Publications

Funded as a laboratory-directed research and development (LDRD) project, the work reported here focuses on the development of a computational methodology to determine the dynamic response of heterogeneous solids on the basis of their composition and microstructural morphology. Using the solid dynamics wavecode CTH, material response is simulated on a scale sufficiently fine to explicitly represent the material`s microstructure. Conducting {open_quotes}numerical experiments{close_quotes} on this scale, the authors explore the influence that the microstructure exerts on the material`s overall response. These results are used in the development of constitutive models that take into account the effects of microstructure without explicit representation of its features. Applying this methodology to a glass-reinforced plastic (GRP) composite, the authors examined the influence of various aspects of the composite`s microstructure on its response in a loading regime typical of impact and penetration. As a prerequisite to the microscale modeling effort, they conducted extensive materials testing on the constituents, S-2 glass and epoxy resin (UF-3283), obtaining the first Hugoniot and spall data for these materials. The results of this work are used in the development of constitutive models for GRP materials in transient-dynamics computer wavecodes.

This document is intended to be a resource for preparers of safety documentation for Sandia National Laboratories, New Mexico facilities. It provides standardized discussions of some topics that are generic to most, if not all, Sandia/NM facilities safety documents. The material provides a ``core`` upon which to develop facility-specific safety documentation. The use of the information in this document will reduce the cost of safety document preparation and improve consistency of information.

The Time Projection Compton Spectrometer (TPCS) is a radiation diagnostic designed to determine the time-integrated energy spectrum between 100 keV -- 2 MeV of flash x-ray sources. This guide is intended as a reference for the routine operator of the TPCS. Contents include a brief overview of the principle of operation, detailed component descriptions, detailed assembly and disassembly procedures, guide to routine operations, and troubleshooting flowcharts. Detailed principle of operation, signal analysis and spectrum unfold algorithms are beyond the scope of this guide; however, the guide makes reference to sources containing this information.

New Mexico State University organized an effort to perform static and dynamic damage-detection tests on the Interstate-40 bridge over the Rio Grande at Albuquerque. The opportunity was available because the 425-ft-long bridge was soon to be replaced. Sandia National Laboratories was asked to provide and operate a shaker that could exert 1000-lb peak amplitude forces for both sinusoidal and random excitations between 2 and 20 Hz. Two Sandia departments collaborated to design and build the shaker, using existing major components connected with Sandia-designed and -fabricated hardware. The shaker was installed and operated successfully for a series of five modal and sinusoidal response tests.

Finding innovative ways to reduce waste streams generated at Department of Energy (DOE) sites by 50% by the year 2000 is a challenge for DOE`s waste minimization efforts. This report examines the usefulness of benchmarking as a waste minimization tool, specifically regarding common waste streams at DOE sites. A team of process experts from a variety of sites, a project leader, and benchmarking consultants completed the project with management support provided by the Waste Minimization Division EM-352. Using a 12-step benchmarking process, the team examined current waste minimization processes for liquid photographic waste used at their sites and used telephone and written questionnaires to find ``best-in-class`` industrv partners willing to share information about their best waste minimization techniques and technologies through a site visit. Eastman Kodak Co., and Johnson Space Center/National Aeronautics and Space Administration (NASA) agreed to be partners. The site visits yielded strategies for source reduction, recycle/recovery of components, regeneration/reuse of solutions, and treatment of residuals, as well as best management practices. An additional benefit of the work was the opportunity for DOE process experts to network and exchange ideas with their peers at similar sites.

The compute power of the individual nodes of massively parallel systems increases steadily, while network latencies and bandwidth have not improved as quickly. Many researches believe that it is necessary to use explicit message passing in order to get the best possible performance out of these systems. High level parallel languages are shunned out of fear they might compromise performance. In this paper we have a look at one such language called Split-C. It fits into a middle ground between efforts such as High Performance Fortran (HPF) and explicit message passing. HPF tries to hide the underlying architecture from the programmer and let the compiler and the run time system make decision about parallelization, location of data, and the mechanisms used to transfer the data from one node to another. On the other hand, explicit message passing leaves all the decision to the programmer. Split-C allows access to a global address space, but leaves the programmer in control of the location of data, and offers a clear cost model for data access. Split-C is based on Active Messages. We have implemented both under the SUNMOS operating system on the Intel Paragon. We will discuss performance issues of Split-C and make direct comparisons to the Thinking Machines CM-5 implementation. We will also scrutinize Active Messages, discuss their properties and drawbacks, and show that other mechanisms can be used to support Split-C.

