transportation activities. Other statistical data tables enumerate the following: the twenty-five commercial contractors receiving the largest dollar commitments; commercial contractors receiving commitments of $1000 or over; integrated contractor and federal agency commitments of $1000 or over from Sandia National Laboratories-Albuquerque and Livermore; and, transportation commitments of $1000 or over from Sandia National Laboratories-Albuquerque and Livermore.

This white paper addresses the issue of banning lead from solders used in electronics manufacturing. The current efforts by legislative bodies and regulatory agencies to curtail the use of lead in manufactured goods, including solders, are described. In response to a ban on lead or the imposition of a tax which makes lead uneconomical for use in solder alloys, alternative technologies including lead-free solders and conductive epoxies are presented. The recommendation is made that both users and producers of solder materials join together as partners in a consortium to address this issue in a timely and cost-effective manner.

The MELCOR code has been used to simulate the ST-1 and ST-2 in-pile product source term experiments performed in the ACRR facility. As expected, there were no major differences observed in the results calculated for the different test conditions. The CORSOR, CORSOR-M and CORSOR-Booth release models all were tested, and the effect of including the surface-volume correction term was evaluated. MELCOR results were compared to test data and to VICTORIA results, and also directly to the correlations and to ST-1/ST-2 results predicted by Battelle using their stand-alone CORSOR code to verify that the models have been implemented correctly in MELCOR. The release rates and total release fractions calculated by MELCOR generally agreed well with the test data, for both volatile and refractory species, with none of the release model options available yielding consistently better agreement with data for species. Sensitivity studies checking for time step and noding effects and machine dependencies were done, and some machine dependencies associated with very small numbers were identified and corrected in the code. Additional sensitivity studies were run on parameters affecting core heatup and core damage, including both variations in code models such as convective heat transfer coefficients, radiation view factors, candling assumptions, and in experimental conditions such as pressures, flow rates, power levels, and insulation thermal conductivity. Code and user input modeling errors encountered in these analyses are described.

This paper presents a method to solve partial differential equations governing two-phase fluid flow by using a genetic algorithm on the NCUBE/2 multiprocessor computer. Genetic algorithms represent a significant departure from traditional approaches of solving fluid flow problems. The inherent parallelism of genetic algorithms offers the prospect of obtaining solutions faster than ever possible. The paper discusses the two-phase flow equations, the genetic representation of the unknowns, the fitness function, the genetic operators, and the implementation of the genetic algorithm on the NCUBE/2 computer. The paper investigates the implementation efficiency using a pipe blowdown test and presents the effects of varying both the genetic parameters and the number of processors. The results show that genetic algorithms provide a major advancement in methods for solving two-phase flow problems. A desired goal of solving these equations for a specific simulation problem in real time or faster requires computers with an order of magnitude more processors or faster than the NCUBE/2`s 1024.

Although plasma cleaning is a recognized substitute for solvent cleaning in removing organic contaminants, current cleaning rates are impractically low for many applications. A set of experiments is described which demonstrate that the rate of plasma removal of organic contaminants can be greatly increased by modification of the plasma chemistry. A comparison of plasma cleaning rates of argon, oxygen and oxygen/sulfur hexafluoride gases shows that the fluorine containing plasma is at least an order of magnitude faster at etching organics. Rates are reported for the removal of polymer films and of A-9 Aluminum cutting fluid. 7 refs.

Measuring the yield of an underground nuclear detonation using sensor cables has been proposed for verification purposes. These cables not only sense the signals associated with the yield they also capture the sensitive primary and secondary electromagnetic pulses associated with the detonation but have nothing to do with the yield. An anti-intrusiveness device is to be connected to the sensor cable to prevent the electromagnetic pulses from passing through to the verifier. The anti-intrusiveness device both attenuates the electromagnetic pulses and adds noise to the cable over the interval of time that the electromagnetic pulses may be present. This report addresses the problem of determining the optimum noise spectral density for masking the electromagnetic pulses. To this end it derives an expression for the lower bound on the error in the estimation of the time separation between two pulses when the time of arrival of neither is known and they are imbedded in Gaussian noise. The noise spectral shapes considered are white, and lowpass, and bandpass.

UPEML is a machine-portable program that emulates a subset of the functions of the standard CDC Update. Machine-portability has been achieved by conforming to ANSI standards for Fortran-77. UPEML is compact and fairly efficient; however, it only allows a restricted syntax as compared with the CDC Update. This program was written primarily to facilitate the use of CDC-based scientific packages on alternate computer systems such as the VAX/VMS mainframes and UNIX workstations. UPEML has also been successfully used on the multiprocessor ELXSI, on CRAYs under both UNICOS and CTSS operating systems, and on Sun, HP, Stardent and IBM workstations. UPEML was originally released with the ITS electron/photon Monte Carlo transport package, which was developed on a CDC-7600 and makes extensive use of conditional file structure to combine several problem geometry and machine options into a single program file. UPEML 3.0 is an enhanced version of the original code and is being independently released for use at any installation or with any code package. Version 3.0 includes enhanced error checking, full ASCII character support, a program library audit capability, and a partial update option in which only selected or modified decks are written to the complete file. Version 3.0 also checks for overlapping corrections, allows processing of pested calls to common decks, and allows the use of alternate files in READ and ADDFILE commands. Finally, UPEML Version 3.0 allows the assignment of input and output files at runtime on the control line.

