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ALT-II armor tile design for upgraded TEXTOR operation

Mcgrath, R.T.

The upgrade of the TEXTOR tokamak at KFA Juelich was recently completed. This upgrade extended the TEXTOR pulse length from 5 seconds to 10 seconds. The auxiliary heating was increased to a total of 8.0 MW through a combination of neutral beam injection and radio frequency heating. Originally, the inertially cooled armor tiles of the full toroidal belt Advanced Limiter Test -- II (ALT-II) were designed for a 5-second operation with total heating of 6.0 MW. The upgrade of TEXTOR will increase the energy deposited per pulse onto the ALT-II by about 300%. Consequently, the graphite armor tiles for the ALT-II had to be redesigned to avoid excessively high graphite armor surface temperatures that would lead to unacceptable contamination of the plasma. This redesign took the form of two major changes in the ALT-II armor tile geometry. The first design change was an increase of the armor tile thermal mass, primarily by increasing the radial thickness of each tile from 17 mm to 20 mm. This increase in the radial tile dimension reduces the overall pumping efficiency of the ALT-II pump limiter by about 30%. The reduction in exhaust efficiency is unfortunate, but could be avoided only by active cooling of the ALT-II armor tiles. The active cooling option was too complicated and expensive to be considered at this time. The second design change involved redefining the plasma facing surface of each armor tile in order to fully utilize the entire surface area. The incident charged particle heat flux was distributed uniformly over the armor tile surfaces by carefully matching the radial, poloidal and toroidal curvature of each tile to the plasma flow in the TEXTOR boundary layer. This geometry redefinition complicates the manufacturing of the armor tiles, but results in significant thermal performance gains. In addition to these geometry upgrades, several material options were analyzed and evaluated.

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Progress in the development of recycling processes for electric vehicle batteries

Jungst, Rudolph G.

Disposition of electric vehicle (EV) batteries after they have reached the end of their useful life is an issue that could impede the widespread acceptance of EVs in the commercial market. This is especially true for advanced battery systems where working recycling processes have not as yet been established. The DOE sponsors an Ad Hoc Electric Vehicle Battery Readiness Working Group to identify barriers to the introduction of commercial EVs and to advise them of specific issues related to battery reclamation/recycling, in-vehicle battery safety, and battery shipping. A Sub-Working Group on the reclamation/recycle topic has been reviewing the status of recycling process development for the principal battery technologies that are candidates for EV use from the near-term to the long-term. Recycling of near-term battery technologies, such as lead-acid and nickel/cadmium, is occurring today and it is believed that sufficient processing capacity can be maintained to keep up with the large number of units that could result from extensive EV use. Reclamation/recycle processes for midterm batteries are partially developed. Good progress has been made in identifying processes to recycle sodium/sulfur batteries at a reasonable cost and pilot scale facilities are being tested or planned. A pre-feasibility cost study on the nickel/metal hydride battery also indicates favorable economics for some of the proposed reclamation processes. Long-term battery technologies, including lithium-polymer and lithium/iron disulfide, are still being designed and developed for EVs, so descriptions for prototype recycling processes are rather general at this point. Due to the long time required to set up new, full-scale recycling facilities, it is important to develop a reclamation/recycling process in parallel with the battery technologies themselves.

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Determining information management needs for enhanced international safeguards

Deland, Sharon M.

The Safeguards Information Management System initiative is a program of the Department of Energy`s (DOE) Office of Arms Control and Nonproliferation aimed at supporting the International Atomic Energy Agency`s (IAEA) efforts to strengthen safeguards through the enhancement of information management capabilities. The DOE hopes to provide the IAEA with the ability to correlate and analyze data from existing and new sources of information, including publicly available information, information on imports and exports, design information, environmental monitoring data, and non-safeguards information. The first step in this effort is to identify and define IAEA requirements. In support of this, we have created a users` requirements document based on interviews with IAEA staff that describes the information management needs of the end user projected by the IAEA, including needs for storage, retrieval, analysis, communication, and visualization of data. Also included are characteristics of the end user and attributes of the current environment. This paper describes our efforts to obtain the required information. We discuss how to accurately represent user needs and involve users for an international organization with a multi-cultural user population. We describe our approach, our experience in setting up and conducting the interviews and brainstorming sessions, and a brief discussion of what we learned.

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Input shaping for vibration-damped slewing of a flexible beam using a heavy-lift hydraulic robot

Parker, G.G.

An input shaping scheme originally used to slew flexible beams via a tabletop D.C. motor is modified for use with an industrial-type, hydraulic-drive robot. This trajectory generation method was originally developed to produce symmetric, rest-to-rest maneuvers of flexible rotating rods where the angular velocity vector and gravitational vector were collinear. In that configuration, out-of-plane oscillations were excited due to centripetal acceleration of the rod. The bang-coast-bang acceleration profile resulted in no oscillations in either plane at the end of the symmetric slew maneuver. In this paper, a smoothed version of the bang-coast-bang acceleration is used for symmetric maneuvers where the angular velocity vector is orthogonal to the gravitational vector. Furthermore, the hydraulic robot servo dynamics are considered explicitly in determining the input joint angle trajectory. An instrumented mass is attached to the tip of a flexible aluminum rod. The first natural frequency of this system is about 1.0Hz. Joint angle responses obtained with encoder sensors are used to identify the servo actuator dynamics.

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Multidimensional thermal-chemical cookoff modeling

Baer, M.R.; Gross, R.J.; Gartling, D.K.; Hobbs, M.L.

