Publications

The uses of the LON, `Local Operating Network,` developed by Echelon Corporation, Palo Alto, California, has been expanded to handle a number of safeguards applications. A magnetic and vibration sensor pack has been developed to monitor for magnetic fields and vibration. This sensor pack can be attached to any source that generates a magnetic field, such as electrical solenoids or motors, to detect when the source is activated. New network nodes that interface directly with the raw data of Sandia developed radiation sensors, for detecting the presence of radiation sources, have been developed. The capacity of the network has been expanded to allow the transmission of large data sets, specifically the transmission of digital video images from the Sandia-developed-Image Compression and Authentication Module (ICAM).

For the past two years Sandia National Laboratories (SNL) has been involved in developing and installing Remote Monitoring Systems (RMS) at a number of sites around the world. Through the cooperation of the various countries and facilities, it has been possible to collect data on the requirements and performance of these systems that are for monitoring the movement of spent nuclear fuel. The data collected shows that the front end detection method can be a very useful concept to reduce the amount of data that has to be collected and, more importantly, reviewed by inspectors. Spent fuel storage monitoring is a major part of the non-proliferation monitoring that must be done since spent fuel is the by-product of all the power and research reactors worldwide. The movement of spent fuel is easier in many respects to monitor since it always requires protective shielding. This paper will describe a number of the Remote Monitoring Systems that have been installed to monitor spent fuel movement and the resulting decrease in data from the use of a sensor-driven front detection system. The reduction of the data collected and stored is also important to remote monitoring since it decreases the time required to transmit the data to a review site.

The accurate analytical determination of the response of radioactive material transportation packages to the hypothetical puncture accident requires inelastic analysis techniques. Use of this improved analysis method recudes the reliance on empirical and approximate methods to determine the safety for puncture accidents. This paper will discuss how inelastic analysis techniques can be used to determine the stresses, strains and deformations resulting from puncture accidents for thin skin materials with different backing materials. A method will be discussed to assure safety for all of these types of packages.

The safety of the transportation of radioactive materials by road and rail has been well studied and documented. However, the safety of waterborne transportation has received much less attention. Recent highly visible waterborne transportation campaigns have led to DOE and IAEA to focus attention on the safety of this transportation mode. In response, Sandia National Laboratories is conducting a program to establish a method to determine the safety of these shipments. As part of that program the mechanics involved in ship-to-ship collisions are being evaluated to determine the loadings imparted to radioactive material transportation packages during these collisions. This paper will report on the results of these evaluations.

This paper describes the results of an International Monitoring System synergy study using Sandia National Laboratory`s IVSEM (Integrated Verification System Evaluation Model). The study compares individual subsystem performance (seismic, infrasound, radionuclide, and hydroacoustic) with integrated system performance. The integrated system exhibits synergy because different sensor technologies cover different locations; thus, the integrated system covers more locations than can any individual subsystem. Energy and system performance can be further enhanced by allowing mixed technology detection and location.

An enhanced version of NetSim and an expanded supporting database were used to predict the detection and location performances of the International Seismic Monitoring System (ISMS) proposed in Working Paper 330 by the Ad Hoc Committee on a Nuclear Test Ban Treaty who supported the Conference on Disarmament in formulating the system monitoring requirements. The primary goals of this effort were to estimate the levels of 9 performance of the proposed ISMS and to predict the enhancements in location accuracy as would be provided by station and regional calibrations. An estimate of the detection threshold indicates that the primary network alone and in its mature state is capable of detecting a fully coupled 1 kiloton nuclear shot contained in consolidated rock anywhere on the earth. Further, the best detection thresholds appear in central Eurasia and range from 3.25 to 3.5 magnitude units. The threshold estimates were based on a 3P at 99% network detection criterion. Location performance estimates indicated that conventional location methods using regional and station calibrations are capable of achieving location accuracies better than 1000 square kilometers with 90% confidence largely everywhere for events with magnitudes at or above the detection threshold of the primary network. The poorest accuracies primarily appear on islands in the southern oceans and in portions of Antarctica. For events having a magnitude of 4.25 the location accuracy exceeds 100 square kilometers in almost the entire northern hemisphere, over a large portion of Africa, and a small portion of South America. Better accuracies than these are possible at larger event magnitudes. Regional and station calibrations yield net reductions in the elliptical areas of uncertainty by factors better than 6.0 using conventional location methods.

The United States Department of Energy (DOE) uses sensitive or classified parts and material that must be protected and accounted for. We believe there is a need for an automated system that can help protect and monitor these parts and material. In response to this need Sandia National Laboratories (SNL) has developed a real-time personnel and material tracking system called PAMTRAK that has been installed at selected DOE facilities. PAMTRAK safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. This paper describes our goals when designing PAMTRAK, the PAMTRAK system components, our current installations, and the benefits a site can expect when using PAMTRAK. So far PAMTRAK has been installed exclusively at government facilities; however, it is also applicable to private industries that need to protect high value assets. Through government programs such as CRADAs, SBIRs, and other mechanisms, the DOE often works with private industry to promote further development and commercialization of national laboratory developed technologies. SNL supports and welcomes partners and new users of PAMTRAK.

A remote monitoring system (RMS) field trial will be conducted for the International Atomic Energy Agency (IAEA) on highly enriched uranium materials in a vault at the Oak Ridge Y-12 Plant. Remote monitoring technologies are being evaluated to verify their capability to enhance the effectiveness and timeliness of IAEA safeguards in storage facilities while reducing the costs of inspections and burdens on the operator. Phase one of the field trial, which involved proving the satellite transmission of sensor data and safeguards images from a video camera activated by seals and motion sensors installed in the vault, was completed in September 1995. Phase two involves formal testing of the RMS as a tool for use by the IAEA during their tasks of monitoring the storage of nuclear material. The field trial to be completed during early 1997 includes access and item monitoring of nuclear materials in two storage trays. The RMS includes a variety of Sandia, Oak Ridge, and Aquila sensor technologies that provide video monitoring, radiation attribute measurements, and container identification to the on-site data acquisition system (DAS) by way of radio-frequency and Echelon LONWorks networks. The accumulated safeguards information will be transmitted to the IAEA via satellite (COMSAT/RSI) and international telephone lines.

The capture and storage of video images have been major engineering challenges for safeguard and security applications since the video camera provided a method to observe remote operations. The problems of designing reliable video cameras were solved in the early 1980`s with the introduction of the CCD (charged couple device) camera. The first CCD cameras cost in the thousands of dollars but have now been replaced by cameras costing in the hundreds. The remaining problem of storing and viewing video images in both attended and unattended video surveillance systems and remote monitoring systems is being solved by sophisticated digital compression systems. One such system is the PC-104 three card set which is literally a ``video engine`` that can provide power for video storage systems. The use of digital images in surveillance systems makes it possible to develop remote monitoring systems, portable video surveillance units, image review stations, and authenticated camera modules. This paper discusses the video card set and how it can be used in many applications.

There are important differences between the safety principles for nuclear weapons and for nuclear reactors. For example, a principal concern for nuclear weapons is to prevent electrical energy from reaching the nuclear package during accidents produced by crashes, fires, and other hazards, whereas the foremost concern for nuclear reactors is to maintain coolant around the core in the event of certain system failures. Not surprisingly, new methods have had to be developed to assess the risk from nuclear weapons. These include fault tree transformations that accommodate time dependencies, thermal and structural analysis techniques that are fast and unconditionally stable, and parameter sampling methods that incorporate intelligent searching. This paper provides an overview of the new methods for nuclear weapons and compares them with existing methods for nuclear reactors. It also presents a new intelligent searching process for identifying potential nuclear detonation vulnerabilities. The new searching technique runs very rapidly on a workstation and shows promise for providing an accurate assessment of potential vulnerabilities with far fewer physical response calculations than would be required using a standard Monte Carlo sampling procedure.

The US Nuclear Regulatory Commission (USNRC) and the European Commission (EC) have conducted a formal expert judgment elicitation jointly to systematically collect the quantitative information needed to perform consequence uncertainty analyses on a broad set of commercial nuclear power plants. Information from three sets of joint US/European expert panels was collected and processed. Information from the three sets of panels was collected in the following areas: in the phenomenological areas of atmospheric dispersion and deposition, in the areas of ingestion pathways and external dosimetry, and in the areas of health effects and internal dosimetry. This exercise has demonstrated that the uncertainty for particular issues as measured by the ratio of the 95th percentile to the 5th percentile can be extremely large (orders of magnitude), or rather small (factor of two). This information has already been used by many of the experts that were involved in this process in areas other than the consequence uncertainty field. The benefit to the field of radiological consequences is just beginning as the results of this study are published and made available to the consequence community.

Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure. Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.

The Cassini spacecraft is a deep space probe whose mission is to explore the planet Saturn and its moons. Since the spacecraft`s electrical requirements will be supplied by radioisotope thermoelectric generators (RTGs), the spacecraft designers and mission planners must assure that potential accidents involving the spacecraft do not pose significant human risk. The Cassini risk analysis team is seeking to perform a quantitative uncertainty analysis as a part of the overall mission risk assessment program. This paper describes the uncertainty analysis methodology to be used for the Cassini mission and compares it to the methods that were originally developed for evaluation of commercial nuclear power reactors.

Sandia National Laboratories has assembled an interdisciplinary team to explore the applicability of probabilistic logic modeling (PLM) techniques to model network reliability for a wide variety of communications network architectures. The authors have found that the reliability and failure modes of current generation network technologies can be effectively modeled using fault tree PLM techniques. They have developed a ``plug-and-play`` fault tree analysis methodology that can be used to model connectivity and the provision of network services in a wide variety of current generation network architectures. They have also developed an efficient search algorithm that can be used to determine the minimal cut sets of an arbitrarily-interconnected (non-hierarchical) network without the construction of a fault tree model. This paper provides an overview of these modeling techniques and describes how they are applied to networks that exhibit hybrid network structures (i.e., a network in which some areas are hierarchical and some areas are not hierarchical).

In November 1988, the US Nuclear Regulatory Commission (NRC) issued Generic Letter 88-20 requesting that all licensees perform an individual Plant Examination (IPE) to identify any plant-specific vulnerability to severe accidents and report the results to the Commission. This paper provides perspectives gained from reviewing 75 Individual Plant Examination (IPE) submittals covering 108 nuclear power plant units. Variability both within and among reactor types is examined to provide perspectives regarding plant-specific design and operational features, and modeling assumptions that play a significant role in the estimates of core damage frequencies in the IPEs.

This paper provides perspectives on human actions gained from reviewing 76 individual plant examination (IPE) submittals. Human actions found to be important in boiling water reactors (BWRs) and in pressurized water reactors (PWRs) are presented and the events most frequently found important are discussed. Since there are numerous factors that can influence the quantification of human error probabilities (HEPs) and introduce significant variability in the resulting HEPs (which in turn can influence which events are found to be important), the variability in HEPs for similar events across IPEs is examined to assess the extent to which variability in results is due to real versus artifactual differences. Finally, similarities and differences in human action observations across BWRs and PWRs are examined.

Arylamine-containing diblock copolymers were prepared via ring- opening metathesis polymerization (ROMP) to afford well-defined phase- separated materials. Alteration of the functionaity in a block, as well as the size of the blocks, allowed for the synthesis of self- assembled monolayers on a copper surface. The arylamine-containing block exhibited a strong binding affinity for the copper surface as seen by neutron reflectivity experiments. In addition, neutron reflectivity data verifies the self-assembly of block copolymer monolayers normal to the copper surface. Block copolymers prepared in this manner allow for the preparation of a wide range of adhesives and corrosion resistant materials. The use of ring-opening metathesis polymerization is important because it permits the synthesis of a variety of functionalized block copolymers.

The Agreement Between the Department of Defense of the United States and The Ministry of the Russian Federation for Atomic Energy (MINATOM) Concerning Control, Accounting, and Physical Protection of Nuclear Material, as well as a subsequent amendment to that agreement and a joint statement signed by the Department of Energy (DOE) and MINATOM, resulted in the selection of the Mayak Production Association (MPA) as one of the Russian enterprises that would participate with DOE Laboratories in expanded cooperation aimed at enhancing Material protection, Control and Accounting (MPC&A) systems in both countries. This paper describes the nature and scope of the expanded cooperation involving MPA and six DOE laboratories at an operating civilian, spent-nuclear-fuel reprocessing plant designated RT-1. RT-1 produces, among other materials, reactor-grade plutonium dioxide, a direct-use material that is stored within the boundaries of this plant. Initial efforts at expanded cooperation will focus on enhancements to the existing MPC&A systems at MPA`s RT-1 plant.

This paper describes an evolutionary development process that will lead to spent fuel measurements that directly measure fissile reactivity. First, the Fork measurement system has been used to verify the burnup of pressurized water reactor (PWR) spent-fuel assemblies at U.S. nuclear utilities. Fork measurements have demonstrated the utility of the passive Fork system to verify reactor records with a single 100-second measurement on each assembly. Second, an Advanced Fork system incorporating collimated gamma-ray spectroscopy has been designed to permit advanced calibration techniques that are independent of reactor burnup records and to allow rapid axial scanning of spent fuel assemblies. Third, an Active Fork system incorporating a neutron source to interrogate spent fuel is proposed to provide the capability to measure fissile reactivity, when compared to measurements on fresh fuel assemblies of the same design. The Advanced and Active Fork systems have wide applicability to spent fuel verification for PWR, boiling water reactor (BWR), and U.S. Department of Energy (DOE) spent fuel.

