Publications

Using Saturn as a driver, we are pursuing both photoresonantly pumped and photoionization/recombination lasers. Our lasing targets are gas cells with thin windows that are pumped by a z pinch 2 cm away radiating 10 TW. In both schemes the lasant and gas fill is neon. To increase our chances of measuring the resonantly photopumped lasing transition we have introduced potassium into a sodium z pinch and have eliminated oxygen from the gas cell windows. We have measured the spatial dependence of ionization balance across the gas cell, and this measurement is consistent with propagation of a shock front across the gas cell target. We have measured blue-shifted satellites to several Li-like neon transitions that may indicate return-current driven jetting a high 1.5e8 cm/sec velocity. Using a gold z-pinch we have shown that key radiation is necessary to excite the He-like lines of neon. An attempt at a single shot gain measurement also indicates that radiation is not the only source of gas cell heating.

This paper presents a full-field dye concentration measurement technique that extends our experimental capabilities to the measurement of transient dye concentration fields within steady state flow fields under unsaturated or saturated conditions. Simple light absorption theory provides a basis for translating images into high resolution dye concentration fields. A series of dye pulse experiments that demonstrate the combined use of the full-field saturation and dye concentration techniques was conducted at four different degrees of saturation. Each of these experimental sequences was evaluated with respect to mass balance, the results being within 5% of the known dye mass input. An image windowing technique allowed us to see increased dispersion due to decreasing moisture content, tailing of concentration at the rear of the dye pulse and slight velocity changes of the dispersive front due to changes in moisture content. The exceptional resolution of dye concentration in space and time provided by this laboratory technique allows systematic experimentation for examining basic processes affecting solute transport within saturated/unsaturated porous media. Future challenges for this work will be to use these techniques to analyze more complex systems involving heterogeneities, scaling laws, and detailed investigations of the relationship between transverse and longitudinal dispersion in unsaturated media.

The Beam Characterization System is being employed at the Sandia`s National Solar Thermal Test Facility to characterize the optical performance of heliostats, point-focus solar collectors, and their optical sub-elements as part of the on-going task to develop solar thermal technologies. With this measurement system, images of concentrated solar flux are acquired using digital imaging and processed to obtain such measures of the collector`s optical performance as beam power, flux distribution, and beam diameter. Key system elements are a diffusely reflective target for imaging collector beams, meteorological instrumentation including a flux gauge to measure flux at one point in the beam, and a calibration technique to establish a pixel-intensity-to-flux-density conversion factor for the image. The system is employed in a variety of collector tests such as beam quality, tracking error, and wind effects. The paper describes the Beam Characterization System and its components and presents, for illustration, sample test results. An analysis of the Beam Characterization System`s sources of measurement error is presented. Lastly, measurement techniques that employ the BCS to align heliostats and to measure or estimate collector surface slope errors are described.

We have measured the laser emission spectra of several vertical cavity surface emitting lasers following pulsed laser excitation, with a time resolution of < 1 ps. Correlations between the observed pulse widths and cavity lifetimes were observed.

A fundamental concern in the design of the potential repository at Yucca Mountain. Nevada is the response of the host rock to the emplacement of heat-generating waste. The thermal perturbation of the rock mass has implications regarding the structural, hydrologic. and geochemical performance of the potential repository. The phenomenological coupling of many of these performance aspects makes repository thermal modeling a difficult task. For many of the more complex, coupled models, it is often necessary to reduce the geometry of the potential repository to a smeared heat-source approximation. Such simplifications have impacts on induced thermal profiles that in turn may influence other predicted responses through one- or two-way thermal couplings. The effect of waste employment layout on host-rock thermal was chosen as the primary emphasis of this study. Using a consistent set of modeling and input assumptions, far-field thermal response predictions made for discrete-source as well as plate source approximations of the repository geometry. Input values used in the simulations are consistent with a design-basis a real power density (APD) of 80 kW/acre as would be achieved assuming a 2010 emplacement start date, a levelized receipt schedule, and a limitation on available area as published in previous design studies. It was found that edge effects resulting from general repository layout have a significant influence on the shapes and extents of isothermal profiles, and should be accounted for in far-field modeling efforts.