Multidimensional thermal/chemical modeling is an essential step in the development of a predictive capability for cookoff of energetic materials in systems subjected to abnormal thermal environments. COYOTE II is a state-of-the-art two- and three-dimensional finite element code for the solution of heat conduction problems including surface-to-surface thermal radiation heat transfer and decomposition chemistry. Multistep finite rate chemistry is incorporated into COYOTE II using an operator-splitting methodology; rate equations are solved element-by-element with a modified matrix-free stiff solver, CHEMEQ. COYOTE II is purposely designed with a user-oriented input structure compatible with the database, the pre-processing mesh generation, and the post-processing tools for data visualization shared with other engineering analysis codes available at Sandia National Laboratories. As demonstrated in a companion paper, decomposition during cookoff in a confined or semi-confined system leads to significant mechanical behavior. Although mechanical effect are not presently considered in COYOTE II, the formalism for including mechanics in multidimensions is under development.

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Structure-property relationships in sol-gel-derived thin films

Brinker, C.J.

The molecular-scale species distributions and intermediate-scale structure of silicate sols influence the microstructures of the corresponding thin films prepared by dip-coating. Using multi-step hydrolysis procedures, the authors find that, depending on the sequence and timing of the successive steps, the species distributions (determined by {sup 29}Si NMR) and intermediate scale structure (determined by SAXS) can change remarkably for sols prepared with the same nominal composition. During film formation, these kinetic effects cause differences in the efficiency of packing of the silicate species, leading to thin film structures with different porosities.

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Portable, solid state, fiber optic coupled Doppler interferometer system for detonation and shock diagnostics

Fleming, K.J.

VISAR (Velocity Interferometer System for Any Reflector) is a specialized Doppler interferometer system that is gaining world-wide acceptance as the standard for shock phenomena analysis. The VISAR`s large power and cooling requirements, and the sensitive and complex nature of the interferometer cavity has restricted the traditional system to the laboratory. This paper describes the new portable VISAR, its peripheral sensors, and the role it played in optically measuring ground shock of an underground nuclear detonation (UGT). The Solid State VISAR uses a prototype diode pumped Nd:YAG laser and solid state detectors that provide a suitcase-size system with low power requirements. A special window and sensors was developed for fiber optic coupling (1 kilometer long) to the VISCAR. The system has proven itself as reliable, easy to use instrument that is capable of field test use and rapid data reduction using only a notebook personal computer (PC).

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Using consumer IC packages in harsh high reliability applications

Palmer, David W.

The improvements in purity of molding materials, the IC wafer passivation layers, and manufacturing quality have resulted over the last decade in extremely high reliability in commercial IC packages. In contrast the ceramic/hermetic package world is suffering from limited availability of the newest IC chips, higher cost, larger size, and decreasing quality and fewer manufacturing lines. Traditional manufacturing line qualification tests are a good start for conversion to commercial plastic parts. However, the use of standard sensitive test chips instead of product die is necessary to perform affordable, quantitative evaluations. These test chips have many integrated sensors measuring chemical, mechanical, thermal, and electrical degradation caused by manufacturing and the package environment. Besides visual, electrical test, and burn-in little has been documented on 100% nondestructive screening of plastic molded parts. Based on realistic process control and system engineer cultural expectations, user screening is necessary. Nondestructive tests of moisture and temperature excursion susceptibility are described.

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Simulation of structural response using a recurrent radial basis function network

Paez, Thomas L.

System behaviors can be accurately simulated using artificial neural networks (ANNs), and one that performs well in simulation of structural response is the radial basis function network. A specific implementation of this is the connectionist normalized linear spline (CNLS) network, investigated in this study. A useful framework for ANN simulation of structural response is the recurrent network. This framework simulates the response of a structure one step at a time. It requires as inputs some measures of the excitation, and the response at previous times. On output, the recurrent ANN yields the response at some time in the future. This framework is practical to implement because every ANN requires training, and this is executed by showing the ANN examples of correct input/output behavior (exemplars), and requiring the ANN to simulate this behavior. In practical applications, hundreds or, perhaps, thousands, of exemplars are required for ANN training. The usual laboratory and non-neural numerical applications to be simulated by ANNs produce these amounts of information. Once the recurrent ANN is trained, it can be provided with excitation information, and used to propagate structural response, simulating the response it was trained to approximate. The structural characteristics, parameters in the CNLS network, and degree of training influence the accuracy of approximation. This investigation studies the accuracy of structural response simulation for a single-degree-of-freedom (SDF), nonlinear system excited by random vibration loading. The ANN used to simulate structural response is a recurrent CNLS network. We investigate the error in structural system simulation.

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Charged particle dynamics in the acceleration gap of the PBFA II ion diode

Bailey, James E.

We are improving the understanding of pulsed-power-driven ion diodes using measurements of the charged particle distributions in the diode anode-cathode (AK) gap. We measure the time - and space-resolved electric field in the AK gap using Stark-shifted Li I 2s-2p emission. The ion density in the gap is determined from the electric field profile and the ion current density. The electron density is inferred by subtracting the net charge density, obtained from the derivative of the electric field profile, from the ion density. The measured electric field and charged particle distributions are compared with results from QUICKSILVER, a 3D particle-in-cell computer code. The comparison validates the fundamental concept of electron build-up in the AK gap. However, the PBFA II diode exhibits considerably richer physics than presently contained in the simulation, suggesting improvements both to the experiments and to our understanding of ion diode physics.

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A test of the Arrhenius extrapolation assumption for a nitrile rubber

Gillen, Kenneth T.

