The first phase of a program to study the resistance of exclusion region barriers to ductile failure when subjected to accident-type, quasi-static extreme mechanical loads has been completed. This first phase consisted to qualification of the analytical tools used to study these types of structural deformations and the development of appropriate criteria to predict ductile failure. A series of tests were performed on hydroformed half-cylinder barrier mock-ups. The qualification activity was considered a success based upon the comparison of the deformations and loads measured during the testing to the response of these structures computed by the finite element modeling. This successful completion of the first phase allows the second phase program to proceed. 12 refs.
We have measured, by {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR), the percent deuteration, the tacticity and the purity of several polymers and one solvent used in the preparation of microcellular foams. The percent deuteration was measured for polystyrene, polyacrylonitrile and polyethylene. The tacticities of polystyrene and polyacrylonitrile were determined. The purity and degradation products of polyacrylonitrile and maleic anhydride were examined. This report documents the experimental procedures and results of these measurements.
Sandia National Laboratories operates the Primary Standards Laboratory (PSL) for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the second half of 1991 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.
The effects of cavern spacing and operating pressure on surface subsidence and cavern storage losses were evaluated using the finite- element method. The base case for the two sensitivity studies was a typical SPR cavern. The predicted responses of the base case and those from the pressurization study compared quite closely to measured surface subsidence and oil pressurization rates. This provided credibility for the analyses and constitutive models used. Subsidence and cavern storage losses were found to be strongly influenced by cavern spacing and pressurization. The relationship between subsidence volume and losses in storage volume varied as cavern spacing and operating pressure deviated from the base case. However, for a typical SPR cavern subsidence volume is proportional to storage loss and when expressed in ft., subsidence is equal to the percentage of storage loss.
The goal of the wet cavity (WC) test series was to investigate the effect of water in a reactor cavity on direct containment heating (DCH). The WC-1 experiment was performed with a dry cavity to obtain baseline data for comparison to the WC-2 experiment. WC-2 was conducted with water 3 cm deep (11.76 kg) in a 1:10 linear scale model of the Zion reactor cavity. The initial conditions for the experiments were similar. For both experiments the molten core debris was simulated by a thermitically generated melt formed from 50 kg of iron oxide/aluminum/chromium powders. After the charge was ignited, the debris was melted by the chemical reaction and was forcibly ejected through a nominal 3.5 cm hole into the scaled reactor cavity by superheated steam at an initial driving pressure of 4.58 MPa. The peak pressure increase in the containment due to the high-pressure melt ejection (HPME) was 0.272 MPa in WC-1 and 0.286 MPa in WC-2. The total amount of hydrogen generated in the experiments was 145 moles of H{sub 2} in WC-1 and 179 moles of H{sub 2} in WC-2. The total mass of debris ejected into the containment was identical for both experiments. These results suggest that water in the cavity slightly enhanced DCH.
Laboratory simulation of the approach of a radar fuze towards a target is an important factor in our ability to accurately measure the radar`s performance. This simulation is achieved, in part, by dynamically delaying and attenuating the radar`s transmitted pulse and sending the result back to the radar`s receiver. Historically, the device used to perform the dynamic delay has been a limiting factor in the evaluation of a radar`s performance and characteristics. A new device has been proposed that appears to have more capability than previous dynamic delay devices. This device is the digital RF memory. This report presents the results of an analysis of a digital RF memory used in a signal-delay application. 2 refs.
This report describes research and development related to Mo-based catalysts supported on hydrous metal oxide in exchangers for use in direct coal liquefaction processes. A group of NiMo catalysts were prepared on different hydrous titanium oxide (HTO) supports to serve as baseline materials for use in determining the effects of altering process parameters on the physical and catalytic properties of NiMoHTO catalysts. The baseline group included catalysts which had hydrogenation activities up to 40% higher than the best commercial NiMo/Al{sub 2}O{sub 3} catalysts used in coal liquefaction pilot plant studies on a weight of catalyst basis while containing 25% less active metal. The results of high resolution electron microscopy (HREM) studies addressing the effects of processing parameters on microstructure are also presented. NiMoHTO catalysts were included in a group of some 30 commercial and experimental catalysts tested at Amoco Oil Co. to determine applicability for upgrading coal resids. The performance of NiMoHTO catalysts in these tests was better than or comparable to the best commercial catalysts available for this application. The initial work with thin-film NiMoHTO catalysts supported on commercial silica gel spheres is presented. Second generation thin-film catalysts containing about 1% Mo have hydrogenation activities of about 75% of those of extruded commercial NiMo/Al{sub 2}O{sub 3} catalysts containing 10--13% Mo and up to 50% of the hydrodesulfurization activity of the commercial catalysts. The use of thin-film HTO technology, which allows for preparation of NiMoHTO catalysts on virtually any substrate lowers catalyst cost by reducing the amount of Ti required and provides engineering forms of HMO materials without development work needed to convert bulk HTO materials into usable engineering forms. Work done with NiMo catalysts supported on hydrous zirconium oxide (HZO) is also presented.
