Publications

Numerical simulations of perforation in steel plates involve the treatment of material failure during the perforation process. One way to model physical material separation is to delete failed elements from the analysis based on an appropriate failure criterion. Different algorithms were used in different transient finite element codes to delete failed elements. This investigation compares the results of PRONTO 2D and LS-DYNA2D codes for a specific steel plate perforation problem. Influences of the deletion algorithms on material parameters are discussed.

A framework for coupled elastoplastic and damage theories is developed, following a rigorous thermodynamic procedure. This framework is sufficiently general to include anisotropic plasticity and damage formulations. Both the plastic yield and damage functions are constructed using homogeneous functions of degree one. The principle of maximum dissipation or maximum entropy production is used to derive the evolution relations together with the loading and unloading conditions. In addition, the convexity of the undamaging elastic domain is shown. For plasticity the resulting evolution of the plastic strains corresponds to an associative flow. This general framework is shown to be sufficiently general to describe several popular theories for both plasticity and damage. Limitations of some existing damage theories are discussed.

Continuum damage theories describe the progressive reduction in stiffness and strength of brittle materials resulting from the initiation and growth of microcracks and microvoids. When brittle materials are loaded into the nonlinear regime, they often exhibit localized zones of intense deformation and the eventual formation of macrocracks. Criteria for diffuse and discontinuous bifurcations have previously been developed and used to study the initiation of necking and localization in elastic-plastic materials. In this investigation, the same bifurcation criteria are applied to continuum damage theories. Since the bifurcation criteria depend on the fourth-order tangent modulus tensor, the first step in this investigation is the derivation of the tangent modulus tensor for a general continuum damage theory. An eigenanalysis of the symmetric part of the tangent modulus tensor is then shown to fully characterize the potential diffuse and discontinuous bifurcations associated with a given continuum damage theory.

The motivation behind exchange I.2 of the USSR/US exchange program of cooperation for magnetic confinement fusion is to more closely simulate tokamak disruptions with a variety of plasma devices within the Soviet Union and the United States and to characterize the effect these simulated disruptions have on candidate PFC materials. Earlier work conducted in the Soviet Union by a team of Soviet and American researchers showed ablation of graphites exposed to a disruption like heat flux from a plasma flow was significantly less than that previously expected [J.M. Gahl et al., Proc. ICFRM-5, J. Nucl. Mater. 191-194 (1992) 454]. Work has continued and results from recent work at the University of New Mexico are in general agreement with earlier results from the Soviet Union. New results from work in the United States and the Soviet Union will be presented. © 1992 Elsevier Science Publishers B.V. All rights reserved.

This paper describes a current research program at Sandia National Laboratories whereby magnetic stripes are produced through the use of a new particle rotation technology. This new process allows the stripes to be produced in bulk and then held in a latent state so that they may be encoded at a later date. Since particle rotation is less dependent on the type of magnetic particle used, very high coercivity particles could provide a way to increase both magnetic tamper-resistance and accidental erasure protection. This research was initially funded by the Department of Energy, Office of Safeguard and Security as a portion of their Science and Technology Base Development, Advanced Security Concepts program. Current program funding is being provided by Sandia National Laboratories as part of their Laboratory Directed Research and Development program.

Given a graph G = (V, E) where each vertex v {element_of} V is assigned a weight w(v) and each edge e {element_of} E is assigned a cost c(e), the quotient of a cut partitioning the vertices of V into sets S and {bar S} is c(S, {bar S})/min{l_brace}w(S), w(S){r_brace}, where c(S, {bar S}) is the sum of the costs of the edges crossing the cut and w(S) and w({bar S}) are the sum of the weights of the vertices in S and {bar S}, respectively. The problem of finding a cut whose quotient is minimum for a graph has in recent years attracted considerable attention, due in large part to the work of Rao and Leighton and Rao. They have shown that an algorithm (exact or approximation) for the minimum-quotient-cut problem can be used to obtain an approximation algorithm for the more famous minimumb-balanced-cut problem, which requires finding a cut (S,{bar S}) minimizing c(S,{bar S}) subject to the constraint bW {le} w(S) {le} (1 {minus} b)W, where W is the total vertex weight and b is some fixed balance in the range 0 < b {le} {1/2}. Unfortunately, the minimum-quotient-cut problem is strongly NP-hard for general graphs, and the best polynomial-time approximation algorithm known for the general problem guarantees only a cut whose quotient is at mostO(lg n) times optimal, where n is the size of the graph. However, for planar graphs, the minimum-quotient-cut problem appears more tractable, as Rao has developed several efficient approximation algorithms for the planar version of the problem capable of finding a cut whose quotient is at most some constant times optimal. In this paper, we improve Rao`s algorithms, both in terms of accuracy and speed. As our first result, we present two pseudopolynomial-time exact algorithms for the planar minimum-quotient-cut problem. As Rao`s most accurate approximation algorithm for the problem -- also a pseudopolynomial-time algorithm -- guarantees only a 1.5-times-optimal cut, our algorithms represent a significant advance.

Advection-dominated flows occur widely in the transport of groundwater contaminants, the movements of fluids in enhanced oil recovery projects, and many other contexts. In numerical models of such flows, adaptive local grid refinement is a conceptually attractive approach for resolving the sharp fronts or layers that tend to characterize the solutions. However, this approach can be difficult to implement in practice. A domain decomposition method developed by Bramble, Ewing, Pasciak, and Schatz, known as the BEPS method, overcomes many of the difficulties. We demonstrate the applicability of the iterative BEPS ideas to finite-element collocation on trial spaces of piecewise Hermite bicubics. The resulting scheme allows one to refine selected parts of a spatial grid without destroying algebraic efficiencies associated with the original coarse grid. We apply the method to two dimensional time-dependent advection-diffusion problems.

The ability to design gating systems that reliably feed and support investment castings is often the result of ``cut-and-try`` methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channel thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.

This paper studied the behavior of retained system poles and transmission zeros in a control design model when the model is truncated. The sensitivity of the transmission zeros due to the tuncation of system dynamics was analytically obtained. The sensitivity of system poles to the truncation of system dynamics was shown to be zero as expected. The effects of actuator-sensor type and location was also studied. The results were illustrated with two example problems. The effect of transmission zero shifts in control design models and the controllers designed from them was illustrated with an example.

A telerobotic system demonstration was developed for the Department of Energy`s Accident Response group to highlight the applications of telerobotic vehicles to accident site inspection. The proof-of- principle system employs two mobile robots, Dixie and RAYBOT, to inspect a simulated accident site. Both robots are controlled serially from a single driving station, allowing an operator to take advantage of having multiple robots at the scene. The telerobotic system is described and some of the advantages of having more than one robot present are discussed. Future plans for the system are also presented.

This report will present a brief overview of the transient dynamics capabilities at Sandia National Laboratories, with an emphasis on recent new developments and current research. In addition, the Sandia National Laboratories (SNL) Engineering Analysis Code Access System (SEACAS), which is a collection of structural and thermal codes and utilities used by analysts at SNL, will be described. The SEACAS system includes pre- and post-processing codes, analysis codes, database translation codes, support libraries, Unix shell scripts for execution, and an installation system. SEACAS is used at SNL on a daily basis as a production, research, and development system for the engineering analysts and code developers. Over the past year, approximately 190 days of CPU time have been used by SEACAS codes on jobs running from a few seconds up to two and one-half days of CPU time. SEACAS is running on several different systems at SNL including Cray Unicos, Hewlett Packard HP-UX, Digital Equipment Ultrix, and Sun SunOS. An overview of SEACAS, including a short description of the codes in the system, will be presented. Abstracts and references for the codes are listed at the end of the report.

Computational mechanics simulation capability via the finite element method is being integrated into the FASTCAST project to allow realistic analyses of investment casting problems. Commercial and in-house software is being coupled to new, solid model based mesh generation capabilities to provide improved access to fluid, thermal and structural simulations. These simulations are being used for the validation of complex gating designs and the study of fundamental problems in casting.

A simple, approximate model of parachute inflation is described. The model is based on the traditional, practical treatment of the fluid resistance of rigid bodies in nonsteady flow, with appropriate extensions to accommodate the change in canopy inflated shape. Correlations for the steady drag and steady radial force as functions of the inflated radius are required as input to the dynamic model. In a novel approach, the radial force is expressed in terms of easily obtainable drag and reefing fine tension measurements. A series of wind tunnel experiments provides the needed correlations. Coefficients associated with the added mass of fluid are evaluated by calibrating the model against an extensive and reliable set of flight data. A parameter is introduced which appears to universally govern the strong dependence of the axial added mass coefficient on motion history. Through comparisons with flight data, the model is shown to realistically predict inflation forces for ribbon and ringslot canopies over a wide range of sizes and deployment conditions.