The Arrhenius relation predicts a linear relation between log of time to property change and inverse absolute temperature, with the Arrhenius activation energy E{sub a} given from the slope. For a nitrile rubber, Arrhenius behavior is observed for elongation vs air-oven aging temperature, with a E{sub a} of 22 kcal/mol. Confidence in extrapolation to low temperatures can be increased by measuring oxygen consumption. From 95 to 52 C, the E{sub a} for oxygen consumption is identical to that for elongation; however, below 52 C, the E{sub a} for oxygen consumption drops slightly to 18 kcal/mol, indicating that the extrapolation assumption probably overestimates the tensile property lifetime by a factor of about 2 at 23 C.

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Prosperity Games prototyping with the board of governors of the Electronic Industries Association, January 20--21, 1994

Bermann, M.

Prosperity Games are an outgrowth and adaptation of move/countermove and seminar War Games. Prosperity Games are simulations that explore complex issues in a variety of areas including economics, politics, sociology, environment, education and research. These issues can be examined from a variety of perspectives ranging from a global, macroeconomic and geopolitical viewpoint down to the details of customer/supplier/market interactions in specific industries. All Prosperity Games are unique in that both the game format and the player contributions vary from game to game. This report documents the Prosperity Game conducted under the sponsorship of the Electronic Industries Association. Almost all of the players were from the electronics industry. The game explored policy changes that could enhance US competitiveness in the manufacturing of consumer electronics. Four teams simulated a presidentially appointed commission comprised of high-level representatives from government, industry, universities and national laboratories. A single team represented the foreign equivalent of this commission, formed to develop counter strategies for any changes in US policies. The deliberations and recommendations of these teams provide valuable insights as to the views of this industry concerning policy changes, foreign competition, and the development, delivery and commercialization of new technologies.

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Selecting features from spatial data for use in stochastic simulation

Rutherford, Brian

An assessment of the long term containment capabilities of a possible nuclear waste disposal site requires both an understanding of the hydrogeology of the region under consideration and an assessment of the uncertainties associated with this understanding. Stochastic simulation - the generation of random {open_quotes}realizations{close_quotes} of the regions hydrogeology, consistent with the available information, provides a way to incorporate various types of uncertainty into a prediction of a complex system response such as site containment capability. One statistical problem in stochastic simulation is: What features of the data should be {open_quotes}mimicked{close_quotes} in the realizations? The answer can depend on the application. A discussion is provided of some of the more common data features used in recent applications. These features include spatial covariance functions and measures of the connectivity of extreme values, as examples. Trends and new directions in this area are summarized including a brief description of some statistics (the features) presently in experimental stages.

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Results of video height of charge measurement for MIDDLE KEY 4

Shagam, Richard N.

This report describes the Height of Charge measurement for the Middle Key 4 test conducted at the FCDNA Permanent High Explosives Test Site (PHETS) on 17 September, 1993. The object of the measurement was to monitor remotely the change in the height of the explosive charge suspended above the test pad once the site had been evacuated until detonation. Should the measurement have shown that the charge changed height by more than 15cm then a hold in the test was to be called so that a height adjustment in the suspension system could be made. The measurement system consisted of a remotely placed video camera linked to the test control center-based measurement computer via a fiber optical video data link, a pole mounted stationary reference target, and a target mounted on the charge bag. Measurement of the change in height was determined using image analysis software on frame grabbed images. Measurements indicate that the charge bag did not deviate from the initial surveyed height of 1747cm by more than 1cm between the last measurement made by the survey crew until detonation 40 minutes later.

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Robust lateral control of highway vehicles

Byrne, Raymond H.

Vehicle lateral dynamics are affected by vehicle mass, longitudinal velocity, vehicle inertia, and the cornering stiffness of the tires. All of these parameters are subject to variation, even over the course of a single trip. Therefore, a practical lateral control system must guarantee stability, and hopefully ride comfort, over a wide range of parameter changes. This paper describes a robust controller which theoretically guarantees stability over a wide range of parameter changes. The robust controller is designed using a frequency domain transfer function approach. An uncertainty band in the frequency domain is determined using simulations over the range of expected parameter variations. Based on this bound, a robust controller is designed by solving the Nevanlinna-Pick interpolation problem. The performance of the robust controller is then evaluated over the range of parameter variations through simulations.

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HEISHI: A fuel performance model for space nuclear applications

Young, Mary L.

HEISHI is a Fortran computer model designed to aid in analysis, prediction, and optimization of fuel characteristics for use in Space Nuclear Thermal Propulsion (SNTP). Calculational results include fission product release rate, fuel failure fraction, mode of fuel failure, stress-strain state, and fuel material morphology. HEISHI contains models for decay chain calculations of retained and released fission products, based on an input power history and release coefficients. Decay chain parameters such as direct fission yield, decay rates, and branching fractions are obtained from a database. HEISHI also contains models for stress-strain behavior of multilayered fuel particles with creep and differential thermal expansion effects, transient particle temperature profile, grain growth, and fuel particle failure fraction. Grain growth is treated as a function of temperature; the failure fraction depends on the coating tensile strength, which in turn is a function of grain size. The HEISHI code is intended for use in analysis of coated fuel particles for use in particle bed reactors; however, much of the code is geometry-independent and applicable to fuel geometries other than spherical.

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Activities at the FAA aging aircraft NDI validation center

Shurtleff, W.