The third experiment of the Integral Effects Test (IET-3) series was conducted to investigate the effects of high pressure melt ejection (HPME) on direct containment heating (DCH). A 1:10 linear scale model of the Zion reactor pressure vessel (RPV), cavity, instrument tunnel, and subcompartment structures were constructed in the Surtsey Test Facility at Sandia National Laboratories (SNL). The RPV was modeled with a melt generator that consisted of a steel pressure barrier, a cast MgO crucible, and a thin steel inner liner. The melt generator/crucible had a semi-hemispherical bottom head containing a graphite limitor plate with a 3.5 cm exit hole to simulate the ablated hole in the RPV bottom head that would be formed by tube ejection in a severe nuclear power plant (NPP) accident. The reactor cavity model contained 3.48 kg of water with a depth of 0.9 cm that correspond to condensate levels in the Zion plant. A steam driven iron oxide/aluminum/chromium thermite was used to simulate HPME. IET-3 replicated the first experiment in the IET series (IET-1) except the Surtsey vessel contained 0.09 MPa air and 0.1 MPa nitrogen. No steam explosions occurred in the cavity in IET-3 experiment. The cavity pressure measurements showed that rapid vaporization of water occurred in the cavity at about the same time as the steam explosion in IET-1. However, the oxygen in the Surtsey vessel in IET-3 resulted in a vigorous hydrogen burn, which caused a significant increase in the peak pressure, 246 kPa compared to 98 kPa in the IET-1 test. The total debris mass ejected into the Surtsey vessel in IET-3 was 34.3 kg, and gas grab sample analysis indicated that 223 moles of hydrogen were produced by steam/metal reactions. About 186 moles of hydrogen burned and 37 moles remained unreacted.
This document presents planned actions, and their associated costs, for addressing the findings in the Environmental, Safety and Health Tiger Team Assessment of the Sandia National Laboratories, Albuquerque, May 1991, hereafter called the Assessment. This Final Action Plan should be read in conjunction with the Assessment to ensure full understanding of the findings addressed herein. The Assessment presented 353 findings in four general categories: (1)Environmental (82 findings); (2) Safety and Health (243 findings); (3) Management and Organization (18 findings); and (4) Self-Assessment (10 findings). Additionally, 436 noncompliance items with Occupational Safety and Health Administration (OSHA) standards were addressed during and immediately after the Tiger Team visit.
This paper addresses problems of synchronization and coordination in the context of faulty shared memory. We present algorithms for the consensus problem, and for reliable shared memory objects, from collections of read/write registers, 2-processor binary test-and-set objects, and read-modify-write registers, some of which may be faulty.
A computer program has been developed to reduce and analyze data from a standardized piezoelectric polymer (PVDF) shock-wave stress rate gauge. The program is menu driven with versatile graphic capabilities, input/output file options, hard copy options, and unique data processing capabilities. This program was designed to analyze digital current-mode'' data recorded from a Bauer PVDF stress-rate gauge and reduce it to a stress-versus-time record. The program was also designed to combine two simulanteously recorded data channels.
The purpose of the molten-salt pump and valve loop test is to demonstrate the performance, reliability, and service life of full-scale hot- and cold-salt pumps and valves for use in commercial central receiver solar power plants. This test was in operation at Sandia National Laboratories National Solar Thermal Test Facility from January 1988 to September 1990. The test hardware consists of two pumped loops; the hot-salt loop'' to simulate the piping and components on the hot (565{degrees}C) side of the receiver and the cold-salt loop'' to simulate piping and components on the receiver's cold (285{degrees}C) side. Each loop contains a pump and five valves sized to be representative of a conceptual 60-MW{sub e} commercial solar power plant design. The hot-salt loop accumulated over 6700 hours of operation and the cold-salt loop over 2500 hours during the test period. This project has demonstrated the performance and reliability required for commercial-scale molten-salt pumps and valves.
