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Integrated environmental, health and safety management; The outcome of the `Necessary and Sufficient Process`

Bendure, Albert O.

This paper presents a paradigm for integrating the many facets of ES&H management based on the necessary and sufficient control of hazards and the resulting risks through a systems approach. The paradigm answers the question ``What is the best approach to managing ES&H to increase value, reduce risk, and improve satisfaction?`` Hazard identification is the foundation of integrated ES&H management. Knowledge of risk is essential to the necessary and sufficient management of risk. A systems approach to identifying and managing risks is essential in achieving integrated ES&H management. Feedback is discussed. The objectives can be applied to the function of risk management using the ``Know, Understand, Manage and Document`` paradigm. The organizational structure is crucial to the success of integrated ES&H management.

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Potential power sources for high-temperature geothermal applications

Guidotti, Ronald A.

The thermal response under geothermal-borehole conditions of a conventional thermal battery was evaluated for various designs by numerical simulations using a finite-element thermal model. This technology, which is based on molten salts, may be suitable as a power source for geothermal borehole applications for data logging. Several promising candidate electrolytes were identified for further study.

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Evaluation of constitutive models for crushed salt

Callahan, G.D.; Loken, M.C.; Hurtado, L.D.; Hansen, F.D.

Three constitutive models are recommended as candidates for describing the deformation of crushed salt. These models are generalized to three-dimensional states of stress to include the effects of mean and deviatoric stress and modified to include effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant (WIPP) and southeastern New Mexico salt is used to determine material parameters for the models. To evaluate the capability of the models, parameter values obtained from fitting the complete database are used to predict the individual tests. Finite element calculations of a WIPP shaft with emplaced crushed salt demonstrate the model predictions.

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Selective, pulsed CVD of platinum on microfilament gas sensors

Manginell, R.P.; Smith, J.H.; Ricco, A.J.; Moreno, D.J.; Hughes, R.C.; Huber, R.J.; Senturia, S.D.

A post-processing, selective micro-chemical vapor deposition (``micro-CVD``) technology for the deposition of catalytic films on surface-micromachined, nitride-passivated polysilicon filaments has been investigated. Atmospheric pressure deposition of Pt on microfilaments was accomplished by thermal decomposition of Pt acetylacetonate; deposition occurs selectively only on those filaments which are electrically heated. Catalyst morphology, characterized by SEM, can be controlled by altering deposition time, filament temperature, and through the use of pulsed heating of the filament during deposition. Morphology plays an important role in determining the sensitivity of these devices when used as combustible gas sensors.

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Characterization of semiconductor bridges (SCB) igniters for use in thermal batteries

Bickes, R.W.; Guidotti, R.A.; Mccampbell, C.B.

Semiconductor bridges (SCB) igniters were evaluated as possible replacements for conventional hot-wire igniters for use in thermal batteries. The all-fire and no-fire characteristics were determined using an up-down scheme; the Neyer/SENSIT program was used to analyze the data. The SCB igniters functioned with a higher no-fire level, relative to a hot-wire igniter, for a given all-fire level. This makes the SCB igniter safer and more reliable than its hot-wire counterpart. The SCB is very resistant to electrostatic discharge and does not require a sensitization mixture for ignition of the primary pyrotechnic charge. These factors, along with its amenability to large-scale production, make the SCB igniter ideally suited for use in thermal batteries.

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Application of chemical-mechanical polishing to planarization of surface-micromachined devises

Nasby, R.D.S.

Chemical-Mechanical Polishing (CMP) has emerged as an enabling technology for manufacturing multi-level metal interconnects used in high-density Integrated Circuits (IC). In this work we present extension of CMP from sub-micron IC manufacturing to fabrication of complex surface-micromachined Micro-ElectroMechanical Systems (MEMS). This planarization technique alleviates processing problems associated with fabrication of multi-level polysilicon structures, eliminates design constraints linked with non-planar topography, and provides an avenue for integrating different process technologies. We discuss the CMP process and present examples of the use of CMP in fabricating MEMS devices such as microengines, pressures sensors, and proof masses for accelerometers along with its use for monolithically integrating MEMS devices with microelectronics.

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Three dimensional finite element simulations of room and pillar mines in rock salt

Hoffman, Edward L.

3-D quasistatic finite element codes are being used at Sandia to simulate large room and pillar mines in rock salt. The two examples presented in this paper are of mines supported by US DOE, under the auspices of the Strategic Petroleum Reserve program. One of the mines is presently used as an oil storage facility. These simulations, validated by field measurements and observations, have provided valuable insight into the failure mechanisms of room and pillar mines in rock salt. The calculations provided the basis for further investigation and the ultimate decision to decommission the DOE oil storage facility.

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Large-scale dynamic compaction of natural salt

Hansen, Francis D.

A large-scale dynamic compaction demonstration of natural salt was successfully completed. About 40 m{sup 3} of salt were compacted in three, 2-m lifts by dropping a 9,000-kg weight from a height of 15 m in a systematic pattern to achieve desired compaction energy. To enhance compaction, 1 wt% water was added to the relatively dry mine-run salt. The average compacted mass fractional density was 0.90 of natural intact salt, and in situ nitrogen permeabilities averaged 9X10{sup -14}m{sup 2}. This established viability of dynamic compacting for placing salt shaft seal components. The demonstration also provided compacted salt parameters needed for shaft seal system design and performance assessments of the Waste Isolation Pilot Plant.

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Issues in workforce composition analysis

Rogers, Jonathan D.

An issue of paramount interest to US industry is the supply and quality of human resources available for this country`s scientific and technological activities. The changing composition of the workforce and the responsibility that an organization has to assure equal opportunity, give rise to various issues. This paper discusses some of the issues associated with the scientific and technical workforce. Specifically, it explores some of the questions pertaining to workforce composition and measures of workforce composition. This paper should be useful to those responsible for personnel policies.

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Constitutive basis of the MDCF model for rock salt

Fossum, A.F.

All valid constitutive equations must satisfy two general invariance principles as well several other principles. In this paper the MDCF (Multimechanism Deformation Coupled Fracture) model for rock salt is shown to be thermodynamically consistent, coordinate invariant, frame indifferent, and physically admissible. Additionally, the stress rates used in the formulation are shown to be kinematically consistent with the Cauchy stress rates.

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Screening study of mixed transition-metal oxides for use as cathodes in thermal batteries

Guidotti, Ronald A.

Over 100 candidates were examined, including commercial materials and many that were synthesized in house. The mixed oxides were based on Ti, V, Nb, Cr, Mo, W, Mn, Fe, Co, Ni, and Cu doped with other transition metals. A number of individual (single-metal) oxides were included for comparison. The candidates were tested in single cells with Li(Si) anodes and separators based on LiCl-KCl eutectic. Screening was done under constant-current conditions at current densities of 125 me/cm{sup 2} and, to a lesser extent, 50 me/cm{sup 2} at 500 C. Relative performance and limitations of the oxide cathodes are discussed.

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Phase 2 report on the evaluation of polyacrylonitrile (PAN) as a binding polymer for absorbers used to treat liquid radioactive wastes

Matalucci, Rudolph V.

The performance of PAN-based composite absorbers was evaluated in dynamic experiments at flow rates ranging from 25--100 bed volumes (BV) per hour. Composite absorbers with active components of ammonium molybdophosphate (AMP) PAN and K-Co ferrocyanide (KCoFC) PAN were used for separating Cs from a 1 M HNO{sub 3} + 1 M NaNO{sub 3} + 2 {times} 10{sup {minus}5} M CsCl acidic simulant solution. KCoFC-PAN and two other FC-based composite absorbers were tested for separating Cs from alkaline simulant solutions containing 0.01 M to 1 M NaOH and 1 M NaNO{sub 3} + x {times} 10{sup {minus}4} M CsCl. The efficiency of the Cs sorption on the AMP-PAN absorber from acidic simulant solutions was negatively influenced by the dissolution of the AMP active component. At flow rates of 50 BV/hr, the decontamination factor of about 10{sup 3} could be maintained for treatment of 380 BV of the feed. With the KCoFC-PAN absorber, the decontamination factor of about 10{sup 3} could be maintained for a feed volume as great as 1,800 BV. In alkaline simulant solutions, significant decomposition of the active components was observed, and the best performance was exhibited by the KCoFC-PAN absorber. Introductory experiments confirmed that Cs may be washed out of the composite absorbers. Regeneration of both absorbers for repetitive use was also found to be possible. The main result of the study is that PAN was proven to be a versatile polymer capable of forming porous composite absorbers with a large number of primary absorbers. The composite absorbers proved to be capable of withstanding the harsh acidic and alkaline conditions and significant radiation doses that may be expected in the treatment of US DOE wastes. A field demonstration is proposed as a follow-on activity.

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Lessons-learned from the document production system redevelopment (DPS/R)

Rouse, M.J.

Increased complexity of the computing environment is probably the most universal observation of developers going into Client/Server computing. The Lessons Learned document Provides some condensed bits of expertise gained by the Document Production System Redevelopment team. The intent is to distribute in a simplified format the knowledge the authors have gained, and to promote discussion of certain areas having unresolved or less-than-perfect resolution. Included are first, a description of the hardware and software used. The lists of hardware and software are a good basic guide for the components of a robust data server and provide a framework for subsequent discussion of technical points learned during the development. The second part of the document is a discussion of fine points about Novell, Sybase and Visual Basic as applied to the DPS/R development. Areas covered include the hardware of the database server, Novell operating system, Sybase database tools and Visual Basic.

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Effect of hydrogen on Ca and Mg acceptors in GaN

Zolper, J.C.

The influence of minority carrier injection on the reactivation of hydrogen passivated Mg in GaN at 175 C has been investigated in p-n junction diodes. The dissociation of the neutral MgH complexes is greatly enhanced in the presence of minority carrier and the reactivation process follows second order kinetics. Conventional annealing under zero-bias conditions does not produce Mg-H dissociation until temperatures {ge} 450 C. These results provide an explanation for the e-beam induced reactivation of Mg acceptors in hydrogenated GaN. Exposure to a hydrogen plasma at 250 C of p-type GaN (Ca) prepared by either Ca{sup +} or Ca{sup +} plus P{sup +} coimplantation leads to a reduction in sheet carrier density of approximately an order of magnitude (1.6 {times} 10{sup 12} cm{sup {minus}2} to 1.8 {times} 10{sup 11} cm{sup {minus}2}), and an accompanying increase in hole mobility (6 cm{sup 2}/Vs to 18 cm{sup 2}/Vs). The passivation process can be reversed by post-hydrogenation annealing at 400--500 C under a N{sub 2} ambient. This reactivation of the acceptors is characteristic of the formation of neutral (Ca-H) complexes in the GaN. The thermal stability of the passivation is similar to that of Mg-H complexes in material prepared in the same manner (implantation) with similar initial doping levels. Hydrogen passivation of acceptor dopants in GaN appears to be a ubiquitous phenomenon, as it is in other p-type semiconductors.