The remand of the US Environmental Protection Agency`s long-term performance standards for radioactive-waste disposal provides an opportunity to suggest modifications that would make the regulation more defensible and remove inconsistencies yet retain the basic structure of the original rule. Proposed modifications are in three specific areas: release and dose limits, probabilistic containment requirements, and transuranic-waste disposal criteria. Examination of the modifications includes discussion of the alternatives, demonstration of methods of development and implementation, comparison of the characteristics, attributes, and deficiencies of possible options within each area, and analysis of the implications for performance assessments. An additional consideration is the impact on the entire regulation when developing or modifying the individual components of the radiological standards.

As part of the NRC-sponsored program to study the implications of Generic Issue 57, Effects of Fire Protection System Actuation on Safety-Related Equipment,'' a subtask was performed to evaluate the applicability of formal decision analysis methods to generic issues cost/benefit-type decisions and to apply these methods to the GI-57 results. In this report, the numerical results obtained from the analysis of three plants (two PWRs and one BWR) as developed in the technical resolution program for GI-57 were studied. For each plant, these results included a calculation of the person-REM averted due to various accident scenarios and various proposed modifications to mitigate the accident scenarios identified. These results were recomputed to break out the benefit in terms of contributions due to random event scenarios, fire event scenarios, and seismic event scenarios. Furthermore, the benefits associated with risk (in terms of person-REM) averted from earthquakes at three different seismic ground motion levels were separately considered. Given this data, formal decision methodologies involving decision trees, value functions, and utility functions were applied to this basic data. It is shown that the formal decision methodology can be applied at several different levels. Examples are given in which the decision between several retrofits is changed from that resulting from a simple cost/benefit-ratio criterion by virtue of the decision-makinger's expressed (and assumed) preferences.

This issue describes several innovative technologies in modern manufacturing. Methods in which the HIRCIS sensor may cut costs in precision machining are described. Computer models and experimental methods aid in the chemical vapor deposition of high-temperature coatings. Shared computer networks provide communication for interactive collaboration. Sol-gel processing of tailored thin films furnish low cost, high quality glass coatings at room temperature. Integrated circuit characterization tools and expertise are available to improve quality and reliability in the microelectronic industry.

This paper describes preliminary experiments to investigate electron-beam radiolysis of model compounds appropriate for crude oil spills on water or soil. Since no previous work in this area is known to exist, the rate of destruction of such concentrated organic materials in aqueous media is not known. The experiments conducted here were designed to provide preliminary estimates of the destruction rate and the estimated costs. Samples of model compounds were irradiated to dose levels up to 700 Mrad (H{sub 2}0) and the change in chemical composition was determined by mass spectrometry/gas chromatography and Fourier transform infrared spectroscopy. It was found that a dose of 700 Mrads reduced the liquid volume of the model compound by 60% and that the major effect of irradiation was the formation of long chain alkanes and dimethyl and ethyl benzenes. Under certain conditions a solid polymer was found to form. When alcohol was present in the model compound, additional products included small quantities of ethane diodic acid, butanol, butanediol, and various other alcohols. Further research is recommended to obtain a better analysis of the products, better values for the destruction rates, and better understanding of dose rate effects.

For nearly 10 years, the Gould Electronics, Incorporated manufacturing plant in Chandler, Arizona, has been a model of how medium-temperature solar thermal energy systems can produce economical industrial process heat (IPH). In 1982, a solar IPH system was designed and built on the site by Solar Kinetics, Inc. The system has remained in operation and continues to provide economical process heat for Gould`s copper foil manufacturing operation. System performance and availability has fluctuated over the years, reaching a low point in early 1990 when the system was nearly inoperative because of equipment reliability problems. Gould teamed with engineers from Sandia National Laboratories` (Sandia) Solar Thermal Design Assistance Center to develop a plan to solve the technical problems and refurbish the field. The IPH system is currently operating at over 90-percent equipment availability, returning to Gould a net energy cost savings on the order of $7,500 per month. This paper presents the history and operation of the system from the perspective of the end user and describes the phased upgrade program undertaken with Sandia to refurbish the system.