The Planning and Staff Support of the Sandia National Laboratories publishes a monthly bulletin titled, Energy and Environment. The bulletin facilitates technology exchange with industries, universities, and with other government agencies. This bulletin is for the month of April 1992 and covers such things as new methods of soldering which reduces environmental threats by avoiding chlorofluorocarbon solvents. Some technologies developed are soldering in controlled atmospheres, acid-vapor soldering, and laser soldering. Another topic in this bulletin is the designing of catalysts of chemical reactions by computers. Biomimetic catalysts are being created by Computer-Aided Molecular Design. These biomimetic catalysts can aid in fuel conversion. In-situ remediation of soils contaminated by heavy metals was another topic in this bulletin. This in-situ process is called, electrokinetic remediation. It uses electrodes to induce a metal-attracting electric field in the ground. The last topic in this bulletin is the design of a semiconductor bridge (SCB) which is used to improve the timing and effectiveness of blasting. Timing and accuracy is important; and the blasting industry is no exception. This SCB gives a low-energy pulse which causes a doped region on a polysilicon substrate into a bright plasma. This plasma discharge causes the ignition and produces an accurate explosion in microseconds. (MB)

Seventeen small-scale brine inflow experiment boreholes have been and are currently being monitored for brine accumulation. All of the boreholes were drilled from underground excavations at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM. Experiments are ongoing in Room D, Room L4, and the Q access drift in the WIPP underground. The boreholes range from approximately 5 to 90 cm in diameter and from 3 to 6 m in length. The objective of these experiments is to provide data for use in the development and validation of a predictive, mechanistic model for brine inflow to the repository. There is considerable variability in the observed responses of the different boreholes, and there are also significant similarities. Two of the boreholes in Room D have yielded no brine in more than 3.5 years, while all 15 of the other boreholes have produced anywhere from 2 to 90 kg of brine. Inflow rates vary by as much as 2 orders of magnitude for boreholes of the same dimensions in the same general location; however, inflow rates measured in most of the boreholes are of the same order of magnitude. Decreasing, increasing, and steady inflow rates have been measured. Nevertheless, 9 of the 15 brine-producing boreholes behaved similarly early in their history. These 9 boreholes all exhibited a relatively high initial inflow rate followed by a fairly smooth decline with time. Variabilities in borehole response can be explained by assuming there are heterogeneities in the formation tested. In most cases these heterogeneities are believed to be excavation-induced. Data from these experiments suggest that flow near excavations has been altered by rock deformation, including fracturing. Additional experiments are required to differentiate between a far-field, near-field, or combination brine source and to characterize the significant flow mechanism or mechanisms.

A high-velocity impact testing technique, utilizing a tethered rocket, is being developed at Sandia National Laboratories. The technique involves tethering a rocket assembly to a pivot location and flying it in a semicircular trajectory to deliver the rocket and payload to an impact target location. Integral to developing this testing technique is the parallel development of accurate simulation models. An operational computer code, called ROAR (Rocket-on-a-Rope), has been developed to simulate the three-dimensional transient dynamic behavior of the tether and motor/payload assembly. This report presents a discussion of the parameters modeled, the governing set of equations, the through-time integration scheme, and the input required to set up a model. Also included is a sample problem and a comparison with experimental results.

The Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups typically hold a joint meeting each year to provide a forum for discussion of technical issues of current interest as well as an opportunity for program reviews by the Department of Energy (DOE). At the meeting in September 1990, reported here, research programs in support of the International Thermonuclear Experimental Reactor (ITER) were highlighted. The first part of the meeting was devoted to research and development (R&D) for ITER on plasma facing components plus introductory presentations on some current projects and design studies. The balance of the meeting was devoted to program reviews, which included presentations by most of the participants in the Small Business Innovative Research (SBIR) Programs with activities related to plasma wall interactions. The Task Groups on Plasma/Wall Interaction and on High Heat Flux Materials and Components were chartered as continuing working groups by the Division of Development and Technology in DOE`s Magnetic Fusion Program. This report is an addition to the series of ``blue cover`` reports on the Joint Meetings of the Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups. Among several preceding meetings were those in October 1989 and January 1988.