This document presents the quality assurance (QA) procedures for Parameter Selection and Expert Judgment Panels used by the performance Assessment Department of Sandia National Laboratories, which directly supports the Waste Isolation Pilot Plant (WIPP). Parameter Selection QA procedures described herein will be incorporated into the general Performance Assessment Quality Assurance Procedures, QAP 2-3; the Expert Judgment Panel procedures will be incorporated into QAP 2-6. Both sets of procedures will apply to all Sandia and Sandia contractor activities related to performance assessment (except where the contractor has its own approved QA procedures). This report presents the philosophy behind the QA procedures, provides the standards adopted for performance assessment Parameter Selection and Expert Judgment Panels, and discusses the implementation of these standards.

This 1991 report contains monitoring data from routine radiological and nonradiological environmental surveillance activities. Summaries of significant environmental compliance programs in progress such as National Environmental Policy Act (NEPA) documentation, environmental permits, environmental restoration (ER), and various waste management programs for Sandia National Laboratories in Albuquerque (SNL, Albuquerque) are included. The maximum offsite dose impact was calculated to be 1.3 {times} 10{sup {minus}3} mrem. The total population within a 50-mile radius of SNL, Albuquerque, received a collective dose of 0.53 person-rem during 1991 from SNL, Albuquerque, operations. As in the previous year, the 1991 operations at SNL, Albuquerque, had no discernible impact on the general public or on the environment.

This preliminary study analyzes the atmospheric entry of a solid core nuclear thermal rocket (NTR) engine under three accidental entry scenarios. Depending on the scenario, results of the analysis showed that, without external thermal protection, an aluminum pressure vessel will fail at altitudes ranging 25 to 73 km. subsequent release the core materials occurs. The graphitic based core materials will undergo partial ablation, with the percent mass loss depending on the geometry of the fuel elements. A carbon-phenolic thermal protection system was sized to prevent pressure vessel aerothermal failure. It was found to increase the mass of the NTR by approximately 15 percent.

This report examines containment requirements for spent-fuel transport containers that are transported under normal and hypothetical accident conditions. A methodology is described that estimates the probability of rod failure and the quantity of radioactive material released from breached rods. This methodology characterizes the dynamic environment of the cask and its contents and deterministically models the peak stresses that are induced in spent-fuel cladding by the mechanical and thermal dynamic environments. The peak stresses are evaluated in relation to probabilistic failure criteria for generated or preexisting ductile tearing and material fractures at cracks partially through the wall in fuel rods. Activity concentrations in the cask cavity are predicted from estimates of the fraction of gases, volatiles, and fuel fines that are released when the rod cladding is breached. Containment requirements based on the source term are calculated in terms of maximum permissible volumetric leak rates from the cask. Calculations are included for representative cask designs.

This report describes a mechanism for compiling the functional language SISAL for Sandia`s Epsilon-2 hybrid dataflow machine. The strategy couples the front-end of the standard SISAL compiler (which generates a data dependence graph intermediate form called IF1) with an optimizing code-generator for Epsilon-2. The Epsilon-2 code-generator is the back-end of a compiler for the functional language Id. It translates a data dependence graph intermediate form called Program Graphs into Epsilon-2 machine code. This report describes a translation path from IF1 graphs to Program Graphs. This report also comments on the relative merits of the IF1 and Program Graph representations.

This memorandum is a synopsis of the description and operation of the equipment used and the events accuring during the calibration of gauges on the vacuum station over the range of 0.0001 to 650 torr.

This report summarizes the environmental surveillance activities conducted by the US Environmental Protection Agency (EPA) and Reynolds Electrical and Engineering Company (REECO) for the Tonopah Test Range (TTR) operated by Sandia National Laboratories (SNL). Other environmental compliance programs such as the National Environmental Policy Act of 1969 (NEPA), environmental permits, environmental restoration, and waste management programs are also included. The 1991 SNL, TTR, operations had no discernible impact on the general public or the environment. This report 3-s prepared for the US Department of Energy (DOE) in compliance with DOE Order 5400.1.

Through a program sponsored by the US Department of Energy (DOE), Cummins Power Generation, Inc. (CPG) and Sandia National Laboratories (SNL) have entered into a joint venture to develop and commercialize economically competitive dish-Stirling systems for remote power applications. Sixteen systems, representing three generations of technology, will be developed, fielded, and tested in the Dish-Stirling Joint Venture Program (JVP). The JVP is funded equally by a consortium led by CPG and by the DOE. After completion of the program, CPG`s commercialization effort will continue with limited production expected to start in 1996. In this paper, the program plan and the technology used in the JVP are outlined. ne current status of the key system components, and the initial results of a system optimization study including current cost and performance estimates, are also provided.

Research in recent years has demonstrated the efficient use of solar thermal energy for driving endothermic chemical reforming reactions in which hydrocarbons are reacted to form syngas. Closed-loop reforming/methanation systems can be used for storage and transport of process heat and for short-term storage for peaking power generation. Open-loop reforming and gasification systems can be used for direct fuel production; for production of syngas feedstock for further processing to bulk ammonia, hydrogen, and liquid fuels; and for destruction of hazardous organic materials. To help identify the most promising areas for future development of this technology, we discuss in this paper the market potential of these applications.

FASTCAST is a Sandia National Laboratories program to produce investment cast prototypical hardware faster by integrating experimental and computational technologies into the casting process. FASTCAST uses the finite element method to characterize the metal flow and solidification processes to reduce uncertainty in the mold design. For the casting process to benefit from finite element analysis, analysis results must be available in a very short time frame. By focusing on the bottleneck of finite element model creation, automated mesh generation can drastically reduce the time span between geometry definition (design) and accurate analysis results. The increased availability of analysis results will diminish the need for trial and error approaches to acquiring production worthy mold and gating systems for investment casting. The CUBIT meshing tool kit is being developed to address the need for rapid mesh generation. CUBIT is being designed to effectively automate the generation of quadrilateral and hexahedral elements. It is a solid-modeler based, two- and three-dimensional preprocessor that prepares solid models for finite element analysis. CUBIT contains several meshing algorithms including two- and three-dimensional mapping, two- and three-dimensional paving (patented), and a general two and one-half dimensional sweeper based upon the plastering algorithm. This paper describes progress in the development of the CUBIT meshing toolkit.

The purpose of this NUREG is to provide technical information on the major components of entry control systems: identity verifiers, weapons detectors, explosives detectors, and special nuclear material (SNM) detectors. For each type of device, information is presented on principles of operation, hardware features, recommended installation, testing methods, and operational procedures. Applications to personnel, handcarried packages, bulk items, and vehicles are addressed.

We have investigated the chemistry of Cu(hfac){sub 2}, (hfac)Cu(VTMS), (hfac)Cu(2-butyne), and hfach on a Pt(111) surface. In contrast to what is observed on copper surfaces. Cu(hfac)2 and hfach lead to the formation of distinctly different adsorbed hfac species on Pt(111). This shows the importance of the copper atoms themselves in determining the surface chemistry of copper {beta}-diketonate CVD precursors. The hfac species on Pt(111) are considerably less stable than hfac on copper, suggesting that unimolecular decomposition may lead to impurity incorporation in the interfacial region when copper is deposited onto a more reactive substrate. In situ CVD studies with Cu(I) {beta}-diketonates show that the bimolecular disproportionation reaction leading to copper CVD is favored over unimolecular precursor decomposition at pressures above approximately 10{sup {minus}5} torr.

Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra. In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample.

Geologic materials are often modeled with discrete spheres because the material is not continuous and discrete spherical models simplify the mathematics. Spherical element models have been created using assemblages of spheres with a specified particle size distribution or by assuming the particles are all the same size and making the assemblage a close-packed array of spheres. Both of these approaches yield a considerable amount of material dilatation upon movement. This has proven to be unsatisfactory for sedimentary rock formations that contain bedding planes where shear movement can occur with minimal dilatation of the interface. A new concept referred to as packing angle has been developed to allow the modeler to build arrays of spheres that are the same size but have the rows of spheres offset from each other. ne row offset is a function of the packing angle and allows the modeler to control the dilatation as rows of spheres experience relative horizontal motion.