Since 1994, the U.S. Department of Energy (DOE) has provided cooperative assistance to the non-nuclear weapons states of the Former Soviet Union. This effort, within DOE`s program of Material Protection, Control, and Accounting (MPC&A), identified the Institute of Nuclear Physics (INP) in Uzbekistan and the Ignalina Nuclear Power Plant (INPP) in Lithuania as sites for cooperative MPC&A projects. The INP, located just outside of Tashkent, is the site of a 10-megawatt WWR-SM research reactor. This reactor is expected to remain operational as a major nuclear research and isotope production reactor for Central Asia. The INPP, located 100 kilometers northeast of the capital city of Vilnius, consists of two Russian-made RBMK reactors with a combined power output of 3,000 megawatts (electric). This power plant has been the subject of international safety and security concerns, which prompted DOE`s cooperative assistance effort. This paper describes U.S. progress in a multi-national effort directed at implementing physical protection upgrades in Lithuania and Uzbekistan. The upgrades agreed upon between DOE and the INP and between DOE and the INPP have been designed to interface with upgrades being implemented by other donor countries. DOE/INPP upgrade projects include providing training on U.S. approaches to physical protection, access control through the main vehicle portal, a hardened central alarm station, and improved guard force communications. DOE/INP upgrade projects in Uzbekistan include an access control system, a hardened fresh fuel storage vault, an interior intrusion detection and assessment system, and an integrated alarm display and assessment system.

The optical correlator described in this report is intended to serve as an attention-focusing processor. The objective is to narrowly bracket the range of a parameter value that characterizes the correlator input. The input is a waveform collected by a satellite-borne receiver. In the correlator, this waveform is simultaneously correlated with an ensemble of ionosphere impulse-response functions, each corresponding to a different total-electron-count (TEC) value. We have found that correlation is an effective method of bracketing the range of TEC values likely to be represented by the input waveform. High accuracy in a computational sense is not required of the correlator. Binarization of the impulse-response functions and the input waveforms prior to correlation results in a lower correlation-peak-to-background-fluctuation (signal-to-noise) ratio than the peak that is obtained when all waveforms retain their grayscale values. The results presented in this report were obtained by means of an acousto-optic correlator previously developed at SNL as well as by simulation. An optical-processor architecture optimized for 1D correlation of long waveforms characteristic of this application is described. Discussions of correlator components, such as optics, acousto-optic cells, digital micromirror devices, laser diodes, and VCSELs are included.

The simplest general kinetic schemes applicable to the oxidation of polymers are presented, discussed and analyzed in terms of the underlying kinetic assumptions. For the classic basic autoxidation scheme (BAS), which involves three bimolecular termination steps and is applicable mainly to unstabilized polymers, typical assumptions used singly or in groups include (1) long kinetic chain length, (2) a specific ratio of the termination rate constants and (3) insensitivity to the oxygen concentration (e.g., domination by a single termination step). Steady-state solutions for the rate of oxidation are given in terms of one, two, three, or four parameters, corresponding respectively to three, two, one, or zero kinetic assumptions. The recently derived four-parameter solution predicts conditions yielding unusual dependencies of the oxidation rate on oxygen concentration and on initiation rate, as well as conditions leading to some unusual diffusion-limited oxidation profile shapes. For stabilized polymers, unimolecular termination schemes are typically more appropriate than bimolecular. Kinetics incorporating unimolecular termination reactions are shown to result in very simple oxidation expressions which have been experimentally verified for both radiation-initiated oxidation of an EPDM and thermoxidative degradation of nitrile and chloroprene elastomers.

One emphasis of weapon surety (safety and security) at Sandia National Laboratories is the assessment of fire-related risk to weapon systems. New developments in computing hardware and software make possible the application of a new generation of very powerful analysis tools for surety assessment. This paper illustrates the application of some of these computational tools to assess the robustness of a conceptual firing set design in severe thermal environments. With these assessment tools, systematic interrogation of the parameter space governing the thermal robustness of the firing set has revealed much greater vulnerability than traditional ad hoc techniques had indicated. These newer techniques should be routinely applied in weapon design and assessment to produce more fully characterized and robust systems where weapon surety is paramount. As well as helping expose and quantify vulnerabilities in systems, these tools can be used in design and resource allocation processes to build safer, more reliable, more optimal systems.

A massively-parallel ab initio computer code, which uses Gaussian bases, pseudopotentials, and the local density approximation, permits the study of transition-metal systems with literally hundreds of atoms. We present total energies and relaxed geometries for Ru, Pd, and Ag clusters with N = 55, 135, and 140 atoms; we also used the DMOL code to study 13-atom Pd and Cu clusters, with and without hydrogen. The N = 55 and 135 clusters were chosen because of simultaneous cubo-octahedral (fcc) and icosahedral (icos) sub-shell closings, and we find icos geometries are preferred. Remarkably large compressions of the central atoms are observed for the icos structures (up to 6% compared with bulk interatomic spacings), while small core compressions ({approx} 1 %) are found for the fcc geometry. In contrast, large surface compressive relaxations are found for the fcc clusters ({approx} 2-3% in average nearest neighbor spacing), while the icos surface displays small compressions ({approx} 1%). Energy differences between icos and fcc are smallest for Pd, and for all systems the single-particle densities of states closely resembles bulk results. Calculations with N = 134 suggest slow changes in relative energy with N. Noting that the 135-atom fcc has a much more open surface than the icos, we also compare N = 140 icos and fcc, the latter forming an octahedron with close packed facets. These icos and fcc clusters have identical average coordinations and the octahedron is found to be preferred for Ru and Pd but not for Ag. Finally, we compare Harris functional and LDA energy differences on the N = 140 clusters, and find fair agreement only for Ag.

A prototype sensor fusion framework called the {open_quotes}Knowledge Assistant{close_quotes} has been developed and tested on a gantry robot at Sandia National Laboratories. This Knowledge Assistant guides the robot operator during the planning, execution, and post analysis stages of the characterization process. During the planning stage, the Knowledge Assistant suggests robot paths and speeds based on knowledge of sensors available and their physical characteristics. During execution, the Knowledge Assistant coordinates the collection of data through a data acquisition {open_quotes}specialist.{close_quotes} During execution and postanalysis, the Knowledge Assistant sends raw data to other {open_quotes}specialists,{close_quotes} which include statistical pattern recognition software, a neural network, and model-based search software. After the specialists return their results, the Knowledge Assistant consolidates the information and returns a report to the robot control system where the sensed objects and their attributes (e.g., estimated dimensions, weight, material composition, etc.) are displayed in the world model. This report highlights the major components of this system.

Nuclear cooperation between Argentina and Brazil has been growing since the early 1980`s and as it grew, so did cooperation with the US Department of Energy (DOE). The Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) was formed in December 1991 to operate the Common System of Accounting and Control of Nuclear Materials (SCCC). In April 1994, ABACC and the DOE signed an Agreement of Cooperation in nuclear material safeguards. This cooperation has included training safeguards inspectors, exchanging nuclear material measurement and containment and surveillance technology, characterizing reference materials, and studying enrichment plant safeguards. The goal of the collaboration is to exchange technology, evaluate new technology in Latin American nuclear facilities, and strengthen regional safeguards. This paper describes the history of the cooperation, its recent activities, and future projects. The cooperation is strongly supported by all three governments: the Republics of Argentina and Brazil and the United States.

With increased awareness of the significant changes of the past several years and their effect on the expectations to international safeguards, it is necessary to reflect on the direction for development of nuclear safeguards in a new era and the resulting implications. The time proven monitoring techniques, based on quantitative factors and demonstrated universal application, have shown their merit. However, the new expectations suggest a possibility that a future IAEA safeguards system could rely more heavily on the value of a comprehensive, transparent, and open implementation regime. With the establishment of such a regime, it is highly likely that remote monitoring will play a significant role. Several states have seen value in cooperating with each other to address the many problems associated with the remote interrogation of integrated monitoring systems. As a consequence the International Remote Monitoring Project was organized to examine the future of remote monitoring in International Safeguards. This paper provides an update on the technical issues, the future plans, and the safeguards implications of cooperative programs relating to remote monitoring. Without providing answers to the policy questions involved, it suggests that it is timely to begin addressing these issues.

To support the signal processing and data visualization needs of CTBT related projects at SNL, a MATLAB based GUI was developed. This program is known as MatSeis. MatSeis was developed quickly using the available MATLAB functionality. It provides a time-distance profile plot integrating origin, waveform, travel-time, and arrival data. Graphical plot controls, data manipulation, and signal processing functions provide a user friendly seismic analysis package. In addition, the full power of MATLAB (the premier tool for general numeric processing and visualization) is available for prototyping new functions by end users. This package is being made available to the seismic community in the hope that it will aid CTBT research and will facilitate cooperative signal processing development. 2 refs., 5 figs.

In the field of explosives detection there is currently a need for a calibrated source of explosives vapor. Such a source could be used to test and calibrate explosives detection systems which identify explosives via the collection of vapor or air borne particulate matter. This paper describes the principles of operation and evaluation of one such explosives vapor generator. This generator is based on the diffusion of vapor from a condensed phase (i.e., solid or liquid) in a source reservoir, and the output has been tied to a National Institute of Standards and Technology (NIST) mass standard. We discuss results of the calibration of this generator using the explosives 2,4,6-trinitrotoluene (TNT) and cyclonite (RDX). The mass output of this generator is stable over hundreds of hours of continuous operation, and is adjustable from the low picograms(pg)/sec range to at least 10 nanograms(ng)/sec. In the case of TNT, the mass output correlates well with predictions based on gas phase diffusion theory. In the case of RDX, the agreement with theory is less good. This may be attributable to a variety of factors, possibly including inaccuracies in the published data on RDX vapor pressure as a function of temperature.

A previously-developed approximation to the first integral of the Poisson equation enables one to obtain solutions for the voltage- current characteristics of a radio-frequency (rf) plasma sheath that are valid over the whole range of inertial response of the ions to an imposed rf voltage or current-specified conditions. The theory reproduced the time-dependent voltage-current characteristics of the two extreme cases corresponding to the Lieberman rf sheath theory and the Metze-Ernie-Oskam theory. In this paper the sheath model is connected to the plasma bulk description, and a prescription is given for the ion relaxation time constant, which determines the time-dependent ion impact energy on the electrode surface. It appears that this connected model should be applicable to those high density, low pressure plasmas in which the Debye length is a small fraction of the ion mean free path, which itself is a small fraction of the plasma dimension.

Edge finishing processes have seemed like ideal candidates for automation. Most edge finishing processes are unpleasant, dangerous, tedious, expensive, not repeatable and labor intensive. Estimates place the cost of manual edge finishing processes at 12% of the total cost of fabricating precision parts. For small, high precision parts, the cost of hand finishing may be as high as 305 of the total part cost. Up to 50% of this cost could be saved through automation. This cost estimate includes the direct costs of edge finishing: the machining hours required and the 30% scrap and rework rate after manual finishing. Not included in these estimates are the indirect costs resulting from cumulative trauma disorders and retraining costs caused by the high turnover rate for finishing jobs.. Despite the apparent economic advantages, edge finishing has proven difficult to automate except in low precision and/or high volume production environments. Finishing automation systems have not been deployed successfully in Department of Energy defense programs (DOE/DP) production, A few systems have been attempted but have been subsequently abandoned for traditional edge finishing approaches: scraping, grinding, and filing the edges using modified dental tools and hand held power tools. Edge finishing automation has been an elusive but potentially lucrative production enhancement. The amount of time required for reconfiguring workcells for new parts, the time required to reprogram the workcells to finish new parts, and automation equipment to respond to fixturing errors and part tolerances are the most common reasons cited for eliminating automation as an option for DOE/DP edge finishing applications. Existing automated finishing systems have proven to be economically viable only where setup and reprogramming costs are a negligible fraction of overall production costs.

The US Department of Energy (DOE) and Gosatomnadzor (GAN) of Russia are engaged in a program of cooperation to enhance the nonproliferation of nuclear weapons by developing a strong national system of nuclear material protection, control and accounting (MPC&A). The purpose of this system is to prevent the theft, diversion or unauthorized use of nuclear materials. DOE and GAN signed an agreement to this effect in June 1995. DOE and GAN have since agreed to cooperate in several important areas including: developing regulatory documents; designing a federal material control and accounting (MC&A) information; providing MPC&A equipment for GAN inspectors and assistance in developing Russian equipment; designing an MPC&A oversight information system for GAN; training inspectors and operators; and upgrading MPC&A at six non-Minatom facilities that operate with highly enriched uranium. In order to assist GAN in its ongoing efforts to enhance its national system of nuclear MPC&A, DOE provides GAN with technical assistance in the form of equipment, supplies, training and other services. This paper will describe the program of cooperation between DOE and GAN to further the national security interests of both the United States and Russia. Specifically, it will focus on those mutually beneficial, technically oriented projects that are encompassed in the program. This cooperative effort represents a vital aspect of DOE`s government-to-government program to support Russia`s nonproliferation efforts.

The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the United States without compromising the national security to the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct- use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring system, and discuss the impacts that remote monitoring will have on the national security of participating countries.

Thermal desorption/gas chromatography (TD/GC) was used to screen soil samples on site for total petroleum hydrocarbon (TPH) content during a RCRA Facility Investigation (RFI). It proved to be a rapid, cost- effective tool for detecting non-aromatic mineral oil in soil. The on- site TD/GC results correlated well with those generated at an off- site laboratory for samples analyzed in accordance with EPA Method 418.1.

Photovoltaic (PV) power systems offer the prospect of allowing a utility company to meet part of the daily peak system load using a renewable resource. Unfortunately, some utilities have peak system- load periods that do not match the peak production hours of a PV system. Adding a battery energy storage system to a grid-connected PV power system will allow dispatching the stored solar energy to the grid at the desired times. Batteries, however, pose system limitations in terms of energy efficiency, maintenance, and cycle life. A new control system has been developed, based on available PV equipment and a data acquisition system, that seeks to minimize the limitations imposed by the battery system while maximizing the use of PV energy. Maintenance requirements for the flooded batteries are reduced, cycle life is maximized, and the battery is operated over an efficient range of states of charge. This paper presents design details and initial performance results on one of the first installed control systems of this type.