The Jet Propulsion Laboratory is developing a large space-truss to support a micro-precision interferometer. A finite element model will be used to design and place passive and active elements in the truss to suppress vibration. To improve the model`s predictive capability, it is desirable to identify uncertain structural parameters in the model by utilizing experimental modal data. Testing of both the components and the system was performed to obtain the data necessary to identify the structural parameters. Extracting a modal model, absent of bias errors, from measured data requires great care in test design and implementation. Testing procedures that are discussed include: verification of non-constraining shaker attachment, quantification of the non-linear structural response, and the design and effects of suspension systems used to simulate a free structure. In addition to these procedures, the accuracy of the measured frequency response functions are evaluated by comparing functions measured with random excitation, using various frequency resolutions, and with step sine excitation.

This publication presents information from Sandia laboratories concerning developments in the following areas: a miniaturized sensor system for the testing and analysis of hazardous wastes;a cross-well seismic receiver for petroleum deposit detection; and computer codes for designing dish-stirling sytems.

The design, calibration, and preliminary test results for an underwater shock gauge are presented. The active element is a 25-{mu}m thick polyvinylidene fluoride shock sensor providing rise times as short as 50 ns. Fast rise time is essential to accurate recording of shock pulses with durations of only a few microseconds. The piezoelectric polymer provides a self-generating pressure sensor requiring neither amplification nor additional active electronic circuitry. The gauge package is designed to minimize electromagnetic interference from the high-voltage fire set used to power the exploding bridge wire pressure source. The gauge package is constructed to withstand the initial water shock as well as subsequent reactions in the water that result in strong water motion and bubble generation. Thin-film diaphragm sensors are not sturdy enough to withstand this environment. Initial tests show that the gauge responds in 200 ns in water and that low-frequency response is sufficient to allow recording for at least 40 {mu}s after the initial shock arrival.

Performance and functionality increases in network environments have in the need for readily accessible mass storage. UNIX{reg_sign}-based networks and mass storage systems are providing the required connectivity and interoperability, however, how UNIX-based mass storage systems are being used is not well documented. This paper describes a study of the usage of the UNIX-based Network Storage Service at Sandia National Laboratories.

A discrete element computer program, DMC (Distinct-Motion Code), has been used for several years to simulate blasting-induced rock motion. Recent enhancements of DMC`s capabilities have included addition of an algorithm that couples together rock motion and gas flow. This allows the user to specify a particular explosive which also specifies equation-of-state and other parameters necessary to model explosive gas flow from the blastwell. Rock loading by the flowing gas is calculated automatically. The mechanism for calculating the rock loading is the subject of this paper. The rock motion effects the gas flow calculation by changing the porosity. DMC is currently being used on a SLTN SPARCstation 2 computer workstation.

Short communication.

Solder wettability of Class II environmentally exposed Cu substrates coated with an organic solderability preservative (OSP) is being investigated. The OSP coatings slightly retarded the wetting behavior of 60Sn-40Pb solder during baseline testing of unaged coupons. A nominal increase in wetting angle, or decrease in wettability, was observed on the inhibited surfaces, particularly when less active fluxes were used. Small increases in the wetting time and decreases in the wetting rate were also measured. Simulated accelerated aging tests are underway to determine the effects of aging in a typical indoor industrial environment on the solder wettability of OSP coated Cu.

Sandia operated by AT&T for the US Department of Energy. Sandia has a billion dollar annual budget and over 8,000 employees. Sandia`s main sites are in Albuquerque, New Mexico; Livermore, California; and Tonopah, Nevada. Sandia has a broad base of engineering and scientific skills that supports the whole product cycle from advanced R&D through manufacturing and end-user support. Sandia`s original mission was to develop the non-nuclear portion of nuclear weapons. In the 1970s, the mission was expanded to include technical work on conventional and alternative energy sources. Recently, the mission was further expanded to include technology transfer and US competitiveness. This report describes the activities in the Component Development and Engineering Support Division 2000 (indicated by the bold lines on the organization chart). Division 2000 develops electrical, electronic, optical, explosive, mechanical, and other components that are the core products of Sandia systems. The Division also develops advanced capabilities in CAD/CAE, test, nondestructive test, programming, reliability, failure analysis, and simulation that are part of the core services required by Sandia systems. For each of the core products and services described in this brochure, there is a corresponding set of science and engineering capabilities that are Sandia`s core competencies. Also, there are systems groups that use these core products and services to develop ultra-reliable systems for Sandia`s customers. Most of these groups have literature available describing their capabilities and expertise.