The fifth experiment of the Integral Effects Test (IET-5) series was conducted to investigate the effects of high pressure melt ejection on direct containment heating. Scale models of the Zion reactor pressure vessel (RPV), cavity, instrument tunnel, and subcompartment structures were constructed in the Surtsey Test Facility at Sandia National Laboratories. The RPV was modeled with a melt generator that consisted of a steel pressure barrier, a cast MgO crucible, and a thin steel inner liner. The melt generator/crucible had a hemispherical bottom head containing a graphite limiter plate with a 4-cm exit hole to simulate the ablated hole in the RPV bottom head that would be formed by ejection of an instrument guide tube in a severe nuclear power plant accident. The cavity contained 3.48 kg of water, and the basement floor inside the crane wall contained 71 kg of water, which corresponded to condensate levels in the Zion plant. A 43-kg initial charge of iron oxide/aluminium/chromium thermite was used to simulate corium debris on the bottom head of the RPV. Molten them-lite was ejected by 6.0 MPa of steam into the reactor cavity.

The purpose of this NUREG is to present technical information that should be useful for understanding and applying locking systems for physical protection and control. There are major sections on hardware for locks, vaults, safes, and security containers. Other topics include management of lock systems and safety considerations. this document also contains notes on standards and specifications and a glossary.

Creep tests were performed on a representative sample of rock salt from borehole Moss Bluff 2 (MB2), Moss Bluff dome near Houston, Texas. Moss Bluff 2 is located at the site of a compressed gas storage cavern of Tejas Power Corporation. Four triaxial experiments were conducted at two values of principal stress difference and two representative temperatures. The minimum observed creep rates at the end of each test varied between 5.2{times}10{sup {minus}9} 1/s and 2.14{times}10{sup {minus}8} 1/s. Comparisons of the present results with existing data for rock salt from other locations suggest that the steadystate creep characteristics of MB2 salt, depth 3349 ft (1098.8 m), are intermediate to those measured for the US Strategic Petroleum Reserve at West Hackberry and Bryan Hound, which included the most creep resistant rock salt ever tested at Sandia National Laboratories. Creep parameters are suggested for first-order sensitivity calculations.

The destruction of the Earth`s protective ozone layer is one of today`s largest environmental concerns. Solvent emissions released during the cleaning of printed wiring boards (PWBs) have been identified as a primary contributor to ozone destruction. No-clean soldering (sometimes referred to as self-cleaning) processes represent an ideal solution since they eliminate the need for cleaning after soldering. Elimination of solvent cleaning operations significantly reduces the emissions of ozone depleting chemicals (ODCs), reduces energy consumption, and reduces product costs. Several no-clean soldering processes have been developed over the past few years. The program`s purpose was to evaluate the no-clean soldering process and to determine if hardware produced by the process is acceptable for military applications. That is, determine if the no-clean process produces hardware that is as reliable as that soldered with the existing rosin-based flux solvent cleaning process.

Sandia National Laboratories performed random vibration and shock tests on a tritium hydride transport vessel that was packaged in an H1616-1 container. The objective of the tests was to determine if the hydride transport vessel remains leaktight under vibration and shock normally incident to transport, which is a requirement that the hydride transport vessel must meet to be shipped in the H1616-1. Helium leak tests before and after the vibration and shock tests showed that the hydride transport vessel remained leaktight under the specified conditions. There were no detrimental effects on the containment vessel of the H1616-1.

Sandia National Laboratories and ICI Explosives USA have worked together since 1987 to develop computer modeling techniques for Rock Blasting. A result of this effort is the computer program DMC (Distinct Motion Code) which was developed for two-dimensional simulation of rock motion following a blast (Taylor and Preece, 1989 & 1992). This program has been used to study blasting-induced rock motion resulting from oil shale mining and has been coupled with a gas flow computation capability for better treatment of the explosive behavior. This past year it has been customized for simulations of bench blasting in coat mines and rock quarries (Preece and Knudsen, 1992b). The explicit descretized nature of DMC gives it an advantage over previous blast modeling programs because subtle differences, such as row delay timing, have an influence on the results. This paper will present a DMC study of the influence on percent cast of row delay timing in a typical coal mine bench blast.

Choosing the appropriate conceptual model of contaminant transport from a hazardous waste site to the underlying aquifer will assist in designing efficient site investigation and remediation strategies. One method of collecting data to support a conceptual model is by comparing ground water sampling results to soil gas sampling results that are collected through existing monitoring wells. This underutilized data collection technique is quick, easy, and inexpensive. Comparing the soil gas results to ground water results can assist in supporting or refuting a conceptual model selection. In addition, soil gas sampling from existing monitoring wells may provide an early warning detection technique to impending ground water contamination. This approach is being implemented at the Chemical Waste Landfill at Sandia National Laboratories in Albuquerque, New Mexico.

The Recirculating Linear Accelerator (RLA) utilizes the Ion Focused Regime (IFR) of beam transport plus a ramped bending field to guide the beam around the curved sections. Several issues of beam transport are considered. Beam transverse perturbations that could result in growth of the ion hose instability are analyzed. It is found that transverse kicks due to bending field errors, energy mismatches and fringe fields are the most important. The scaling of these perturbations with beam and channel parameters is derived. The effect of ramping of the bending field on the preformed plasma channel is then considered. For RLA experimental parameters the effect is found to be very small. For high energies however, in addition to axial heating, it is found that ramping the field causes compression of the plasma channel along the radius of curvature. This compression results in a quasi-equilibrium plasma electron temperature along the field lines which leads to collisionless transport towards the walls. The analysis of compression is done in an approximate way using a single particle picture and the channel expansion is analyzed using an envelope solution which gives a simple expression for the expansion time. This solution is then verified by Buckshot simulations. For a bending field of 2 kG ramped in 2 {mu}-secs and an argon channel (RLA parameters) we estimate that the channel radius doubling time (along field lines) is of the order of 0.5 {mu}-secs. Finally the effect of electron impact ionization due to axially heated electrons by the action of the inductive field is estimated. It is found that in Argon gas the electron avalanche time could be as low as 0.5 {mu}-sec which is smaller than the field ramp time.

Piping penetrations in nuclear power plant steel containments are surrounded by flexible metal bellows. The purpose of the bellows is to maintain the containment pressure boundary integrity while permitting relative movement between the piping and the containment wall. In a severe accident, bellows may be subjected to high temperatures, pressure, and combinations of lateral and axial deflections. Sandia National Laboratories (SNL), under sponsorship of the Nuclear Regulatory Commission (NRC), is performing a series of tests to investigate the performance of containment bellows under severe accident conditions.

Radioactive spent fuel assemblies are a source of hazardous waste that will have to be dealt with in the near future. It is anticipated that the spent fuel assemblies will be transported to disposal sites in spent fuel transportation casks. In order to design a reliable and safe transportation cask, the maximum cladding temperature of the spent fuel rod arrays must be calculated. The maximum rod temperature is a limiting factor in the amount of spent fuel that can be loaded in a transportation cask. The scope of this work is to demonstrate that reasonable and conservative spent fuel rod temperature predictions can be made using commercially available thermal analysis codes. The demonstration is accomplished by a comparison between numerical temperature predictions, with a commercially available thermal analysis code, and experimental temperature data for electrical rod heaters simulating a horizontally oriented spent fuel rod bundle.

Prior work has shown that the piezoelectric response of shock-compressed PVDF film prepared with attention to mechanical and electrical processing exhibits precise, well-defined, reproducible behavior to 10 GPa. Higher pressure response continues to pressures approaching 50 GPa, and appears to provide a basis for a very high pressure stress-rate gauge. Previous work shows that differences in response were sometimes observed. The present report describes studies in progress undertaken to increase the precision of the polarization of the PVDF and to develop optimum sensors and shock gauge package designs. Results obtained on such careful prepared PVDF shock gauges show that differences in electrical charge response less than few percent are observed between 10 and 25 GPa.

Recent progress in the design, synthesis, and activity testing of catalysts for partial oxidation of light alkanes is described. The first testing results for the designed halogenated dodeca-substituted iron-porphyrin catalysts are presented. The results validate the design goals selected and suggest improvements to the current catalyst designs.