This report presents the results of laboratory tests conducted on soil core samples obtained prior to an instantaneous profile test conducted west of the Mixed Waste Landfill in Technical Area III. The instantaneous profile test was conducted to measure in situ hydrologic parameters controlling unsaturated flow and contaminant transport in the near - surface vadose zone. Soil core samples from the instantaneous profile test plot were tested in the Sandia National Laboratory`s Environmental Restoration Project Hydrology Laboratory to measure saturated hydraulic conductivity and the relationships between moisture content and soil water tension. Data from laboratory tests and the instantaneous profile field test were then modeled using the computer code RETC to quantify moisture content, soil water tension, and unsaturated hydraulic conductivity relationships. Results content, soil verified that a combination of laboratory and field data yielded a more complete definition of hydrologic properties than either laboratory or field data alone. Results also indicated that at native moisture contents, the potential for significant unsaturated aqueous flow is limited, while at saturated or near - saturated conditions, preferential flow may occur.

Over an extended period of time station noise spectra were collected from various sources for use in estimating the detection and location performance of global networks of seismic stations. As the database of noise spectra enlarged and duplicate entries became available, an effort was mounted to more carefully select station noise spectra while discarding others. This report discusses the methodology and criteria by which the noise spectra were selected. It also identifies and illustrates the station noise spectra which survived the selection process and which currently contribute to the modeling efforts. The resulting catalog of noise statistics not only benefits those who model network performance but also those who wish to select stations on the basis of their noise level as may occur in designing networks or in selecting seismological data for analysis on the basis of station noise level. In view of the various ways by which station noise were estimated by the different contributors, it is advisable that future efforts which predict network performance have available station noise data and spectral estimation methods which are compatible with the statistics underlying seismic noise. This appropriately requires (1) averaging noise over seasonal and/or diurnal cycles, (2) averaging noise over time intervals comparable to those employed by actual detectors, and (3) using logarithmic measures of the noise.

The Explosive Components Facility (ECF) is a major, low-hazard, non-nuclear, research and development facility of the Sandia National Laboratories/Albuquerque (SNL). Sandia Corporation, a subsidiary of Lockheed-Martin, operates this designated User Facility for the Department of Energy (DOE). The ECF consolidates many SNL energetic-materials activities and provides a unique combination of explosive-technologies, neutronic-components, batteries, and weapons-evaluation capabilities. This paper describes the project objectives, the basic building features, programmatic capabilities, and the processes used to beneficially occupy and assess readiness to operate.

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 a linear shaped charge (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 have been shown to produce increased jet penetrations in given targets, more reproducible jet penetration, and more efficient explosive cross-section geometries using a minimum amount of explosive. The Linear Explosive Shaped Charge Analysis (LESCA) code developed at Sandia National Laboratories has been used to assist in the design of PLSCs. LESCA predictions for PLSC jet tip velocities, jet-target impact angles, and jet penetration in aluminum and steel targets are compared to measured data. The advantages of PLSC over conventional LSC are presented. As an example problem, the LESCA code was used to analytically develop a conceptual design for a PLSC component to sever a three-inch thick 1018 steel plate at a water depth of 500 feet (15 atmospheres).

This paper describes high reliability radiation hardened computers built by Sandia for application aboard DOE satellite programs requiring 32 bit processing. The computers highlight a radiation hardened (10 kGy(Si)) R3000 executing up to 10 million reduced instruction set instructions (RISC) per second (MIPS), a dual purpose module control bus used for real-time default and power management which allows for extended mission operation on as little as 1.2 watts, and a local area network capable of 480 Mbits/s. The central processing unit (CPU) is the NASA Goddard R3000 nicknamed the ``Mongoose or Mongoose 1``. The Sandia Satellite Computer (SSC) uses Rational`s Ada compiler, debugger, operating system kernel, and enhanced floating point emulation library targeted at the Mongoose. The SSC gives Sandia the capability of processing complex types of spacecraft attitude determination and control algorithms and of modifying programmed control laws via ground command. And in general, SSC offers end users the ability to process data onboard the spacecraft that would normally have been sent to the ground which allows reconsideration of traditional space-grounded partitioning options.

The continued exploration of Mars is a high priority item with NASA`s interplanetary science community. It has long been a desire of this group to define an experiment that would investigate the possible presence and location of water/ice beneath the Martian surface. Until recently, however, there has not been a flight experiment dedicated to achieving this goal. This paper describes a concept design effort conducted at Sandia National Labs in collaboration with JPL and CalTech that has produced a feasible flight system to investigate this question.

Under acidic sol-gel polymerization conditions, 1,3-bis(triethoxysilyl)-propane (1) and 1,4-bis(triethoxysilyl)butane (2) were shown to preferentially form cyclic disilsesquioxanes 3 and 4 rather than the expected 1,3-propylene- and 1,4-butylene-bridged polysilsesquioxane gels. Formation of 3 and 4 is driven by a combination of an intramolecular cyclization to six and seven membered rings, and a pronounced reduction in reactivity under acidic conditions as a function of increasing degree of condensation. The ease with which these relatively unreactive cyclic monomers and dimers are formed (under acidic conditions) helps to explain the difficulties in forming gels from 1 and 2. The stability of cyclic disilsesquioxanes was confirmed withe the synthesis of 3 and 4 in gram quantities; the cyclic disilsesquioxanes react slowly to give tricyclic dimers containing a thermodynamically stable eight membered siloxane ring. Continued reactions were shown to perserve the cyclic structure, opening up the possibility of utilizing cyclic disilsesquioxanes as sol-gel monomers. Preliminary polymerization studies with these new, carbohydrate-like monomers revealed the formation of network poly(cyclic disilsesquioxanes) under acidic conditions and polymerization with ring-opening under basic conditions.

The goal of this laboratory-directed research and development (LDRD) project was to develop a new and efficient electronic structure algorithm that would scale linearly with system size. Since the start of the program this field has received much attention in the literature as well as in terms of focused symposia and at least one dedicated international workshop. The major success of this program is the development of a unique algorithm for minimization of the density functional energy which replaces the diagonalization of the Kohn-Sham hamiltonian with block diagonalization into explicit occupied and partially occupied (in metals) subspaces and an implicit unoccupied subspace. The progress reported here represents an important step toward the simultaneous goals of linear scaling, controlled accuracy, efficiency and transferability. The method is specifically designed to deal with localized, non-orthogonal basis sets to maximize transferability and state by state iteration to minimize any charge-sloshing instabilities and accelerate convergence. The computational demands of the algorithm do scale as the particle number, permitting applications to problems involving many inequivalent atoms. Our targeted goal is at least 10,000 inequivalent atoms on a teraflop computer. This report describes our algorithm, some proof-of-principle examples and a state of the field at the conclusion of this LDRD.

Accident source terms, source term probabilities, consequences, and risks are developed for ship collisions that might occur in U.S. ports during the shipment of spent fuel from foreign research reactors to the United States in break-bulk freighters.

This paper presents a comparison of calculations of severe accident progression for several postulated accident sequences for representative Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR) nuclear power plants performed with the MELCOR 1.8.3 and the MAAP4 computer codes. The PWR system examined in this study is a 1100 MWe system similar in design to a Westinghouse 3-loop plant with a large dry containment; the BWR is a 1100 MWe system similar in design to General Electric BWR/4 with a Mark I containment. A total of nine accident sequences were studied with both codes. Results of these calculations are compared to identify major differences in the timing of key events in the calculated accident progression or other important aspects of severe accident behavior, and to identify specific sources of the observed differences.

The topics covered in this session include: slimhole testing and data acquisition, theoretical and numerical models for slimholes, and an overview of the analysis of slimhole data acquired by the Japanese. The fundamental issues discussed are concerned with assessing the efficacy of slimhole testing for the evaluation of geothermal reservoirs. the term reservoir evaluation is here taken to mean the assessment of the potential of the geothermal reservoir for the profitable production of electrical power. As an introduction to the subsequent presentations and discussions, a brief summary of the more important aspects of the use of slimholes in reservoir evaluation is given.

Converting a large, heterogeneous, networked, environment to ATM (Asynchronous Transfer Mode) can yield many benefits. Before these benefits can be reaped, however, numerous decisions must be made and implemented. This paper presents a case study which describes the steps that were necessary to convert a backbone network at Sandia National Laboratories in Albuquerque, New Mexico to ATM. It presents each step by explaining its importance and what options were considered along with their tradeoffs. It is hoped that organizations contemplating converting to ATM will have a better understanding of how the transition is implemented after reading this paper.

A study using long-period seismic data showed that seismic events can be detected and located based on correlations of processed waveform profiles with the profile expected for an event. In this technique both time and space are discretized and events are found by forming profiles and calculating correlations for all time-distance points. events are declared at points with large correlations. In the first phase of the Waveform Correlation Event Detection System (WCEDS) Project at Sandia Labs we have developed a prototype automatic event detection system based on Shearer`s work which shows promise for treaty monitoring applications. Many modifications have been made to meet the requirements of the monitoring environment. A new full matrix multiplication has been developed which can reduce the number of computations needed for the data correlation by as much as two orders of magnitude for large grids. New methodology has also been developed to deal with the problems caused by false correlations (sidelobes) generated during the correlation process. When an event has been detected, masking matrices are set up which will mask all correlation sidelobes due to the event, allowing other events with intermingled phases to be found. This process is repeated until a detection threshold is reached. The system was tested on one hour of Incorporated Research Institutions for Seismology (IRIS) broadband data and built all 4 of the events listed in the National Earthquake Information Center (NEIC) Preliminary Determination of Epicenters (PDE) which were observable by the IRIS network. A continuous execution scheme has been developed for the system but has not yet been implemented. Improvements to the efficiency of the code are in various stages of development. Many refinements would have to be made to the system before it could be used as part of an actual monitoring system, but at this stage we know of no clear barriers which would prevent an eventual implementation of the system.

For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

A set of model interface guidelines, called MIG, is presented as a means by which any compliant numerical material model can be rapidly installed into any parent code without having to modify the model subroutines. Here, {open_quotes}model{close_quotes} usually means a material model such as one that computes stress as a function of strain, though the term may be extended to any numerical operation. {open_quotes}Parent code{close_quotes} means a hydrocode, finite element code, etc. which uses the model and enforces, say, the fundamental laws of motion and thermodynamics. MIG requires the model developer (who creates the model package) to specify model needs in a standardized but flexible way. MIG includes a dictionary of technical terms that allows developers and parent code architects to share a common vocabulary when specifying field variables. For portability, database management is the responsibility of the parent code. Input/output occurs via structured calling arguments. As much model information as possible (such as the lists of required inputs, as well as lists of precharacterized material data and special needs) is supplied by the model developer in an ASCII text file. Every MIG-compliant model also has three required subroutines to check data, to request extra field variables, and to perform model physics. To date, the MIG scheme has proven flexible in beta installations of a simple yield model, plus a more complicated viscodamage yield model, three electromechanical models, and a complicated anisotropic microcrack constitutive model. The MIG yield model has been successfully installed using identical subroutines in three vectorized parent codes and one parallel C++ code, all predicting comparable results. By maintaining one model for many codes, MIG facilitates code-to-code comparisons and reduces duplication of effort, thereby reducing the cost of installing and sharing models in diverse new codes.

This report provides a study of gases in microporous solids using molecular modeling. The theory of gas transport in porous materials as well as the molecular modeling literature is briefly reviewed. Work complete is described and analyzed with retard to the prevailing theory. The work covers two simple subjects, construction of porous solid models and diffusion of He, H{sub 2}, Ar and CH{sub 4} down a pressure gradient across the material models as in typical membrane permeation experiments. The broader objective is to enhance our capability to efficiently and accurately develop, produce and apply microporous materials.

A new class of inorganic ion exchange material called crystalline silicotitanates (CST) has been developed for radioactive waste treatment in a collaborative effort between Sandia National Laboratories and Texas A&M University. The Sandia National Laboratories Laboratory Directed Research and Development program provided the initial funding for this effort and this report summarizes the rapid progress that was achieved. A wide range of compositions were synthesized, evaluated for cesium (Cs) removal efficiency, and a composition called TAM-5 was developed that exhibits high selectivity and affinity for Cs and strontium (Sr). Tests show it can remove parts per million concentrations of Cs{sup +} from highly alkaline, high-sodium, simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. In experiments with solutions that simulate highly alkaline Hanford defense wastes, the crystalline silicotitanates exhibit distribution coefficients for Cs{sup +} of greater than 2,000 ml/g, and distribution coefficients greater than 10,000 ml/g for solutions adjusted to a pH between 1 and 10. In addition, the CSTs were found to exhibit distribution coefficients for Sr{sup +} greater than 100,000 ml/g and for plutonium of 2,000 ml/g from simulated Hanford waste. The CST crystal structure was determined and positions of individual atoms identified using x-ray and neutron diffraction. The structural information has permitted identification of the ion exchange sites and provided insights into the strong effect of pH on Cs ion exchange. Information on the synthesis, composition, and structure of CST is considered proprietary and is not discussed in this report.

Groundwater in and around underground radioactive waste repositories has several potential effects on repository performance. Repository excavation produces conditions where the repository is underpressured relative to the surrounding host rock, resulting in groundwater inflow to the repository. The presence of groundwater has been shown to enhance gas generation from emplaced waste forms, which expedites repository pressurization. Repository pressurization results in an increased driving force for dissolved radionuclide movement away from the repository. Repository excavation also produces a zone surrounding the repository having disturbed hydrologic and geochemical properties. Within the disturbed rock zone (DRZ), intrinsic permeability and porosity change over time due to the formation of microfractures and grain boundary dilation. Additionally, elastic and inelastic changes in pore volume may cause variation in the near-field fluid pressure and fluid saturation distributions that influence groundwater flow toward the repository excavation. Increased permeability, decreased pore-fluid pressure, and partially saturated conditions in the DRZ contribute to enhancing potential release pathways away from the repository. It is important for a repository performance assessment to consider chemical processes, hydrologic processes, as well as the complex coupling between these processes.