The goal of the Stretched-Membrane Dish Program is the development of a dish solar concentrator fabricated with a single optical element capable of collecting 60 kWt. Solar Kinetics, Inc., has constructed a prototype 7-meter dish to demonstrate the manufacturability and optical performance of this innovative design. The reflective surface of the dish consists of a plastically deformed metal membrane with a separate reflective polymer membrane on top, both held in place by a low-level vacuum. Sandia conducted a test program to determine the on-sum performance of the dish. The vacuum setting was varied 8.9- to 17. 2-cm of water column and the vertex to target distance was varied over a range of 15.24 cm to evaluate beam quality. The optimal setting for the vacuum was 11.4 centimeters of water column with the best beam quality of 6.4 centimeters behind the theoretical focal point of the dish. Flux arrays based on slope error from the CIRCE2 computer code were compared to the measured flux array of the dish. The uniformly distributed slope error of 2.3 milliradians was determined as the value that would produce a modeled array with the minimum mean square difference to the measured array. Cold water calorimetry measured a power of 23.3 {plus minus} .3 kWt. Reflectivity change from an initial value of 88.3% to 76.7% over a one year period. 12 refs.
Pulsed high field magnet coils are an integral part of the applied-B ion diode used in the light ion Inertial Confinement Fusion program at Sandia National Laboratories. Several factors have contributed in recent years to the need for higher magnetic fields of these applied-B ion diodes. These increased magnetic field requirements have precipitated the development of better engineering tools and techniques for use in the design of applied-B ion diodes. This paper describes the status of the applied-B ion diode engineering at Sandia. The design process and considerations are discussed. A systematic approach for maximizing the field achievable from a particular coil system consisting of the capacitor bank, the feeds, and the coil is presented. A coupled electromechanical finite element analysis is also described.
Rock mechanisms parameters such as the in situ stresses, elastic properties, failure characteristics, and poro-elastic response are important to most completion and stimulation operations. Perforating, hydraulic fracturing, wellbore stability, and sand production are examples of technology that are largely controlled by the rock mechanics of the process. While much research has been performed in these areas, there has been insufficient application that research by industry. In addition, there are new research needs that must be addressed for technology advancement.
We describe the use of the object-oriented language C++ in the development of a hydrocode simulation system, PCTH. The system is designed to be horizontally and vertically portable from low-end workstations to next generation massively parallel supercomputers. The development of the PCTH system and the issues and rationale considered in moving to the object oriented paradigm will be discussed.
The goals and time constraints of developing the next generation shock code, RHALE++, for the Computational Dynamics and Adaptive Structures Department at Sandia National Laboratories have forced the development team to closely examine their program development environment. After a thorough investigation of possible programming languages, the development team has switched from a FORTRAN programming environment to C++. This decision is based on the flexibility, strong type checking, and object-oriented features of the C++ programming language. RHALE++ is a three dimensional, multi-material, arbitrary Lagrangian Eulerian hydrocode. Currently, RHALE++ is being developed for von Neumann, vector, and MIMD/SIMD computer architectures. Using the object oriented features of C++ facilitates development on these different computer architectures since architecture dependences such as inter processor communication, can be hidden in base classes. However, the object oriented features of the language can create significant losses in efficiency and memory utilization. Techniques, such as reference counting, have been developed to address efficiency problems that are inherent in the language. Presently, there has been very little efficiency loss realized on SUN scalar and nCUBE massively parallel computers; however, although some vectorization has been accomplished on CRAY systems, significant efficiency losses exist. This paper presents the current status of using C++ as the development language for RHALE++ and the efficiency that has been realized on SUN, CRAY, and nCUBE systems.
In this report we will consider how radiation measurements on spent fuel can contribute to verifying the loading of burnup credit casks. Measurements can be used in burnup credit operations to help prevent misloading of fuel that does not meet the minimum specifications for a particular cask design. Passive neutron and gross gamma-ray measurements are proposed as a means of qualifying spent fuel assemblies. Active systems to measure reactivity or fissile content are necessarily more complex and appear to offer no obvious advantage to burnup credit applications over simpler systems. 4 refs., 2 figs.