Space Nuclear Reactor Systems, especially those used for propulsion, often have expected operation run times much shorter than those for land-based nuclear power plants. This produces substantially different radionuclide inventories to be considered in the safety analyses of space nuclear systems. This presentation describes an analysis utilizing ORIGEN2 and DKPOWER to provide comparisons among representative land-based and space systems. These comparisons enable early, conceptual considerations of safety issues and features in the preliminary design phases of operational systems, test facilities, and operations by identifying differences between the requirements for space systems and the established practice for land-based power systems. Early indications are that separation distance is much more effective as a safety measure for space nuclear systems than for power reactors because greater decay of the radionuclide activity occurs during the time to transport the inventory a given distance. In addition, the inventories of long-lived actinides are very low for space reactor systems.

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests.

This report details the Science Fair Self-Help Development Program, which was initiated in a pilot project at three middle schools in Albuquerque, NM, during school year 1991-1992. The purpose of the program was to provide guidance to schools in developing their own parental and community resources into a sustainable support group whose major function would be to assist the school's science teachers and administration in all aspects of the science fair. The report documents the development of the Self-Help Program and the results of the pilot testing.

This document presents the quality assurance (QA) philosophy and procedures for analyses and report reviews used by the Performance Assessment Department of Sandia National Laboratories, which directly supports the Waste Isolation Pilot Plant (WIPP). Analysis procedures described herein will be incorporated into the Performance Assessment Analysis Quality Assurance Procedures (QAP 2-4), and report review procedures will be incorporated into QAP 2-5; both will apply to all Sandia and Sandia contractor activities related to performance assessment (except where the contractor has its own approved QA procedures). This report presents the philosophy behind the OA procedures, provides the standards adopted for performance assessment analysis and report review, discusses the implementation of these standards, and summarizes the software executive package, CAMCON, which aids in implementing the standards.

The choice of technologies for the delivery of very high bandwidth throughout a facility capable of ultimately achieving gigabits per second performance, is a crucial one for any high technology facility. The components of a high bandwidth delivery system include high performance sources and sinks in the form of central facilities (major mainframes, large file storage and specialized peripherals) and powerful, full bandwidth distributed local area networks (LANs). In order to deliver bandwidth among the sources and sinks, a ubiquitous inter-/intra-building cable plant consisting of single mode and multimode fiber as well as twisted pair copper is required. The selection of the ``glue`` to transport and interconnect the LANs with the central facility over the pervasive cable plant is the focus of this paper. A design philosophy for high performance communications systems is proposed. A description of the traditional problems that must be overcome to provide very high bandwidth beyond the narrow confines of a computer center is given. The advantages of ATM switching and SONET physical transport are explored in the structured design presentation. The applicability of Asynchronous Transfer Mode (ATM) switching (interconnection) and Synchronous Optical NETwork (SONET) (transport) for high bandwidth delivery is described using the environment and requirements of Sandia National Laboratories as a context to examine the suitability of those technologies. The synergy and utility of ATM and SONET in the campus network are explored. Other methods for distributing high data rates are compared and contrasted to ATM and SONET with respect to cable plant impact, reliability/availability, maintainability, and capacity. Sandia is implementing a standards based foundation utilizing a pervasive single mode fiber cable plant, SONET transport, and ATM switching to meet the goals of gigabit networking.

Aerospace components are often subjected to pyroshock events during flight and deployment, and must be qualified to this frequently severe environment. Laboratory simulation of pyroshock using a mechanically excited resonant fixture, has gained favor at Sandia for testing small (<8 inch cube) weapon components. With this method, each different shock environment required a different resonant fixture that was designed such that it`s response matched the environment. A new test method has been developed which eliminates the need to have a different resonant fixture for each test requirement. This is accomplished by means of a tunable resonant fixture that has a response which is adjustable over a wide frequency range. The adjustment of the fixture`s response is done in a simple and deterministic way. This report covers the first phase of this research, which includes design conception through fabrication and evaluation of hardware capable of testing components with up to a 10 inch {times} 10 inch base. This method will ultimately allow the testing of much larger items, perhaps as large as entire small satellites.

The application of the finite element method to problems in conduction and convection heat transfer is described. The formulation of the basic equations is presented for nonisothermal, incompressible, viscous flows and nonisothermal flows in porous media; typical solution algorithms for both transient and time-independent problems are described. Example analyses are included for problems in heat conduction, forced convection and free convection.

An exact two-dimensional solution is derived for determining the fluid flow rates into a borehole and to the surface from which the borehole was drilled. The solution is for a single fluid phase in a disturbed rock zone (DRZ) that surrounds the borehole with a radius specified to be either finite or infinite. The solution is restricted to constant homogeneous rock and fluid properties in the DRZ, and pressures in the borehole and at the surface of the drift that are maintained constant at ambient conditions. A major objective of the work is to provide a benchmark for more detailed numerical calculations that include variable physical properties and an arbitrary DRZ geometry. However in addition, this work extends previous exact solutions for one-dimensional flow by: (1) allowing for a DRZ of finite but arbitrary extent, (2) accounting for depressurization due to mining the drift before drilling the borehole, and (3) accounting for two-dimensional variations of the fluid pressure caused by simultaneous fluid flow to the drift and to the borehole.

This Manual was established in October 1992 to document the business processes used by the environment, safety, and health (ES&H) Training Department (7524) in providing services to internal Sandia National Laboratories (SNL) customers and to meet Tiger Team findings and milestones. This documentation will be revised as the department improves its processes. This manual implements the processes and procedures followed by the ES&H Training Department in support of the ES&H Training Program. The first part of the manual describes the corporate wide administrative process; the second part describes the department wide administrative process; and parts three, four, and five describe workgroup processes. Terms are defined in the Glossary at the back of the manual.

The application of the finite element method to problems in non-Newtonian fluid mechanics is described. The formulation of the basic equations is presented for both inelastic and viscoelastic constitutive models. Solution algorithms for treating the material nonlinearities associated with inelastic fluids are described; typical solution procedures for the implicit stress-rate equations of viscoelastic fluids are also presented. Methods for the simulation of various types of free-surface flows are also outlined. Simple example analyses are included for both types of fluid models.

In FY91, the Intelligent Machines Technologies Group at Sandia National Laboratories (SNL) developed a robotic prototype system that automates the removal of nuclear material from gloveboxes (called bagout) at Rocky Flats Plant (RFP). This work was funded by RFP and the Office of Security and Safeguards (OSS) at the Department of Energy (DOE) through the Facility Systems Engineering Department. With increasing concerns of dose reduction to meet ever-changing environmental, safety, and health (ES&H) standards, the need for an automated process to handle high-dose operations will increase. By removing the operators from the ``hands-on`` operation of bagout, the automated glovebox bagout (AGB) system reduces the dose. The automated platform uses a commercially available robot in combination with automated fixturing and computer control to provide a system that removes the material from the glovebox through the bag, seals the bag, and stores the bagged material into containers. Material waste is reduced by modifying the bagging process using an rf sealer instead of the conventional ``twist and tape`` method and by reducing the bag diameter used for bagout. Security and safeguards is achieved primarily by relieving the operator of handling the material. In addition, accountability for the special nuclear materials is achieved through verification of the procedure. Security measures designed against insider threat have also been developed.

A classic model of aerosol scrubbing from bubbles rising through water is applied to the decontamination of gases produced during core debris interactions with concrete. The model, originally developed by Fuchs, describes aerosol capture by diffusion, sedimentation, and inertial impaction. This original model for spherical bubbles is modified to account for ellipsoidal distortion of the bubbles. Eighteen uncertain variables are identified in the application of the model to the decontamination of aerosols produced during core debris interactions with concrete by a water pool of specified depth and subcooling. These uncertain variables include properties of the aerosols, the bubbles, the water and the ambient pressure. Ranges for the values of the uncertain variables are defined based on the literature and experience. Probability density functions for values of these uncertain variables are hypothesized. The model of decontamination is applied in a Monte Carlo sampling of the decontamination by pools of specified depth and subcooling. Results are analyzed using a nonparametric, order statistical analysis that allows quantitative differentiation of stochastic and phenomenological uncertainty. The sampled values of the decontamination factors are used to construct estimated probability density functions for the decontamination factor at confidence levels of 50%, 90% and 95%. The decontamination factors for pools 30, 50, 100, 200, 300, and 500 cm deep and subcooling levels of 0, 2, 5, 10, 20, 30, 50, and 70{degree}C are correlated by simple polynomial regression. These polynomial equations can be used to estimate decontamination factors at prescribed confidence levels.

Sandia National Laboratories has recently placed into production a mass storage system based on the UniTree{sup TM} Central File Manager software. this paper describes the current status of the system. Background information on the selection criteria is given and the hardware and software configurations are shown. The system has been in production since April, 1992 and the usage and performance statistics, as obtained thus far, are presented.