Aging Aircraft NDI Validation Center (AANC) was established by the FAA Technical Center (FAATC) at Sandia National Laboratories in August of 1991. The Validation Center supports the inspection portion of the FAA`s National Aging Aircraft Program which was mandated by Congress in the 1988 Aviation Safety Act. The ultimate customers of the AANC include the FAA, airframe and engine manufacturers, airlines, and third party maintenance facilities. One goal of the AANC is to provide independent validation of technologies intended to enhance the structural inspection of aging commuter and transport aircraft. Another goal is to assist in transferring emerging inspection technology from other parts of the FAA`s program to the aircraft industry. The deliverables from both these activities are an assessment of the reliability and cost benefits of an inspection technology as applied to a particular inspection or class of inspections. The validation process consists of a quantitative and systematic assessment of the reliability and cost/benefits on a Nondestructive Inspection (NDI) process. A NDI process is defined as the NDI systems and procedures used for inspections. This includes the NDI operator, inspection environment, and the object being inspected. The phases of the validation process are: 1. Conceptual, 2. Preliminary design, 3. Final design, and 4. Field implementation. The AAANC usually gets involved in the validation process during Phases 2 and 3. The Center supports field trials with a full array of test specimens and established procedures for conducting the trials. Phase 4 reliability includes field trials using independent inspectors either at the Center`s hangar or at outside maintenance facilities. Three activities are summarized below where inspection technology has been validated in the field. These are: (1) eddy current inspection reliability experiment; (2) magneto optic imager validation; and (3) inspection tool improvement.

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Low electron beam energy CIVA analysis of passivated ICs

Cole Jr., E.I.; Soden, J.M.; Dodd, B.A.; Henderson, C.L.

Low Energy Charge-Induced Voltage Alteration (LECIVA) is a new scanning electron microscopy technique developed to localize open conductors in passivated ICs. LECIVA takes advantage of recent experimental work showing that the dielectric surface equilibrium voltage has an electron flux density dependence at low electron beam energies ({le}1.0 keV). The equilibrium voltage changes from positive to negative as the electron flux density is increased. Like Charge-Induced Voltage Alteration (CIVA), LECIVA images are produced from the voltage fluctuations of a constant current power supply as an electron beam is scanned over the IC surface. LECIVA image contrast is generated only by the electrically open part of a conductor, yielding, the same high selectivity demonstrated by CIVA. Because LECIVA is performed at low beam energies, radiation damage by the primary electrons and x-rays to MOS structures is far less than that caused by CIVA. LECIVA may also be performed on commercial electron beam test systems that do not have high primary electron beam energy capabilities. The physics of LECIVA signal generation are described. LECIVA imaging examples illustrate its utility on both a standard scanning electron microscope (SEM) and a commercial electron beam test system.

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Ion emission intensity ratios as a function of electrode gap, melting current, and pressure during low current vacuum arc remelting

Williamson, Rodney L.

The arc energy distribution in the electrode gap plays a central role in the vacuum arc remelting (VAR) process. However, very little has been done to investigate the response of this important process variable to changes in process parameters. Emission spectroscopy was used to investigate variations in arc energy in the annulus of a VAR furnace during melting of 0.43 m diameter Alloy 718 electrode into 0.51 in diameter ingot. Time averaged (1 second) intensity data from various chromium atom and ion (Cr{sup +}) emission lines were simultaneously collected and selected intensity ratios were subsequently used as air energy indicators. These studies were carried out as a function of melting current, electrode gap, and CO partial pressure. The data were modeled and the ion electronic energy was found to be a function of electrode gap, the energy content of the ionic vapor decreasing with increasing gap length; the ion ratios were not found to be sensitive to pressure. On the other hand, the chromium atom electronic energy was difficult to model in the factor space investigated, but was determined to be sensitive, to pressure. The difference in character of the chromium ion and atom energy fluctuations in the furnace annulus are attributed to the difference in the origins of these arc species and the non-equilibrium nature of the metal vapor arc. Most of the ion population is emitted directly from cathode spots, whereas much of the atomic vapor arises due to vaporization from the electrode and pool surfaces. Also, the positively charged ionic species interact more strongly with the electron gas than the neutral atomic species, the two distributions never equilibrating due to the low pressure.

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The GPS Burst Detector W-Sensor

Mccrady, D.D.; Phipps, P.

The NAVSTAR satellites have two missions: navigation and nuclear detonation detection. The main objective of this paper is to describe one of the key elements of the Nuclear Detonation Detection System (NDS), the Burst Detector W-Sensor (BDW) that was developed for the Air Force Space and Missle Systems Center, its mission on GPS Block IIR, and how it utilizes GPS timing signals to precisely locate nuclear detonations (NUDET). The paper will also cover the interface to the Burst Detector Processor (BDP) which links the BDW to the ground station where the BDW is controlled and where data from multiple satellites are processed to determine the location of the NUDET. The Block IIR BDW is the culmination of a development program that has produced a state-of-the-art, space qualified digital receiver/processor that dissipates only 30 Watts, weighs 57 pounds, and has a 12in. {times} l4.2in. {times} 7.16in. footprint. The paper will highlight several of the key multilayer printed circuit cards without which the required power, weight, size, and radiation requirements could not have been met. In addition, key functions of the system software will be covered. The paper will be concluded with a discussion of the high speed digital signal processing and algorithm used to determine the time-of-arrival (TOA) of the electromagnetic pulse (EMP) from the NUDET.

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VUV spectroscopic observations on the SABRE applied-B ion diode

Filuk, A.B.; Nash, T.J.; Noack, D.D.

We are using VUV spectroscopy to study the ion source region on the SABRE applied-B extraction ion diode. The VUV diagnostic views the anode-cathode gap perpendicular to the ion acceleration direction, and images a region 0--1 mm from the anode onto the entrance slit of a I m normal-incidence spectrometer. Time resolution is obtained by gating multiple striplines of a CuI- or MgF{sub 2} -coated micro-channel plate intensifier. We report on results with a passive proton/carbon ion source. Lines of carbon and oxygen are observed over 900--1600 {angstrom}. The optical depths of most of the lines are less than or of order 1. Unfolding the Doppler broadening of the ion lines in the source plasma, we calculate the contribution of the source to the accelerated C IV ion micro-divergence as 4 mrad at peak power. Collisional-radiative modeling of oxygen line intensities provides the source plasma average electron density of 7{times}10{sup 16} cm{sup {minus}3} and temperature of 10 eV Measurements are planned with a lithium ion source and with VUV absorption spectroscopy.