We have investigated tailoring damage effects of explosive devices by addition of unconventional materials, specifically combustible metals. Initial small-scale as well as full-scale testing has been performed. The explosives functioned to disperse and ignite these materials. Incendiary, enhanced-blast, and fragment-damage effect have been identified. These types of effects can be used to extend the damage done to hardened facilities. In other cases it is desirable to disable the target with minimal collateral damage. Use of unconventional materials allows the capability to tailor the damage and effects of explosive devices for these and other applications. Current work includes testing of an incendiary warhead for a penetrator.

This paper outlines the use of a failure modes and effects analysis for the safety assessment of a robotic system being developed at Sandia National Laboratories. The robotic system, the weigh and leak check system, is to replace a manual process for weight and leakage of nuclear materials at the DOE Pantex facility. Failure modes and effects analyses were completed for the robotics process to ensure that safety goals for the systems have been met. Due to the flexible nature of the robot configuration, traditional failure modes and effects analysis (FMEA) were not applicable. In addition, the primary focus of safety assessments of robotics systems has been the protection of personnel in the immediate area. In this application, the safety analysis must account for the sensitivities of the payload as well as traditional issues. A unique variation on the classical FMEA was developed that permits an organized and quite effective tool to be used to assure that safety was adequately considered during the development of the robotic system. The fundamental aspects of the approach are outlined in the paper.

Since 1978, Sandia National Laboratories has provided training courses in the systematic design of Physical Protection Systems (PPS). One such course, the International Training Course (TC) on the Physical Protection of Nuclear Facilities and Materials, is sponsored by the Department of Energy`s International Safeguards Division , the International Atomic Energy Agency, and the Department of State. Since 1978, twelve 3- and 4-week classes have been conducted by Sandia for these sponsors. One- and two-week adaptations of this course have been developed for other customers, and, since 1994, nine of these abbreviated courses have been presented in the Russian language to participants from the Former Soviet Union (SU). These courses have been performed in support of the Department of Energy`s program on Material Protection, Control and Accounting (MPC&A) for the Russian Federation and the Newly Independent States. MPC&A physical protection training assumes participants have more narrowly defined backgrounds. In using affective approaches, the overall goal of training in the context of the MPC&A Program is to develop modern and effective, indigenous capabilities for physical protection system design and analysis within the SU. This paper contrasts the cognitive and affective approaches to training and indicates why different approaches are required for the ITC and the MPC&A Programs.

A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.

One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs.

Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Sandia National Laboratories Environmental Restoration Technologies Department is developing environmental restoration technologies through funding form the US Department of Energy`s (DOE`s) Office of Science and Technology. Initially, this technology development has been through the Mixed Waste Landfill Integrated Demonstration (MWLID). It is currently being developed through the Contaminant Plume containment and Remediation Focus Area, the Landfill Stabilization Focus Area, and the Characterization, Monitoring, and Sensor Cross-Cutting Program. This Technology Integration Project (TIP) was responsible for transferring MWLID-developed technologies for routine use by environmental restoration groups throughout the DOE complex and commercializing these technologies to the private sector. The MWLID`s technology transfer/commercialization successes were achieved by involving private industry in development, demonstration, and technology transfer/commercialization activities; gathering and disseminating information about MWLID activities and technologies; and promoting stakeholder and regulatory involvement. From FY91 through FY95, 30 Technical Task Plans (TTPs) were funded. From these TTPs, the MWLID can claim 15 technology transfer/commercialization successes. Another seven technology transfer/commercialization successes are expected. With the changeover to the focus areas, the TIP continued the technology transfer/commercialization efforts begun under the MWLID.

The analysis of component fatigue lifetime for a wind energy conversion system (WECS) requires that the component load spectrum be formulated in terms of stress cycles. Typically, these stress cycles are obtained from time series data using a cycle identification scheme. As discussed by many authors, the matrix or matrices of cycle counts that describe the stresses on a turbine are constructed from relatively short, representative samples of time series data. The ability to correctly represent the long-term behavior of the distribution of stress cycles from these representative samples is critical to the analysis of service lifetimes. Several techniques are currently used to convert representative samples to the lifetime cyclic loads on the turbine. There has been recently developed a set of fitting algorithms that is particularly useful for matching the body of the distribution of fatigue stress cycles on a turbine component. Fitting techniques are now incorporated into the LIFE2 fatigue/fracture analysis code for wind turbines. In this paper, the authors provide an overview of the fitting algorithms and describe the pre- and post-count algorithms developed to permit their use in the LIFE2 code. Typical case studies are used to illustrate the use of the technique.

A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log{sub 10} saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs.

A folded compact range configuration has been developed ant the Sandia National Laboratories` compact range antenna and radar-cross- section measurement facility as a means of performing indoor, environmentally-controlled, far-field simulations of synthetic aperture radar (SAR) measurements of distributed target samples (i.e. gravel, sand, etc.). The folded compact range configuration has previously been used to perform coherent-change-detection (CCD) measurements, which allow disturbances to distributed targets on the order of fractions of a wavelength to be detected. This report describes follow-on CCD measurements of other distributed target samples, and also investigates the sensitivity of the CCD measurement process to changes in the relative spatial location of the SAR sensor between observations of the target. Additionally, this report describes the theoretical and practical aspects of performing interferometric inverse-synthetic-aperture-radar (IFISAR) measurements in the folded compact range environment. IFISAR measurements provide resolution of the relative heights of targets with accuracies on the order of a wavelength. Several examples are given of digital height maps that have been generated from measurements performed at the folded compact range facility.

In the manufacture of printed wiring boards (PWB), plasma etchback and desmear processes facilitate the making of good mechanical and electrical bonds of copper inner layers to copper plating. Without sufficient plasma treatment, internal layer copper features receive inadequate polymer removal which results in circuit discontinuity during the plating process. Additionally, the plasma serves to roughen the polymer wall of drilled holes which improves copper adhesion. To ensure proper plasma treatment, careful adherence to strict production guidelines is essential. These guidelines include attention to several critical criteria in placement, pretreatment and treatment of the PWBs during the plasma process; process verification via post plasma testing; and careful process monitoring throughout. In this brief, some guidelines for process monitoring and control will be discussed. A description of a new plasma monitor utilizing optical emission spectroscopy (OES), developed cooperatively between Sandia National Laboratories, National Consortium for Manufacturing Sciences (NCMS) and Texas Instruments Inc., will be discussed along with possible benefits derived from in situ monitoring of plasma systems.

This information package was prepared for both new and experienced users of the SPHINX (Short Pulse High Intensity Nanosecond X-radiator) flash X-Ray facility. It was compiled to help facilitate experiment design and preparation for both the experimenter(s) and the SPHINX operational staff. The major areas covered include: Recording Systems Capabilities,Recording System Cable Plant, Physical Dimensions of SPHINX and the SPHINX Test cell, SPHINX Operating Parameters and Modes, Dose Rate Map, Experiment Safety Approval Form, and a Feedback Questionnaire. This package will be updated as the SPHINX facilities and capabilities are enhanced.

This paper is the first step in the resolution of the direct containment heating (DCH) issue for the Zion nuclear power plant using the risk oriented accident analysis methodology (ROAAM). This paper includes the definition of a probabilistic framework that decomposes the DCH problem into three probability density functions that reflect the most uncertain initial conditions (UO2 mass, zirconium oxidation fraction, and steel mass). Uncertainties in the initial conditions are significant, but our quantification approach is based on establishing reasonable bounds that are not unnecessarily conservative. To this end, we also make use of the ROAAM ideas of enveloping scenarios and 'splintering'. Two causal relations (CRs) are used in this framework: CR1 is a model that calculates the peak pressure in the containment as a function of the initial conditions, and CR2 is a model that returns the frequency of containment failure as a function of pressure within the containment. Uncertainty in CR1 is accounted for by the use of two independently developed phenomenological models, the convection-limited containment heating model and the two-cell equilibrium model, and by probabilistically distributing the key parameter in both, which is the ratio of the melt entrainment time to the system blowdown time constant. The two phenomenological models have been compared with an extensive database including recent integral simulations at two different physical scales (1:10-scale in the Surtsey facility at Sandia National Laboratories and 1:40-scale in the COREXIT facility at Argonne National Laboratory). The loads predicted by these models were significantly lower than those from previous parametric calculations. The containment load distributions do not intersect the containment strength (fragility) curve in any significant way, resulting in containment failure probabilities less than 10-3 for all scenarios considered. Sensitivity analyses did not show any areas of large sensitivity. The feasibility of extrapolating containment loads distributions to most other pressurized water reactors is explored.

The use of hydrous titanium oxide (HTO) ion-exchange materials as supports for iron and chromium based dehydrogenation catalysts is compared to current commercial catalyst systems in order to determine the potential of HTO technology for impacting this important chemical processing area. The best Fe/HTO catalysts synthesized to date achieve ethylbenzene conversions to styrene approaching those of commercial catalysts, even though the Fe/HTO catalysts contain no promoters while the commercial catalysts contain several different promoters, including K, Cr, and Ce. Addition of promoters to Fe/HTO catalyst is expected to result in further conversion improvements such that the activity of the commercial catalysts may be equaled or exceeded. Fe/HTO and Cr/HTO catalysts achieve only modest conversions of isobutane to isobutene that are far below available commercial catalysts. With the Cr/HTO catalysts, however, activity normalized to Cr loading far exceeds that of the commercial catalyst. Since optimum Cr loading conditions have not yet been identified, there is ample room for increases in both Cr loading and catalyst activity. Even if Cr/HTO and Fe/HTO catalysts do not ultimately exceed the performance obtained with commercial catalysts, the ability to cast HTO materials in the form of thin films may present important advantages for catalytic membrane reactor systems. These potential advantages are discussed and evaluated.

The Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan and the US Department of Energy (DOE) are cooperating on the development of a remote monitoring system for nuclear nonproliferation efforts. This cooperation is part of a broader safeguards agreement between PNC and DOE. A remote monitoring system is being installed in a spent fuel storage area at PNC`s experimental reactor facility Joyo in Oarai. The system has been designed by Sandia National Laboratories (SNL) and is closely related to those used in other SNL remote monitoring projects. The Joyo project will particularly study the unique aspects of remote monitoring in contribution to nuclear nonproliferation. The project will also test and evaluate the fundamental design and implementation of the remote monitoring system in its application to regional and international safeguards efficiency. This paper will present a short history of the cooperation, the details of the monitoring system and a general schedule of activities.

A double quantum well (QW) subject to in-plane magnetic fields B∥ has the dispersion curves of its two QWs shifted in k-space. When the QWs are strongly coupled, an anticrossing and partial energy gap occur, yielding a tunable multi-component Fermi surface. We report measurements of the resultant features in the conductance, the capacitive density of states and giant deviations in the cyclotron effective masses.

As a part of the International Remote Monitoring Project, during March 1995, a Remote Monitoring System (RMS) was installed at the Embalse Nuclear Power Station in Embalse, Argentina. This system monitors the status of four typical Candu spent fuel dry storage silos. The monitoring equipment for each silo consists of analog sensors for temperature and gamma radiation measurement; digital sensors for motion detection; and electronic fiber-optic seals. The monitoring system for each silo is connected to a wireless Authenticate Item Monitoring System (AIMS). This paper describes the operation of the RMS during the first year of the trial and presents the results of the signals reported by the system compared with the on site inspections conducted by the regulatory bodies, ABACC, IAEA, ENREN. As an additional security feature, each sensor periodically transmits authenticated State-of-Health (SOH) messages. This feature provides assurance that all sensors are operational and have not been tampered with. The details of the transmitted information and the incidents of loss of SOH, referred to as Missing SOH Event, and the possible causes which produced the MSOHE are described. The RMS at the embalse facility uses gamma radiation detectors in a strong radiation field of spent fuel dry storage silos. The detectors are Geiger Muller tubes and Silicon solid state diodes. The study of the thermal drift of electronics in GM detectors and the possible radiation damage in silicon detectors is shown. Since the initial installation, the system has been successfully interrogated from Buenos Aires and Albuquerque. The experience gained, and the small changes made in the hardware in order to improve the performance of the system is presented.

Pulsed power offers and efficient, high energy, economical source of x-rays for inertial confinement fusion (ICF) research. We are pursuing two main approaches to ICF driven with pulsed power accelerators: intense light ion beams and z-pinches. This paper describes recent progress in each approach and plans for future development.

Risks in software systems arise from many directions. There are risks that the software is faulty, that the system may be attacked, that safety hazards exist, that the system may be inoperable or untimely, that an abnormal event may cause unexpected actions, etc. Risk analysis tools should support and document risk-mitigation decisions and facilitate understanding of residual risks. These tools must be based on a sound theory of risk, which does not exist today. Probabilistic risk assessment techniques apply to physically-based systems where failure modes and event dependence are fairly well understood. But they cannot be blindly applied to software systems, which do not share these characteristics. Moreover, we need to meld many diverse aspects of risk for software systems. This presentation will explore some thought-provoking ideas about modeling, problem spaces, solution approaches, math, decision friendly output, and the role of risk analysis in the software lifecycle.

The purpose of the Programmatic Risk Management System (PRMS) is to evaluate and manage potential risks associated with proposed projects (i.e., new products or processes, or possible research and technological development projects). Although the PRMS considers some technical aspects of risk, the primary focus of the methodology is programmatic risk. That is, the methodology permits an assessment of risks associated with such issues as the ability to successfully produce a product that performs in accordance with all customer requirements, and the availability and allocation of resources (money, equipment, facilities, skilled personnel). The PRMS process consists of five formalized activities that are essential for effective management of risks associated with proposed projects. These activities include risk assessment, development of appropriate risk mitigation strategies, estimating strategy implementation cost, ranking of risk mitigation strategies for resource allocation, and scheduling of strategy implementing. The PRMS utilizes a ranking system that allows the user to identify the most cost-effective investment of resources of minimizing risk.