The switch delay time of the MC3858 sprytron was measured using a test matrix consisting of 36 different trigger circuit configurations. The test matrix allowed the measurement of switch delay times for peak trigger voltages ranging from 47 V to 1340 V and for stored trigger energies ranging from 0.023 mJ to 2.7 mJ. The average switch delay time was independent of peak trigger voltage above approximately 800 V. Similarly, the average switch delay was independent of trigger stored energy above approximately 0.5 mJ. Below these saturation values, the average switch delay increases rapidly with decreasing trigger voltage or esergy. In contrast to the average switch delay time, the shot-to-shot variability in switch delay time does not appear to be strongly affected by peak trigger voltage as long as the trigger voltage is groater than 100 V. Below 100 V, the variability in switch delay time rises rapidly due to failure of the trigger to undergo immediate high voltage breakdown when trigger voltage is applied. The effect of an abnormally-high-resistance trigger probe on switch delay time was also investigated. It was found that a high-resistance probe behaved as a second overvoltage gap in the trigger circuit. Operation with a peak trigger voltage greater than the breakdown voltage of this second gap yielded delay times comparable to operation with a normal trigger. Operation with a peak trigger voltage less than the breakdown voltage of this second gap increased the switch delay time by an amount comparable to the time required to ramp the trigger circuit output up to the breakdown voltage of the second gap. Finally, the effect that varying the bias voltage applied to the sprytron has on switch delay time was measured. The switch delay time did not appear to depend on bias voltage for bias voltages between 725 V and 2420 V.

Performance assessment modeling for High Level Waste (HLW) disposal incorporates three different types of uncertainty. These include data and parameter uncertainty, modeling uncertainty (which includes conceptual, mathematical, and numerical), and uncertainty associated with predicting the future state of the system. In this study, the potential impact of conceptual model uncertainty on the estimated performance of a hypothetical high-level radioactive waste disposal site in unsaturated, fractured tuff has been assessed for a given group of conceptual models. This was accomplished by taking a series of six, one-dimensional conceptual models, which differed only by the fundamental assumptions used to develop them, and conducting ground-water flow and radionuclide transport simulations. Complementary cumulative distribution functions (CCDFs) representing integrated radionuclide release to the water table indicate that differences in the basic assumptions used to develop conceptual models can have a significant impact on the estimated performance of the site. Because each of the conceptual models employed the same mathematical and numerical models, contained the same data and parameter values and ranges, and did not consider the possible future states of the system, changes in the CCDF could be attributed primarily to differences in conceptual modeling assumptions. Studies such as this one could help prioritize site characterization activities by identifying critical and uncertain assumptions used in model development, thereby providing guidance as to where reduction of uncertainty is most important.

The tectonics program for the proposed high-level nuclear waste repository at Yucca Mountain in southwestern Nevada must evaluate the potential for surface faulting beneath the prospective surface facilities. To help meet this goal, Quaternary surficial mapping studies and photolineament analyses were conducted to provide data for evaluating the location, recency, and style of faulting with Midway Valley at the eastern base of Yucca Mountain, the preferred location of these surface facilities. This interim report presents the preliminary results of this work.

Sandia is a government-owned, contractor-operated national laboratory that AT&T has operated on a no-profit, no-fee basis since 1949. We have been an integral part of the nuclear weapons program, providing total concept-to-retirement engineering for every warhead and bomb in the nuclear weapon stockpile. We are proud of our contributions to national security. Our scientific and engineering skills, our facilities, and our experience have benefited not only the nuclear weapons program but have also contributed significantly to their areas of national security, including conventional defense, energy, and industrial competitiveness. Likewise, these capabilities position us well to continue a tradition of exceptional service in the national service in the national interest. Sandia is a multiprogram national laboratory with mission responsibilities in nuclear weapons, arms control and verification, energy and environment, and technology transfer. Our work for the DOE Assistant Secretary for Defense Programs constitutes 50% of the laboratory`s effort. Sandia`s arms control, verification, and related intelligence and security programs, funded by DOE and by other agencies constitute the largest aggregation of such work at any facility in the world. We also support DOE with technology development -- in particular, specialized robotics and waste characterization and treatment processes to assist in the cleanup of contaminated sites. Research and development to support the National Energy Strategy is another substantial laboratory activity. Sandia`s successful developments in renewable, nuclear, and fossil energy technologies have saved the country billions of dollars in energy supply and utilization. Technology transfer is conducted across all Sandia programs.

A series of cyclic, direct-shear tests was conducted on several replicas of a tensile fracture of welded tuff to verify the graphical method proposed by Saeb (1989) and by Amedei and Saeb (1990). Tests were performed under different levels of constant normal load and constant normal stiffness. Each test consisted of five cycles of forward and reverse shear. The effect of cyclic loading on the fracture shear behavior was investigated. Fracture surface asperity degradation was quantified by comparing fracture fractal dimensions before and after shear.

The purpose of this talk is to set the scene with a definition of records management, records and federal records. It is also to introduce some techniques to ensure that office files are properly organized and maintained, rapidly retrievable, complete, and ready for appropriate disposition the NARA (National Archives and Records Administration) way.

A designed and assembled method for a non-adjustable Interferometer cavity has been developed at Sandia National Laboratories which has enabled the development of a Fixed-Cavity Velocity Interferometer System for Any Reflector (VISAR). In this system, the critical interference adjustments are performed during assembly of the interferometer cavity, freeing the user from an otherwise repetitive task. The Fixed-Cavity VISAR System is constructed in modular form. Compared to previous VISAR systems, it is easy to use, and gives high quality results. 6 refs.