Nuclear power plants have experienced actuations of fire protection systems (FPSs) under conditions for which these systems were not intended to actuate. They have also experienced advertent actuations with the presence of a fire. These actuations have often damaged nearby plant equipment. A review of past occurrences of both types of such events on nuclear power plant safety has been performed. Thirteen different scenarios leading to actuation of fire protection systems due to a variety of causes were identified. These scenarios range from inadvertant actuation caused by human errors to hardware failures and include seismic root causes and seismic/fire interactions. A quantification of these thirteen scenarios, where applicable, was performed on a BWR4/MKI. This report estimates the contribution of FPS actuations to core damage frequency and to risk.

Data are presented from the Geomechanical Evaluation (first phase), a very large scale in situ test fielded underground at the Waste Isolation Pilot Plant (WIPP). These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1984 and the test has been in operation since that time; gage data in this report cover the period from December 1984 through November 1990.

Nuclear power plants have experienced actuations of fire protection systems (FPSs) under conditions for which these systems were not intended to actuate and also have experienced advertent actuations with the presence of a fire. These actuations have often damaged safety-related equipment. A review of the impact of past occurrences of both types of such events and their impact on plant safety systems, an analysis of the risk impacts of such events on nuclear power plant safety, and a cost-benefit analysis of potential corrective measures have been performed. Thirteen different scenarios leading to actuation of fire protection systems due to a variety of causes were identified. These scenarios ranged from inadvertent actuation caused by human error to hardware failure, and include seismic root causes and seismic/fire interactions. A quantification of these thirteen root causes, where applicable, was performed on generically applicable scenarios. This document, Volume 2, contains appendices A,B, and C of this report.

Nuclear power plants have experienced actuations of fire protection systems (FPSs) under conditions for which these systems were not intended to actuate and also have experienced advertent actuations with the presence of a fire. These actuations have often damaged nearby plant equipment. A review of the impact of past occurrences of both types of such events, a quantification of the risk of FPS actuation, a sensitivity study of the quantification of the risk of FPS actuation and risk calculations in terms of person-REM have been performed. Thirteen different scenarios leading to actuation of fire protection systems due to a variety of causes were identified. A quantification of these thirteen scenarios, where applicable, was performed on a 3-loop Westinghouse Pressurized water Reactor (PWR). These scenarios ranged from inadvertent actuation caused by human error to hardware failures, and include seismic root causes and seismic/fire interaction. This report estimates the contribution of FPS actuations to core damage frequency and risk.

The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided.

Brine inflow to the Waste Isolation Pilot Plant is important in assessing the performance of the repository, and a mechanistic model is needed for performance calculations. Brine inflow experiments are being conducted, and formation parameters such as the permeability and diffusivity are inferred from these data using a simplified one-dimensional radial, uniform property, single-phase Darcy flow model. This model has met with limited success in interpreting some of the recent data. Much of the data could not be satisfactorily fit with the above model because the brine inflow rate increases with time, so a more mechanistic model is being developed based on the TOUGH and TOUGH2 computer codes. These codes are much more complex than the simplified model and include a number of parameters that have not been measured. Therefore, a one-dimensional brine inflow sensitivity study has been undertaken to evaluate the importance of a number of these parameters in influencing the behavior of brine inflow to open boreholes. In addition, two-phase conditions have been included in the study, and the sensitivity of gas inflow rates and the formation pressure and saturation distributions after 1 year are examined. These results should be helpful in determining what additional measurements are necessary to assist in the development of a more mechanistic brine inflow model.

The Precision Linear Shaped Charge (PLSC) design concept involves the independent fabrication and assembly of the liner (wedge of PLSC), the tamper/confinement, and explosive. The liner is the most important part of an LSC and should be fabricated by a more quality controlled, precise process than the tamper material. Also, this concept allows the liner material to be different from the tamper material. The explosive can be loaded between the liner and tamper as the last step in the assembly process rather than the first step as in conventional LSC designs. PLSC designs are shown to produce increased jet penetrations in given targets, more reproducible jet penetration, and more efficient explosive cross sections using a minimum amount of explosive. The Linear Explosive Shaped Charge Analysis (LESCA) code developed at SandiaNational Laboratories has been used to assist in the design of PLSCs. LESCA predictions for PLSC jet penetration in aluminum targets, jet tip velocities and jet-target impact angles are compared to measured data.