Cl{sub 2}+Ar Reactive-Ion-Beam Etching is demonstrated for anisotropic, low-damage etching of InAlGaAs semiconductor alloys for use as optical transmission modulators at 1.32 {mu}m wavelength.

Two thin-walled Al tubes were filled with epoxy which were cured isothermally; one tube was instrumented with strain gauges, and the other with thermocouples. Finite element codes were used. Predicted and measured centerline hoop strains are shown; predictions and measurements agree. This is being applied to encapsulated components.

The primary research objective of the work described here is to design, synthesize, and characterize new materials for use as chemical sensor interfaces, integrate these materials, using appropriate transducers, into sensor arrays, and then develop appropriate mathematical algorithms for interpreting the array response. In this paper, we will discuss two new types of materials we have developed that are ideally suited for use as chemically sensitive interfaces for array-based chemical sensing applications, since they: (1) provide general specificity towards classes of functional groups rather than individual compounds; (2) are intermediate in structure between monolayers and polymers; (3) exhibit both endo- and exo-recognition. The first class of materials is surface-confined dendrimers and the second is hyperbranched polymers.

We have studied the different driving forces behind syneresis in MTES/TEOS gels by aging them in different H{sub 2}O/EtOH pore fluids. We show using shrinkage, density, contact angle, and N{sub 2} sorption measurements, the influence of gel/solvent interactions on the microstructural evolution during drying. Competing effects of syneresis (that occurs during aging) and drying shrinkage resulted in the overall linear shrinkage of the organically modified gels to be constant at {approximately}50%. Increasing the hydrophobicity of the gels caused the driving force for syneresis to change from primarily condensation reactions to a combination of condensation and solid/liquid interfacial energy. In addition the condensation driven shrinkage was observed to be irreversible, whereas the interfacial free energy driven shrinkage was observed to be partially reversible. Nitrogen sorption experiments show that xerogels with the same overall extent of shrinkage can have vastly different microstructures due to the effects of microphase separation.

Solar dish/Stirling systems using sodium heat pipe receivers are being developed by industry and government laboratories here and abroad. The unique demands of this application lead to heat pipe wicks with very large surface areas and complex three-dimensional flow patterns. These characteristics can enhance the mass transport and concentration of constituents of the wick material, resulting in wick corrosion and plugging. As the test times for heat pipe receivers lengthen, we are beginning to see these effects both indirectly, as they affect performance, and directly in post-test examinations. We are also beginning to develop corrective measures. In this paper, we report on our test experiences, our post-test examinations, and on our initial effort to ameliorate various problems.

A unifying framework is developed for the analysis of brittle materials. Heretofore diverse classes of models result from different choices for unspecified coefficient and distribution functions in the unified theory. Material response is described in terms of expectation integrals of transverse symmetry tensors. First, a canonical body containing cracks of all the same orientation is argued to possess macroscopic transverse isotropy. An orthogonal basis for the linear subspace consisting of all double-symmetric transversely-isotropic fourth-order tensors associated with a given material vector is introduced and applied to deduce the explicit functional dependence of the compliance of such contrived materials on the shared crack orientation. A principle of superposition of strain rates is used to write the compliance for a more realistic material consisting of cracks of random size and orientation as an expectation integral of the transverse compliance for each orientation times the joint distribution function for the size and orientation. Utilizing an evolving (initially exponential) size- dependence in the joint distribution, the general theory gives unprecedented agreement with measurements of the dynamic response of alumina to impact loading, especially upon release where the calculations predict the development of considerable deformation- induced anisotropy, challenging the conventional notion of shocks as isotropic phenomena.

This paper describes the design, implementation and performance of a port of the Argonne National Laboratory/Mississippi State University MPICH implementation of the Message Passing Interface standard to the Cray T3D massively parallel processing system. A description of the factors influencing the design and the various stages of implementation are presented. Performance results revealing superior bandwidth and comparable latency as compared to other full message passing systems on the T3D are shown. Further planned improvements and optimizations, including an analysis of a port to the T3E, are mentioned.

Development of this pyrotechnic occurred because of the need for a static insensitive material to meet personnel safety requirements and related system safety issues in nuclear weapon energetic material component designs. Ti subhydride materials are made by the thermal dehydrding of commercial Ti hydride powder to the desired equivalent hydrogen composition in the Ti lattice. These Ti subhydrides, when blended with K perchlorate, meet the static insensitivity requirement of not being initiated from an equivalent human body electrostatic discharge. Individual material and blend qualification requirements provide a reproducible material from lot to lot. These pyrotechnic formulations meet the high reliability requirements (0.9995) for initiation and performance parameters and have the necessary stability and compatibility to meet long lived requirements of more than 25 years. Various experiences and problems are also discussed that have led to a mature technology for Ti subhydride/K perchlorate during its use in energetic material component designs.

SmartWeld is a concurrent engineering system that integrates product design and processing decisions within an electronic desktop engineering environment. It is being developed to provide designers, process engineers, researchers and manufacturing technologists with transparent access to the right process information, process models, process experience and process experts, to realize``right the first time`` manufacturing. Empirical understanding along with process models are synthesized within a knowledge-based system to identify robust fabrication procedures based on cost, schedule, and performance. Integration of process simulation tools with design tools enables the designer to assess a number of design and process options on the computer rather than on the manufacturing floor. Task models and generic process models are being embedded within user friendly GUI`s to more readily enable the customer to use the SmartWeld system and its software tool set without extensive training. The integrated system architecture under development provides interactive communications and shared application capabilities across a variety of workstation and PC-type platforms either locally or at remote sites.

Compared to other metrology approaches, electrical test structures for the measurement of dimensional characteristics such as linewidth and overlay directly relate to the electrical performance of the circuits being fabricated. The inherent disadvantage of electrical techniques is that they can be applied only to the extraction of the dimensions of features patterned in electrically-conducting materials. They can not be directly applied to patterned resist films or dielectric material layers. In the case of narrow on-wafer features patterned in resist, for example, linewidths are preferably extracted by electron-beam methods. These methods are sufficiently repeatable for monitoring fabrication-process variations. However, the traceability of the units in which linewidth is expressed is thwarted by the unavailability of suitable calibration artifacts. In the case of overlay metrology, the same limitations as regards electrical conduction apply. However, similar advantages accrue in principle to electrical overlay methods when they can be utilized. It is the electrical quality of the overlay of a conducting via relative to underlying or overlying conducting material which is of driving importance for circuit functionality. This may differ from the overlay values extracted from the same patterns by commonly-used optical overlay tools. Further refinements in the state of the art in both electrical linewidth and electrical overlay metrologies are desirable as feature sizes and spacings continue to shrink in emerging generations of devices. This paper discusses some recent innovations which have been recently introduced and indicates new roles for electrical metrology in low-cost certification of reference materials for both linewidth and overlay applications.

Dynamic compaction of mine-run salt is being investigated for the Waste Isolation Pilot Plant (WIPP), where compacted salt is being considered for repository sealing applications. One large-scale and two intermediate-scale dynamic compaction demonstrations were conducted. Initial fractional densities of the compacted salt range form 0.85 to 0.90, and permeabilities vary. Dynamically-compacted specimens were further consolidated in the laboratory by application of hydrostatic pressure. Permeability as a function of density was determined, and consolidation microprocesses were studied. Experimental results, in conjunction with modeling results, indicate that the compacted salt will function as a viable seal material.

As part of the demonstration of compliance with federal regulations, a shaft seal system has been designed for the Waste Isolation Pilot Plant. The system completely fills the 650 m shafts with components consisting of the common engineering materials, each of which possesses low permeability, longevity, and can be constructed using available technology. Design investigations couple rock mechanics and fluid flow analysis and tests of these materials within the natural geological setting, and demonstrate the effectiveness of the design.

Because many of the phenomenologically based codes used to support risk assessments require lone execution times, it is important to have a rationally based means for optimizing the choice of parameter values that are input to the code calculations. For this reason, we have developed a method for intelligently searching the space of parameter values to deduce, with as few computations as possible, the values that are most likely to lead to high risk. We have applied the method to a problem involving electrical initiation of an explosive due to the response of the system to fires. We have shown that our method can locate potential risk vulnerabilities with far fewer time-consuming physical response computations than would be necessary using standard sampling approaches.

The status of nuclear materials in both the U.S. and Former Soviet Union is changing based upon the execution of agreements relative to weapons materials production and weapon dismantlement. The result of these activities is that a considerably different emphasis is being placed on how nuclear materials are viewed and utilized. Even though much effort is being expended on the final disposition of these materials, the interim need for storage and security of the material is increasing. Both safety and security requirements exist to govern activities when these materials are placed in storage. These requirements are intended to provide confidence that the material is not being misused and that the storage operations are conducted safely. Both of these goals can be significantly enhanced if technological monitoring of the material is performed. This paper will briefly discuss the traditional manual methods of U.S. and international material monitoring and then present approaches and technology that are available to achieve the same goals under the evolving environment.

Prioritizing waste generators is necessary to determine which are the best candidates for Pollution Prevention Opportunity Assessments (PPOAs). This paper describes the Sandia National Laboratories/New Mexico (SNL/NM) PPOA Ranking System. The system uses a multimedia approach that considers hazardous and radioactive waste disposal data, and hazardous chemical usage data (from which air emissions are extrapolated). Pollution prevention information is included, from the SNL Pollution Prevention Opportunities database that identifies waste streams that have readily apparent pollution prevention opportunities. The system also considers the relative costs of waste management and the chargeback fees paid for waste generation. From these data, organizations are ranked with an algorithm developed in Microsoft Access{trademark} on a personal computer. The concept could readily be transferred to other facilities needing to decide where to perform PPOAs.

Cost and schedule overruns are often caused by poor requirements that are produced by people who do not understand the requirements process. This report provides a high-level overview of the system requirements process, explaining types, sources, and characteristics of good requirements. System requirements, however, are seldom stated by the customer. Therefore, this report shows ways to help you work with your customer to discover the system requirements. It also explains terminology commonly used in the requirements development field, such as verification, validation, technical performance measures, and the various design reviews.

Parameter estimation for modern viscoplastic constitutive models often requires data from many tests. Sensitivity coefficients can be used to design an efficient test matrix and reduce testing requirements. The present study derives sensitivity coefficients for each model parameter in the Munson-Dawson constitutive model and evaluates them for several load histories.

Knowledge of the charge efficiency of lead-acid batteries near top-of-charge is important to the design of small photovoltaic systems. In order to know how much energy is required from the photovoltaic array in order to accomplish the task of meeting load, including periodic full battery charge, a detailed knowledge of the battery charging efficiency as a function of state of charge is required, particularly in the high state-of-charge regime, as photovoltaic systems are typically designed to operate in the upper 20 to 30% of battery state-of-charge. This paper presents the results of a process for determining battery charging efficiency near top-of-charge and discusses the impact of these findings on the design of small PV systems.

As the successor to SUNMOS [8], the Puma operating system provides a flexible, lightweight, high performance message passing environment for massively parallel computers. Message passing in Puma is accomplished through the use of a new mechanism known as a portal. Puma is currently running on the Intel Paragon and is being developed for the Intel TeraFLOPS machine. In this paper we discuss issues regarding the development of the Argonne National Laboratory/Mississippi State University implementation of the Message Passing Interface standard on top of portals. Included is a description of the design and implementation for both MPI point-to- point and collective communications, and MPI-2 one-sided communications.

The Nuclear Weapons Guidance Team is an interagency committee led by Earl Whiteman, DOE that chartered the generation of EP40100, Concurrent Qualification and its successor EP401099, Concurrent Engineering and Qualification. As this new philosophy of concurrent operations has evolved and as implementation has been initiated, conflicts and insufficiencies in the remaining Engineering Procedures (EPs) have become more apparent. At the Guidance Team meeting in November 1995, this issue was explored and several approaches were considered. It was concluded at this meeting, that a smaller set of interagency EPs described in a hierarchical system could provide the necessary interagency direction to support complex-wide implementation. This set consolidates many existing EP processes where consistency and commonality are critical to success of the extended enterprise. The Guidance Team subsequently chartered an interagency team to initiate development activity associated with the envisioned new EP set. This team had participation from seven Nuclear Weapons Complex (NWC) sites as well as DOE/AL and DP-14 (team members are acknowledged later in this report). Per the Guidance Team, this team, referred to as the Architecture Subcommittee, was to map out and define an EP Architecture for the interagency EPs, make recommendations regarding a more agile process for EP approval and suggest an aggressive timeline to develop the combined EPs. The Architecture Subcommittee was asked to brief their output at the February Guidance Team meeting. This SAND report documents the results of the Architecture Subcommittee`s recommendations.

Moessbauer spectroscopy has been used to determine the iron-bearing phases in the coal, catalysts, and IOM products used and generated in the Direct Coal Liquefaction (DCL) catalyst testing program at Sandia National Laboratories, New Mexico. DCL experiments were conducted with a Blind Canyon, Utah, coal both thermally and with three different iron-based catalysts: (1) a sulfated hematite catalyst (Fe{sub 2}O{sub 3}/SO{sub 4}{sup 2{minus}}), (2) a 6-line ferrihydrite catalyst, and (3) iron-oxide impregnated directly into coal. The catalysts were added to the coal at both a 0.5 and a 1.0 wt% level and sufficient sulfur was added to ensure complete sulfidation of the iron. The Moessbauer spectrum of the Blind Canyon coal revealed that the major iron-bearing mineral present was ankerite, Ca(Fe,Mg)(CO{sub 3}){sub 2}, which converts firs to {gamma}-Fe (austenitic iron) before undergoing partial sulfidation to pyrrhotite in the thermal runs. The percentages of pyrrhotite formed in the catalytic runs were higher than those in the thermal runs indicating that sulfidation of the added iron occurs more rapidly than with the ankerite. Moessbauer data on the amount of pyrrhotite present does not correlate well with THF and heptane conversion percentages, indicating that other parameters like catalyst dispersion must also be considered.