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Ion implantation in compound semiconductors for high-performance electronic devices

Zolper, J.C.

Advanced electronic devices based on compound semiconductors often make use of selective area ion implantation doping or isolation. The implantation processing becomes more complex as the device dimensions are reduced and more complex material systems are employed. The authors review several applications of ion implantation to high performance junction field effect transistors (JFETs) and heterostructure field effect transistors (HFETs) that are based on compound semiconductors, including: GaAs, AlGaAs, InGaP, and AlGaSb.

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Garnet phosphors prepared via hydrothermal synthesis

Phillips, Mark L.

This project studied hydrothermal synthesis as a route to producing green-emitting cathodoluminescent phosphorus isostructural with yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}, or YAG). Aqueous precipitation of Y, Gd, Al, Ga, and Tb salts produced amorphous gels, which were heated with water at 600 C and 3,200 bar to produce crystalline YAG:Tb, Y{sub 3}Ga{sub 5}O{sub 12}:Tb, Y{sub 3}Al{sub 3}Ga{sub 2}O{sub 12}:Tb, and Gd{sub 3}Ga{sub 5}O{sub 12}:Tb powders. Process parameters were identified that yielded submicron YAG:Tb and Y{sub 3}Ga{sub 5}O{sub 12}:Tb powders without grinding. Cathodoluminescent efficiencies were measured as functions of power density at 600 V, using both the hydrothermal garnets and identical phosphor compositions synthesized at high temperatures. Saturation behavior was independent of synthetic technique, however, the hydrothermal phosphorus were less susceptible to damage (irreversible efficiency loss) at very high power densities (up to 0.1 W/cm{sup 2}). The fine grain sizes available with hydrothermal synthesis make it an attractive method for preparing garnet phosphorus for field emission, projection, and head-up displays.

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Laser Engineered Net Shaping (LENS{trademark}) for additive component processing

Keicher, David M.

Sandia National Laboratories is presently developing an additive component processing technology called Laser Engineered Net Shaping, (LENS{trademark}). This process allows complex 3-dimensional solid metallic objects to be directly fabricated from a CAD solid model. Currently, this process functions similar to the Stereo Lithography process in which a faceted file is generated from the CAD solid model and then sliced into a sequence of layers. The sliced file is then input into another interpreter program which converts the sliced file into a series of tool path patterns required to build the entire layer. The component is fabricated by first generating an outline of the key component features and then filled using a rastering technique. This file is then used to drive the laser system to produce the desired component one layer at a time. This process differs from present rapid prototyping (RP) processes in that a fully dense, metallic component can be produced using this process.

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The growth and doping of Al(As)Sb by metal-organic chemical vapor deposition

Biefeld, Robert M.

AlSb and AlAs{sub x}Sb{sub 1{minus}x} epitaxial films grown by metal-organic chemical vapor deposition were successfully doped p- or n-type using diethylzinc or tetraethyltin, respectively. AlSb films were grown at 500 C and 76 torr using trimethylamine or ethyldimethylamine alane and triethylantimony. The authors examined the growth of AlAsSb using temperature of 500 to 600 C, pressures of 65 to 630 torr, V/III ratios of 1--17, and growth rates of 0.3 to 2.7 {micro}m/hour in a horizontal quartz reactor. SIMS showed C and O levels below 2 {times} 10{sup 18} cm{sup {minus}3} and 6 {times} 10{sup 18} cm{sup {minus}3} respectively for undoped AlSb. Similar levels of O were found in AlAs{sub 0.16}Sb{sub 0.84} films but C levels were an order of magnitude less in undoped and Sn-doped AlAs{sub 0.16}Sb{sub 0.84} films. Hall measurements of AlAs{sub 0.16}Sb{sub 0.84} showed hole concentrations between 1 {times} 10{sup 17} cm{sup {minus}3} to 5 {times} 10{sup 18} cm{sup {minus}3} for Zn-doped material and electron concentrations in the low to mid 10{sup 18} cm{sup {minus}3} for Sn-doped material. They have grown pseudomorphic InAs/InAsSb quantum well active regions on AlAsSb cladding layers. Photoluminescence of these layers has been observed up to 300 K.

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Application of a NAPL partitioning interwell tracer test (PITT) to support DNAPL remediation at the Sandia National Laboratories/New Mexico chemical waste landfill

Fate, Richard E.

Chlorinated solvents as dense non-aqueous phase liquid (DNAPL) are present at a large number of hazardous waste sites across the U.S. and world. DNAPL is difficult to detect in the subsurface, much less characterize to any degree of accuracy. Without proper site characterization, remedial decisions are often difficult to make and technically effective, cost-efficient remediations are even more difficult to obtain. A new non-aqueous phase liquid (NAPL) characterization technology that is superior to conventional technologies has been developed and applied at full-scale. This technology, referred to as the Partitioning Interwell Tracer Test (PITT), has been adopted from oil-field practices and tailored to environmental application in the vadose and saturated zones. A PITT has been applied for the first time at full-scale to characterize DNAPL in the vadose zone. The PITT was applied in December 1995 beneath two side-by-side organic disposal pits at Sandia National Laboratories/New Mexico (SNL/NM) RCRA Interim Status Chemical Waste Landfill (CWL), located in Albuquerque, New Mexico. DNAPL, consisting of a mixture of chlorinated solvents, aromatic hydrocarbons, and PCE oils, is known to exist in at least one of the two buried pits. The vadose zone PITT was conducted by injecting a slug of non-partitioning and NAPL-partitioning tracers into and through a zone of interest under a controlled forced gradient. The forced gradient was created by a balanced extraction of soil gas at a location 55 feet from the injector. The extracted gas stream was sampled over time to define tracer break-through curves. Soil gas sampling ports from multilevel monitoring installations were sampled to define break-through curves at specific locations and depths. Analytical instrumentation such as gas chromatographs and a photoacoustical analyzers operated autonomously, were used for tracer detection.

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Accelerator production of tritium authorization basis strategy

Miller, L.A.; Edwards, J.; Rose, S.

The Accelerator Production of Tritium (APT) project has proposed a strategy to develop the APT authorization basis and safety case based on DOE orders and fundamental requirements for safe operation. The strategy is viable regardless of whether the APT is regulated by DOE or by an external regulatory body. Currently the operation of Department of Energy (DOE) facilities is authorized by DOE and regulated by DOE orders and regulations while meeting the environmental protection requirements of the Environmental Protection Agency (EPA) and the states. In the spring of 1994, Congress proposed legislation and held hearings related to requiring all DOE operations to be subject to external regulation. On January 25, 1995, DOE, with the support of the White House Council on Environmental Quality, created the Advisory Committee on External Regulation of Department of Energy Nuclear Safety. This committee divided its recommendations into three areas: (1) facility safety, (2) worker safety, and (3) environmental protection. In the area of facility safety the committee recommended external regulation of DOE nuclear facilities by either the Nuclear Regulatory Commission (NRC) or a restructured Defense Nuclear Facilities Safety Board (DNFSB). In the area of worker safety, the committee recommended that the Occupational Safety and Health Administration (OSHA) regulate DOE nuclear facilities. In the environmental protection area, the committee did not recommend a change in the regulation by the EPA and the states of DOE nuclear facilities. If these recommendations are accepted, all DOE nuclear facilities will be impacted to some extent.

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Nuclear source term evaluation for launch accident environments

Mcculloch, W.H.

When United States space missions involve launching vehicles carrying significant quantities of nuclear material, US law requires that prior to launch the mission be approved by the Office of the President. This approval is to be based on an evaluation of the nuclear safety risks associated with the mission and the projected benefits. To assist in the technical evaluation of risks for each mission, an Interagency Nuclear Safety Review Panel (INSRP) is instituted to provide an independent assessment of the mission risks. INSRP`s assessment begins with a review of the safety analysis for the mission completed by the organization proposing the mission and documented in a Safety Analysis Report (SAR). In addition, INSRP may execute other analyses it deems necessary. Results are documented and passed to the decision maker in a Safety Evaluation Report (SER). The INSRP review and evaluation process has been described in some detail in a number of papers.

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Multi-Spectral Pushbroom Imaging Radiometer (MPIR) for remote sensing studies

Phipps, G.S.

A Multi-spectral Pushbroom Imaging Radiometer (MPIR) has been developed as a well-calibrated, imaging radiometer for studies of cloud properties from an unmanned aerospace vehicle platform. The instrument is designed to fly at altitudes up to 20 km and produce data from nine spectral detector modules. Each module has its own telescope optics, linear detector array, spectral filter, and necessary electronics. Cryogenic cooling for the long-wavelength infrared modules, as well as temperature regulation of the short- wavelength modules, is provided by a liquid nitrogen system designed to operate for multi-day missions. Pre- and post-flight calibration, combined with an on-board calibration chopper, provide an instrument with state-of-the-art radiometric measurement accuracies. Each module has a {+-}40{degree} across-track field-of-view and images a curved footprint onto its linear detector array. The long-wavelength array types have 256 detector elements while the short-wavelength arrays can have 512 elements. A modular design allows individual spectral bands to be changed to match the requirements for a particular mission.

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The effects of silicon doping on the performance of PMAN carbon anodes in Li-ion cells

Guidotti, Ronald A.

Carbons derived from polymethylacrylonitrile (PMAN) have been studied for use as intercalation anodes in Li-ion cells. The effect of Si doping upon the electrochemical performance of PMAN carbons was studied using tetravinylsilane (TVS) and tetramethysilane (TMS) as sources of Si during the formation of the PMAN precursors. The carbons were characterized by galvanostatic cycling, cyclic voltammetry, and complex impedance. The presence of 9 to 11 w/o Si in the PMAN lattice greatly increased the irreversible capacity of these materials.