Experiments were conducted to assess the effects of high potential testing of cables and to assess the survivability of aged and damaged cables under Loss-of-Coolant Accident (LOCA) conditions. High potential testing at 240 Vdc/mil on undamaged cables suggested that no damage was incurred on the selected virgin cables. During aging and LOCA testing, Okonite ethylene propylene rubber (EPR) cables with a bonded jacket experienced unexpected failures. The failures appear to be primarily related to the level of thermal aging and the presence of a bonded jacket that ages more rapidly than the insulation. For Brand Rex crosslinked polyolefin (XLPO) cables, the results suggest that 7 mils of insulation remaining should give the cables a high probability of surviving accident exposure following aging. The voltage necessary to detect when 7 mils of insulation remain on unaged Brand Rex cables is approximately 35 kVdc. This voltage level would almost certainly be unacceptable to a utility for use as a damage assessment tool. However, additional tests indicated that a 35 kvdc voltage application would not damage virgin Brand Rex cables when tested in water. Although two damaged Rockbestos silicone rubber cables also failed during the accident test, no correlation between failures and level of damage was apparent.

Japan is clearly the leader in ocean energy technologies. The United Kingdom also has had many ocean energy research projects, but unlike Japan, most of the British projects have not progressed from the feasibility study stage to the demonstration stage. Federally funded ocean energy research in the US was stopped because it was perceived the technologies could not compete with conventional sources of fuel. Despite the probable small market for ocean energy technologies, the short sighted viewpoint of the US government regarding funding of these technologies may be harmful to US economic competitiveness. The technologies may have important uses in other applications, such as offshore construction and oil and gas drilling. Discontinuing the research and development of these technologies may cause the US to lose knowledge and miss market opportunities. If the US wishes to maintain its knowledge base and a market presence for ocean energy technologies, it may wish to consider entering into a cooperative agreement with Japan and/or the United Kingdom. Cooperative agreements are beneficial not only for technology transfer but also for cost-sharing.

The goal of this project was to produce a document that contains information on the usability and performance of commercially available, fieldable, and portable scanner systems as they apply to aircraft NDI inspections. In particular, the scanners are used to generate images of eddy current, ultrasonic, or bond tester inspection data. The scanner designs include manual scanners, semiautomated scanners, and fully automated scanners. A brief description of the functionality of each scanner type, a sketch, and a fist of the companies that support the particular design are provided. Vendors of each scanner type provided hands-on demonstrations of their equipment on real aircraft samples in the FAA Aging Aircraft Nondestructive Inspection Validation Center (AANC) in Albuquerque, NM. From evaluations recorded during the demonstrations, a matrix of scanner features and factors and ranking of the capabilities and limitations of the design, portability, articulation, performance, usability, and computer hardware/software was constructed to provide a quick reference for comparing the different scanner types. Illustrations of C-scan images obtained during the demonstration are shown.

This document presents a set of proposed business process and procedures in support of the Production Capability Assurance Program (PCAP) Data Base. These processes and procedures have been adopted by the DOE Albuquerque Weapon Quality Division. Section 1 presents processes and procedures. The procedures support the PCAP Data Base. These procedures fall into the following three (3) categories: Input, Administrative, and Maintenance. Each process has supporting procedures that clearly define the effort to support the PCAP Data Base. The Input category consists of data receipt, data entry, and entry verification and validation. Data entry is entering data that has been received in either a magnetic or hard copy form. Entry verification and validation communicates results of data entry back to the data source. The Administrative category includes change control, access control, coordination of data base and system errors or problems, and coordination of data base and system enhancements. Access control addresses the issues of granting access to the PCAP data base and access to specific functionality such as: update, delete, and specific report initiation. The Maintenance category includes both hardware and software maintenance, data archival and restoration, and the correction of both major and minor software and system problems. Data archival and restoration consists of backing up of the data base and, if necessary, the loading of the data base from archival media in the event of a system disaster. Section 2 defines the roles and responsibilities associated with the processes/procedures. There are four (4) roles: System Administration, Data Base Administration, System Maintenance, and Data Base Maintenance.

Abstract not provided.

This report contain viewgraphs of papers from the following sessions: plasma facing components issues for future machines; recent PMI results from several tokamaks; high heat flux technology; plasma facing components design and applications; plasma facing component materials and irradiation damage; boundary layer plasma; plasma disruptions; conditioning and tritium; and erosion/redeposition.