In this report the authors describe the methods they have developed for producing stable periodic mesoporous silica gels, thin films of mesoporous silica for sensor applications, a route to nonaqueous synthesis, and the use of various additives in controlling the pore size and structure of these materials. Mesoporous silica is formed by templating silica precursors around micelles of cationic quaternary ammonium surfactants. During the synthesis these micelles undergo a phase transition to a hexagonal, lamellar or cubic liquid crystalline state, thus imposing periodic order on the amorphous silica which occupies the interface of the hydrophilic cationic headgroups of the surfactants. The product of the bulk wet synthesis is a gel composed of micron size silica/surfactant particles, each of which consists of one or more crystalline domains of silica condensed around the surfactant template. The wet gel can then be washed and pyrolyzed to remove the surfactant template, yielding the periodic mesoporous silica product.

In an effort to establish joint activities in the disposition of fissile materials from nuclear materials, the US and Russia agreed to conduct joint work to develop consistent comparisons of various alternatives for the disposition of weapons-grade plutonium. Joint working groups were established for the analysis of alternatives for plutonium management for water reactors, fast reactors, storage, geological formations, immobilization and stabilization of solutions and other forms. In addition cross-cutting working groups were established for economic analysis and nonproliferation (NP). This paper reviews the activities of the NP working group in support of these studies. The NP working group provided integrated support in the area of nuclear NP to the other US/Russian Study teams. It involved both domestic safeguards and security and international safeguards. The analysis of NP involved consideration of the resistance to theft or diversion and resistance to retrieval, extraction or reuse.

Polymer-based routes to ceramic oxides take advantage of precursor chemistry and structure to produce materials with a range of pore sizes. Polymer precursor routes to non-oxide ceramics offer products with superior thermal and chemical stability in many cases. Polymethylsilane (PMS), a versatile cross linked SiC precursor, [(MeHSi){sub x}(MeSi){sub y}], was synthesized using published procedures to yield fluid precursors with a low (20--40%) degree of cross linking. Unique, highly cross linked (60--70%), solid polymers were produced under reaction conditions which carefully conserve the volatile monomer. These two polymers were converted to SiC to determine the relative importance of the various contributions to porosity, and to assess the role of precursor structure on porosity development in non-oxides. Initial results indicate that precursor structure has little effect on porosity. The development of the porosity appears to be dominated by high temperature thermochemistry and/or microstructural changes.

Zeolite films are sought as components of molecular sieve membranes. Different routes used to prepare zeolite composite membranes include growing zeolite layers from gels on porous supports, depositing oriented zeolites on supports, and dispersing zeolites in polymeric membranes. In most cases, it is very difficult to control and avoid the formation of cracks and/or pinholes. The approach to membrane synthesis is based on hydrothermally converting films of layered aluminosilicates into zeolite films. The authors have demonstrated this concept by preparing zeolite A membranes on alumina supports from kaolin films. The authors have optimized the process parameters not only for desired bulk properties, but also for preparing thin (ca. 5 {micro}m), continuous zeolite A films. Scanning electron microscopy shows highly intergrown zeolite A crystals over most of the surface area of the membrane, but gas permeation experiments indicate existence of mesoporous defects and/or intercrystalline gaps. It has been demonstrated that the thickness of the final zeolite A membrane can be controlled by limiting the amount of precursor kaolin present in the membrane.

This project focuses on the modification of silica and alumina surfaces by titania and hydrous titanium oxide ion-exchange films, and the use of these modified materials as supports for MoS{sub 2} catalysts. FTIR studies of molybdena interaction with {gamma}-Al{sub 2}O{sub 3} demonstrate that at low loadings Mo interacts with the most basic hydroxyl groups, and that these hydroxyls are associated with tetrahedrally coordinated Al. Furthermore, hydrodesulfurization (HDS) activity as a function of Mo loading shows a maximum in specific activity with loading. The Mo species bound to tetrahedrally coordinated Al sites are therefore believed to be inactive for the HDS reaction. Only after the tetrahedral Al sites have completely consumed does molybdena adsorb on the alumina in a manner that leads to an active catalyst. According to this scheme, the activity of alumina supported MoS{sub 2} catalysts could be greatly improved by either titrating the tetrahedral Al sites with a modifier, or by using {alpha}-Al{sub 2}O{sub 3} which contains no tetrahedrally coordinated Al. HDS tests over MoS{sub 2} supported on both {alpha}-Al{sub 2}O{sub 3} and {gamma}-Al{sub 2}O{sub 3} modified by a titania film confirm this hypothesis. Neither support material gives rise to a maximum in activity with Mo loading, but rather exhibits a smooth decrease in activity with loading. Furthermore, for equivalent Mo loadings the activity of both of these support materials exceeds that of unmodified {gamma}-Al{sub 2}O{sub 3} due to the fact that no Mo is tied up in the inactive form. FTIR, XPS, and TEM are currently being used to determine whether the model can indeed account for the observed activity trends. Although the surface area of {alpha}-Al{sub 2}O{sub 3} is too low for use as a commercial catalyst, the titania coated {gamma}-Al{sub 2}O{sub 3} represents an important, practical improvement in support materials for hydrotreating catalysts.

The DOE/DOD Environmental Data Bank was established in 1959 as a central location for storing weapons and equipment environments information from a variety of DOE, DOD, and industrial sources and continues to be maintained by Sandia National Laboratories. The Environmental Data Bank contains approximately 2,900 documents regarding normal and abnormal environments that describe the handling, storage, transportation, use, and general phases, which occur during the life of a weapon system. The Environmental Data Bank contains a vast assortment of resources that document crash, fire, and chemical environments resulting from aircraft, rail, ship, and truck accidents, as well as crash and thermal tests conducted on shipping containers. Also included are studies on the hazards of exposure to liquid natural gas fireballs, chemical fireballs, and hydrogen fireballs. This paper describes the DOE/DOD Environmental Data Bank system, its structure, data sources, and usage, with particular emphasis on its use for safety assessments at Sandia National Laboratories.

In this paper the authors identify factors which influence the safety philosophy used in the US commercial/industrial sector and compare them against those factors which influence nuclear weapons safety. Commercial/industrial safety is guided by private and public safety standards. Generally, private safety standards tend to emphasize product reliability issues while public (i.e., government) safety standards tend to emphasize human factors issues. Safety in the nuclear weapons arena is driven by federal requirements and memoranda of understanding (MOUs) between the Departments of Defense and Energy. Safety is achieved through passive design features integrated into the nuclear weapon. Though the common strand between commercial/industrial and nuclear weapons safety is the minimization of risk posed to the general population (i.e., public safety), the authors found that each sector tends to employ a different safety approach to view and resolve high-consequence safety issues.

Over forty safety and security related research and development projects have been initiated between Sandia National Laboratories and the Russian nuclear weapons laboratories VNIIEF and VNIITF. About half of these projects have been completed. All relate to either safety or security methodology development, processes, accident environment analysis and testing, accident databases, assessments or product design of devices. All projects have a potential benefit to various safety or security programs and some may directly have commercial applications. In general, these projects could benefit risk assessments associated with systems that could result in accidents or incidents having high public consequences. These systems typically have already been engineered to have very low assessed probabilities of occurrence of such accidents or incidents. This paper gives an overview of the Sandia surety program with a focus on the potential for future collaboration between Sandia, three Russian Institutes; VNIIEF, VNIITF and VNIIA, and other industry and government organizations. The intent is to serve as an introduction to a roundtable session on Russian Safety Collaboration at the 14th International System Safety Conference. The current Sandia collaboration program scope and rationale is presented along with the evolved program focus. An overview of the projects is given and a few specific projects are briefly highlighted with tangible results to date.

Much work has been devoted to high consequence events with low frequency of occurrence. Characteristic of these events are bridge failure (such as that of the Tacoma Narrows), building failure (such as the collapse of a walkway at a Kansas City hotel), or compromise of a major chemical containment system (such as at Bhopal, India). Such events, although rare, have an extreme personal, societal, and financial impact. An interesting variation is demonstrated by financial losses due to fraud and abuse in the money management system. The impact can be huge, entailing very high aggregate costs, but these are a result of the contribution of many small attacks and not the result of a single (or few) massive events. Public awareness is raised through publicized events such as the junk bond fraud perpetrated by Milikin or gross mismanagement in the failure of the Barings Bank through unsupervised trading activities by Leeson in Singapore. These event,s although seemingly large (financial losses may be on the order of several billion dollars), are but small contributors to the estimated $114 billion loss to all types of financial fraud in 1993. This paper explores the magnitude of financial system losses and identifies new areas for analysis of high consequence events including the potential effect of malevolent intent.

One of the benefits resulting from the collapse of the Soviet Union is the increased dialogue currently taking place between American and Russian nuclear weapons scientists in various technical arenas. One of these arenas currently being investigated involves collaborative studies which illustrate how risk assessment is perceived and utilized in the Former Soviet Union (FSU). The collaborative studies indicate that, while similarities exist with respect to some methodologies, the assumptions and approaches in performing risk assessments were, and still are, somewhat different in the FSU as opposed to that in the US. The purpose of this paper is to highlight the present knowledge of risk assessment methodologies and philosophies within the two largest nuclear weapons laboratories of the Former Soviet Union, Arzamas-16 and Chelyabinsk-70. Furthermore, This paper will address the relative progress of new risk assessment methodologies, such as Fuzzy Logic, within the framework of current risk assessment methods at these two institutes.

Over the past several years, the authors have performed experimental studies focused on understanding small-scale flow processes within discrete fractures and individual matrix blocks; much of the understanding gained in that time differs from that underlying the basic assumptions used in effective media representations. Here they synthesize the process level understanding gained from their laboratory studies to explore how such small-scale processes may influence the behavior of fluid flow in fracture networks and ensembles of matrix blocks at levels sufficient to impact the formulation of intermediate-scale effective media properties. They also explore, by means of a thought experiment, how these same small-scale processes could couple to produce a large-scale system response inconsistent with current conceptual models based on continuum representations of flow through unsaturated, fractured rock. Based on their findings, a number of modifications to existing dual permeability models are suggested that should allow them improved applicability; however, even with these modifications, it is likely that continuum representations of flow through unsaturated fractured rock will have limited validity and must therefore be applied with caution.

The goal of this work is to extend the use of existing path expression theory and methodologies to ensure that critical software event sequences are maintained even in the face of malevolent attacks and harsh or unstable operating environments. This will be accomplished by providing dynamic fault management measures directly to the software developer and to their varied development environments. This paper discusses the perceived problems, a brief overview of path expressions, and the author`s proposed extension areas. The authors discuss how the traditional path expression usage and implementation differs from the intended usage and implementation.

Garnet phosphors have potential for use in field emission displays (FEDs). Green-emitting Gd{sub 3}Ga{sub 5}O{sub 12}:Tb (GGG:Tb) and Y{sub 3}Al{sub 5}O{sub 12}:Tb (YAG:Tb) are possible alternatives to ZnO:Zn, because of their excellent resistance to burn, low-voltage efficiency, (3.5 lm/W from GGG:Tb at 800 V), and saturation resistance at high power densities. Hydrothermal and combustion synthesis techniques were employed to improve the low-voltage efficiency of YAG:Tb, and Y{sub 3}Ga{sub 5}O{sub 12}:Tb (YGG:Tb). Synthetic technique did not affect low-voltage (100--1,000 V) efficiency, but affected the particle size, morphology, and burn resistance. The small particle size phosphors obtained via hydrothermal (<1 {micro}m) and combustion reactions (<1 {micro}m) would benefit projection TV, high-definition TV (HDTV), and heads-up displays (HUDs), where smaller pixel sizes are required for high resolution.

Inductively Coupled Plasma (ICP) sources are extremely promising for large-area, high-ion density etching or deposition processes. In this review the authors compare results for GaAs and GaN etching with both ICP and Electron Cyclotron Resonance (ECR) sources on the same single-wafer platform. The ICP is shown to be capable of very high rates with excellent anisotropy for fabrication of GaAs vias or deep mesas in GaAs or GaN waveguide structures.

Vulnerability analyses for information systems are complicated because the systems are often geographically distributed. Sandia National Laboratories has assembled an interdisciplinary team to explore the applicability of probabilistic logic modeling (PLM) techniques (including vulnerability and vital area analysis) to examine the risks associated with networked information systems. The authors have found that the reliability and failure modes of many network technologies can be effectively assessed using fault trees and other PLM methods. The results of these models are compatible with an expanded set of vital area analysis techniques that can model both physical locations and virtual (logical) locations to identify both categories of vital areas simultaneously. These results can also be used with optimization techniques to direct the analyst toward the most cost-effective security solution.

The in-scattering processes, which reduce the decay of the active medium polarization, should be included in a consistent treatment of semiconductor laser gain. The in-scattering processes affect the laser gain by decreasing the influence of the high k-states, which contribute absorption to the spectrum. A theory, based on the semiconductor-Bloch equations with the effects of carrier-carrier scattering treated at the level of the quantum kinetic equations in the Markov limit, predicts gain spectra that do not exhibit absorption below the renormalized band gap, in agreement with experiment. When compared to gain calculations where the in-scattering contribution is neglected, the theory predicts markedly different properties for intrinsic laser parameters, such as peak gain, gain bandwidth, differential gain and carrier density at transparency, especially at low carrier densities.

Critical software must be safe, secure, and dependable. Traditionally, these have been pursued as separate disciplines. This presentation looks at the traditional approaches and highlights commonalities and differences among them. Each can learn from the history of the others. More importantly, it is imperative to seek a systems approach which blends all three.

Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.

