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.