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Unlimited-bandwidth distributed optical phase modulators and detectors: Design and fabrication issues

Vawter, G.A.; Hietala, V.M.; Kravitz, S.H.; Armendariz, M.G.

Practical and theoretical limits on the bandwidth of distributed optical phase modulators and traveling-wave photodetectors are given. For the case of perfect velocity matching, RF transmission losses are the main performance-limiting factor. However, some high-performance modulators require highly-capacitive transmission lines making proper slow-wave operation difficult to achieve.

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Evaluation of conservatisms and environmental effects in ASME Code, Section III, Class 1 fatigue analysis

Nakos, James T.

This report documents the results of a study regarding the conservatisms in ASME Code Section 3, Class 1 component fatigue evaluations and the effects of Light Water Reactor (LWR) water environments on fatigue margins. After review of numerous Class 1 stress reports, it is apparent that there is a substantial amount of conservatism present in many existing component fatigue evaluations. With little effort, existing evaluations could be modified to reduce the overall predicted fatigue usage. Areas of conservatism include design transients considerably more severe than those experienced during service, conservative grouping of transients, conservatisms that have been removed in later editions of Section 3, bounding heat transfer and stress analysis, and use of the ``elastic-plastic penalty factor`` (K{sub 3}). Environmental effects were evaluated for two typical components that experience severe transient thermal cycling during service, based on both design transients and actual plant data. For all reasonable values of actual operating parameters, environmental effects reduced predicted margins, but fatigue usage was still bounded by the ASME Section 3 fatigue design curves. It was concluded that the potential increase in predicted fatigue usage due to environmental effects should be more than offset by decreases in predicted fatigue usage if re-analysis were conducted to reduce the conservatisms that are present in existing component fatigue evaluations.

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Effective-stress-law behavior of Austin chalk rocks for deformation and fracture conductivity

Warpinski, Norman R.

Austin chalk core has been tested to determine the effective law for deformation of the matrix material and the stress-sensitive conductivity of the natural fractures. For deformation behavior, two samples provided data on the variations of the poroelastic parameter, {alpha}, for Austin chalk, giving values around 0.4. The effective-stress-law behavior of a Saratoga limestone sample was also measured for the purpose of obtaining a comparison with a somewhat more porous carbonate rock. {alpha} for this rock was found to be near 0.9. The low {alpha} for the Austin chalk suggests that stresses in the reservoir, or around the wellbore, will not change much with changes in pore pressure, as the contribution of the fluid pressure is small. Three natural fractures from the Austin chalk were tested, but two of the fractures were very tight and probably do not contribute much to production. The third sample was highly conductive and showed some stress sensitivity with a factor of three reduction in conductivity over a net stress increase of 3000 psi. Natural fractures also showed a propensity for permanent damage when net stressed exceeded about 3000 psi. This damage was irreversible and significantly affected conductivity. {alpha} was difficult to determine and most tests were inconclusive, although the results from one sample suggested that {alpha} was near unity.

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Virtual enterprise model for the electronic components business in the Nuclear Weapons Complex

Long, Kevin R.

The electronic components business within the Nuclear Weapons Complex spans organizational and Department of Energy contractor boundaries. An assessment of the current processes indicates a need for fundamentally changing the way electronic components are developed, procured, and manufactured. A model is provided based on a virtual enterprise that recognizes distinctive competencies within the Nuclear Weapons Complex and at the vendors. The model incorporates changes that reduce component delivery cycle time and improve cost effectiveness while delivering components of the appropriate quality.

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MELTER: A model of the thermal response of cargos transported in the Safe-Secure Trailer subject to fire environments for risk assessment applications

Larsen, M.E.

MELTER is an analysis of cargo responses inside a fire-threatened Safe-Secure Trailer (SST) developed for the Defense Program Transportation Risk Assessment (DPTRA). Many simplifying assumptions are required to make the subject problem tractable. MELTER incorporates modeling which balances the competing requirements of execution speed, generality, completeness of essential physics, and robustness. Input parameters affecting the analysis include those defining the fire scenario, those defining the cargo loaded in the SST, and those defining properties of the SST. For a specified fire, SST, and cargo geometry MELTER predicts the critical fire duration that will lead to a failure. The principal features of the analysis include: (a) Geometric considerations to interpret fire-scenario descriptors in terms of a thermal radiation boundary condition, (b) a simple model of the SST`s wall combining the diffusion model for radiation through optically-thick media with an endothermic reaction front to describe the charring of dimensional, rigid foam in the SST wall, (c) a transient radiation enclosure model, (d) a one-dimensional, spherical idealization of the shipped cargos providing modularity so that cargos of interest can be inserted into the model, and (e) associated numerical methods to integrate coupled, differential equations and find roots.

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Measured voltages and currents internal to closed metal cylinders due to diffusion of simulated lightning currents

Schnetzer, G.H.; Fisher, R.J.