This report contains a summary of large-scale experiments conducted at Sandia National Laboratories under the Solar Detoxification of Water project. The objectives of the work performed were to determine the potential of using solar radiation to destroy organic contaminants in water by photocatalysis and to develop the process and improve its performance. For these experiments, we used parabolic troughs to focus sunlight onto glass pipes mounted at the trough's focus. Water spiked with a contaminant and containing suspended titanium dioxide catalyst was pumped through the illuminated glass pipe, activating the catalyst with the ultraviolet portion of the solar spectrum. The activated catalyst creates oxidizers that attack and destroy the organics. Included in this report are a summary and discussion of the implications of experiments conducted to determine: the effect of process kinetics on the destruction of chlorinated solvents (such trichloroethylene, perchloroethylene, trichloroethane, methylene chloride, chloroform and carbon tetrachloride), the enhancement due to added hydrogen peroxide, the optimal catalyst loading, the effect of light intensity, the inhibition due to bicarbonates, and catalyst issues.

The high-temperature stability of current and proposed aviation fuels is a major factor in the design of advanced technology aircraft engines. Efforts to develop highly stable formulations and thereby mitigate fouling problems in aircraft fuel system components would clearly benefit from a predictive model that describes the important parameters in thermally induced degradation of the liquid fuel as well as the deposition of solid species. To generate such a model, diagnostic tools are needed to characterize adequately fluid dynamics, heat transfer, mass transfer and complex chemical processes that occur in thermally stressed fuels. In this paper, the authors describe preliminary results in the use of a dynamic light scattering technique, photon correlation spectroscopy (PCS), to address one aspect of the fuel stability problem; i.e., incipient particle formation and subsequent growth in mean particle size as a function of tempreture, exposure time, degree of oxidation, etc.

Accident severity categories are used in many risk analyses for the classification and treatment of accidents involving vehicles transporting radioactive materials. Any number or definition of severity categories may be used in an analysis. A methodology which allow accident probabilities associated with one severity category scheme to be transferred to another severity category scheme is described. The supporting data and information necessary to apply the methodology are also discussed. The ability to transfer accident probabilities between severity category schemes will allow some comparisons of different studies at the category level. The methodology can be employed to transfer any quantity between category schemes if the appropriate supporting information is available.

This paper will describe two data bases which provide supporting information on radioactive material transport experience in the United States. The Radioactive Material Incident Report (RMIR) documents accident/incident experience from 1971 to the present from data acquired from the US Department of Transportation (DOT) and the Nuclear Regulatory Commission (NRC). The Radioactive Material Postnotification (RAMPOST) data base documents the shipments that have taken place for Highway Route Controlled Quantities (HRCQ) of radioactive material. HRCQ shipments are post notified (that is, after the shipment) to the DOT.

A large buildup in interface traps has been observed in commercial and radiation-hardened MOS transistors at very long times after irradiation (> 10{sup 6} s). This latent buildup may have important implications for CMOS response in space. 13 refs.

The highest {Tc}`s achieved in organic electron-donor-based systems occur in two isostructural ET salts, viz., {kappa}-[(ET){sub 2}Cu][N(CN){sub 2}]X, X = Br ({Tc} = 11.6 K, ambient pressure), X = Cl ({Tc} = 12.8 K, 0.3 kbar) whereas for the electron-acceptor-based systems derived from C{sub 60} they occur in K{sub 3}C{sub 60} ({Tc} = 19 K), Rb{sub 3}C{sub 60} ({Tc} = 29 K), Rb{sub x}Cs{sub y}C{sub 60} ({Tc} 33 K) and Rb{sub x}Tl{sub y}C{sub 60} ({Tc} {approx} 45 K). Research performed at Argonne National Laboratory, and based on the ET and C{sub 60} systems, is reviewed.

A new approach for solving two-dimensional clustering problems is presented. The method is based on an inhibitory template which is applied to each pair of dots in a data set. Direct clustering of the pair is inhibited (allowed) if another dot is present (absent), respectively, within the area of the template. The performance of the method is thus entirely determined by the shape of the template. Psychophysical experiments have been used to define the template shape for this work, so that the resulting method requires no pattern-dependent adjustment of any parameters. The novel concept of a psychophysically-defined template and the absence of adjustable parameters set this approach apart from previous work. The useful grouping performance of this approach is demonstrated with the successful grouping of a variety of dot patterns selected from the clustering literature.

Sandia National Laboratories (SNL) Environmental Restoration (ER) Program has recently implemented a highly structured CS{sup 2} required by DOE. It is a complex system which has evolved over a period of a year and a half. During the implementation of this system, problem areas were discovered in cost estimating, allocation of management costs, and integration of the CS{sup 2} system with the Sandia Financial Information System. In addition to problem areas, benefits of the system were fund in the areas of schedule adjustment, projecting personnel requirements, budgeting, and responding to audits. Finally, a number of lessons were learned regarding how to successfully implement the system.