An examination of the effect of a realistic (though conservative) hot day environment on the thermal transient behavior of spent fuel shipping casks is made. These results are compared to those that develop under the prescribed normal thermal condition of 10 CFR 71. Of specific concern are the characteristics of propagating thermal waves, which are set up by diurnal variations of temperature and insolation in the outdoor environment. In order to arrive at a realistic approximation of these variations on a conservative hot day, actual temperature and insolation measurements have been obtained from the National Climatic Data Center (NCDC) for representatively hot and high heat flux days. Thus, the use of authentic meteorological data ensures the realistic approach sought. Further supporting the desired realism of the modeling effort is the use of realistic cask configurations in which multiple laminations of structural, shielding, and other materials are expected to attenuate the propagating thermal waves. The completed analysis revealed that the majority of wall temperatures, for a wide variety of spent fuel shipping cask configurations, fall well below those predicted by enforcement of the regulatory environmental conditions of 10 CFR 71. It was found that maximum temperatures at the cask surface occasionally lie above temperatures predicted under the prescribed regulatory conditions. However, the temperature differences are small enough that the normal conservative assumptions that are made in the course of typical cask evaluations should correct for any potential violations. The analysis demonstrates that diurnal temperature variations that penetrate the cask wall all have maxima substantially less than the corresponding regulatory solutions. Therefore it is certain that vital cask components and the spent fuel itself will not exceed the temperatures calculated by use of the conditions of 10 CFR 71.

This report summarizes the findings of a nationwide survey of public perceptions of nuclear weapons in the post-cold war environment. Participants included 1,301 members of the general public, 1,155 randomly selected members of the Union of Concerned Scientists, and 1,226 employees randomly selected from the technical staffs of four DOE national laboratories. A majority of respondents from all three samples perceived the post-cold war security environment to pose increased likelihood of nuclear war, nuclear proliferation, and nuclear terrorism. Public perceptions of nuclear weapons threats, risks, utilities, and benefits were found to systematically affect nuclear weapons policy preferences in predictable ways. Highly significant relationships were also found between public trust and nuclear weapons policy preferences. As public trust and official government information about nuclear weapons increased, perceptions of nuclear weapons management risks decreased and perceptions of nuclear weapons utilities and benefits increased. A majority of respondents favored decreasing funding for: (1) developing and testing new nuclear weapons; (2) maintaining existing nuclear weapons, and (3) maintaining the ability to develop and improve nuclear weapons. Substantial support was found among all three groups for increasing funding for: (1) enhancing nuclear weapons safety; (2) training nuclear weapons personnel; (3) preventing nuclear proliferation; and (4) preventing nuclear terrorism. Most respondents considered nuclear weapons to be a persistent feature of the post-cold war security environment.

On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a low order nonlinear dynamic model containing only 40 degrees of freedom. This model was then used as a design tool to estimate joint dynamics. Using this design tool, joint configurations were modified, and an acceptable joint redesign determined. The results of this analysis showed that the implementation of metal stops welded to support shafts for the purpose of preventing joint separation is a suitable joint redesign. Moreover, it was found that, for quakes of Landers` magnitude, mirror breakage due to enhanced vibration in the trough assembly is unlikely.

This manual discusses the technical issues associated with monitoring solar-thermal systems. It discusses some successful monitoring programs that have been implemented in the past. It gives the rationale for selecting a program of monitoring and gives guidelines for the design of new programs. In this report, solar thermal monitoring systems are classified into three levels. For each level, the report discusses the kinds of information obtained by monitoring, the effort needed to support the monitoring program, the hardware required, and the costs involved. Ultimately, all monitoring programs share one common requirement: the collection of accurate data that characterize some aspect or aspects of the system under study. This report addresses most of the issues involved with monitoring solar thermal systems. It does not address such topics as design fundamentals of thermal systems or the relative merits of the many different technologies employed for collection of solar energy.

This report describes the results of a two-year laboratory directed research and development project to explore advanced concepts in Heavy Ion Backscattering Spectrometry (HIBS), undertaken with the goal of extending the sensitivity of this relatively new technique to levels unattainable by any other existing trace element surface analysis. Improvements in sensitivity are required for the application of HIBS to contamination control in the microelectronics industry. Tools with sensitivity approaching 10{sup 8} atoms/cm{sup 2} are expected to be essential for enabling advanced IC production by the year 2000. During the project the authors developed a new analysis chamber with channeling goniometer and a prototype time-of-flight detector with a demonstrated sensitivity of {approximately} 5 {times} 10{sup 8} atoms/cm{sup 2} for Au on Si and {approximately} 5 {times} 10{sup 10} for Fe, and sufficient mass resolution to separate contributions from Fe and Cu.

The Greater Confinement Disposal (GCD) facility was established in Area 5 at the Nevada Test Site for containment of waste inappropriate for shallow land burial. Some transuranic (TRU) waste has been disposed of at the GCD facility, and compliance of this disposal system with EPA regulation 40 CFR 191 must be evaluated. We have adopted an iterative approach in which performance assessment results guide site data collection, which in turn influences the parameters and models used in performance assessment. The first iteration was based upon readily available data, and indicated that the GCD facility would likely comply with 40 CFR 191 and that the downward flux of water through the vadose zone (recharge) had a major influence on the results. Very large recharge rates, such as might occur under a cooler, wetter climate, could result in noncompliance. A project was initiated to study recharge in Area 5 by use of three environmental tracers. The recharge rate is so small that the nearest groundwater aquifer will not be contaminated in less than 10,000 years. Thus upward liquid diffusion of radionuclides remained as the sole release pathway. This second assessment iteration refined the upward pathway models and updated the parameter distributions based upon new site information. A new plant uptake model was introduced to the upward diffusion pathway; adsorption and erosion were also incorporated into the model. Several modifications were also made to the gas phase radon transport model. Plutonium solubility and sorption coefficient distributions were changed based upon new information, and on-site measurements were used to update the moisture content distributions. The results of the assessment using these models indicate that the GCD facility is likely to comply with all sections of 40 CFR 191 under undisturbed conditions.