One mechanism for the penetration of lightning energy into the interior of a weapon is by current diffusion through the exterior metal case. Tests were conducted in which simulated lightning currents were driven over the exteriors of similar aluminum and ferrous steel cylinders of 0.125-in wall thickness. Under conditions in which the test currents were driven asymmetrically over the exteriors of the cylinders, voltages were measured between various test points in the interior as functions of the amplitude and duration of the applied current. The maximum recorded open-circuit voltage, which occurred in the steel cylinder, was 1.7 V. On separate shots, currents flowing on a low impedance shorting conductor between the same set of test points were also measured, yielding a maximum current of 630 A, again occurring across the interior of the steel cylinder. Under symmetrical exterior drive current conditions, a maximum end-to-end internal voltage of 4.1 V was obtained, also in the steel cylinder, with a corresponding current of 480 A measured on a coaxial conductor connected between the two end plates of the cylinder. Data were acquired over a range of input current amplitudes between about 40 and 100 kA. These data provide the experimental basis for validating models that can subsequently be applied to real weapons and other objects of interest.

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ESD hazards associated with CO{sub 2} refrigeration

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

Apparent malfunctions of two Trajectory Sensing Signal Generators (TSSGs) were observed during B61-3/4/10 trajectory arming tests at the Pantex Weapons Evaluation Test Laboratory (WETL). On two subsequent occasions, the TSSG used in the B83 bomb developed single-channel failures during tests at WETL. It was concluded that the failures were related to the electrostatic discharge (ESD) hazard associated with the use of a Thermotron{reg_sign} liquid carbon dioxide (CO{sub 2}) refrigeration system. It was demonstrated that during temperature conditioning, the case of the TSSG can acquire a substantial electrostatic charge as a result of triboelectric processes. A series of tests was performed to identify the charging mechanisms associated with liquid CO{sub 2} refrigeration systems and a quantitative assessment of the ESD hazard was made. The conclusions and recommendations derived in these tests were summarized in a Significant Finding Investigations Closeout. The purpose of this report is to provide formal documentation for, and elaboration on, issues addressed in the Findings.

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Measured responses of internal enclosures and cables due to burnthrough penetration of weapon cases by lightning

Schnetzer, G.H.; Fisher, R.J.; Dinallo, M.A.

The electrical effects of lightning penetration of the outer case of a weapon on internal structures, such as a firing set housing, and on samples of a flat, flexline detonator cable have been investigated experimentally. Maximum open-circuit voltages measured on either simulated structures (126 V) or the cable (46 V) located directly behind the point of penetration were well below any level that is foreseen to create a threat to nuclear safety. On the other hand, it was found that once full burnthrough of the barrier occurred, significant fractions of the incident continuing currents coupled to both the simulated internal structure (up to 300 A) or to the cable sample (69 A) when each was electrically connected internally to case ground. No occurrence was observed of the injection of large amplitude currents from return strokes occurring after barrier penetration. Under circumstances in which small volumes of trapped gases exist behind penetration sites, rapid heating of the gas by return strokes occurring after burnthrough has been shown to produced large mechanical impulses to the adjacent surfaces.

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An evaluation of solid state video frame recorders

Terry, Preston L.

The Department of Energy (DOE) has tasked Sandia with conducting a market survey to identify and evaluate pertinent solid state recorders. This report identifies the chosen recorders and explains why they were selected. It details test procedures and provides the results of the evaluation. Our main focus in this evaluation was to determine whether the frame grabber altered signal quality. To determine the effect on the signal, we evaluated specific parameters: sensitivity, resolution, signal-to-noise ratio, and intrascene dynamic range. These factors were evaluated at the input and output of the frame grabber.

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In situ permeable flow sensors at the Savannah River Integrated Demonstration: Phase 2 results

Ballard, Sanford

A suite of In Situ Permeable Flow Sensors was deployed at the site of the Savannah River Integrated Demonstration to monitor the interaction between the groundwater flow regime and air injected into the saturated subsurface through a horizontal well. One of the goals of the experiment was to determine if a groundwater circulation system was induced by the air injection process. The data suggest that no such circulation system was established, perhaps due to the heterogeneous nature of the sediments through which the injected gas has to travel. The steady state and transient groundwater flow patterns observed suggest that the injected air followed high permeability pathways from the injection well to the water table. The preferential pathways through the essentially horizontal impermeable layers appear to have been created by drilling activities at the site.

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Principles and guidelines for diversity in teamwork

Berman, M.; Crespin, G.; Garcia, L.R.; Jansma, R.; Lovato, L.; Randall, G.; Sanchez, A.

As part of Sandia`s Corporate Diversity Program, a Diversity Action Team was assembled to study the impact of diversity on teamwork. We reviewed the available literature on successful teaming, both with homogeneous (more alike than different) and heterogeneous teams. Although many principles and guidelines for successful homogeneous teams also apply to diverse teams, we believe that a document concentrating on diverse teams will be useful both for Sandians and for the outside world.

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A pollution prevention chargeback system at Sandia National Laboratories, New Mexico

Davis, R.; Fish, J.; Brown, C.

Sandia National Laboratories, New Mexico (Sandia/NM) has successfully developed and implemented a chargeback system to fund the implementation of Pollution Prevention activities. In the process of establishing this system, many valuable lessons have been learned. This paper describes how the chargeback system currently functions, the benefits and drawbacks of implementing such a system, and recommendations for implementing a chargeback system at other facilities. The initial goals in establishing a chargeback system were to create (1) funding for pollution prevention implementation, including specific pollution prevention projects; and (2) awareness on the part of the line organizations of the quantities and types of waste that they generate, thus providing them with a direct incentive to reduce that waste. The chargeback system inputs waste generation data and then filters and sorts the data to serve two purposes: (1) the operation of the chargeback system; and (2) the detailed waste generation reporting used for assessing processes and identifying pollution prevention opportunities.

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Test results on direct containment heating by high-pressure melt ejection into the Surtsey vessel: The TDS test series

Allen, Mark S.