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Capacity loss and faradaic efficiency of lithium thionyl chloride cells

Hoier, S.; Schlaikjer, C.; Johnson, A.; Riley, S.

In lithium/thionyl chloride (Li/TC) cells, a lithium limited design was thought to be safer than a cathode limited design because the amount of lithium left in discharged cells would be minimal. However, lithium corrosion reduces the capacity faster than does cathode degradation during storage. The optimization of the ratio of lithium to carbon was studied, considering storage time and temperature. The efficiency of converting chemical energy into electrical energy has been studied for the case of D cells with surface area from 45 to 345 cm{sup 2}, under constant and various pulsed loads. Microcalorimetric monitoring of the heat output during discharge allowed the direct measurement of faradaic efficiency, and showed that self discharge is far more pervasive that previously acknowledged. Typical faradaic efficiencies for constant load varied from 30% at low current density to 90% at moderate and 75 % at high current density. Pulsed current further depresses these efficiencies, except at very low average current density.

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TORO II: A finite element computer program for nonlinear quasi-static problems in electromagnetics: Part 1, Theoretical background

Gartling, David K.

The theoretical and numerical background for the finite element computer program, TORO II, is presented in detail. TORO II is designed for the multi-dimensional analysis of nonlinear, electromagnetic field problems described by the quasi-static form of Maxwell`s equations. A general description of the boundary value problems treated by the program is presented. The finite element formulation and the associated numerical methods used in TORO II are also outlined. Instructions for the use of the code are documented in SAND96-0903; examples of problems analyzed with the code are also provided in the user`s manual. 24 refs., 8 figs.

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TORO II: A finite element computer program for nonlinear quasi-static problems in electromagnetics: Part 2, User`s manual

Gartling, David K.

User instructions are given for the finite element, electromagnetics program, TORO II. The theoretical background and numerical methods used in the program are documented in SAND95-2472. The present document also describes a number of example problems that have been analyzed with the code and provides sample input files for typical simulations. 20 refs., 34 figs., 3 tabs.

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MP Salsa: a finite element computer program for reacting flow problems. Part 1--theoretical development

Shadid, John N.

The theoretical background for the finite element computer program, MPSalsa, is presented in detail. MPSalsa is designed to solve laminar, low Mach number, two- or three-dimensional incompressible and variable density reacting fluid flows on massively parallel computers, using a Petrov-Galerkin finite element formulation. The code has the capability to solve coupled fluid flow, heat transport, multicomponent species transport, and finite-rate chemical reactions, and to solver coupled multiple Poisson or advection-diffusion- reaction equations. The program employs the CHEMKIN library to provide a rigorous treatment of multicomponent ideal gas kinetics and transport. Chemical reactions occurring in the gas phase and on surfaces are treated by calls to CHEMKIN and SURFACE CHEMKIN, respectively. The code employs unstructured meshes, using the EXODUS II finite element data base suite of programs for its input and output files. MPSalsa solves both transient and steady flows by using fully implicit time integration, an inexact Newton method and iterative solvers based on preconditioned Krylov methods as implemented in the Aztec solver library.

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Re-evaluation of the eutectic region of the LiBr-KBr-LiF system

Guidotti, Ronald A.

The separator pellet in a thermal battery consists of electrolyte immobilized by a binder (typically, MgO powder). The melting point of the electrolyte determines the effective operating window for its use in a thermal battery. The development of a two-hour thermal battery required the use of a molten salt that had a lower melting point and larger liquidus range than the LiCl-KCl eutectic which melts at 352 C. Several candidate eutectic electrolyte systems were evaluated for their suitability for this application. One was the LiCl-LiBr-KBr eutectic used at Argonne National Laboratories for high-temperature rechargeable batteries for electric-vehicle applications. Using a custom-designed high-temperature conductivity cell, the authors were able to readily determine the liquidus region for the various compositions studied around the original eutectic for the LiBr-KBr-LiF system. The actual eutectic composition was found to be 60.0 m/o LiBr-37.5 m/o KBr-2.5 m/o LiF with a melting point of 324 {+-} 0.5 C.

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Two-dimensional nonlinear finite element analysis of well damage due to reservoir compaction, well-to-well interactions, and localization on weak layers

Fredrich, Joanne T.

In this paper the authors present the results of a coupled nonlinear finite element geomechanics model for reservoir compaction and well-to-well interactions for the high-porosity, low strength diatomite reservoirs of the Belridge field near Bakersfield, California. They show that well damage and failures can occur under the action of two distinct mechanisms: shear deformations induced by pore compaction, and subsidence, and shear deformations due to well-to-well interactions during production or water injection. They show such casting damage or failure can be localized to weak layers that slide or slip under shear due to subsidence. The magnitude of shear displacements and surface subsidence agree with field observations.

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Oxidation and frictional performance of solid lubricants used in weapon stronglinks

Dugger, Michael T.

The oxidation and performance of the solid film lubricant used in a majority of the surety devices in the enduring stockpile have been investigated. Oxidation of this lubricant in air at 150 C produces a significant increase in the molybdenum oxide to sulfide ratio, indicative of degradation of the primary lubricating constituent of the composite lubricant. Oxidation is more extensive on samples that were burnished such that the substrate is exposed over a fraction of the surface, relative to those which were only lightly burnished. Friction results indicate that oxidation in air did not increase the initial or steady-state friction coefficient for lightly burnished surfaces. However, surfaces burnished to expose substrate material experienced a significant increase in both initial and steady-state friction. Oxidation of lubricated parts retrieved from aged stronglinks has also been demonstrated.

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Mechanics of interfacial crack propagation in microscratching

De Boer, Maarten P.

There are two main issues regarding thin film debonding. The first is the nucleation of interfacial cracks, while the second is the propagation of cracks. From a mechanical testing point of view, scratch testing primarily serves to address the former issue, while indentation testing is a method of addressing the latter. A new probing technique has been developed to test thin film mechanical properties. In the Microwedge Scratch Test (MWST), a wedge shaped diamond indenter tip is drawn along a fine line, while simultaneously being driven into the line. The authors compare microwedge scratching of Zone 1 and Zone T thin film specimens of sputtered W on SiO{sub 2}. Symptomatic of its poor mechanical properties, the Zone 1 film displays three separate crack systems. Because of its superior grain boundary strength, the Zone T film displayed only one of these--an interfacial crack system. Using bimaterial linear elastic fracture mechanics, governing equations are developed for propagating interfacial cracks, including expressions for strain energy release rate, bending strain, and mode mixity. Grain boundary fracture strength information may be deduced from the Zone 1 films, while adhesion may be inferred from the Zone T films.

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Gas-phase diffusion in porous media: Evaluation of an advective- dispersive formulation and the dusty-gas model including comparison to data for binary mixtures

Webb, Stephen W.

Two models for gas-phase diffusion and advection in porous media, the Advective-Dispersive Model (ADM) and the Dusty-Gas Model (DGM), are reviewed. The ADM, which is more widely used, is based on a linear addition of advection calculated by Darcy`s Law and ordinary diffusion using Fick`s Law. Knudsen diffusion is often included through the use of a Klinkenberg factor for advection, while the effect of a porous medium on the diffusion process is through a porosity-tortuosity-gas saturation multiplier. Another, more comprehensive approach for gas-phase transport in porous media has been formulated by Evans and Mason, and is referred to as the Dusty- Gas Model (DGM). This model applies the kinetic theory of gases to the gaseous components and the porous media (or ``dust``) to develop an approach for combined transport due to ordinary and Knudsen diffusion and advection including porous medium effects. While these two models both consider advection and diffusion, the formulations are considerably different, especially for ordinary diffusion. The various components of flow (advection and diffusion) are compared for both models. Results from these two models are compared to isothermal experimental data for He-Ar gas diffusion in a low-permeability graphite. Air-water vapor comparisons have also been performed, although data are not available, for the low-permeability graphite system used for the helium-argon data. Radial and linear air-water heat pipes involving heat, advection, capillary transport, and diffusion under nonisothermal conditions have also been considered.

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A review of porous media enhanced vapor-phase diffusion mechanisms, models, and data: Does enhanced vapor-phase diffusion exist?

Ho, Clifford K.

A review of mechanisms, models, and data relevant to the postulated phenomenon of enhanced vapor-phase diffusion in porous media is presented. Information is obtained from literature spanning two different disciplines (soil science and engineering) to gain a diverse perspective on this topic. Findings indicate that while enhanced vapor diffusion tends to correct the discrepancies observed between past theory and experiments, no direct evidence exists to support the postulated processes causing enhanced vapor diffusion. Numerical modeling analyses of experiments representative of the two disciplines are presented in this paper to assess the sensitivity of different systems to enhanced vapor diffusion. Pore-scale modeling is also performed to evaluate the relative significance of enhanced vapor diffusion mechanisms when compared to Fickian diffusion. The results demonstrate the need for additional experiments so that more discerning analyses can be performed.

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Sandia WIPP calibration traceability

Schuhen, Michael D.

This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

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Plane shock generator explosive lens

Vigil, Manuel G.

Sandia National Laboratories' design and development of an optimized Plane Shock Generator Explosive Lens (PSGEL) is detailed in this report. This PSGEL component is designed to generate a planar shock wave transmitted to perform a function through a steel bulkhead without rupturing or destroying the integrity of the bulkhead. The PSGEL component consists of a detonator, explosive, brass cone, and confinement or tamper housing. The purpose of the PSGEL component is to generate a plane shock wave input to a stainless steel bulkhead (wave separator) with a ferro-electric (PZT) ceramic disk attached to the steel on the surface opposite the PSGEL. The planar shock wave depolarizes the PZT 65/35 ferro-electric ceramic to produce an electrical output. Elastic, plastic I and plastic II waves with different velocities are generated in the steel bulkhead. The depolarization of the PZT ceramic is produced by the elastic wave of specific amplitude (10-20 kilobars) and this process must be completed before (about 0.15 microseconds) the first plastic wave arrives at the PZT ceramic. Measured particle velocity versus time profiles, using a Velocity Interferometer System for Any Reflector (VISAR), are presented for the brass and steel output free surfaces. Shock wave planarity data, using an electronic streak camera, are presented for the brass and steel wave separator free surfaces.

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Telecommunications administration standard

Gustwiller, K.D.