Prosperity Games{trademark} are an outgrowth and adaptation of move/countermove and seminar War Games. Prosperity Games{trademark} are simulations that explore complex issues in a variety of areas including economics, politics, sociology, environment, education and research. These issues can be examined from a variety of perspectives ranging from a global, macroeconomic and geopolitical viewpoint down to the details of customer/supplier/market interactions in specific industries. All Prosperity Games{trademark} are unique in that both the game format and the player contributions vary from game to game. This report documents the Biomedical Technology Prosperity Game{trademark} conducted under the sponsorship of Sandia National Laboratories, the Defense Advanced Research Projects Agency, and the Koop Foundation, Inc. Players were drawn from all stakeholders involved in biomedical technologies including patients, hospitals, doctors, insurance companies, legislators, suppliers/manufacturers, regulators, funding organizations, universities/laboratories, and the legal profession. The primary objectives of this game were to: (1) Identify advanced/critical technology issues that affect the cost and quality of health care. (2) Explore the development, patenting, manufacturing and licensing of needed technologies that would decrease costs while maintaining or improving quality. (3) Identify policy and regulatory changes that would reduce costs and improve quality and timeliness of health care delivery. (4) Identify and apply existing resources and facilities to develop and implement improved technologies and policies. (5) Begin to develop Biomedical Technology Roadmaps for industry and government cooperation. The deliberations and recommendations of these players provided valuable insights as to the views of this diverse group of decision makers concerning biomedical issues. Significant progress was made in the roadmapping of key areas in the biomedical technology field.

The behavior of chemical species adsorbed on solid surfaces and exchanged into clay interlayers plays a significant role in controlling many natural and technologically important processes, including rheological behavior, catalysis, plant growth, transport in natural pore fluids and those near anthropogenic hazardous waste sites, and water-mineral interaction. Adsorption and exchange reactions have been the focus of intense study for many decades. Only more recently, however, have there been extensive spectroscopic studies of surface species. Among the spectroscopic methods useful for studying surface and exchanged species (e.g., infrared, X-ray photoelectron spectroscopy [XPS] and X-ray absorption spectroscopy [XAS]), nuclear magnetic resonance spectroscopy (NMR) has the considerable advantage of providing not only structural information via the chemical shift and quadrupole coupling constant but dynamical information in the Hz-mHz range via lineshape analysis and relaxation rate measurements. It is also possible to obtain data in the presence of a separate fluid phase, which is essential for many applications. This paper illustrates the range of applications of NMR methods to surface and exchanged species through review of recent work from our laboratory on Cs in clay interlayers and Cs, Na and phosphate adsorbed on oxide surfaces. The substrate materials used for these experiments and our long-term objectives are related to problems of geochemical interest, but the principals and techniques are of fundamental interest and applicable to a wide range of technological problems.

The software construction process consists of a mixture of informal and formal steps. By their very nature, informal steps cannot be formally verified. Empirical evidence suggests that a majority of software errors originate in the informal steps of the software development process. For this reason, when constructing high assurance software, it is essential that a significant effort be made to increase one`s confidence (i.e., to validate) that the informal steps have been made correctly. Visualization and animation can be used to provide an `intuitive proof` that the informal steps in the software construction process are correct. In addition, the formal portion of software construction often permits/demands artistic (informal) decisions to be made (e.g., design decisions). Such decisions often have unexpected/unforeseen consequences that are only discovered later in the development process. Visualization and animation techniques can be brought to bear on this aspect of the software construction process by providing a better intuitive understanding of the impact of the informal decisions that are made in program development. This increases the likelihood that undesirable decisions can be avoided or at least detected earlier in the development process.

US DOE national laboratories and Russian institutes are becoming increasingly cooperative in support of nonproliferation of nuclear materials. This paper describes completed projects, current work, and areas of possible future cooperation between US laboratories and a Russian Ministry of Atomic Energy (MINATOM) entity, Special Scientific and Production State Enterprise (SNPO). The Kurchatov Institute, SNPO, and the US national laboratories jointly completed a physical protection system (PPS) for a facility housing two reactors at Kurchatov Institute within a very short time frame in 1994. Spin- off projects from this work resulted in a US-witnessed acceptance test of the new system adhering to a procedure adopted in Russia, and visits by DOE laboratories` personnel to SNPO`s sensor development and test facilities at Dubna and Penza. SNPO was one of the MINATOM sites at which Lawrence Livermore National Laboratory and Sandia National Laboratories (SNL) conducted a vulnerability assessment training course. Current cooperative projects include additional physical protection upgrades at Kurchatov where SNPO is involved as an installer and supplier of sensors, alarm display, video, and fiber optic equipment. Two additional contracts between SNL and SNPO result in information on Russian sensor performance and cost and an exchange of US and Russian sensors. Russian sensors will be tested in the United States,a nd US sensors will be tested in Russia. Pacific Northwest Laboratory administers a contract to document the process of certifying physical protection equipment for use at MINATOM facilities. Recent interest in transportation security has opened a new area of cooperation between the national laboratories and SNPO. Future projects are expected to include SNPO participation in physical protection upgrades at other locations in Russia, pedestrian and vehicle portal development, positive personnel identifier testing, and the exchange and testing of additional equipment.

Soil vapor surveys were performed to characterize the approximate location of soil contaminants at a hazardous waste site. The samplers were from two separate companies and a comparison was made between the results of the two techniques. These results will be used to design further investigations at the site.

Material which is not in direct contact with detonating explosives may still be driven by the explosion through impact by driven material or by attachment to driven material. In such circumstances the assumption of inelastic collision permits estimation of the final velocity of an assemblage. Examples of the utility of this assumption are demonstrated through use of Gurney equations. The inelastic collision calculation may also be used for metal parts which are driven by explosives partially covering the metal. We offer a new discounting angle to account for side energy losses from laterally unconfined explosive charges in cases where the detonation wave travels parallel to the surface which is driven.

This report summarizes the results of the Precision Guided Parachute LDRD, a two year program at Sandia National Laboratories which developed a Global Positioning System (GPS) guided parachute capable of autonomous flight and landings. A detailed computer model of a gliding parachute was developed for software only simulations. A hardware in-the-loop simulator was developed and used for flight package system integration and design validation. Initial parachute drop tests were conducted at Sandia`s Coyote Canyon Cable Facility, followed by a series of airdrops using Ross Aircraft`s Twin Otter at the Burris Ranch Drop Zone. Final flights demonstrated in-flight wind estimation and the capability to fly a commanded heading. In the past, the cost and logistical complexity of an initial navigation system ruled out actively guiding a parachute. The advent of the low-cost, light-weight Global Positioning System (GPS) has eliminated this barrier. By using GPS position and velocity measurements, a guided parachute can autonomously steer itself to a targeted point on the ground through the use of control drums attached to the control lanyards of the parachute. By actively correcting for drop point errors and wind drift, the guidance accuracy of this system should be on the order of GPS position errors. This would be a significant improvement over unguided airdrops which may have errors of a mile or more.

This LDRD (Laboratory Directed Research and Development) project was funded for two years beginning in October 1992 (FY93) and was designed as a multidisciplinary approach to determining the structural and physical properties of C{sub 60} intercalated with various gases. The purpose of the study was to evaluate the relative permeation and diffusion of various gases with an ultimate goal of finding an effective filter for gas separations. A variety of probes including NMR, X-ray and neutron diffraction; IR spectroscopy, thermogravimetric analysis and mass spectroscopy were employed on C{sub 60} impregnated with a number of gases including O{sub 2}, N{sub 2}, Ar, Ne, H{sub 2}, NO and CH{sub 4}. In order to increase the absorption and decrease the effective time constraints for bulk samples, these gases were intercalated into the C{sub 60} using pressures to several kbar. The results of these measurements which were quite encouraging for separation of O{sub 2} and N{sub 2} and for H{sub 2} from N{sub 2} led to 17 manuscripts which have been published in peer reviewed journals. The abstracts of these manuscripts are shown below along with a complete citation to the full text.

Simplified formulae are developed for estimating the aerosol decontamination that can be achieved by natural processes in the containments of pressurized water reactors and in the drywells of boiling water reactors under severe accident conditions. These simplified formulae were derived by correlation of results of Monte Carlo uncertainty analyses of detailed models of aerosol behavior under accident conditions. Monte Carlo uncertainty analyses of decontamination by natural aerosol processes are reported for 1,000, 2,000, 3,000, and 4,000 MW(th) pressurized water reactors and for 1,500, 2,500, and 3,500 MW(th) boiling water reactors. Uncertainty distributions for the decontamination factors and decontamination coefficients as functions of time were developed in the Monte Carlo analyses by considering uncertainties in aerosol processes, material properties, reactor geometry and severe accident progression. Phenomenological uncertainties examined in this work included uncertainties in aerosol coagulation by gravitational collision, Brownian diffusion, turbulent diffusion and turbulent inertia. Uncertainties in aerosol deposition by gravitational settling, thermophoresis, diffusiophoresis, and turbulent diffusion were examined. Electrostatic charging of aerosol particles in severe accidents is discussed. Such charging could affect both the coagulation and deposition of aerosol particles. Electrostatic effects are not considered in most available models of aerosol behavior during severe accidents and cause uncertainties in predicted natural decontamination processes that could not be taken in to account in this work. Median (50%), 90 and 10% values of the uncertainty distributions for effective decontamination coefficients were correlated with time and reactor thermal power. These correlations constitute a simplified model that can be used to estimate the decontamination by natural aerosol processes at 3 levels of conservatism. Applications of the model are described.

We report results in three areas of research relevant to the fabrication of monolithic multi-junction photovoltaic devices. (1) The use of compliant intervening layers grown between highly mismatched materials, GaAs and GaP (same lattice constant as Si), is shown to increase the structural quality of the GaAs overgrowth. (2) The use of digital alloys applied to the MBE growth of GaAs{sub x}Sb{sub l-x} (a candidate material for a two junction solar cell) provides increased control of the alloy composition without degrading the optical properties. (3) A nitrogen plasma discharge is shown to be an excellent p-type doping source for CdTe and ZnTe, both of which are candidate materials for a two junction solar cell.

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. A 25kW electric system takes advantage of existing Stirling-cycle engines and existing parabolic concentrator designs. In previous work, the concentrated sunlight impinged directly on the heater head tubes of the Stirling Thermal Motors (STM) 4-120 engine. A Sandia-designed felt-metal-wick heat pipe receiver was fitted to the STM 4-120 engine for on-sun testing on Sandia`s Test Bed Solar Concentrator. The heat pipe uses sodium metal as an intermediate two-phase heat transfer fluid. The receiver replaces the directly-illuminated heater head previously tested. The heat pipe receiver provides heat isothermally to the engine, and the heater head tube length is reduced, both resulting in improved engine performance. The receiver also has less thermal losses than the tube receiver. The heat pipe receiver design is based on Sandia`s second-generation felt-wick heat pipe receiver. This paper presents the interface design, and compares the heat pipe/engine test results to those of the directly-illuminated receiver/engine package.

Sol-gel polymerication of {alpha}, {omega}-bis(triethoxysilyl)alkanes normally leads to alkylene-bridged polysilsesquioxanes in the form of insoluble, highly crosslinked polymeric gels. Hydrolysis of the six ethoxide groups on each monomer gives silanols that then condense to form a network of siloxane bonds. Unlike most Sol-gel precursors, these flexible hydrocarbon-bridged monomers can participate not only in intermolecular condensation reactions that lead to polymeric networks, but in intramolecular condensation reactions leading to cyclic disilsesquioxanes as well. Partitioning between these two reaction manifolds should be an important determinant of the manner in which the network polymer is assembled and, be an important determinant of the manner in which the network polymer is assembled and, ultimately, the final morphologies of the crosslinked gels. The relative importance of the two pathways should be dependent on a variety of factors, including the reaction mechanism (acid or base catalysis), the concentration of {alpha}, {omega}(triethoxysilyl)alkane and, most importantly for this study, the length of the alkylene bridging group.

The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

When software is used in safety-critical, security-critical, or mission-critical situations, it is imperative to understand and manage the risks involved. A risk assessment methodology and toolset have been developed which are specific to software systems and address a broad range of risks including security, safety, and correct operation. A unique aspect of this methodology is the use of a modeling technique that captures interactions and tradeoffs among risk mitigators. This paper describes the concepts and components of the methodology and presents its application to example systems.

A particular out-of-specification mechanical dimension on Type-N(f) [Type-N(female)] microwave connectors sometimes disqualifies otherwise perfectly acceptable microwave devices from being used in calibration systems. The Miniature Machining Group at Sandia National Laboratories applied a technique called Electrical Discharge Machining (EDM) to quickly and economically machine these devices without disassembly. In so doing, they facilitated the use of existing components without the need to purchase new devices. The technique also improves an uncertainty of calibration known as Mismatch Uncertainty by optimizing the reflection coefficient of the calibration test port. This effects a reduction in overall calibration uncertainties.

This report provides a baseline update to provide the background information necessary for personnel to prepare clear and consise NEPA documentation. The environment of the Sandia National Laboratories is described in this document, including the ecology, meteorology, climatology, seismology, emissions, cultural resources and land use, visual resources, noise pollution, transportation, and socioeconomics.

The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document.

A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.

Sandia National Laboratories (SNL) and Underwriters Laboratories, Inc., (UL) have jointly established the Security Equipment and Systems Certification Program (SESCP). The goal of this program is to enhance industrial and national security by providing a nationally recognized method for making informed selection and use decisions when buying security equipment and systems. The SESCP will provide a coordinated structure for private and governmental security standardization review. Members will participate in meetings to identify security problems, develop ad-hoc subcommittees (as needed) to address these identified problems, and to maintain a communications network that encourages a meaningful exchange of ideas. This program will enhance national security by providing improved security equipment and security systems based on consistent, reliable standards and certification programs.

After 5 y storage at Allied Signal, a subassembly with SA1388-1 diodes failed testing and the cause was an unacceptable current leak rate in one of the diodes. This was traced to a CuS deposit in a single production lot of diodes; however only about 0.3% failed the specification. A study was performed to determine the cause and potential long-term significance of this problem. Probable cause was determined to be the P-bearing braze material not being compatible with the Ag immersion plating solution (cyanide-based) and to the storage environment containing sulfur.