In previous years, a suite of interim models had been developed for the CONTAIN code for analyzing direct containment heating (DCH) accidents. The initial development and application of these DCH models are described in a previous WRS paper. While useful, these interim models were incomplete and were highly parametric. The parametric nature of the interim CONTAIN DCH models was necessary at the time because of the lack of relevant DCH experimental data, and to facilitate sensitivity studies aimed at improving our understanding of the most important governing processes in a DCH event. However, today our understanding of DCH phenomenology is significantly improved from when the interim DCH models were developed. This understanding largely stems from recently completed NRC-sponsored DCH experiments at Sandia National Laboratories and Argonne National Laboratory. New models have been developed and added to the CONTAIN code for modeling DCH events to reflect this improvement in our understanding of DCH. The purpose of this paper is to describe the new DCH models in CONTAIN. A demonstration of the new models by comparing simplified calculations against relevant DCH test data will also be presented in this paper. This paper is an extension of the preliminary descriptions of the DCH model improvements presented in the 19th WRS paper. The new models that have been added to CONTAIN for analyzing DCH are briefly discussed below. The following paragraphs also include brief discussions of the motivation and/or basis for the developed improvement. The models are described in greater detail in the full paper.

This report describes a full screen menu system developed using IBM`s Interactive System Productivity Facility (ISPF) and the REXX programming language. The software was developed for the 2800 IBM/VM Electrical Computer Aided Design (ECAD) system. The system was developed to deliver electronic drawing definitions to a corporate drawing release system. Although this report documents the status of the menu system when it was retired, the methodologies used and the requirements defined are very applicable to replacement systems.

A critical enabling technology in the evolutionary development of nuclear thermal propulsion (NTP) is the ability to predict the system performance under a variety of operating conditions. Since October 1991, US (DOE), (DOD) and NASA have initiated critical technology development efforts for NTP systems to be used on Space Exploration Initiative (SEI) missions to the Moon and Mars. This paper presents the strategy and progress of an interagency NASA/DOE/DOD team for NTP system modeling. It is the intent of the interagency team to develop several levels of computer programs to simulate various NTP systems. An interagency team was formed for this task to use the best capabilities available and to assure appropriate peer review. The vision and strategy of the interagency team for developing NTP system models will be discussed in this paper. A review of the progress on the Level 1 interagency model is also presented.

Laser two-focus (L2F) velocimetry has been used to measure particle velocities in the Wire Arc Plasma spray process. Particle velocities were measured for aluminum, stainless steel, and copper feedstock with wire diameters of 1.6 mm and 0.9 mm. The Wire Arc Plasma gun was operated in both a single-gas mode, using air, and in a two-gas mode, using a mixture of argon/35% hydrogen as the primary plasma gas with pure argon as the secondary gas. The results indicate that maximum particle velocities are as high as 180 m/s for aluminum sprayed using air and 130 m/s using the argon/hydrogen mixture. The results also show that arc current and wire feed rate have little effect on particle velocity; however, particle velocities increase significantly with decreasing wire diameter and with decreasing density of the feedstock material.

The computer programs SLAAP and DATA are currently being used by Division 2743 for data analysis. These programs had not been previously verified to determine if they were producing correct results. The objective of the study described in this report was to verify these programs by comparing their results to those obtained with GRAFAID, a verified data analysis program. To accomplish this, five acceleration-time histories were selected. For each time history, the shock response spectrum, integral, double integral, derivative and Fourier transform were computed using SLAAP, DATA and GRAFAID. The results of each operation for each time history were overlay plotted for comparison. The results show only minor differences in some cases. These differences are deterministic and are due to differences in the algorithms or block size restrictions of the three programs.

Experimental and analytical studies have been conducted to investigate gas, particle, and coating dynamics in the vacuum plasma spray (VPS) process for a tungsten powder. VPS coatings were examined metallographically and the results compared with the model`s predictions. The plasma was numerically modeled from the cathode tip to the spray distance in the free plume for the experimental conditions of this study. This information was then used as boundary conditions to solve the particle dynamics. The predicted temperature and velocity of the powder particles at standoff were then used as initial conditions for a coating dynamics code. The code predicts the coating morphology for the specific process parameters. The predicted characteristics exhibit good correlation with the observed coating properties.

The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

This paper addresses the problem of manipulation planning in the presence of uncertainty. We begin by reviewing the worst-case planning techniques introduced in and show that these methods are hampered by an information gap inherent to worst-case analysis techniques. As the task uncertainty increases, these methods fail to produce useful information even though a high-quality plan may exist. To fill this gap, we present the probabilistic backprojection, which describes the likelihood that a given action will achieve the task goal from a given initial state. We provide a constructive definition of the probabilistic backprojection and related probabilistic models of manipulation task mechanics, and show how these models unify and enhance several past results in manipulation planning. These models capture the fundamental nature of the task behavior, but appear to be very complex. Methods for computing these models are sketched, but efficient computational methods remain unknown.

Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. To function as a one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Columb Energy network (RCE). The ART 2-A neural network has given the best results, with 100% within-class, and out-of-class generalization. Experiments show that the network`s performance is sensitive to vigilance and number of training set presentations.

Microwave parameters drifted significantly for two out of twenty- nine GaAs MESFET-based MMICs during ten weeks of storage at 125{degrees}C and 150{degrees}C. Analysis using measured, post- storage, FET characteristics and the microwave behavior indicates that all of the FETs in the MMICs drifted, most likely due to contamination.

Early solution miners encountered occasional difficulties with nonsymmetric caverns (including ``wings`` and ``chimneys``), gas releases, insoluble stringers, and excessive anhydrite ``sands.`` Apparently there was no early recognition of trends for these encounters, although certain areas were avoided after problems appeared consistently within them. Solution mining has now matured, and an accumulation of experience indicates that anomalous salt features occur on a number of Gulf Coast domes. Trends incorporating concentrations of anomalous features will be referred to as ``anomalous zones,`` or AZs (after Kupfer). The main objective of this Project is to determine the effects of AZ encounters on solution-mined caverns and related storage operations in domes. Geological features of salt domes related directly to cavern operations and AZs will be described briefly, but discussions of topics related generally to the evolution of Gulf Coast salt structures are beyond the scope of this Project.

Measurements of the effects of pressure on the thermal electron emission rate and capture cross section for a variety of deep electronic levels in GaAs, GaP and their alloys have yielded the pressure dependences of the energies of these levels in the bandgaps, allowed evaluation of the breathing mode lattice relaxations accompanying carrier emission or capture by these levels and revealed trends which lead to new insights into the nature of the responsible defects. Emphasis is on deep levels believed to be associated with simple defects. Specifically, results will be summarized for the donor levels of the dominant native defect known as EL2 in CAM, which is believed to be associated with the arsenic antisite, and on the radiation-induced El and E2 levels in GaAs, GaP and their alloys, which are believed to be due to arsenic (or phosphorous) vacancies. The results are discussed in terms of models for the defects responsible for these deep levels.

Applications for the controlled thermal expansion alloy Fe-29Ni-17Co often require joining by fusion welding processes. In addition, these applications usually require hermetic and high reliability joints. The small size of typical components normally dictates the use of autogenous welding processes, so that the hot cracking tendency of Fe-29Ni-17Co is of concem. The solidification behavoir and hot cracking tendency of commercial Fe-29Ni-17Co has been evaluated using diffcrential thermal analysis (DTA), Varestraint testing, light and electron microscopy, and laser welding trials. DTA and microstructural analysis indicated that the solidification of Fe-29Ni-17Co occurs as single phase austenite, does not exhibit the formation of terminal solidification phases, and results in only minimal segregation of major alloying elements. Varestraitit testing indicated that the hot cracking behavior of Fe-29Ni-17Co is similar to, though somewhat more pronounced than, 304L and 316 stainless steels. Relative to other Fe-Ni-Co and Ni-based alloys, however, the hot cracking response of this alloy is fiverable. Pulsed laser welding trials indicated that the phosphorus and sulfur levels in this heat of Fe-29Ni-17Co were insufficient to pmmote cracking in bead-on-plate welds.