The administration of telecommunications is critical to proper maintenance and operation. The intent is to be able to properly support telecommunications for the distribution of all information within a building/campus. This standard will provide a uniform administration scheme that is independent of applications, and will establish guidelines for owners, installers, designers and contractors. This standard will accommodate existing building wiring, new building wiring and outside plant wiring. Existing buildings may not readily adapt to all applications of this standard, but the requirement for telecommunications administration is applicable to all buildings. Administration of the telecommunications infrastructure includes documentation (labels, records, drawings, reports, and work orders) of cables, termination hardware, patching and cross-connect facilities, telecommunications rooms, and other telecommunications spaces (conduits, grounding, and cable pathways are documented by Facilities Engineering). The investment in properly documenting telecommunications is a worthwhile effort. It is necessary to adhere to these standards to ensure quality and efficiency for the operation and maintenance of the telecommunications infrastructure for Sandia National Laboratories.

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Authentication of data for monitoring a comprehensive test ban treaty

Draelos, Timothy J.

The important issue of data integrity in the CTBT International Monitoring System (IMS) is discussed and a brief tutorial on data authentication techniques is offered. The utilization of data authentication as a solution to the data integrity problem is evaluated. Public key data authentication is recommended for multilateral monitoring regimes such as the CTBT. The ramifications and system considerations of applying data authentication at various locations in the IMS, or not at all, are reviewed in a data surety context. The paper concludes with a recommendation of authenticating data at all critical monitoring stations.

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Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

Chanin, D.I.; Murfin, W.B.

A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occur in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response.

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Fiber optic hydrogen sensor

Butler, Michael A.

This report covers the development of fiber optic hydrogen and temperature sensors for monitoring dissolved hydrogen gas in transformer oil. The concentration of hydrogen gas is a measure of the corona and spark discharge within the transformer and reflects the state of health of the transformer. Key features of the instrument include use of palladium alloys to enhance hydrogen sensitivity, a microprocessor controlled instrument with RS-232, liquid crystal readout, and 4-20 ma. current loop interfaces. Calibration data for both sensors can be down loaded to the instrument through the RS-232 interface. This project was supported by the Technology Transfer Initiative in collaboration with J. W. Harley, Inc. through the mechanism of a cooperative research and development agreement (CRADA).

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Surface waviness resulting from single point diamond dressing in cylindrical grinding

Redmond, James M.

This paper describes an experimental investigation of workpiece surface waviness that stems from poor single point diamond wheel dressing procedures in cylindrical grinding. If done improperly, single point dressing can produce a thread on the grinding wheel surface that is then imposed on the workpiece during machining. The circumferential waviness exhibited by the threaded workpiece is similar to that resulting from one per rev vibrations of the grinding wheel. In order to differentiate between these two sources of waviness, a geometrical approach to predicting the circumferential and axial waves produced during grinding is presented. The concepts presented are illustrated through a series of plunge grinding tests incorporating dressing procedures of varying quality. Test results verify that dressing induced circumferential waviness is similar to waviness resulting from one per rev type vibrations of the grinding wheel. The two sources can be distinguished, however, through examination of the workpiece waviness in the axial direction.

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Integrated Safety, Environmental and Emergency Management System (ISEEMS)

Silver, R.

The Risk Management and NEPA (National Environmental Policy Act) Department of Sandia National Laboratories/New Mexico (SNL/NM) recognized the need for hazard and environmental data analysis and management to support the line managers` need to know, understand, manage and document the hazards in their facilities and activities. The Integrated Safety, Environmental, and Emergency Management System (ISEEMS) was developed in response to this need. SNL needed a process that would quickly and easily determine if a facility or project activity contained only standard industrial hazards and therefore require minimal safety documentation, or if non-standard industrial hazards existed which would require more extensive analysis and documentation. Many facilities and project activities at SNL would benefit from the quick screening process used in ISEEMS. In addition, a process was needed that would expedite the NEPA process. ISEEMS takes advantage of the fact that there is some information needed for the NEPA process that is also needed for the safety documentation process. The ISEEMS process enables SNL line organizations to identify and manage hazards and environmental concerns at a level of effort commensurate with the hazards themselves by adopting a necessary and sufficient (graded) approach to compliance. All hazard-related information contained within ISEEMS is location based and can be displayed using on-line maps and building floor plans. This visual representation provides for quick assimilation and analysis.

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Analysis of Strategic Petroleum Reserve bubble point pressure data

Lott, Stephen E.

Mathematical models are presented to predict the bubble pressure for 481 cavern oil samples withdrawn from the Bryan Mound, West Hackberry, Big Hill, and Bayou Choctaw Strategic Petroleum Reserve sites. The predicted bubble point pressure is compared to experimentally measured bubble point pressure to resolve potential sources of error introduced to the experimental analysis. In order to gain a higher level of confidence in the measurement of the bubble point pressure, a stochastic analysis of the data is recommended in the future.

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Process measurement assurance program

Pettit, Richard B.

This paper describes a new method for determining, improving, and controlling the measurement process errors (or measurement uncertainty) of a measurement system used to monitor product as it is manufactured. The method is called the Process Measurement Assurance Program (PMAP). It integrates metrology early into the product realization process and is a step beyond statistical process control (SPC), which monitors only the product. In this method, a control standard is used to continuously monitor the status of the measurement system. Analysis of the control standard data allow the determination of the measurement error inherent in the product data and allow one to separate the variability in the manufacturing process from variability in the measurement process. These errors can be then associated with either the measurement equipment, variability of the measurement process, operator bias, or local environmental effects. Another goal of PMAP is to determine appropriate re-calibration intervals for the measurement system, which may be significantly longer or shorter than the interval typically assigned by the calibration organization.

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Testing of an impedance heating system for solar power tower applications

Pacheco, James E.

A non-conventional type of heating system is being tested at Sandia National Laboratories for solar thermal power tower applications. In this system, called impedance heating, electric current flows directly through the pipe to maintain the desired temperature. The pipe becomes the resistor where the heat is generated. Impedance heating has many advantages over previously used mineral insulated (MI) heat trace. An impedance heating system should be much more reliable than heat trace cable since delicate junctions and cabling are not used and the main component, a transformer, is inherently reliable. A big advantage of impedance heating is the system can be sized to rapidly heat up the piping to provide rapid response times necessary in cyclic power plants such as solar power towers. In this paper, experimental results from testing an impedance heating system are compared to MI cable heat trace. We found impedance heating was able to heat piping rapidly and effectively. There were not significant stray currents and impedance heating did not affect instrumentation.

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Solar central receiver technology: the Solar Two Project

Prairie, Michael R.

Solar Two will be the world`s largest operating solar central receiver power plant. It is expected to begin operating in April 1996; it is currently undergoing start-up and checkout. The plant will use sunlight reflected from 1926 sun-tracking mirrors to heat molten nitrate salt flowing in a heat exchanger (receiver) that sits atop a 200 foot tower. The heated salt will be stored in a tank for use, when needed, to generate superheated steam for producing electricity with a conventional Rankine-cycle turbine/generator. The purpose of the project is to validate molten-salt solar central receiver technology and to reduce the perceived risks associated with the first full-scale commercial plants. Already, much has been learned during the project including the effects of trace contaminants in the salt and the large effect of wind on the receiver. There is also much that remains to be learned. This report describes the technical status of the Solar Two project including a summary of lessons learned to date.

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Probabilistic fatigue methodology and wind turbine reliability

Lange, C.H.

Wind turbines subjected to highly irregular loadings due to wind, gravity, and gyroscopic effects are especially vulnerable to fatigue damage. The objective of this study is to develop and illustrate methods for the probabilistic analysis and design of fatigue-sensitive wind turbine components. A computer program (CYCLES) that estimates fatigue reliability of structural and mechanical components has been developed. A FORM/SORM analysis is used to compute failure probabilities and importance factors of the random variables. The limit state equation includes uncertainty in environmental loading, gross structural response, and local fatigue properties. Several techniques are shown to better study fatigue loads data. Common one-parameter models, such as the Rayleigh and exponential models are shown to produce dramatically different estimates of load distributions and fatigue damage. Improved fits may be achieved with the two-parameter Weibull model. High b values require better modeling of relatively large stress ranges; this is effectively done by matching at least two moments (Weibull) and better by matching still higher moments. For this purpose, a new, four-moment {open_quotes}generalized Weibull{close_quotes} model is introduced. Load and resistance factor design (LRFD) methodology for design against fatigue is proposed and demonstrated using data from two horizontal-axis wind turbines. To estimate fatigue damage, wind turbine blade loads have been represented by their first three statistical moments across a range of wind conditions. Based on the moments {mu}{sub 1}{hor_ellipsis}{mu}{sub 3}, new {open_quotes}quadratic Weibull{close_quotes} load distribution models are introduced. The fatigue reliability is found to be notably affected by the choice of load distribution model.

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An investigation of temperature measurement methods in nuclear power plant reactor pressure vessel annealing

Nakos, James T.

The objective of this project was to provide an assessment of several methods by which the temperature of a commercial nuclear power plant reactor pressure vessel (RPV) could be measured during an annealing process. This project was a coordinated effort between DOE`s Office of Nuclear Energy, Science and Technology; DOE`s Light Water Reactor Technology Center at Sandia National Laboratories; and the Electric Power Research Institute`s Non- Destructive Evaluation Center. Ball- thermocouple probes similar to those described in NUREG/CR-5760, spring-loaded, metal- sheathed thermocouple probes, and 1778 air- suspended thermocouples were investigated in experiments that heated a section of an RPV wall to simulate a thermal annealing treatment. A parametric study of ball material, emissivity, thermal conductivity, and thermocouple function locations was conducted. Also investigated was a sheathed thermocouple failure mode known as shunting (electrical breakdown of insulation separating the thermocouple wires). Large errors were found between the temperature as measured by the probes and the true RPV wall temperature during heat-up and cool-down. At the annealing soak temperature, in this case 454{degrees}C [850`F], all sensors measured the same temperature within about {plus_minus}5% (23.6{degrees}C [42.5{degrees}F]). Because of these errors, actual RPV wall heating and cooling rates differed from those prescribed (by up to 29%). Shunting does not appear to be a problem under these conditions. The large temperature measurement errors led to the development of a thermal model that predicts the RPV wall temperature from the temperature of a ball- probe. Comparisons between the model and the experimental data for ball-probes indicate that the model could be a useful tool in predicting the actual RPV temperature based on the indicated ball- probe temperature. The model does not predict the temperature as well for the spring-loaded and air suspended probes.