The Technology Development and Scoping (TDS) test series was conducted to test and develop instrumentation and procedures for performing steam-driven, high-pressure melt ejection (HPME) experiments at the Surtsey Test Facility to investigate direct containment heating (DCH). Seven experiments, designated TDS-1 through TDS-7, were performed in this test series. These experiments were conducted using similar initial conditions; the primary variable was the initial pressure in the Surtsey vessel. All experiments in this test series were performed with a steam driving gas pressure of {approx_equal} 4 MPa, 80 kg of lumina/iron/chromium thermite melt simulant, an initial hole diameter of 4.8 cm (which ablated to a final hole diameter of {approx_equal} 6 cm), and a 1/10th linear scale model of the Surry reactor cavity. The Surtsey vessel was purged with argon (<0.25 mol% O{sub 2}) to limit the recombination of hydrogen and oxygen, and gas grab samples were taken to measure the amount of hydrogen produced.

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Stabilizing S.P.H. with conservative smoothing

Swegle, Jeffrey W.

There is an instability in certain S.P.H. (Smoothed Particle Hydrodynamics method) material dynamics computations. Evidence from analyses and experiments suggests that the instabilities in S.P.H. are not removable with artificial viscosities. However, the analysis shows that a type of conservative smoothing does remove the instability. Also, numerical experiments, on certain test problems, show that SPHCS, and S.P.H. code with conservative smoothing, compares well in accuracy with computations based on the von Neumann-Richtmyer method.

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Nevada Test Site closure program

Shenk, D.P.

This report is a summary of the history, design and development, procurement, fabrication, installation and operation of the closures used as containment devices on underground nuclear tests at the Nevada Test Site. It also addresses the closure program mothball and start-up procedures. The Closure Program Document Index and equipment inventories, included as appendices, serve as location directories for future document reference and equipment use.

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Particle beam fusion progress report for 1989

Sweeney, Mary A.

This report summarizes the progress on the pulsed power approach to inertial confinement fusion. In 1989, the authors achieved a proton focal intensity of 5 TW/cm{sup 2} on PBFA-II in a 15-cm-radius applied magnetic-field (applied-B) ion diode. This is an improvement by a factor of 4 compared to previous PBFA-II experiments. They completed development of the three-dimensional (3-D), electromagnetic, particle-in-cell code QUICKSILVER and obtained the first 3-D simulations of an applied-B ion diode. The simulations, together with analytic theory, suggest that control of electromagnetic instabilities could reduce ion divergence. In experiments using a lithium fluoride source, they delivered 26 kJ of lithium energy to the diode axis. Rutherford-scattered ion diagnostics have been developed and tested using a conical foil located inside the diode. They can now obtain energy density profiles by using range filters and recording ion images on nuclear track recording film. Timing uncertainties in power flow experiments on PBFA-II have been reduced by a factor of 5. They are investigating three plasma opening switches that use magnetic fields to control and confine the injected plasma. These new switches provide better power flow than the standard plasma erosion switch. Advanced pulsed-power fusion drivers will require extraction-geometry applied-B ion diodes. During this reporting period, progress was made in evaluating the generation, transport, and focus of multiple ion beams in an extraction geometry and in assessing the probable damage to a target chamber first wall.

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Conservative smoothing versus artificial viscosity

Guenther, C.; Hicks, D.L.; Swegle, J.W.

This report was stimulated by some recent investigations of S.P.H. (Smoothed Particle Hydrodynamics method). Solid dynamics computations with S.P.H. show symptoms of instabilities which are not eliminated by artificial viscosities. Both analysis and experiment indicate that conservative smoothing eliminates the instabilities in S.P.H. computations which artificial viscosities cannot. Questions were raised as to whether conservative smoothing might smear solutions more than artificial viscosity. Conservative smoothing, properly used, can produce more accurate solutions than the von Neumann-Richtmyer-Landshoff artificial viscosity which has been the standard for many years. The authors illustrate this using the vNR scheme on a test problem with known exact solution involving a shock collision in an ideal gas. They show that the norms of the errors with conservative smoothing are significantly smaller than the norms of the errors with artificial viscosity.

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Prosperity Games prototyping with the American Electronics Association, March 8--9, 1994

Berman, M.

Prosperity Games are an outgrowth and adaptation of move/countermove and seminar War Games. Prosperity Games are simulations that explore complex issues in a variety of areas including economics, politics, sociology, environment, education and research. These issues can be examined from a variety of perspectives ranging from a global, macroeconomic and geopolitical viewpoint down to the details of customer/supplier/market interactions in specific industries. All Prosperity Games are unique in that both the game format and the player contributions vary from game to game. This report documents the Prosperity Game conducted under the sponsorship of the American Electronics Association in conjunction with the Electronics Subcommittee of the Civilian Industrial Technology Committee of the National Science and Technology Council. Players were drawn from government, national laboratories, and universities, as well as from the electronics industry. The game explored policy changes that could enhance US competitiveness in the manufacturing of consumer electronics. Two teams simulated a presidentially appointed commission comprised of high-level representatives from government, industry, universities and national laboratories. A single team represented the foreign equivalent of this commission, formed to develop counter strategies for any changes in US policies. The deliberations and recommendations of these teams provide valuable insights as to the views of this diverse group of decision makers concerning policy changes, foreign competition, and the development, delivery and commercialization of new technologies.

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Testing Technology: A Sandia technology bulletin

Goetsch, Robert S.

Inside this issue is a farewell to Testing Technology message from technical advisor, Ruth David. Also included are articles on: Testing the I-40 bridge over the Rio Grande, simulated reactor meltdown studies, an inexpensive monitor for testing integrated circuits, testing of antihelicoptor mines, and quality assurance on aircraft inspection.

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Tonopah Test Range EGS graphics tracking display system: HP370

Meyer, R.H.; Bauhs, K.C.