Ferroelectric PZT 53:47 thin films were prepared by two different solution deposition methodologies. Both routes utilized carboxylate and alkoxide precursors and acetic acid, which served as both a solvent and a chemical modifier. We have studied the effects of solution preparation conditions on film microstructure and ferroelectric properties, and have used NMR spectroscopy to characterize chemical differences between the two precursor solutions. Films prepared by a sequential precursor addition (SPA) process were characterized by slightly lossy hysteresis loops, with a P{sub r} of 18.7 {mu}C/cm{sup 2} and an E{sub c} of 55.2 kV/cm. Films prepared by an inverted mixing order (IMO) process were characterized by well saturated hysteresis loops, a P{sub r} of 26.2 {mu}C/cm{sup 2} and an E{sub c} of 43.3 kV/cm. While NMR investigations indicated that the chemical environments of both the proton and carbon species were similar for the two processes, differences in the amounts of by-products (esters, and therefore, water) formed were noted. These differences apparently impacted ceramic microstructure. Although both films were characterized by a columnar growth morphology, the SPA derived film displayed a residual pyrochlore layer at the film surface, which did not transform into the stable perovskite phase. The presence of this layer resulted in poor dielectric properties and lossy ferroelectric behavior.

CEPXS/ONELD is a discrete ordinates transport code package that can model the electron-photon cascade from 100 MeV to 1 keV. The CEPXS code generates fully-coupled multigroup-Legendre cross section data. This data is used by the general-purpose discrete ordinates code, ONELD, which is derived from the Los Alamos ONEDANT and ONETRAN codes. Version 1.0 of CEPXS/ONELD was released in 1989 and has been primarily used to analyze the effect of radiation environments on electronics. Version 2.0 is under development and will include user-friendly features such as the automatic selection of group structure, spatial mesh structure, and S{sub N} order.

Changing the focus of a corporate compensation and performance review system from process orientation to data base orientation results in a more integrated and flexible design. Data modeling of the business system provides both systems and human resource professionals insight into the underlying constants of the review process. Descriptions of the business and data modeling processes are followed by a detailed presentation of the data base model. Benefits derived from designing a system based on the model include elimination of hard-coding, better audit capabilities, a consistent approach to exception processing, and flexibility of integrating changes in compensation policy and philosophy.

This paper will address the purpose, scope, and approach of the Department of Energy Tiger Team Assessments. It will use the Tiger Team Assessment experience of Sandia National Laboratories at Albuquerque, New Mexico, as illustration.

The photocurrent response, photo-induced changes in hysteresis behavior, and electrooptic (birefringence) effects of sol-gel derived PZT film have been characterized as part of an effort to evaluate ferroelectric films for image storage and processing applications.

One of the common waste streams generated throughout the nuclear weapon complex is ``hardware`` originating from the nuclear weapons program. The activities associated with this hardware at Sandia National Laboratories (SNL) include design and development, environmental testing, reliability and stockpile surveillance testing, and military liaison training. SNL-designed electronic assemblies include radars, arming/fusing/firing systems, power sources, and use-control and safety systems. Waste stream characterization using process knowledge is difficult due to the age of some components and lack of design information oriented towards hazardous constituent identification. Chemical analysis methods such as the Toxicity Characteristic Leaching Procedure (TCLP) are complicated by the inhomogeneous character of these components and the fact that many assemblies have aluminum or stainless steel cases, with the electronics encapsulated in a foam or epoxy matrix. In addition, some components may contain explosives, radioactive materials, toxic substances (PCBs, asbestos), and other regulated or personnel hazards which must be identified prior to handling and disposal. In spite of the above difficulties, we have succeeded in characterizing a limited number of weapon components using a combination of process knowledge and chemical analysis. For these components, we have shown that if the material is regulated as RCRA hazardous waste, it is because the waste exhibits one or more hazardous characteristics; primarily reactivity and/or toxicity (Pb, Cd).

A brief discussion of the following topics is given in this report: Liquid Metal Divertors; Lithium Droplet Beam Divertor; Preferential Pumping of Helium; Reduced Erosion with Cu-Li, W-Li, etc.; Reduction of Erosion by Thermionic Emission; Reduced Erosion in Boronized Graphites; Proposal for Materials Experiments in TRIAM; Carbon-SiC for Plasma Facing Components; Helium Pumping with Palladium; Large Area Pump Limiter; Techniques for Enhanced Heat Removal; New Outlook on Gaseous Divertors; Gaseous Divertor Simulations; Impurity Seeding to Control ITER Particle and Heat Loads; Gaseous Divertor Experiments; Electrical Biasing to Control SOL Particle Fluxes; Biased Limiter in TEXTOR and Biased Divertor in PBX-M; Particle and Heat Flux Control Using Ponderomotive Forces; Helium Exhaust Using ICRF; Ergodic Magnetic Limiter Experiments in JFT-2M; and Helium Exhaust Using Fishbones.