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Breakdown of the resistor-network model for steady-state hopping conduction

Emin, David E.

General master equations are used to study steady-state hopping transport in a disordered solid. We express a site`s occupancy in terms of its quasi-electrochemical potential (QECP); currents flow between sites whose QECP`s differ. Coupled nonlinear circuit equations for the QECP`s result from the steady-state condition and the boundary condition that the total QECP drop is the applied emf. When the site-to-site QECP differences are much smaller than the thermal energy, K{sub B}t, the effect of current flow on site occupancies is ignorable. These equations then reduce to those of a resistance network. However, the resistor-network model fails: (a) at low temperatures, (b) with increasing disorder, and (c) with increasing emf. We therefore study hopping conduction beyond this approximation. Exact examples show the importance of current-induced charge redistribution in non-ohmic steady-state flow.

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Smart Gun Technology project. Final report

Weiss, D.R.

The goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user form firing a law officer`s firearm by implementing user-recognizing-and-authorizing (or {open_quotes}smart{close_quotes}) surety technologies. This project was funded by the National Institute of Justice. This report lists the findings and results of the project`s three primary objectives. First, to find and document the requirements for a smart firearm technology that law enforcement officers will value. Second, to investigate, evaluate, and prioritize technologies that meet the requirements for a law enforcement officer`s smart firearm. Third, to demonstrate and document the most promising technology`s usefulness in models of a smart firearm.

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Estimates of the solubilities of waste element radionuclides in waste isolation pilot plant brines: A report by the expert panel on the source term

Trauth, K.M.

Evaluation of the long-term performance of the WIPP includes estimation of the cumulative releases of radionuclide elements to the accessible environment. Nonradioactive lead is added because of the large quantity expected in WIPP wastes. To estimate the solubilities of these elements in WIPP brines, the Panel used the following approach. Existing thermodynamic data were used to identify the most likely aqueous species in solution through the construction of aqueous speciation diagrams. Existing thermodynamic data and expert judgment were used to identify potential solubility-limiting solid phases. Thermodynamic data were used to calculate the activities of the radionuclide aqueous species in equilibrium with each solid. Activity coefficients of the radionuclide-bearing aqueous species were estimated using Pitzer`s equations. These activity coefficients were then used to calculate the concentration of each radionuclide at the 0.1 and 0.9 fractiles. The 0.5 fractile was chosen to represent experimental data with activity coefficient corrections as described above. Expert judgment was used to develop the 0.0, 0.25, 0.75, and 1.0 fractiles by considering the sensitivity of solubility to the potential variability in the composition of brine and gas, and the extent of waste contaminants, and extending the probability distributions accordingly. The results were used in the 1991 and 1992 performance assessment calculations. 68 refs.

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Proving refinement transformations for deriving high-assurance software

Winter, V.L.

The construction of a high-assurance system requires some evidence, ideally a proof, that the system as implemented will behave as required. Direct proofs of implementations do not scale up well as systems become more complex and therefore are of limited value. In recent years, refinement-based approaches have been investigated as a means to manage the complexity inherent in the verification process. In a refinement-based approach, a high-level specification is converted into an implementation through a number of refinement steps. The hope is that the proofs of the individual refinement steps will be easier than a direct proof of the implementation. However, if stepwise refinement is performed manually, the number of steps is severely limited, implying that the size of each step is large. If refinement steps are large, then proofs of their correctness will not be much easier than a direct proof of the implementation. The authors describe an approach to refinement-based software development that is based on automatic application of refinements, expressed as program transformations. This automation has the desirable effect that the refinement steps can be extremely small and, thus, easy to prove correct. They give an overview of the TAMPR transformation system that the use for automated refinement. They then focus on some aspects of the semantic framework that they have been developing to enable proofs that TAMPR transformations are correctness preserving. With this framework, proofs of correctness for transformations can be obtained with the assistance of an automated reasoning system.

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Crashworthiness of the AT-400A shipping container

Gruda, Jeffrey D.

Shipping containers used for transporting radioactive material must be certified using federal regulations. These regulations require the container be tested or evaluated in severe mechanical and thermal environments which represent hypothetical accident scenarios. The containers are certified if the inner container remains leaktight. This paper presents results from finite element simulations of the accidents which include subjecting the AT-400A (for Pu from dismantled nuclear weapons) to a 30-foot (9 m) drop onto an unyielding target and crushing the container with an 1100 lb (500 kg) steel plate dropped from 30 feet. The nonlinear PRONTO3D finite element results were validated using test results. The simulations of the various impacts and crushes identified trends and worst-case orientations. They also showed that there is a significant margin of safety based on the failure of the containment vessel.

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Demonstration of close-coupled barriers for subsurface containment of buried waste

Dwyer, B.P.

A close-coupled barrier is produced by first installing a conventional cement grout curtain followed by a thin inner lining of a polymer grout. The resultant barrier is a cement polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. Close-coupled barrier technology is applicable for final, interim, or emergency containment of subsurface waste forms. Consequently, when considering the diversity of technology application, the construction emplacement and material technology maturity, general site operational requirements, and regulatory compliance incentives, the close-coupled barrier system provides an alternative for any hazardous or mixed waste remediation plan. This paper discusses the installation of a close-coupled barrier and the subsequent integrity verification. The demonstration was installed at a benign site at the Hanford Geotechnical Test Facility, 400 Area, Hanford, Washington. The composite barrier was emplaced beneath a 7,500 liter tank. The tank was chosen to simulate a typical DOE Complex waste form. The stresses induced on the waste form were evaluated during barrier construction. The barrier was constructed using conventional jet grouting techniques. Drilling was completed at a 45{degree} angle to the ground, forming a conical shaped barrier with the waste form inside the cone. Two overlapping rows of cylindrical cement columns were grouted in a honeycomb fashion to form the secondary backdrop barrier layer. The primary barrier, a high molecular weight polymer manufactured by 3M Company, was then installed providing a relatively thin inner liner for the secondary barrier. The primary barrier was emplaced by panel jet grouting with a dual wall drill stem, two phase jet grouting system.

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Diamond switches for high temperature electronics

Loubriel, Guillermo M.

Diamond switches are well suited for use in high temperature electronics. Laboratory feasibility of diamond switching at 1 kV and 18 A was demonstrated. DC blocking voltages up to 1 kV were demonstrated. A 50 {Omega} load line was switched using a diamond switch, with switch on-state resistivity {approx}7 {Omega}-cm. An electron beam, {approx}150 keV energy, {approx}2 {mu}s full width at half maximum was used to control the 5 mm x 5 mm x 100 {mu}m thick diamond switch. The conduction current temporal history mimics that of the electron beam. These data were taken at room temperature.

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Life-testing oxide confined VCSELs: Too good to last?

Proceedings of SPIE - The International Society for Optical Engineering

Lear, K.L.

The use of native oxides (selective oxidation) in vertical cavity surface emitting lasers has produced dramatic improvements in these laser diodes but has also been suspected of causing poor reliability because of incidental reports of short lifetimes and physical considerations. Here we discuss the results of thousands of hours life-tests for oxide confined and implant confined devices at current densities from 1 to 12 kA/cmr. There was a single infant mortality failure from a sample of 14 oxide confined lasers with the remainder showing relatively stable operation. The failed device is analyzed in terms of light current characteristics and near-field electroluminescence images, and potential screening criteria are proposed.

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Comprehensive numerical modeling of vertical-cavity surface-emitting lasers

IEEE Journal of Quantum Electronics

Hadley, G.R.

We present a comprehensive numerical model for vertical-cavity surface-emitting lasers that includes all major processes affecting cw operation of axisymmetric devices. In particular, our model includes a description of the 2-D transport of electrons and holes through the cladding layers to the quantum well(s), diffusion and recombination of these carriers within the wells, the 2-D transport of heat throughout the device, and a multilateral-mode effective index optical model. The optical gain acquired by photons traversing the quantum wells is computed including the effects of strained band structure and quantum confinement. We employ our model to predict the behavior of higher-order lateral modes in proton-implanted devices and to provide an understanding of index-guiding in devices fabricated using selective oxidation.

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Materials compatibility issues associated with aqueous alkaline cleaners

Lopez, Edwin P.

As part of the Environmentally Conscious Manufacturing (ECM) technology, and in support of various mechanical assembly applications, several aqueous alkaline cleaners were studied as potential candidates for cleaning mechanical piece parts. Historically, ozone depleting and hazardous chlorinated cleaners have been used to degrease mechanical assemblies. In an effort to replace these chemicals, several cleaning processes, including aqueous alkaline cleaners, were screened as potential candidates using a variety of criteria, including aqueous alkaline cleaners, were screened as potential candidates using a variety of criteria, including: cleaning efficiency, materials compatibility, etch rate, corrosion, immersion tests, temperature/humidity exposure, and an exposure to a simulated indoor industrial environment. Cleaning efficiency was determined using visual examination, Auger electron spectroscopy, X-ray photoelectron spectroscopy, MESERAN, and goniometer/contact angle measurements. Several cleaners were identified as potential alternatives based solely on the cleaning results. Some of the cleaners, however, left undesirable residues. This paper will focus on materials compatibility issues of these aqueous cleaners after immersion tests, an etch rate study, and exposures to temperature/humidity and a standard industrial environment.

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Compatibility of packaging components with simulant mixed waste

Nigrey, Paul J.

The purpose of hazardous and radioactive materials packaging is to enable these materials to be transported without posing a threat to the health or property of the general public. To achieve this aim, regulations in the US have been written establishing general design requirements for such packagings. While no regulations have been written specifically for mixed waste packaging, regulations for the constituents of mixed wastes, i.e., hazardous and radioactive substances, have been codified by the US Department of Transportation (US DOT, 49 CFR 173) and the US Nuclear Regulatory Commission (NRC, 10 CFR 71). Based on these national requirements, a Chemical Compatibility Testing Program was developed in the Transportation Systems Department at Sandia National Laboratories (SNL). The program provides a basis to assure any regulatory body that the issue of packaging material compatibility towards hazardous and radioactive materials has been addressed. In this paper, the authors present the results of the second phase of this testing program. The first phase screened five liner materials and six seal materials towards four simulant mixed wastes. This phase involved the comprehensive testing of five candidate liner materials to an aqueous Hanford Tank simulant mixed waste. The comprehensive testing protocol involved exposing the respective materials a matrix of four gamma radiation doses ({approximately} 1, 3, 6, and 40 kGy), three temperatures (18, 50, and 60 C), and four exposure times (7, 14, 28, and 180 days). Following their exposure to these combinations of conditions, the materials were evaluated by measuring five material properties. These properties were specific gravity, dimensional changes, hardness, stress cracking, and mechanical properties.