High energy electron beam accelerator technology has been developed over the past three decades in response to military and energy-related requirements for weapons simulators, directed-energy weapons, and inertially-confined fusion. These applications required high instantaneous power, large beam energy, high accelerated particle energy, and high current. These accelerators are generally referred to as ``pulsed power`` devices, and are typified by accelerating potential of millions of volts (MV), beam current in thousands of amperes (KA), pulse duration of tens to hundreds of nanoseconds, kilojoules of beam energy, and instantaneous power of gigawatts to teffawatts (10{sup 9} to 10{sup 12} watts). Much of the early development work was directed toward single pulse machines, but recent work has extended these pulsed power devices to continuously repetitive applications. These relativistic beams penetrate deeply into materials, with stopping range on the order of a centimeter. Such high instantaneous power deposited in depth offers possibilities for new material fabrication and processing capabilities that can only now be explored. Fundamental techniques of pulse compression, high voltage requirements, beam generation and transport under space-charge-dominated conditions will be discussed in this paper.

The Remote Security Station (RSS) was developed by Sandia National Laboratories for the Defense Nuclear Agency to investigate issues pertaining to robotics and sensor fusion in physical security systems. This final report documents the status of the RSS program at its completion in April 1992. The RSS system consists of the Man Portable Security Station (MaPSS) and the Telemanaged Mobile Security Station (TMSS), which are integrated by the Operator`s Control Unit (OCU) into a flexible exterior perimeter security system. The RSS system uses optical, infrared, microwave, and acoustic intrusion detection sensors in conjunction with sensor fusion techniques to increase the probability of detection and to decrease the nuisance alarm rate of the system. Major improvements to the system developed during the final year are an autonomous patrol capability, which allows TMSS to execute security patrols with limited operator interaction, and a neural network approach to sensor fusion, which significantly improves the system`s ability to filter out nuisance alarms due to adverse weather conditions.

The In Situ Permeable Flow Sensor, a new technology which uses a thermal perturbation technique to directly measure the 3-dimensional groundwater flow velocity vector at a point in permeable, unconsolidated geologic formations, has been used to monitor changes in the groundwater flow regime around an experimental air stripping waste remediation activity. While design flaws in the first version of the technology, which were used during the experiment being reported here, precluded measurements of the horizontal component of the flow velocity, measurements of the vertical component of the flow velocity were obtained. Results indicate that significant changes in the vertical flow velocity were induced by the air injection system. One flow sensor, MHM6, measured a vertical flow velocity of 4 m/yr or less when the air injection system was not operating and 25 m/yr when the air injection system was on. This may be caused by air bubbles moving past the probes or may be the result of the establishment of a more widespread flow regime in the groundwater induced by the air injection system. In the latter case, significantly more groundwater would be remediated by the air stripping operation since groundwater would be circulated through the zone of influence of the air injection system. Newly designed flow sensors, already in the ground at Savannah River to monitor Phase II of the project, are capable of measuring horizontal as well as vertical components of flow velocity.

In previous work, failure of early versions of the zinc/bromine battery was traced to degradation and warpage of the carbon-plastic electrode. These electrodes were fabricated from copolymers of ethylene and propylene (EP) containing structures that were found to be susceptible to degradation by the electrolyte. In this work, we evaluated two developmental electrodes from Johnson Controls Battery Group, Inc., in which the EP copolymer was replaced with a high-density polyethylene (HDPE) that contained glass-fiber reinforcing fillers. The glass fiber content of these two electrodes was different (19% vs. 31%). We determined the effect of electrolyte on sorption behavior, dimensional stability, chemical stability, and thermal, mechanical, and electrical properties under real-time and accelerated aging conditions. We also characterized unaged samples of both electrodes to determine their chemical composition and physical structure. We found that high glass content in the electrode minimizes sorption and increases dimensional stability. Both high and low glass content electrodes were found to be chemically and thermally stable toward the electrolyte. A slight decrease in the storage modulus (G{prime}) of both electrodes was attributed to sorption of non-ionic and hydrophobic ingredients in the electrolyte. The electrical conductivity of both electrodes appeared to improve (increase) upon exposure to the electrolyte. No time or temperature trends were observed for the chemical, thermal, or mechanical properties of electrodes made from HDPE. Since decreases in these properties were noted for electrodes made from EP copolymers under similar conditions, it appears that the HDPE-based electrodes have superior long-term stability in the ZnBr{sub 2} environment.

Hydrostatic and constant-stress-difference (CSD) experiments were conducted at RT on 3 different sintering runs of unpoled, Nb-doped lead-zirconate-titanate ceramic (PZT 95/5-2Nb) in order to quantify influence of shear stress on displacive, martensitic-like, first-order, rhombohedral {r_arrow} orthorhombic phase transformation. In hydrostatic compression at RT, the transformation began at about 260 MPa, and was usually incompletely reversed upon return to ambient. Strains associated with the transformation were isotropic, both on first and subsequent hydrostatic cycles. Results for CSD tests were quite different. First, the confining pressure and mean stress at which the transition begins decreased linearly with increasing stress difference. Second, the rate of transformation decreased with increasing shear stress and the accompanying purely elastic shear strain. This contrasts with the typical observation that shear stresses increase reaction and transformation kinetics. Third, strain was not isotropic during the transformation: axial strains were greater and lateral strains smaller than for the hydrostatic case, though volumetric strain behavior was comparable for the two types of tests. However, this effect does not appear to be an example of true transformational plasticity: no additional unexpected strains accumulated during subsequent cycles through transition under nonhydrostatic loading. If subsequent hydrostatic cycles were performed on samples previously run under CSD conditions, strain anisotropy was again observed, indicating that the earlier superimposed shear stress produced a permanent mechanical anisotropy in the material. The mechanical anisotropy probably results from a ``one-time`` crystallographic preferred orientation that developed during the transformation under shear stress. Finally, in a few specimens from one particular sintering run, sporadic evidence for a ``shape memory effect`` was observed.

This document contains the planned actions to correct the deficiences identified in the Tiger Team Assessments of Sandia California (August 1990) and Sandia New Mexico (May 1991). Information is also included on the management structures, estimated costs, root causes, prioritization and schedules for the Action Plan. This Plan is an integration of the two individual Action Plans to provide a cost effective, integrated program for implemenation by Sandia and monitoring by DOE. This volume (2) contains information and corrective action plans pertaining to safety and health and management practices.

A Level III Probabilistic Risk Assessment (PRA) has been performed for LaSalle Unit 2 under the Risk Methods Integration and Evaluation Program (RMIEP) and the Phenomenology and Risk Uncertainty Evaluation Program (PRUEP). This report documents the phenomenological calculations and sources of. uncertainty in the calculations performed with HELCOR in support of the Level II portion of the PRA. These calculations are an integral part of the Level II analysis since they provide quantitative input to the Accident Progression Event Tree (APET) and Source Term Model (LASSOR). However, the uncertainty associated with the code results must be considered in the use of the results. The MELCOR calculations performed include four integrated calculations: (1) a high-pressure short-term station blackout, (2) a low-pressure short-term station blackout, (3) an intermediate-term station blackout, and (4) a long-term station blackout. Several sensitivity studies investigating the effect of variations in containment failure size and location, as well as hydrogen ignition concentration are also documented.

This volume presents the results of the initiating event and accident sequence delineation analyses of the LaSalle Unit II nuclear power plant performed as part of the Level III PRA being performed by Sandia National Laboratories for the Nuclear Regulatory Commission. The initiating event identification included a thorough review of extant data and a detailed plant specific search for special initiators. For the LaSalle analysis, the following initiating events were defined: eight general transients, ten special initiators, four LOCAs inside containment, one LOCA outside containment, and two interfacing LOCAs. Three accident sequence event trees were constructed: LOCA, transient, and ATWS. These trees were general in nature so that a tree represented all initiators of a particular type (i.e., the LOCA tree was constructed for evaluating small, medium, and large LOCAs simultaneously). The effects of the specific initiators on the systems and the different success criteria were handled by including the initiating events directly in the system fault trees. The accident sequence event trees were extended to include the evaluation of containment vulnerable sequences. These internal event accident sequence event trees were also used for the evaluation of the seismic, fire, and flood analyses.

Sequential indicator simulation (SIS) is a geostatistical technique designed to aid in the characterization of uncertainty about the structure or behavior of natural systems. This report discusses a simulation experiment designed to study the quality of uncertainty bounds generated using SIS. The results indicate that, while SIS may produce reasonable uncertainty bounds in many situations, factors like the number and location of available sample data, the quality of variogram models produced by the user, and the characteristics of the geologic region to be modeled, can all have substantial effects on the accuracy and precision of estimated confidence limits. It is recommended that users of SIS conduct validation studies for the technique on their particular regions of interest before accepting the output uncertainty bounds.