The effects of argon addition to the vacuum arc remelting (VAR) process were studied in both laboratory and industrial experiments while remelting Alloy 718. The results demonstrate that argon can be added to an industrial VAR furnace to relatively high partial pressures without decreasing the melt rate, drip-short frequency, or constricting the arc plasma to a local region of the electrode surface. Laboratory experiments illustrate that this result is dependent on electrode chemistry, possibly related to magnesium content.

Melt pool shape in VAR is controlled by fluid flow, which is governed by the balance between two opposing flow fields. At low melt currents, flow is dominated by thermal buoyancy. In these instances, metal is swept radially outward on the pool surface, resulting in relatively shallow melt pools but increased heat transfer to the crucible at the melt pool surface. At high melt currents, flow is primarily driven by magento-hydrodynamic forces. In these cases, the surface flow is radially inward and downward, resulting in a constricted arc, the pool depth and relative heat transfer to the crucible are intermediate, even though the melt rate is significantly lower than either diffuse arc condition. Constricted arc conditions also result in erratic heat transfer behavior and non-uniformities in pool shape.

This report describes the Training and Qualification Program at the Simulation Technology Laboratory (STL). The main facility at STL is Hermes III, a twenty megavolt accelerator which is used to test military hardware for vulnerability to gamma-rays. The facility is operated and maintained by a staff of twenty engineers and technicians. This program is designed to ensure that these personnel are adequately trained and qualified to perform their jobs in a safe and efficient manner. Copies of actual documents used in the program are included in appendices. This program meets all the requirements for training and qualification in the DOE Orders on Conduct of Operations and Quality Assurance, and may be useful to other organizations desiring to come into compliance with these orders.

Division 2473 has characterized the performance of three types of focusing lenses used for CO{sub 2} laser beam welding. Specifically, we evaluated the plano-convex, positive meniscus, and aspheric lenses with focal lengths ranging from 1.25 to 5.0 inches. The measured responses were the resultant weld depth and width of bead-on-plate welds made using a range of focus positions. The welding parameters were 185 to 700 watts continuous wave beam power and 30 inches per minute travel speed. The results of this study quantified the weld profile dimensions as a function of lens type and focal length, beam power, depth of focus, and verified the coincidence of maximum weld depth and width.

The WC-1 and WC-3 experiments were conducted using a dry, 1:10 linear scale model of the Zion reactor cavity to obtain baseline data for comparison to future experiments that will have water in the cavity. WC-1 and WC-3 were performed with similar initial conditions except for the exit hole between the melt generator and the scaled model of the reactor cavity. For both experiments the molten core debris was simulated by a thermitically generated melt formed from 50 kg of iron oxide/aluminum/chromium powders. After the thermite was ignited in WC-1, the melt was forcibly ejected by 374 moles of slightly superheated steam at an initial driving pressure of 4.6 MPa through an exit hole with an actual diameter of 4.14 cm into the scaled model of the reactor cavity. In WC-3, the molten thermite was ejected by 300 moles of slightly superheated steam at an initial driving pressure of 3.8 MPa through an exit hole with an actual diameter of 10.1 cm into the scaled model of the reactor cavity. Because of the larger exit hole diameter, WC-3 had a shorter blowdown time than WC-1, 0.8`s compared to 3.0`s. WC-3 also had a higher debris velocity than WC-1, 54 m/s compared to 17.5 m/s. Posttest sieve analysis of debris recovered from the Surtsey vessel gave identical results in WC-1 and WC-3 for the sieve mass median particle diameter, i.e. 1.45 mm. The total mass ejected into the Surtsey vessel in WC-3 was 45.0 kg compared to 47.9 kg in WC-1. The peak pressure increase in Surtsey due to the high-pressure melt ejection (HPME) was 0.275 MPa in WC-3 and 0.272 in WC-1. Steam/metal reactions produced 181 moles of of hydrogen in WC-3 and 145 moles of hydrogen in WC-1.

Transport models used for performance assessment of the Waste Isolation Pilot Plant (WIPP) in the event of human intrusion into the repository currently rely on the K{sub d} linear sorption isotherm model to predict rates of radionuclide migration. The vast majority of K{sub d} data was measured in static (batch) experiment on powdered substrate; most data specific to the Culebra dolomite were gathered in this way for five radioelements of concern using up to four different water compositions. This report summarizes the available data, examines inconsistencies between these data and the assumptions of the K{sub d} model, and discusses potential difficulties in using existing sorption data for predictive modeling of radionuclide retardation through adsorption modeling are presented as an alternative to the K{sub d} model.

ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of linear time-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a machine-portable utility that emulates the basic features of the CDC UPDATE processor, the user selects on of eight codes for running on a machine of one of at least four major vendors. The ease with which this utility is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is maximized by employing the best available cross sections and sampling distributions, and the most complete physical model for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. Feasibility of construction permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications through simple update procedures. Version 3.0, the latest version of ITS, contains major improvements to the physical model, additional variance reduction via both internal restructuring and new user options, and expanded input/output capabilities.