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The emerging versatility of a scannerless range imager

Sackos, John T.

Sandia National Laboratories is nearing the completion of the initial development of a unique type of range imaging sensor. This innovative imaging optical radar is based on an active flood-light scene illuminator and an image intensified CCD camera receiver. It is an all solid-state device (no moving parts) and offers significant size, performance, reliability, simplicity, and affordability advantages over other types of 3-D sensor technologies, including: scanned laser radar, stereo vision, and structured lighting. The sensor is based on low cost, commercially available hardware, and is very well suited for affordable application to a wide variety of military and commercial uses, including: munition guidance, target recognition, robotic vision, automated inspection, driver enhanced vision, collision avoidance, site security and monitoring, terrain mapping, and facility surveying. This paper reviews the sensor technology and its development for the advanced conventional munition guidance application, and discusses a few of the many other emerging applications for this new innovative sensor technology.

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Properties of H, O and C in GaN

Shul, Randy J.

The electrical properties of the light ion impurities H, O and C in GaN have been examined in both as-grown and implanted material. H is found to efficiently passivate acceptors such as Mg, Ca and C. Reactivation occurs at {ge} 450 C and is enhanced by minority carrier injection. The hydrogen does not leave the GaN crystal until > 800 C, and its diffusivity is relatively high ({approximately} 10{sup {minus}11} cm{sup 2}/s) even at low temperatures (< 200 C) during injection by wet etching, boiling in water or plasma exposure. Oxygen shows a low donor activation efficiency when implanted into GaN, with an ionization level of 30--40 meV. It is essentially immobile up to 1,100 C. Carbon can produce low p-type levels (3 {times} 10{sup 17} cm{sup {minus}3}) in GaN during MOMBE, although there is some evidence it may also create n-type conduction in other nitrides.

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Plasma chemistries for dry etching GaN, AlN, InGaN and InAlN

Shul, Randy J.

Etch rates up to 7,000 {angstrom}/min. for GaN are obtained in Cl{sub 2}/H{sub 2}/Ar or BCl{sub 3}/Ar ECR discharges at 1--3mTorr and moderate dc biases. Typical rates with HI/H{sub 2} are about a factor of three lower under the same conditions, while CH{sub 4}/H{sub 2} produces maximum rates of only {approximately}2,000 {angstrom}/min. The role of additives such as SF{sub 6}, N{sub 2}, H{sub 2} or Ar to the basic chlorine, bromine, iodine or methane-hydrogen plasma chemistries are discussed. Their effect can be either chemical (in forming volatile products with N) or physical (in breaking bonds or enhancing desorption of the etch products). The nitrides differ from conventional III-V`s in that bond-breaking to allow formation of the etch products is a critical factor. Threshold ion energies for the onset of etching of GaN, InGaN and InAlN are {ge} 75 eV.

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NCMS PWB Surface Finishes Team project summary

Kokas, J.; Desantis, C.; Wenger, G.

The NCMS PWB Surface Finishes Consortium is just about at the end of the five year program. Dozens of projects related to surface finishes and PWB solder-ability were performed by the team throughout the program, and many of them are listed in this paper. They are listed with a cross reference to where and when a technical paper was presented describing the results of the research. However, due to time and space constraints, this paper can summarize the details of only three of the major research projects accomplished by the team. The first project described is an ``Evaluation of PWB Surface Finishes.`` It describes the solderability, reliability, and wire bondability of numerous surface finishes. The second project outlined is an ``Evaluation of PWB Solderability Test Methods.`` The third project outlined is the ``Development and Evaluation of Organic Solderability Preservatives.``

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Sandia`s network for supercomputing `95: Validating the progress of Asynchronous Transfer Mode (ATM) switching

Vahle, Michael O.

The Advanced Networking Integration Department at Sandia National Laboratories has used the annual Supercomputing conference sponsored by the IEEE and ACM for the past three years as a forum to demonstrate and focus communication and networking developments. For Supercomputing `95, Sandia elected: to demonstrate the functionality and capability of an AT&T Globeview 20Gbps Asynchronous Transfer Mode (ATM) switch, which represents the core of Sandia`s corporate network, to build and utilize a three node 622 megabit per second Paragon network, and to extend the DOD`s ACTS ATM Internet from Sandia, New Mexico to the conference`s show floor in San Diego, California, for video demonstrations. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations supports Sandia`s overall strategies in ATM networking.

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Collaborating with human factors when designing an electronic textbook

Ratner, J.A.

The development of on-line engineering textbooks presents new challenges to authors to effectively integrate text and tools in an electronic environment. By incorporating human factors principles of interface design and cognitive psychology early in the design process, a team at Sandia National Laboratories was able to make the end product more usable and shorten the prototyping and editing phases. A critical issue was simultaneous development of paper and on-line versions of the textbook. In addition, interface consistency presented difficulties with distinct goals and limitations for each media. Many of these problems were resolved swiftly with human factors input using templates, style guides and iterative usability testing of both paper and on-line versions. Writing style continuity was also problematic with numerous authors contributing to the text.

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Rapid world modelling for robotics

Little, Charles

The ability to use an interactive world model, whether it is for robotics simulation or most other virtual graphical environments, relies on the users ability to create an accurate world model. Typically this is a tedious process, requiring many hours to create 3-D CAD models of the surfaces within a workspace. The goal of this ongoing project is to develop usable methods to rapidly build world models of real world workspaces. This brings structure to an unstructured environment and allows graphical based robotics control to be accomplished in a reasonable time frame when traditional CAD modelling is not enough. To accomplish this, 3D range sensors are deployed to capture surface data within the workspace. This data is then transformed into surface maps, or models. A 3D world model of the workspace is built quickly and accurately, without ever having to put people in the environment.

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The faradaic efficiency of the lithium-thionyl chloride battery

Hoier, S.N.; Eisenmann, E.T.

The efficiency of converting chemical energy into electrical energy has been studied for the case of D-size, low and medium rate lithium-thionyl chloride (Li/TC) cells, under DC and various pulsed loads. Microcalorimetric monitoring of the heat output during discharge allowed the direct measurement of the faradaic efficiency, and showed that self-discharge is far more pervasive than previously acknowledged by researchers and battery manufacturers. Evaluations of the cell dynamics prove that current load and temperature fluctuations combine to disrupt the lithium passivation and to greatly enhance self-discharge. Typical faradaic efficiencies for DC range from abut 30% at low current density to 90% at moderate and 75% at high current density. Pulsed current further depresses these efficiency levels, except at very low average current densities. The decreased faradaic efficiency of Li/TC batteries in certain pulse situations needs to be studied further to define the range of applications for which it can be successfully used.

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Proving refinement transformations using extended denotational semantics

Winter, V.L.

TAMPR is a fully automatic transformation system based on syntactic rewrites. Our approach in a correctness proof is to map the transformation into an axiomatized mathematical domain where formal (and automated) reasoning can be performed. This mapping is accomplished via an extended denotational semantic paradigm. In this approach, the abstract notion of a program state is distributed between an environment function and a store function. Such a distribution introduces properties that go beyond the abstract state that is being modeled. The reasoning framework needs to be aware of these properties in order to successfully complete a correctness proof. This paper discusses some of our experiences in proving the correctness of TAMPR transformations.

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Sodium/sulfur battery engineering for stationary energy storage. Final report

Braithwaite, J.W.

The use of modular systems to distribute power using batteries to store off-peak energy and a state of the art power inverter is envisioned to offer important national benefits. A 4-year, cost- shared contract was performed to design and develop a modular, 300kVA/300-kWh system for utility and customer applications. Called Nas-P{sub AC}, this system uses advanced sodium/sulfur batteries and requires only about 20% of the space of a lead-acid-based system with a smaller energy content. Ten, 300-VDC, 40-kWh sodium/sulfur battery packs are accommodated behind a power conversion system envelope with integrated digital control. The resulting design facilities transportation, site selection, and deployment because the system is quiet and non-polluting, and can be located in proximity to the load. This report contains a detailed description of the design and supporting hardware development performed under this contract.

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Destruction of explosives in groundwater and process water using photocatalytic and biological methods

Rodacy, Philip J.

The environmentally safe destruction of pinkwater is a significant problem that requires a multidisciplinary approach to solve. We have investigated the application of advanced oxidation processes, including the use of both UV light source and laser technologies. The reactions were run under both oxidizing and reducing atmospheres. Aerobic and anaerobic biotreatments were examined as both pre- and post-treatments to the oxidation processes. The toxicity of the wastewater at various stages of treatment was determined. Membrane preconcentration schemes were examined to determine their effectiveness as part of the total pinkwater treatment scheme.

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Environmental assessment for operations, upgrades, and modifications in SNL/NM Technical Area IV

Zawadzkas, Gerald A.

The proposed action for this EA for Sandia National Laboratories/New Mexico Technical Area IV, includes continuing existing operations, modification of an existing accelerator (Particle Beam Fusion Accelerator II) to support defnese-related Z-pinch experiments, and construction of two transformer oil storage tanks to support the expansion of the Advanced Pulsed Power Research Module, a single pulse accelerator. Based on the analyses in the EA, DOE believes that the proposed action is not a major federal action significantly affecting the quality of the human environment within the meaning of NEPA and CEQ NEPA implementing regulations in 40 CFR 1508.18 and 1508.27. Therefore, an environmental impact statement is not required, and a Finding of No Significant Impact is issued.

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Evaluation of intrusion sensors and video assessment in areas of restricted passage

Ringler, C.E.

This report discusses an evaluation of intrusion sensors and video assessment in areas of restricted passage. The discussion focuses on applications of sensors and video assessment in suspended ceilings and air ducts. It also includes current and proposed requirements for intrusion detection and assessment. Detection and nuisance alarm characteristics of selected sensors as well as assessment capabilities of low-cost board cameras were included in the evaluation.

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Laboratory evaluation of the IriScan prototype biometric identifier

Bouchier, F.; Ahrens, J.S.; Wells, G.