Salzbrenner, R.; Wellman, G.W.; Sorenson, K.B.; Mcconnell, P.
Depleted uranium (DU) is used in high level radioactive waste transport containers as a gamma shield. The mechanical response of this material has generally not been included in calculations intended to assure that these casks will maintain their containment function during all normal use and accident conditions. If DU could be qualified as a structural component, the thickness of other materials (e.g. stainless steel) in the primary containment boundary could be reduced, thereby allowing a reduction in cask mass and/or an increase in payload capacity. This study was conducted to determine the mechanical behavior of a range of DU alloys in order to extend the limited set of mechanical properties reported in the literature. These mechanical properties were used as the basis for finite element calculations to quantify the potential for claiming structural credit for DU.
Variations of bed void fraction in a full-scale, reacting, fixed-bed coal gasifier have been deduced from measured axial pressure profiles obtained during gasification of seven coal types ranging from lignite to bituminous. Packed-bed pressure correlations were used to calculate the void fractions based on monotonic polynomial fits of measured pressure profiles. Insights into the fixed-bed combustion processes affected by the void distribution were obtained by a one-dimensional, steady-state, fixed-bed combustion model. Predicted temperature profiles from this model compare reasonably well to experimental data. The bed void distributions are not linear but are perturbed by vigorous reactions in the devolatilization and oxidation zones. Results indicate that a dramatic increase in temperature and associated gas release causes the bed to expand and the gas void space to increase. Increased void space localized in the combustion zone causes the steep temperature gradient to decrease and the location of the maximum temperature to shift. Also, large feed gas flow rates cause the void fraction in the ash zone to increase.
Crosshole shear-wave seismic surveys have been used to monitor the distribution of injected air in the subsurface during an in situ air stripping waste remediation project at the Savannah River site in South Carolina. To remove the contaminant, in this case TCE`s from a leaking sewer line, two horizontal wells were drilled at depths of 20 m and 52 m. Air was pumped into the lower well and a vacuum was applied to the upper well to extract the injected air. As the air passed through the subsurface, TCE`s were dissolved into the gas and brought out the extraction well. Monitoring of the air injection by crosshole shear wave seismics is feasible due to the changes in soil saturation during injection resulting in a corresponding change in seismic velocities. Using a downhole shear-wave source and clamped downhole receiver, two sets of shear-wave data were taken. The first data were taken before the start of air injection, and the second taken during. The difference in travel times between the two data sets were tomographically inverted to obtain velocity differences. Velocity changes ranging up to 3% were mapped corresponding to saturation changes up to 24%. The distribution of these changes shows a desaturation around the position of the injection well with a plume extending in the direction of the extraction well. Layers with higher clay content show distinctively less change in saturation than the regions with higher sand content.
Numerical optimization has been successfully used to obtain optimal designs in a more efficient and structured manner in many industries. Optimization of sizing variables is already a widely used design tool and even though shape optimization is still an active research topic, significant successes have been achieved for many structural analysis problems. The transportation cask design problem seems to have the formulation and requirements to benefit from numerical optimization. Complex structural, thermal and radiation shielding analyses associated with cask design constraints can be integrated and automated through numerical optimization to help meet the growing needs for safe and reliable shipping containers. Improved overall package safety and efficiency with cost savings in the design and fabrication can also be realized. Sandia National Laboratories (SNL) has the opportunity to be a significant contributor in the development of new sophisticated transportation cask design tools. Current state-of-the-art technology at SNL in the areas of structural mechanics, thermal mechanics, numerical analysis, adaptive finite element analysis, automatic mesh generation, and transportation cask design can be combined to enhance current industry-standard cask design and analysis techniques through numerical optimization.
This report describes in details the operations necessary to perform a test on the Sandia National Laboratories 18-Inch Actuator. This report is to sever as a training aid for personnel learning to operate the Actuator. A complete description of the construction and operation of the Actuator is also given. The control system, data acquisition system, and high-pressure air supply system are also described. Detailed checklists, with an emphasis on safety, are presented for test operations and for maintenance.
The Hazardous Material Identification Process is a guide to pre-characterization of excess weapon hardware for environmental and safety hazards prior to introduction of the hardware into a waste stream. A procedure for planning predisposal processing of hardware for declassification, demilitarization, and separation/expenditure of certain hazards is included. Final characterization of the resultant waste streams is left to the cognizant waste management agency or organization.