A new algorithm for the treatment of sliding interfaces between solids with or without friction in an Eulerian wavecode is described. The algorithm has been implemented in the two-dimensional version of the CTH code. The code was used to simulate penetration and perforation of aluminum plates by rigid, conical-nosed tungsten projectiles. Comparison with experimental data is provided.

The first phase of a program to study the resistance of exclusion region barriers to ductile failure when subjected to accident-type, quasi-static extreme mechanical loads has been completed. This first phase consisted to qualification of the analytical tools used to study these types of structural deformations and the development of appropriate criteria to predict ductile failure. A series of tests were performed on hydroformed half-cylinder barrier mock-ups. The qualification activity was considered a success based upon the comparison of the deformations and loads measured during the testing to the response of these structures computed by the finite element modeling. This successful completion of the first phase allows the second phase program to proceed. 12 refs.

We have measured, by {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR), the percent deuteration, the tacticity and the purity of several polymers and one solvent used in the preparation of microcellular foams. The percent deuteration was measured for polystyrene, polyacrylonitrile and polyethylene. The tacticities of polystyrene and polyacrylonitrile were determined. The purity and degradation products of polyacrylonitrile and maleic anhydride were examined. This report documents the experimental procedures and results of these measurements.

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 second half of 1991 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.

The effects of cavern spacing and operating pressure on surface subsidence and cavern storage losses were evaluated using the finite- element method. The base case for the two sensitivity studies was a typical SPR cavern. The predicted responses of the base case and those from the pressurization study compared quite closely to measured surface subsidence and oil pressurization rates. This provided credibility for the analyses and constitutive models used. Subsidence and cavern storage losses were found to be strongly influenced by cavern spacing and pressurization. The relationship between subsidence volume and losses in storage volume varied as cavern spacing and operating pressure deviated from the base case. However, for a typical SPR cavern subsidence volume is proportional to storage loss and when expressed in ft., subsidence is equal to the percentage of storage loss.

The goal of the wet cavity (WC) test series was to investigate the effect of water in a reactor cavity on direct containment heating (DCH). The WC-1 experiment was performed with a dry cavity to obtain baseline data for comparison to the WC-2 experiment. WC-2 was conducted with water 3 cm deep (11.76 kg) in a 1:10 linear scale model of the Zion reactor cavity. The initial conditions for the experiments were similar. For both experiments the molten core debris was simulated by a thermitically generated melt formed from 50 kg of iron oxide/aluminum/chromium powders. After the charge was ignited, the debris was melted by the chemical reaction and was forcibly ejected through a nominal 3.5 cm hole into the scaled reactor cavity by superheated steam at an initial driving pressure of 4.58 MPa. The peak pressure increase in the containment due to the high-pressure melt ejection (HPME) was 0.272 MPa in WC-1 and 0.286 MPa in WC-2. The total amount of hydrogen generated in the experiments was 145 moles of H{sub 2} in WC-1 and 179 moles of H{sub 2} in WC-2. The total mass of debris ejected into the containment was identical for both experiments. These results suggest that water in the cavity slightly enhanced DCH.

Laboratory simulation of the approach of a radar fuze towards a target is an important factor in our ability to accurately measure the radar`s performance. This simulation is achieved, in part, by dynamically delaying and attenuating the radar`s transmitted pulse and sending the result back to the radar`s receiver. Historically, the device used to perform the dynamic delay has been a limiting factor in the evaluation of a radar`s performance and characteristics. A new device has been proposed that appears to have more capability than previous dynamic delay devices. This device is the digital RF memory. This report presents the results of an analysis of a digital RF memory used in a signal-delay application. 2 refs.

This report describes research and development related to Mo-based catalysts supported on hydrous metal oxide in exchangers for use in direct coal liquefaction processes. A group of NiMo catalysts were prepared on different hydrous titanium oxide (HTO) supports to serve as baseline materials for use in determining the effects of altering process parameters on the physical and catalytic properties of NiMoHTO catalysts. The baseline group included catalysts which had hydrogenation activities up to 40% higher than the best commercial NiMo/Al{sub 2}O{sub 3} catalysts used in coal liquefaction pilot plant studies on a weight of catalyst basis while containing 25% less active metal. The results of high resolution electron microscopy (HREM) studies addressing the effects of processing parameters on microstructure are also presented. NiMoHTO catalysts were included in a group of some 30 commercial and experimental catalysts tested at Amoco Oil Co. to determine applicability for upgrading coal resids. The performance of NiMoHTO catalysts in these tests was better than or comparable to the best commercial catalysts available for this application. The initial work with thin-film NiMoHTO catalysts supported on commercial silica gel spheres is presented. Second generation thin-film catalysts containing about 1% Mo have hydrogenation activities of about 75% of those of extruded commercial NiMo/Al{sub 2}O{sub 3} catalysts containing 10--13% Mo and up to 50% of the hydrodesulfurization activity of the commercial catalysts. The use of thin-film HTO technology, which allows for preparation of NiMoHTO catalysts on virtually any substrate lowers catalyst cost by reducing the amount of Ti required and provides engineering forms of HMO materials without development work needed to convert bulk HTO materials into usable engineering forms. Work done with NiMo catalysts supported on hydrous zirconium oxide (HZO) is also presented.