One thing that all access control applications have in common is the need to identify those individuals authorized to gain access to an area. Traditionally, the identification is based on something that person possesses, such as a key or badge, or something they know, such as a PIN or password. Biometric identifiers make their decisions based on the physiological or behavioral characteristics of individuals. The potential of biometrics devices to positively identify individuals has made them attractive for use in access control and computer security applications. However, no systems perform perfectly, so it is important to understand what a biometric device`s performance is under real world conditions before deciding to implement one in an access control system. This paper will describe the evaluation of a prototype biometric identifier provided by IriScan Incorporated. This identifier was developed to recognize individual human beings based on the distinctive visual characteristics of the irises of their eyes. The main goal of the evaluation was to determine whether the system has potential as an access control device within the Department of Energy (DOE). The primary interest was an estimate of the accuracy of the system in terms of false accept and false reject rates. Data was also collected to estimate throughput time and user acceptability. The performance of the system during the test will be discussed. Lessons learned during the test which may aid in further testing and simplify implementation of a production system will also be discussed.

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Lens designs for high irradiance application of multi-kilowatt Nd:YAG welding lasers

Keicher, David M.

Multi-kilowatt Nd:YAG lasers provide an appealing solution for aluminum laser welding applications due to increased bulk absorption and ease of beam delivery as compared to high power CO{sub 2} laser systems. However, high numerical aperture optics are required to overcome the relatively poor beam quality associated with these lasers and to achieve a high irradiance. Several lens designs have been developed and evaluated to achieve the high irradiance values required to provide good coupling into aluminum alloys. The results of these tests demonstrate that near diffraction limited performance can be achieved for high numerical aperture elements. Additionally, an inverse-telephoto lens design has been developed and characterized to further demonstrate the feasibility of producing a high irradiance with a functional working distance from the weld surface.

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High performance storage system at Sandia National Labs

Cahoon, R.M.

Scientific computing centers are acquiring large, distributed memory machines. With memory systems of .25 to 2.5 terabytes, these machines will deliver 1-10 teraflop computing capabilities. The need to move 10`s or 100`s of gigabytes, and the need to provide petabyte storage systems are issues that must be addressed before the year 2000. Work currently underway at Sandia addresses these issues. The High Performance Storage System (HPSS) is in limited production and the mass storage environment to support Sandia`s teraflop computer system is being constructed. 26 refs., 5 figs.

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Petrographic and X-ray diffraction analyses of selected samples from Marker Bed 139 at the Waste Isolation Pilot Plant

Fredrich, Joanne T.

The Waste Isolation Pilot Plant (WIPP) is located 660 m underground in the Salado Formation which consists of thick, horizontally bedded pure and impure salt and thin, laterally continuous clay and anhydrite interbeds. The Salado Two-Phase Flow Laboratory Program was established to provide site-specific-two-phase flow and other related rock properties to support performance assessment modeling of the WIPP repository. Owing to their potentially significant role in the hydrologic response of the repository, the program initially focused on the anhydrite interbeds, and in particular, on Marker Bed 139 (MB 139), which lies approximately 1 m below the planned waste storage rooms. This report synthesizes petrographic and X-ray powder diffraction studies performed to support the Salado Two-Phase Flow Laboratory Program. Experimental scoping activities in this area were performed in FY 1993 by three independent laboratories in order to: (1) quantify the mineral composition to support laboratory studies of hydrologic properties and facilitate correlation of transport properties with composition; (2) describe textures, including grain size; and (3) describe observed porosity. Samples from various depths were prepared from six 6-inch diameter cores which were obtained by drilling into the marker bed from the floor of two separate rooms. The petrographic analyses are augmented here with additional study of the original thin sections, and the pore structure observations are also examined in relation to an independent observational study of microcracks in Marker Bed 139 core samples performed in FY 1994 by the Geomechanics Department at Sandia National Laboratories.

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Effect of explicit representation of detailed stratigraphy on brine and gas flow at the Waste Isolation Pilot Plant

Webb, Stephen W.

Stratigraphic units of the Salado Formation at the Waste Isolation Pilot Plant (WIPP) disposal room horizon includes various layers of halite, polyhalitic halite, argillaceous halite, clay, and anhydrite. Current models, including those used in the WIPP Performance Assessment calculations, employ a ``composite stratigraphy`` approach in modeling. This study was initiated to evaluate the impact that an explicit representation of detailed stratigraphy around the repository may have on fluid flow compared to the simplified ``composite stratigraphy`` models currently employed. Sensitivity of model results to intrinsic permeability anisotropy, interbed fracturing, two-phase characteristic curves, and gas-generation rates were studied. The results of this study indicate that explicit representation of the stratigraphy maintains higher pressures and does not allow as much fluid to leave the disposal room as compared to the ``composite stratigraphy`` approach. However, the differences are relatively small. Gas migration distances are also different between the two approaches. However, for the two cases in which explicit layering results were considerably different than the composite model (anisotropic and vapor-limited), the gas-migration distances for both models were negligible. For the cases in which gas migration distances were considerable, van Genuchten/Parker and interbed fracture, the differences between the two models were fairly insignificant. Overall, this study suggests that explicit representation of the stratigraphy in the WIPP PA models is not required for the parameter variations modeled if ``global quantities`` (e.g., disposal room pressures, net brine and gas flux into and out of disposal rooms) are the only concern.

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Radioactive scrap metal decontamination technology assessment report

Schlienger, M.E.

Within the DOE complex there exists a tremendous quantity of radioactive scrap metal. As an example, it is estimated that within the gaseous diffusion plants there exists in excess of 700,000 tons of contaminated stainless steel. At present, valuable material is being disposed of when it could be converted into a high quality product. Liquid metal processing represents a true recycling opportunity for this material. By applying the primary production processes towards the material`s decontamination and re-use, the value of the strategic resource is maintained while drastically reducing the volume of material in need of burial. Potential processes for the liquid metal decontamination of radioactively contaminated metal are discussed and contrasted. Opportunities and technology development issues are identified and discussed. The processes compared are: surface decontamination; size reduction, packaging and burial; melting technologies; electric arc melting; plasma arc centrifugal treatment; air induction melting; vacuum induction melting; and vacuum induction melting and electroslag remelting.

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Computational implementation of a systems prioritization methodology for the Waste Isolation Pilot Plant: A preliminary example

Helton, J.C.; Anderson, D.R.; Baker, B.L.

A systems prioritization methodology (SPM) is under development to provide guidance to the US DOE on experimental programs and design modifications to be supported in the development of a successful licensing application for the Waste Isolation Pilot Plant (WIPP) for the geologic disposal of transuranic (TRU) waste. The purpose of the SPM is to determine the probabilities that the implementation of different combinations of experimental programs and design modifications, referred to as activity sets, will lead to compliance. Appropriate tradeoffs between compliance probability, implementation cost and implementation time can then be made in the selection of the activity set to be supported in the development of a licensing application. Descriptions are given for the conceptual structure of the SPM and the manner in which this structure determines the computational implementation of an example SPM application. Due to the sophisticated structure of the SPM and the computational demands of many of its components, the overall computational structure must be organized carefully to provide the compliance probabilities for the large number of activity sets under consideration at an acceptable computational cost. Conceptually, the determination of each compliance probability is equivalent to a large numerical integration problem. 96 refs., 31 figs., 36 tabs.

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Preliminary data from an instantaneous profile test conducted near the Mixed Waste Landfill, Technical Area 3, Sandia National Laboratories/New Mexico

Strong, Warren R.

This paper presents data from an instantaneous profile test conducted near the Sandia National Laboratories/New Mexico Mixed Waste Landfill in Technical Area 3. The test was performed from December 1993 through 1995 as part of the environmental Restoration Project`s Phase 2 RCRA Facility Investigation of the Mixed Waste Landfill. The purpose of the test was to measure the unsaturated hydraulic properties of soils near the Mixed Waste Landfill. The instantaneous profile test and instrumentation are described, and the pressure and moisture content data from the test are presented. These data may be useful for understanding the unsaturated hydraulic properties of soils in Technical Area 3 and for model validation, verification, and calibration.

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Adaptive Sampling approach to environmental site characterization at Joliet Army Ammunition Plant: Phase 2 demonstration

Thompson, Grace E.

Adaptive sampling programs provide real opportunities to save considerable time and money when characterizing hazardous waste sites. This Strategic Environmental Research and Development Program (SERDP) project demonstrated two decision-support technologies, SitePlanner{trademark} and Plume{trademark}, that can facilitate the design and deployment of an adaptive sampling program. A demonstration took place at Joliet Army Ammunition Plant (JAAP), and was unique in that it was tightly coupled with ongoing Army characterization work at the facility, with close scrutiny by both state and federal regulators. The demonstration was conducted in partnership with the Army Environmental Center`s (AEC) Installation Restoration Program and AEC`s Technology Development Program. AEC supported researchers from Tufts University who demonstrated innovative field analytical techniques for the analysis of TNT and DNT. SitePlanner{trademark} is an object-oriented database specifically designed for site characterization that provides an effective way to compile, integrate, manage and display site characterization data as it is being generated. Plume{trademark} uses a combination of Bayesian analysis and geostatistics to provide technical staff with the ability to quantitatively merge soft and hard information for an estimate of the extent of contamination. Plume{trademark} provides an estimate of contamination extent, measures the uncertainty associated with the estimate, determines the value of additional sampling, and locates additional samples so that their value is maximized.

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Recommendations for computer modeling codes to support the UMTRA groundwater restoration project

Tucker, Mark D.

The Uranium Mill Tailings Remediation Action (UMTRA) Project is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the US. The surface restoration phase, which includes containment and stabilization of the abandoned uranium mill tailings piles, has a specific termination date and is nearing completion. Therefore, attention has now turned to the groundwater restoration phase, which began in 1991. Regulated constituents in groundwater whose concentrations or activities exceed maximum contaminant levels (MCLs) or background levels at one or more sites include, but are not limited to, uranium, selenium, arsenic, molybdenum, nitrate, gross alpha, radium-226 and radium-228. The purpose of this report is to recommend computer codes that can be used to assist the UMTRA groundwater restoration effort. The report includes a survey of applicable codes in each of the following areas: (1) groundwater flow and contaminant transport modeling codes, (2) hydrogeochemical modeling codes, (3) pump and treat optimization codes, and (4) decision support tools. Following the survey of the applicable codes, specific codes that can best meet the needs of the UMTRA groundwater restoration program in each of the four areas are recommended.