This report describes the HP370 component of the Enhanced Graphics System (EGS) used at Tonopah Test Range (TTR). Selected Radar data is fed into the computer systems and the resulting tracking symbols are displayed on high-resolution video monitors in real time. These tracking symbols overlay background maps and are used for monitoring/controlling various flight vehicles. This report discusses both the operational aspects and the internal configuration of the HP370 Workstation portion of the EGS system.

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Voltages across assembly joints due to direct-strike lightning currents

Fisher, R.J.

An extensive set of direct-strike lightning tests has been carried out on a set of facsimile assembly joints of the kinds employed in the design of nuclear weapon cases. Taken as a whole, the test hardware included all the conceptual design elements that are embodied, either singly or in combination, in any specific assembly joint incorporated into any stockpiled weapon. During the present testing, the effects of all key design parameters on the voltages developed across the interior of the joints were investigated under a range of lightning stroke current parameter values. Design parameter variations included the types and number of joint fasteners, mechanical preload, surface finish tolerance and coatings, and the material from which the joint assembly was fabricated. Variations of the simulated lightning stroke current included amplitude (30-, 100-, and 200-kA peak), rise time, and decay time. The maximum voltage observed on any of the test joints that incorporated proper metal-to-metal surface contact was 65 V. Typical response values were more on the order of 20 V. In order to assess the effect of the presence of a dielectric coating (either intentional or as a result of corrosion) between the mating surfaces of a joint, a special configuration was tested in which the mating parts of the test assembly were coated with a 1-mil-thick dielectric anodizing layer. First strokes to these test assemblies resulted in very narrow voltage spikes of amplitudes up to 900 V. The durations of these spikes were less than 0.1 {mu}s. However, beyond these initial spikes, the voltages typically had amplitudes of up to 400 V for durations of 3 to 5 {mu}s.

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Development of concentrator solar cells

Ruby, Douglas S.

A limited pilot production run on PESC silicon solar cells for use at high concentrations (200 to 400 suns) is summarized. The front contact design of the cells was modified for operation without prismatic covers. The original objective of the contract was to systematically complete a process consolidation phase, in which all the, process improvements developed during the contract would be combined in a pilot production run. This pilot run was going to provide, a basis for estimating cell costs when produced at high throughput. Because of DOE funding limitations, the Photovoltaic Concentrator Initiative is on hold, and Applied Solar`s contract was operated at a low level of effort for most of 1993. The results obtained from the reduced scope pilot run showed the effects of discontinuous process optimization and characterization. However, the run provided valuable insight into the technical areas that can be optimized to achieve the original goals of the contract.

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The numerical integration and 3-D finite element formulation of a viscoelastic model of glass

Chambers, Robert S.

The use of glasses is widespread in making hermetic, insulating seals for many electronic components. Flat panel displays and fiber optic connectors are other products utilizing glass as a structural element. When glass is cooled from sealing temperatures, residual stresses are generated due to mismatches in thermal shrinkage created by the dissimilar material properties of the adjoining materials. Because glass is such a brittle material at room temperature, tensile residual stresses must be kept small to ensure durability and avoid cracking. Although production designs and the required manufacturing process development can be deduced empirically, this is an expensive and time consuming process that does not necessarily lead to an optimal design. Agile manufacturing demands that analyses be used to reduce development costs and schedules by providing insight and guiding the design process through the development cycle. To make these gains, however, viscoelastic models of glass must be available along with the right tool to use them. A viscoelastic model of glass can be used to simulate the stress and volume relaxation that occurs at elevated temperatures as the molecular structure of the glass seeks to equilibrate to the state of the supercooled liquid. The substance of the numerical treatment needed to support the implementation of the model in a 3-D finite element program is presented herein. An accurate second-order, central difference integrator is proposed for the constitutive equations, and numerical solutions are compared to those obtained with other integrators. Inherent convergence problems are reviewed and fixes are described. The resulting algorithms are generally applicable to the broad class of viscoelastic material models. First-order error estimates are used as a basis for developing a scheme for automatic time step controls, and several demonstration problems are presented to illustrate the performance of the methodology.

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Zeroing in on requirements: Sandia National Laboratories` approach to meaningful program improvement

Richards, Robert R.

The necessity to evaluate our participant Quality Assurance (QA) Program for the Yucca Mountain Site Characterization Project (YMP) against the Office of Civilian Radioactive Waste Management (OCRWM) Quality Assurance Requirements and Description (QARD) issued December 1992, presented an opportunity to improve the QA Program. For some time, the SNL YMP technical staff had complained that the QA requirements imposed on their work were cumbersome and inhibited their ability to perform investigations using scientific methods. There was some truth to this, since SNL had over the years developed some procedures with many detailed controls that were far beyond what was required by project QA requirements. This had occurred either as a result of responding to numerous audit findings with a ``make the auditor happy`` attitude or with an attempt to cover every contingency. Procedures affecting scientific work were authored by the technical staff in an effort to provide them with ownership of the process; unfortunately, there were problems. Procedures were inconsistent because of the varied writing styles and differing perceptions of the degree of QA controls required to implement the program. It was extremely difficult to get all of the technical staff to accept the QA program as it was intended. These issues were endemic to the program and resulted in the QARD, the actual requirements, being written by a team of QA professionals. Once new QARD requirements were issued, an opportunity to evaluate the QA Program and to revise it not only to meet the QARD, but also to make it more plausible and meaningful to the technical staff, was presented. The discussion that follows will describe how the program was changed, will present both the positive and negative experiences observed by SNL personnel during the QARD transition, and will provide some recommendations.

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Results 96201–96250 of 99,299
Results 96201–96250 of 99,299