In 1992, NIST announced a proposed standard for a collision-free hash function. The algorithm for producing the hash value is known as the Secure Hash Algorithm (SHA), and the standard using the algorithm in known as the Secure Hash Standard (SHS). Later, an announcement was made that a scientist at NSA had discovered a weakness in the original algorithm. A revision to this standard was then announced as FIPS 180-1, and includes a slight change to the algorithm that eliminates the weakness. This new algorithm is called SHA-1. In this report we describe a portable and efficient implementation of SHA-1 in the C language. Performance information is given, as well as tips for porting the code to other architectures. We conclude with some observations on the efficiency of the algorithm, and a discussion of how the efficiency of SHA might be improved.

Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propulsion (SNTP) program. Some preliminary results of evaluating this facility for use in testing other NTP concepts are also summarized.

Developing security plans and supporting security tests is a very important part of the Department of Energy accreditation process. This paper will discuss the general testing methodology that was used to achieve DOE accreditation of the Secure UNICOS environment at Sandia National Laboratories, Albuquerque. In addition, some specific security testing procedures, test and problem areas will be described.

A formulation is given of constitutive equations valid for large deformations for materials with elastic range and internal state variables intended to describe the internal structure of the material. A material description is used to construct a purely mechanical theory which largely follows that of Carroll. The assumption that the work done in finite closed cycles of homogeneous deformation is non-negative leads to an elastic potential and a dissipation inequality which, in turn, implies a normality condition, by an argument adapted from that of Lin and Naghdi. When the theory is generalized to include temperature dependence, the Clausius-Duhem inequality leads by well-known arguments to an elastic potential and nonnegative dissipation. Rate effects are included by assuming that the inelastic strain rate is a function of the dynamic overstress, but the results of the work assumption or the thermodynamic argument are unchanged. Some remarks regarding implications for stability are made.

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the different methods to handle effluent from nuclear thermal propulsion system ground tests.

Three dimensional multichip modules (MCMS) present an unusual challenge to the thermal designer. For example, high thermal resistance between upper planes of the MCM and the thermally anchored bottom plane can lead to the development of excessive temperatures. As new designs emerge, it becomes desirable to have methods of experimentally determining interior temperatures in the module in order to validate complex finite element calculations. In order to develop methods for assessing the thermal performance of a 3D MCM, we have developed a test module with three planes or slices. In this paper, we report on some initial calculations and measurements for the 3D MCM. In addition, we discuss the improvement in thermal performance obtained by replacing the top slice with a diamond substrate. Finite element method (FEM) thermal calculations have been done with both the workstation based analyzer P/Thermal from PDA Engineering and the PC program, Inertia from Modern Computer Aided Engineering. These analyses have assumed no heat losses by radiation or convection.

This report describes the linearly-polarized, loaded cavity-backed slot (LCBS) antenna developed for Reentry Vehicles (RVs) and the development process used by the Antenna Development Department. It includes typical antenna engineering design considerations or requirements, fabrication/assembly process, and performance characteristics. Antenna design theory is reduced to the basic concepts useful in designing LCBS antennas for reentry vehicles.

This document describes the components necessary to put together a video animation system. It is primarily intended for use at Sandia National Laboratories as it describes the components used in systems at Sandia. The main document covers the operation of the equipment in some detail and is intended for either the system maintainer or an advanced user. There is an appendix for each of the three systems in use by the Engineering Sciences Directorate which contain instructions for the general user.

A series of experiments has been performed on the Sandia HyperVelocity Launcher (HVL) to evaluate the effectiveness of a Whipple bumper shield to orbital space debris at impact velocities in excess of 10 km/s. Upon impact by a 0.67 g (0.87 mm thick) flier plate, the thin aluminum bumper shield disintegrates into a debris cloud. The debris cloud front propagates axially at velocities of [approximately]14 km/s and expands radially at a velocity of [approximately]7 km/s. Subsequent loading on a 3.2 mm thick aluminum substructure by the debris penetrates the substructure completely. However, when the mass of the flier plate is reduced to 0.33 g, the substructure, although damaged, is not perforated over the duration of the experiment. Numerical simulations performed using the multi-dimensional hydrodynamics code CTH also predict complete penetration of the substructure by the subsequent debris cloud for a 0.87 g flier plate. The numerical simulations for a 0.33 g flier plate show a strong dependence on assumed impact geometry. For the assumption of a spherical projectile impact geometry, perforation of the substructure by the subsequent debris cloud is not predicted by CTH.

This study involved the shock characterization of Diallyl Phthalate (DAP), in particular, the equation of state as measured by the shock Hugoniot. Tests were done between 1 and 11 GPa impact shock pressure. The Hugoniot parameters were determined to be: [rho][sub 0]= 1.743, C[sub 0] = 2.20, and S = 2.33.

Nuclear power plants have experienced inadvertent actuations of fire protection systems (FPS) under conditions for which these systems were not intended to actuate. They have also experienced advertent actuations with the presence of a fire. These actuations have often damaged plant equipment. This document provides a review of the impact of past occurrences of both types of such events on nuclear power plant safety. Thirteen different scenarios leading to actuation of fire protection systems due to a variety of causes were identified. These scenarios ranged from inadvertent actuation caused by human error to hardware failure and includes seismic root causes and seismic/fire interaction. A quantification of these thirteen scenarios, where applicable, was performed on a Babcock and Wilcox Pressurized Water Reactor (lowered loop design). This report estimates the contribution of FPS actuations to core damage frequency and to risk.

Efficient use of a distributed memory parallel computer requires that the computational load be balanced across processors in a way that minimizes interprocessor communication. We present a new domain mapping algorithm that extends recent work in which ideas from spectral graph theory have been applied to this problem. Our generalization of spectral graph bisection involves a novel use of multiple eigenvectors to allow for division of a computation into four or eight parts at each stage of a recursive decomposition. The resulting method is suitable for scientific computations like irregular finite elements or differences performed on hypercube or mesh architecture machines. Experimental results confirm that the new method provides better decompositions arrived at more economically and robustly than with previous spectral methods. We have also improved upon the known spectral lower bound for graph bisection.

An inductively heated experiment SURC-1, using UO[sub 2]-ZrO[sub 2] material, was executed to measure and assess the thermal, gas, and aerosol source terms produced during core debris/concrete interactions. The SURC-1 experiment eroded a total of 27 cm of limestone concrete during 130 minutes of sustained interaction using 204.2 kg of molten prototypic UO[sub 2]-ZrO[sub 2] core debris material that included 18 kg of zr metal and 3.4 kg of fission product simulants. The melt pool temperature ranged from 2100 to 2400[degrees]C during the first 50 minutes of the test, followed by steady temperatures of 2000 to 2100[degrees]C during the middle portion of the test and temperatures of 1800 to 2000[degrees]C during the final 50 minutes of testing. The total erosion during the first 50 minutes was 16 cm with an additional 2 cm during the middle part of the test and 9 cm of ablation during the final 50 minutes. Aerosols were continuously released in concentrations ranging from 30 to 200 g/m[sup 3]. Comprehensive gas flow rates, gas compositions, and aerosol compositions were also measured during the SURC-1 test.

This document describes a panel discussion held on March 18, 1992 as part of a conference entitled Market Hub Technology'' . The purpose of the conference was to stimulate dialogue among various segments of the natural gas industry on the technology limits of an economic policy issue that has the potential to significantly alter the structure and functioning of the natural gas industry. Attendees included key US gas industry representatives, Federal Energy Regulatory Commission (FERC) commissioners, and others. The conference explored the concept of market centers, or hubs, and related technologies. It covered the technology currently available for the establishment of an integrated system of physical market hubs, and explored technology requirements for the further development of useful and efficient hubs. The discussion identified two primary barriers to the acceptance and implementation of a market center distribution system for natural gas. The first barrier is the potential change in the configuration of the market such a system would introduce and the resistance various industry segments would mount to such change. The second is the lack of industry standardization in the physical and business infrastructures.