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Ultraminiature resonator accelerometer

Koehler, D.R.

A new family of microminiature sensors and clocks is being developed with widespread application potential for missile and weapons applications, as biomedical sensors, as vehicle status monitors, and as high-volume animal identification and health sensors. To satisfy fundamental technology development needs, a micromachined clock and an accelerometer have initially been undertaken as development projects. A thickness-mode quartz resonator housed in a micromachined silicon package is used as the frequency-modulated basic component of the sensor family. Resonator design philosophy follows trapped energy principles and temperature compensation methodology through crystal orientation control, with operation in the 20--100 MHz range, corresponding to quartz wafer thicknesses in the 75--15 micron range. High-volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Chemical etching of quartz, as well as micromachining of silicon, achieves the surface and volume mechanical features necessary to fashion the resonating element and the mating package. Integration of the associated oscillator and signal analysis circuitry into the silicon package is inherent to the realization of a size reduction requirement. A low temperature In and In/Sn bonding technology allows assembly of the dissimilar quartz and silicon materials, an otherwise challenging task. Unique design features include robust vibration and shock performance, capacitance sensing with micromachined diaphragms, circuit integration, capacitance-to-frequency transduction, and extremely small dimensioning. Accelerometer sensitivities were measured in the 1--3 ppm/g range for the milligram proof-mass structures employed in the prototypes evaluated to date.

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A user`s guide to SABLE 2.0: The Sandia Automated Boolean Logic Evaluation software

Wyss, Gregory D.

This document is a reference guide for the Sandia Automated Boolean Logic Evaluation software (SABLE) version 2.0 developed at Sandia National Laboratories. SABLE 2.0 is designed to solve and quantify fault trees on IBM-compatible personal computers using the Microsoft Windows operating environment. SABLE 2.0 consists of a Windows user interface combined with a fault tree solution engine that is derived from the well-known SETS fault tree analysis code. This manual explains the fundamentals of solving fault trees and shows how to use the Windows SABLE 2.0 interface to specify a problem, solve the problem, and view the output.

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A viscoplastic theory for braze alloys

Neilsen, Michael K.

A new viscoplastic theory for CusilABA and other braze alloys has been developed. Like previous viscoplastic theories,this new theory uses a hyperbolic sine function of effective stress in its kinetic equation for the inelastic strain rate. This new theory has an internal state variable which accounts for isotropic hardening and recovery and a second-order, internal state tensor which accounts for kinematic hardening and recovery. Unlike previous theories, the new theory uses evolution equations for the state variables which describe competing mechanisms of power law hardening and static recovery. The evolution equations used in previous theories describe competing mechanisms of linear hardening, dynamic and static recovery. The new viscoplastic theory was implemented in several finite element codes and used in several metal-to-ceramic brazing simulations. Two approaches for obtaining material parameters for the new viscoplastic theory were developed.

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Simplified models of growth, defect formation, and thermal conductivity in diamond chemical vapor deposition

Coltrin, Michael E.

A simplified surface reaction mechanism is presented for the CVD of diamond thin films. The mechanism also accounts for formation of point defects in the diamond lattice, an alternate, undesirable reaction pathway. Both methyl radicals and atomic C are considered as growth precursors. While not rigorous in all details, the mechanism is useful in describing the CVD diamond process over a wide range of reaction conditions. It should find utility in reactor modeling studies, for example in optimizing diamond growth rate while minimizing defect formation. This report also presents a simple model relating the diamond point-defect density to the thermal conductivity of the material.

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Identifying industrial best practices for the waste minimization of low-level radioactive materials

Levin, V.

In US DOE, changing circumstances are affecting the management and disposal of solid, low-level radioactive waste (LLW). From 1977 to 1991, the nuclear power industry achieved major reductions in solid waste disposal, and DOE is interested in applying those practices to reduce solid waste at DOE facilities. Project focus was to identify and document commercial nuclear industry best practices for radiological control programs supporting routine operations, outages, and decontamination and decommissioning activities. The project team (DOE facility and nuclear power industry representatives) defined a Work Control Process Model, collected nuclear power industry Best Practices, and made recommendations to minimize LLW at DOE facilities.

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Modeling, system identification, and control for slosh-free motion of an open container of liquid

Feddema, John T.

This report discusses work performed under a Cooperative Research And Development Agreement (CRADA) with Corning, Inc., to analyze and test various techniques for controlling the motion of a high speed robotic arm carrying an open container of viscous liquid, in this case, molten glass. A computer model was generated to estimate the modes of oscillation of the liquid based on the shape of the container and the viscosity of the liquid. This fluid model was experimentally verified and tuned based on experimental data from a capacitive sensor on the side of the container. A model of the robot dynamics was also developed and verified through experimental tests on a Fanuc S-800 robot arm. These two models were used to estimate the overall modes of oscillation of an open container of liquid being carried by a robot arm. Using the estimated modes, inverse dynamic control techniques were used to determine a motion profile which would eliminate waves on the liquid`s surface. Experimental tests showed that residual surface waves in an open container of water at the end of motion were reduced by over 95% and that in-motion surface waves were reduced by over 75%.

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Ceramic powder synthesis in supercritical fluids

Adkins, Carol L.

Gas-phase processing plays an important role in the commercial production of a number of ceramic powders. These include titanium dioxide, carbon black, zinc oxide, and silicon dioxide. The total annual output of these materials is on the order of 2 million tons. The physical processes involved in gas-phase synthesis are typical of those involved in solution -phase synthesis: chemical reaction kinetics, mass transfer, nucleation, coagulation, and condensation. This report focuses on the work done under a Laboratory-Directed Research and Development (LDRD) project that explored the use of various high pressure techniques for ceramic powder synthesis. Under this project, two approaches were taken. First, a continuous flow, high pressure water reactor was built and studied for powder synthesis. And second, a supercritical carbon dioxide static reactor, which was used in conjunction with surfactants, was built and used to generate oxide powders.

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Guide to preparing SAND reports. Revised

Hurley, Mabel R.

This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

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Development of Green Box sensor module technologies for rail applications

Rey, D.

Results of a joint Sandia National Laboratories, University of New Mexico, and New Mexico Engineering Research Institute project to investigate an architecture implementing real-time monitoring and tracking technologies in the railroad industry is presented. The work, supported by the New Mexico State Transportation Authority, examines a family of smart sensor products that can be tailored to the specific needs of the user. The concept uses a strap-on sensor package, designed as a value-added component, integrated into existing industry systems and standards. Advances in sensor microelectronics and digital signal processing permit us to produce a class of smart sensors that interpret raw data and transmit inferred information. As applied to freight trains, the sensors` primary purpose is to minimize operating costs by decreasing losses due to theft, and by reducing the number, severity, and consequence of hazardous materials incidents. The system would be capable of numerous activities including: monitoring cargo integrity, controlling system braking and vehicle acceleration, recognizing component failure conditions, and logging sensor data. A cost-benefit analysis examines the loss of revenue resulting from theft, hazardous materials incidents, and accidents. Customer survey data are combined with the cost benefit analysis and used to guide the product requirements definition for a series of specific applications. A common electrical architecture is developed to support the product line and permit rapid product realization. Results of a concept validation, which used commercial hardware and was conducted on a revenue-generating train, are also reported.

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Sandia Airspace Recording System (SARS) software reference manual

Tenney, J.L.

SARS is a data acquisition system designed to gather and process radar data from aircraft flights. A database of flight trajectories has been developed for Albuquerque, NM, and Amarillo, TX. The data is used for safety analysis and risk assessment reports. To support this database effort, Sandia developed a collection of hardware and software tools to collect and post process the aircraft radar data. This document describes the data reduction tools which comprise the SARS, and maintenance procedures for the hardware and software system.

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Inside Sandia, April 1996

Locke, T.

Brief articles in this issue are entitled: New testing techniques, textiles on the information superhighway, and knowledge preservation; Structural health monitoring techniques and robust analysis tools assess aging and damaged structures; Sandia`s VCSELs (Vertical-Cavity Surface-Emitting Lasers): sparking a laser diode revolution; Fiber-optic instrumentation trims weeks off the wait for cervical cancer test results; DAMA (Demand Activated Manufacturing Architecture) project boosts competitiveness of US textile industry; SEAMIST (Science and Engineering Associates Membrane Instrumentation and Sampling Technique) cuts contamination cleanup costs; RePAVing the roads to the past (Relevant Point of Access Video); and Sandia receives DOE basic energy sciences award for sol-gel achievements.

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Materials and processes research and the information highway

Hurd, Alan J.

A workshop was held on April 12 and 13, 1996, to provide a forum for gathering information pertinent to using the information highway (the Internet and the World Wide Web) for materials and processes (M&P) research. The workshop`s objectives were to identify the priority needs of materials and processes researchers that could be addressed through the Internet, to describe the relevant capabilities of the information highway, to review existing applications of the highway in materials research and related fields for lessons learned, and to identify potential opportunities and key issues. The workshop was planned and organized by the Committee on Materials and Processes Research and the Information Highway, which was established by the National Materials Advisory Board (NMAB) of the National Research Council (NRC). The workshop was requested and sponsored by the Defense Reliance Technology Panel for Advanced Materials.

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Materials issues in lithium ion rechargeable battery technology

SAMPE Journal

Doughty, Daniel H.

Lithium ion rechargeable batteries are predicted to replace Ni/Cd as the workhorse consumer battery. The pace of development of this battery system is determined in large part by the availability of materials and the understanding of interfacial reactions between materials. Lithium ion technology is based on the use of two lithium intercalating electrodes. Carbon is the most commonly used anode material, while the cathode materials of choice have been layered lithium metal chalcogenides (LiMX2) and lithium spinel-type compounds. Electrolytes may be either organic liquids or polymers. Although the first practical use of graphite intercalation compounds as battery anodes was reported in 1981 for molten salt cells and, in 1983, for ambient temperature systems, it was not until Sony Energytech announced a new lithium ion intercalating carbon anode in 1990, that interest peaked. The reason for this heightened interest is that these electrochemical cells have the high energy density, high voltage, and light weight of metallic lithium, but without the disadvantages of dendrite formation on charge, improving their safety and cycle life This publication will review recent developments in the field and materials needs that will enhance future prospects for this important electrochemical system.

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Results 92601–92700 of 96,771
Results 92601–92700 of 96,771