This document lists acronyms used in technical writing. The immense list is supplemented by an appendix containing chemical elements, classified information access, common abbreviations used for functions, conversion factors for selected SI units, a flowcharting template, greek alphabet, metrix terminology, proofreader`s marks, signs and symbols, and state abbreviations.

No abstract available.

To better facilitate working with industry, groups of industrial participants, and partners in alliances or consortia, Sandia National laboratories presents information helpful to those outside groups as to the forms of arrangements that may be used to better facilitate partnering relationships between Sandia National Laboratories and consortia or alliances of outside parties. It is expected that these alliances and consortia will include both large and small for-profit industrial concerns, as well as not-for-profit entities such as universities, institutes, other research facilities, and other nonprofit institutions or consortia containing institutions. The intent of this report is to provide such outside groups with information that will facilitate rapid interactions with Sandia National Laboratories through some of these forms of business which will be discussed in this report. These are not the only approaches to facilitating business interactions with Sandia National Laboratories and it is not intended that this report be legal advice or required approaches to doing business with Sandia National Laboratories. The intent of this report is merely to suggest ways in which Sandia National Laboratories can work with outside parties in the most expeditious manner.

A qualitative three-dimensional analysis of the saturated zone flow system was performed for a 8 km {times} 8 km region including the potential Yucca Mountain repository site. Certain recognized geologic features of unknown hydraulic properties were introduced to assess the general response of the flow field to these features. Two of these features, the Solitario Canyon fault and the proposed fault in Drill Hole Wash, appear to constrain flow and allow calibration.

A smooth artificial joint in Topopah Spring Member tuff was sheared at constant normal stress at velocities from 0 to 100 {mu}m/s to determine the velocity-dependence of shear strength. Two different initial conditions were used: (1) unprimed -- the joint had been shear stress-free since last application of normal stress, and before renewed shear loading; and (2) primed -- the joint had undergone a slip history after application of normal stress, but before the current shear loading. Observed steady-state rate effects were found to be about 3 times lager than for some other silicate rocks. These different initial conditions affected the character of the stress-slip curve immediately after the onset of slip. Priming the joint causes a peak in the stress-slip response followed by a transient decay to the steady-state stress, i.e., slip weakening. Slide-hold-slide tests exhibit time-dependent strengthening. When the joint was subjected to constant shear stress, no slip was observed; that is, joint creep did not occur. One set of rate data was collected from a surface submerged in tap water, the friction was higher for this surface, but the rate sensitivity was the same as that for surfaces tested in the air-dry condition.

An analysis planned to validate regional climate model results for a past climate state at Yucca Mountain, Nevada, against paleoclimate evidence for the period is described. This analysis, which will use the GENESIS model of global climate nested with the RegCM2 regional climate model, is part of a larger study for DOE`s Yucca Mountain Site Characterization Project that is evaluating the impacts of long term future climate change on performance of the potential high level nuclear waste repository at Yucca Mountain. The planned analysis and anticipated results are presented.

Samples of tuffaceous rock were studied as part of the site characterization for a potential nuclear waste repository at Yucca Mountain in southern Nevada. These efforts were scoping in nature, and their results, along with those of other investigations, are being used to develop suitable procedures for determining bulk properties of tuffaceous rock in support of thermal and mechanical properties evaluations. Comparisons were made between various sample preparation, handling, and measurement techniques for both zeolitized and nonzeolitized tuff in order to assess their effects on bulk property determinations. Laboratory tests included extensive drying regimes to evaluate dehydration behavior, the acquisition of data derived from both gas and water pycnometers to compare their suitability in determining grain densities, a comparison of particle size effects, and a set of experiments to evaluate whole core saturation methods. The results affirm the added complexity of these types of measurements where there is a zeolite component in the sample mineralogy. Absolute values for the bulk properties of zeolitized tuff are immeasurable due to the complex nature of their dehydration behavior. However, the results of the techniques that were investigated provide a basis for the development of preferred, consistent methods for determining the grain density, dry and saturated bulk densities, and porosity of tuffaceous rock, including zeolitic tuff in support of thermal and mechanical properties evaluations.