The third experiment of the Integral Effects Test (IET-3) series was conducted to investigate the effects of high pressure melt ejection (HPME) on direct containment heating (DCH). A 1:10 linear scale model of the Zion reactor pressure vessel (RPV), cavity, instrument tunnel, and subcompartment structures were constructed in the Surtsey Test Facility at Sandia National Laboratories (SNL). The RPV was modeled with a melt generator that consisted of a steel pressure barrier, a cast MgO crucible, and a thin steel inner liner. The melt generator/crucible had a semi-hemispherical bottom head containing a graphite limitor plate with a 3.5 cm exit hole to simulate the ablated hole in the RPV bottom head that would be formed by tube ejection in a severe nuclear power plant (NPP) accident. The reactor cavity model contained 3.48 kg of water with a depth of 0.9 cm that correspond to condensate levels in the Zion plant. A steam driven iron oxide/aluminum/chromium thermite was used to simulate HPME. IET-3 replicated the first experiment in the IET series (IET-1) except the Surtsey vessel contained 0.09 MPa air and 0.1 MPa nitrogen. No steam explosions occurred in the cavity in IET-3 experiment. The cavity pressure measurements showed that rapid vaporization of water occurred in the cavity at about the same time as the steam explosion in IET-1. However, the oxygen in the Surtsey vessel in IET-3 resulted in a vigorous hydrogen burn, which caused a significant increase in the peak pressure, 246 kPa compared to 98 kPa in the IET-1 test. The total debris mass ejected into the Surtsey vessel in IET-3 was 34.3 kg, and gas grab sample analysis indicated that 223 moles of hydrogen were produced by steam/metal reactions. About 186 moles of hydrogen burned and 37 moles remained unreacted.

This document presents planned actions, and their associated costs, for addressing the findings in the Environmental, Safety and Health Tiger Team Assessment of the Sandia National Laboratories, Albuquerque, May 1991, hereafter called the Assessment. This Final Action Plan should be read in conjunction with the Assessment to ensure full understanding of the findings addressed herein. The Assessment presented 353 findings in four general categories: (1)Environmental (82 findings); (2) Safety and Health (243 findings); (3) Management and Organization (18 findings); and (4) Self-Assessment (10 findings). Additionally, 436 noncompliance items with Occupational Safety and Health Administration (OSHA) standards were addressed during and immediately after the Tiger Team visit.

This paper addresses problems of synchronization and coordination in the context of faulty shared memory. We present algorithms for the consensus problem, and for reliable shared memory objects, from collections of read/write registers, 2-processor binary test-and-set objects, and read-modify-write registers, some of which may be faulty.

An entirely new ion beam analysis technique is described: single event upset (SEU) imaging. SEU-imaging utilizes the scanning of a mu-focused MeV ion beam across an integrated circuit. This beam generates both electrons and logic state changes which are monitored by a computer. The data is collected in a way that permits the generation of visual images which depict both the physical appearance of the scanned region (through the ion-induced electron signals) and the areas of the IC which are susceptible to upset (through detection of chip malfunctions). Comparison of these images with the chip design facilitates matching the individual transistor components with the upset-sensitive region. While our initial results with 1 μm resolution ion beams have demonstrated the viability of this new technique in directly identifying the sources of upset in mun-scale integrated circuits, the trend toward submun feature size will necessitate higher-resolution muprobes and improved appearance-imaging systems in future applications of this new technique. © 1992.

A computer program has been developed to reduce and analyze data from a standardized piezoelectric polymer (PVDF) shock-wave stress rate gauge. The program is menu driven with versatile graphic capabilities, input/output file options, hard copy options, and unique data processing capabilities. This program was designed to analyze digital current-mode'' data recorded from a Bauer PVDF stress-rate gauge and reduce it to a stress-versus-time record. The program was also designed to combine two simulanteously recorded data channels.

The purpose of the molten-salt pump and valve loop test is to demonstrate the performance, reliability, and service life of full-scale hot- and cold-salt pumps and valves for use in commercial central receiver solar power plants. This test was in operation at Sandia National Laboratories National Solar Thermal Test Facility from January 1988 to September 1990. The test hardware consists of two pumped loops; the hot-salt loop'' to simulate the piping and components on the hot (565{degrees}C) side of the receiver and the cold-salt loop'' to simulate piping and components on the receiver's cold (285{degrees}C) side. Each loop contains a pump and five valves sized to be representative of a conceptual 60-MW{sub e} commercial solar power plant design. The hot-salt loop accumulated over 6700 hours of operation and the cold-salt loop over 2500 hours during the test period. This project has demonstrated the performance and reliability required for commercial-scale molten-salt pumps and valves.