A single EMCH concentrator module for the Photovoltaics for Utility Scale Application (PVUSA), Emerging Technologies-1 (EMT-1) program has been electrically and environmentally tested to the requirements in Sandia's SAND86-2743 document Qualification Tests for Photovoltaic Concentrator Cell Assemblies; and Modules.'' Module testing was divided into three parts: (1) initial characterization, (2) environmental testing, and (3) supplemental testing. Testing began with module inspection for damage, adequate name plate information, grounding off-axis beam damage, and baseline electrical performance. The included thermal cycling, humidity/freeze cycling, rainwater intrusion, and hail impact, and hi-pot testing. After both thermal cycling and environmental testing, the module was electrically tested. The supplemental testing not required by the Sandia qualification document was conducted for engineering evaluation. These tests included wet insulation resistance measurements and cell temperature measurements after installation of heat sink fin extensions. The test sequence revealed some module deficiencies which include RTV adhesive/sealant problems, high cell temperatures, off-track beam damage, and low wet insulation resistance values.

SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program to simulate the integrated performance of systems involving fluid mechanics, heat transfer, and reactor dynamics. SAFSIM provides sufficient versatility to allow the engineering simulation of almost any system, from a backyard sprinkler system to a clustered nuclear reactor propulsion system. In addition to versatility, speed and robustness are primary goals of SAFSIM. SAFSIM contains three basic physics modules: (1) a one-dimensional finite element fluid mechanics module with multiple flow network capability; (2) a one-dimensional finite element structure heat transfer module with multiple convection and radiation exchange surface capability; and (3) a point reactor dynamics module with reactivity feedback and decay heat capability. SAFSIM can be used for gas (compressible) or liquid (incompressible) single-phase flow systems with primary emphasis on gases (or supercritical fluids). This document contains a description of all the information required to create an input file for SAFSIM execution.

This report describes the features of monolithic, series connected photovoltaic converters which have been developed for applications where voltages are required that are higher than available using conventional single junction solar cells. These devices are intended to play a significant role in advanced weapon systems development. They are also appropriate for any other applications where electric power is needed in remote regions and electrical connection to the region is deemed detrimental for whatever reasons. Development of this technology at two outside contractors has been accomplished through competitive procurement in response to an internally generated Statement of Work. Detailed comparisons are made of data taken from converters of each type from both contractors. The primary advantage of these converters is that they are high voltage/low current devices compared to conventional single junction solar cells. This allows them to directly drive a wider range of loads without the necessity of power conditioning, such as provided by a transformer. Discussions of load analysis for given applications are included.

This report describes the SE3158 design and development tester that was designed by Digital Subsystem III Division 2314 at Sandia to support the development of the MC4073 SRAM II Programmer. The primary purpose of the SE3158 is to test the MC4073 SRAM II Programmer during its development phase.

Thermochemical data fits for approximately 900 gaseous and 600 condensed species found in the JANAF tables (Chase et al. 1985) have been completed for use with the TIGER non-ideal thermoequilibrium code (Cowperthwaite and Zwisler 1973). The TIGER code has been modified to allow systems containing up to 400 gaseous and 100 condensed constituents composed of up to 50 elements. Gaseous covolumes have been estimated following the procedure outlined by Mader (1979) using estimates of van der Waals radii for 48 elements and three-dimensional molecular mechanics. Molecular structures for all gaseous components were explicitly defined in terms of atomic coordinates in Å (Hobbs and Baer 1992a). The Becker-Kistiakowsky-Wilson equation of state (BKW-EOS) has been calibrated near C-J states using detonation temperatures measured in liquid and solid explosives and a large product species data base. Detonation temperatures for liquid and solid explosives were predicted adequately with a single set of BKW parameters. Values for the empirical BKW constants α, β, κ, and θ were 0.5, 0.174, 11.85, and 5160, respectively. Values for the covolume factors, κi, were assumed to be invariant. The liquid explosives included mixtures of hydrazine nitrate with hydrazine, hydrazine hydrate, and water; mixtures of tetranitromethane with nitromethane; liquid isomers ethylnitrate and 2-nitroethanol; and nitroglycerine. The solid explosives included HMX, RDX, PETN, Tetryl, and TNT. Color contour plots of HMX equilibrium products as well as thermodynamic variables are shown in pressure and temperature space. Similar plots for a pyrotechnic reaction composed of TiH2 and KClO4 are also reported. Calculations for a typical HMX-based propellant are also discussed. © 1992 Springer-Verlag.

The advent of chips which include one or more CPUS, some local memory, and rudimentary communications and routing hardware has opened a new area in computer architecture design. What is the best way to connect these chips to solve particular problems? This paper defines the efficiency of a wiring scheme for a set of communication patterns. It then gives upper and lower bounds on the best efficiency achievable. It also presents simple wiring schemes for some stencil patterns used in mesh-based discrete simulations.

Along with the third-order nonlinear susceptibility, χ(3), the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter for conjugated polymers used in active integrated optical devices. Photothermal deflection spectroscopy (PDS) is an ideal technique for determining the absorption coefficients of thin films of 'transparent' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers, poly(1,4-phenylene-vinylene) (and derivatives) and polydiacetylene-4BCMU, in the spectral region from 0.55 to 3 eV. We find that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1-10 cm-1. In the region below 1 eV, overtones of C-H stretching modes dominate the absorption behavior. We also observe that irradiation of all of these polymers with light above ∼ 2.5 eV produces enhanced absorption below the fundamental edge. In the absence of light, these excitations decay with characteristic times of 10-1000 s and in some cases they may determine the effective IR transparency in the energy range 1.0-1.8 eV. © 1992.

An inductively heated experiment, SURC-2, using prototypic U0{sub 2}-ZrO{sub 2} materials was executed as part of the Integral Core-Concrete Interactions Experiments Program. The purpose of this experimental program was to measure and assess the variety of source terms produced during core debris/concrete interactions. These source terms include thermal energy released to both the reactor basemat and the containment environment, as well as flammable gas, condensable vapor and toxic or radioactive aerosols generated during the course of a severe reactor accident. The SURC-2 experiment eroded a total of 35 cm of basaltic concrete during 160 minutes of sustained interaction using 203.9 kg of prototypic U0{sub 2}-ZrO{sub 2} core debris material that included 18 kg of Zr metal and 3.4 kg of fission product simulants. The meltpool temperature ranged from 2400--1900{degrees}C during the first 50 minutes of the test followed by steady temperatures of 1750--1800{degrees}C during the middle portion of the test and increased temperatures of 1800--1900{degrees}C during the final 50 minutes of testing. The total erosion during the first 50 minutes was 15 cm with an additional 7 cm during the middle part of the test and 13 cm of ablation during the final 50 minutes. Comprehensive gas flowrates, gas compositions, and aerosol release rates were also measured during the SURC-2 test. When combined with the SURC-1 results, SURC-2 forms a complete data base for prototypic U0{sub 2}-ZrO{sub 2} core debris interactions with concrete.

This manual is a user`s guide to the SE3253 and SE3254 versions of the 5AH10 Battery Maintenance Tester, a charger/discharger and test system for the 24-Cell 5-Ah Nickel-Cadmium Battery Pack. The manual provides information on rack equipment, power, communications, theory of operations, user interface, and operating procedures. Copies of users manuals for all equipment comprising the Battery Maintenance Tester are included as appendices.

The unique requirements and contraints of space nuclear systems require careful consideration in the development of a safety policy. The Nuclear Safety Policy Working Group (NSPWG) for the Space Exploration Initiative has proposed a hierarchical approach with safety policy at the top of the hierarchy. This policy allows safety requirements to be tailored to specific applications while still providing reassurance to regulators and the general public that the necessary measures have been taken to assure safe application of space nuclear systems. The safety policy used by the NSPWG is recommended for all space nuclear programs and missions.

This paper presents the results of a reliability analysis for a solar central receiver power plant that employs a salt-in-tube receiver. Because reliability data for a number of critical plant components have only recently been collected, this is the first time a credible analysis can be performed. This type of power plant will be built by a consortium of western US utilities led by the Southern California Edison Company. The 10 MW plant is known as Solar Two and is scheduled to be on-line in 1994. It is a prototype which should lead to the construction of 100 MW commercial-scale plants by the year 2000. The availability calculation was performed with the UNIRAM computer code. The analysis predicted a forced outage rate of 5.4% and an overall plant availability, including scheduled outages, of 91%. The code also identified the most important contributors to plant unavailability. Control system failures were identified as the most important cause of forced outages. Receiver problems were rated second with turbine outages third. The overall plant availability of 91% exceeds the goal identified by the US utility study. This paper discuses the availability calculation and presents evidence why the 91% availability is a credible estimate. 16 refs.

Interagency panels evaluating nuclear thermal propulsion development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and design issues of a proposed ground test complex for evaluating nuclear thermal propulsion engines and fuel elements being developed for the Space Nuclear Thermal Propulsion (SNTP) program. 2 refs.