Solid free form fabrication is a fast growing automated manufacturing technology that has reduced the time between initial concept and fabrication. Starting with CAD renditions of new components, techniques such as stereolithography and selective laser sintering are being used to fabricate highly accurate complex 3-D objects using polymers. Together with investment casting, sacrificial polymeric objects are used to minimize cost and time to fabricate tooling used to make complex metal casting. This paper describes recent developments in LENS{trademark} (Laser Engineered Net Shaping) to fabricate the metal components {ital directly} from CAD solid models and thus further reduce the lead time. Like stereolithography or selective sintering, LENS builds metal parts line by line and layer by layer. Metal particles are injected into a laser beam where they are melted and deposited onto a substrate as a miniature weld pool. The trace of the laser beam on the substrate is driven by the definition of CAD models until the desired net-shaped densified metal component is produced.

Three years ago, production requirements for a T73-tempered aluminium 7075 (Al 7075-T73) component were curtailed and the ``in-process`` parts were stored. During recent attempts to complete processing, visible defects were discovered in this component. Defects at such an early stage in the 20+ year lifetime of the component pose reliability concerns. Chemical and microstructural analysis, mechanical testing, and corrosion evaluation were performed to determine the impact of the defects on material properties.

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. This paper will describe the insulator stack design and present the results of the ELECTRO and IVORY analyses.

The group III-nitrides continue to generate interest due to their wide band gaps and high dielectric constants. These materials have made significant impact on the compound semiconductor community as blue and ultraviolet light emitting diodes (LEDs). Realization of more advanced devices; including lasers and high temperature electronics, requires dry etch processes which are well controlled, smooth, highly anisotropic and have etch rates exceeding 0.5 {mu}m/min. In this paper, we compare electron cyclotron resonance (ECR), inductively coupled plasma (ICP), and reactive ion etch (RIE) etch results for GaN. These are the first ICP etch results reported for GaN. We also report ECR etch rates for GaN as a function of growth technique.

We have been investigating the applicability of fuzzy mathematics in safety assessments (PSAs). It is a very efficient approach, both in terms of methodology development time and program execution time. Most importantly, it processes subjective information subjectively, not as if it were based on measured data. One of the most useful results of this work is that we have shown the potential for significant differences (especially in perceived margin relative to a decision threshold) between fuzzy mathematics analysis and conventional PSA analysis. This difference is due to subtle factors inherent in the choice of probability distributions for modeling uncertainty. Since subjective uncertainty, stochastic variability, and dependence are all parts of most practical situations, a technique has been developed for combining the three effects. The methodology is based on hybrid numbers and on Frechet inequality dependency bounds analysis. Some new results have also been obtained in the areas of efficient disjoint set representations and constrained uncertainty and variability analysis.

We have found that nanosecond optical parametric oscillators pumped well above threshold by single longitudinal mode pulse produce signal and idler light that is nearly purely phase modulated, even for unseeded operation.

There is a need for an automated system for protecting and monitoring sensitive or classified parts and material. Sandia has developed a real-time personnel and material tracking system (PAMTRAK) that has been installed at selected DOE facilities. It safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. It includes remote control and alarm display capabilities and a complementary program in Keyhole to display measured material attributes remotely. This paper describes the design goals, the system components, current installations, and the benefits a site can expect when using PAMTRAK.

Expert system implementation can take numerous forms ranging form traditional declarative rule-based systems with if-then syntax to imperative programming languages that capture expertise in procedural code. The artificial intelligence community generally thinks of expert systems as rules or rule-bases and an inference engine to process the knowledge. The welding advisor developed at Sandia National Laboratories and described in this paper deviates from this by codifying expertise using object representation and methods. Objects allow computer scientists to model the world as humans perceive it giving us a very natural way to encode expert knowledge. The design of the welding advisor, which generates and evaluates solutions, will be compared and contrasted to a traditional rule- based system.

Traditional definitions of risk partition concern into the probability of occurrence and the consequence of the event. Most safety analyses focus on probabilistic assessment of an occurrence and the amount of some measurable result of the event, but the real meaning of the ``consequence`` partition is usually afforded less attention. In particular, acceptable social consequence (consequence accepted by the public) frequently differs significantly from the metrics commonly proposed by risk analysts. This paper addresses some of the important system development issues associated with consequences, focusing on ``high consequence operations safety.``

Field ion microscopy show a strong correlation between mobility and shape of small clusters on fcc(100) metal surfaces. For self-diffusion on Rh(100) this correlation lead to an oscillatory behavior in the activation energy of surface diffusion as a function of cluster size. Comparison of measured activation energies to theory indicate that the mechanism of cluster diffusion involves individual displacements of edge atoms (ie, perimeter diffusion). Rate-determining step in migration of clusters is partial detachment of one of the perimeter atoms. Relative ease of adatom motion along straight edges of stationary clusters also permits measurements of diffusion barriers at steps, which can be useful in interpretation of fractal vs compact island growth on fcc metal surfaces.

GaAs-based Metal Semiconductor Field Effect transistors (MESFETs) and High Electron Mobility Transistors (HEMTs) have been the focus of research for high-temperature operation due to the 1.42 eV band gap of GaAs that reduces thermal carrier generation as compared to 1.1 eV silicon-based electronics. Although schemes have been proposed to minimize substrate currents at elevated temperatures, high-temperature operation of these devices is ultimately limited by the gate leakage current of the Schottky gate contact. Since a Junction Field Effect Transistor (JFET) has a higher gate barrier to current flow than a Schottky barrier MESFET as a result of the p/n junction gate, JFETs should have superior performance at elevated temperatures. This paper compares the high-temperature performance of a self-aligned GaAs MESFET and JFET. Both devices suffer from substrate leakage at high temperature; however, the JFET has superior gate characteristics and maintains a larger fraction of its room temperature transconductance at 300 C.

We have studied the chemical selectivity and sensitivity of surface acoustic wave (SAW) sensors covered by (COO{sup {minus}}){sub 2}/Cu{sup 2+}-terminated interfaces by examining the response of self-assembled monolayer (SAM) films formed from the solution phase for 36, 84, and 180 h adsorption times. These organomercaptan SAMs were prepared on thin-film Au surfaces having variable, controlled grain size. The SAW response from the carboxylate coordinated Cu{sup 2+}-terminated SAM is compared to that from methyl-terminated SAM, as these films interact with a vapor-phase organophosphonate analyte and the vapors of common organic solvents. Results have implications for designing and reliably fabricating chemical sensors that respond to specific organic analytes.

Ion implantation doping and isolation has played a critical role in realizing high performance photonic and electronic devices in all mature semiconductor materials; this is also expected for binary III-Nitride materials (InN, GaN, AlN) and their alloys as epitaxy improves and more advanced device structures fabricated. This paper reports on recent progress in ion implantation doping of III-Nitride materials that has led to the first demonstration of a GaN JFET (junction field effect transistor). The JFET was fabricated with all ion implantation doping; in particular, p-type doping of GaN with Ca has been demonstrated with an estimated acceptor ionization energy of 169 meV. O-implantation has also been studied and shown to yield n-type conduction with an ionization energy of {similar_to}29 meV. Neither Ca or O display measurable redistribution during a 1125 C, 15 s activation anneal which sets an upper limit on their diffusivity at this temperature of 2.7{times}10{sup {minus}13}cm{sup 2}/s.

Asynchronous Transfer Mode (ATM) is a new data communications technology that promises to integrate voice, video, and data traffic into a common network infrastructure. In order to fully utilize ATM`s ability to transfer real-time data at high rates, applications will start to access the ATM layer directly. As a result of this trend, security mechanisms at the ATM layer will be required. A number of research programs are currently in progress which seek to better understand the unique issues associated with ATM security. This paper describes some of these issues, and the approaches taken by various organizations in the design of ATM layer security mechanisms. Efforts within the ATM Forum to address the user communities need for ATM security are also described.

We present a manipulator placement algorithm for minimizing the length of the manipulator motion performing a visit-point task such as spot welding. Given a set of points for the tool of a manipulator to visit, our algorithm finds the shortest robot motion required to visit the points from each possible base configuration. The base configurations resulting in the shortest motion is selected as the optimal robot placement. The shortest robot motion required for visiting multiple points from a given base configuration is computed using a variant of the traveling salesman algorithm in the robot joint space and a point-to-point path planner that plans collision free robot paths between two configurations. Our robot placement algorithm is expected to reduce the robot cycle time during visit- point tasks, as well as speeding up the robot set-up process when building a manufacturing line.

In recent years, much of the progress in Computer-Aided Manufacturing has emphasized the use of simulation, finite-element analysis, and other science-based techniques to plan and evaluate manufacturing processes. These approaches are all based on the idea that we can build sufficiently faithful models of complex manufacturing processes such as machining, welding, and casting. Although there has been considerable progress in this area, it continues to suffer from difficulties: the first of these is that the kind of highly accurate models that this approach requires may take many person months to construct, and the second is the large amount of computing resources needed to run these simulations. Two design advisors, Near Net-Shape Advisor and Design for Machinability Advisor, are being developed to explore the role of heuristic, knowledge-based systems for manufacturing processes, both as an alternative to more analytical techniques, and also in support of these techniques. Currently the advisors are both in the prototype stage. All indications lead to the conclusion that the advisors will be successful and lay the groundwork for additional systems such as these in the future.

Lithium wall conditioning has been used in a recent campaign evaluating high performance negative central shear (NCS) discharges. During this campaign, the highest values of stored energy (4.4 MJ), neutron rate (2.4 x 10{sup 16}/s), and nT{sub i}{tau} (7 x 10{sup 20} m{sup -3}-keV-s) achieved to date in DIII-D were obtained. High performance NCS discharges were achieved prior to beginning lithium conditioning, but it is clear that shot reproducibility and performance were improved by lithium conditioning. Central and edge oxygen concentrations were reduced after lithium conditioning, Lithium conditioning, consisting of up to four pellets injected at the end of the preceding discharge, allowed the duration of the usual inter-shot helium glow discharge to be reduced and reproducible high auxiliary power discharges, P{sub NBI} {<=} 22 MW, were obtained with plasma currents up to 2.4 MA.

From the beginnings of the U.S. nuclear weapons program, military and civilian dual- agency judgment has been fundamental to achieving nuclear weapon and weapon system safety. This interaction was initiated by the Atomic Energy Act of 1946, which created the Atomic Energy Commission (AEC). The principle of using dual-agency judgment has been perpetuated in the design and assessment of the weapon and weapon system acceptance process since that time. This fundamental approach is still used today in all phases of the weapon life. In this paper, an overview of the history and philosophy of the approach is described.

We have synthesized monolithic particulate gels of periodic mesoporous silica by adding tetramethoxysilane to a homogeneous alkaline micellar precursor solution. The gels exhibit 5 characteristic length scales over 4 orders of magnitude: fractal domains larger than the particle size (>500 nm), particles that are {approximately}150 to 500 nm in diameter, interparticle pores that are on the order of the particle size, a feature in the gas adsorption measurements that indicates pores {approximately}10-50 nm, and periodic hexagonal arrays of {approximately}3 nm channels within each particle. The wet gel monoliths exhibit calculated densities as low as {approximately}0.02 g/cc; the dried and calcined gels have bulk densities that range from {approximately}0.3-0.5 g/cc. The materials possess large interparticle ({approximately}1.0-2.3 cc/g) and intraparticle ({approximately}0.6 cc/g) porosities.

This paper reviews several coupled theoretical and experimental investigations of the effect of microstructure on momentum transport in concentrated suspensions. An expression to predict the apparent suspension viscosity of mixtures of rods and spheres is developed and verified with falling-ball viscometry experiments. The effects of suspension-scale slip (relative to the bulk continuum) are studied with a sensitive spinning-ball rheometer, and the results are explained with a novel theoretical method. The first noninvasive, nuclear magnetic resonance imaging measurements of the evolution of velocity and concentration profiles in pressure-driven entrance flows of initially well mixed suspensions in a circular conduit are described, as well as more complex two-dimensional flows with recirculation, e.g. flow in a journal bearing. These data in nonhomogeneous flows and complementary three-dimensional video imaging of individual tracer particles in homogeneous flows are providing much needed information on the effects of flow on particle interactions and effective theological properties at the macroscale.

Four of the better developed resist schemes that are outgrowths of DUV (248 and 193 nm) resist development are considered as candidates for EUV. They are as follows: trilayer, a thin imaging layer on top of a refractor masking/pattern transfer layer on top of a planarizing and processing layer (PPL); solution developed, organometallic bilayer where the imaging and masking layer have been combined into one material on top of a PPL; and finally silylated resists. They are examined in a very general form without regard to the specifics of chemistry of the variations within each group, but rather to what is common to each group and how that affects their effectiveness as candidates for a near term EUV resist. In particular they are examined with respect to sensitivity, potential resolution, optical density, etching selectivity during pattern transfer, and any issues associated with pattern fidelity such as swelling.

We have deposited ZrO{sub 2}, TiO{sub 2}, and SnO{sub 2} films on ST-cut quartz surface acoustic wave (SAW) devices via sol-gel techniques. The films range from 100 to 300 nm thick and have porosities after calcination at 300{degrees}C that range from 82-88 % for ZrO{sub 2}, 77-81% for TiO{sub 2}, and 57-66% for SnO{sub 2}. In all cases, we have varied the synthesis and processing parameters over a wide range to optimize film properties: metal ion concentration (0.05-1.0 M), the H{sub 2}O:metal ratio (0.3-5.3), the acid concentration in the sol (0.02-0.7 M), the modifier ligand:metal ratio (r = 0.0-1.0), the processing conditions (100-900{degrees}C). The modifier ligand, triethanolamine (TEA), is added to each solution to allow multilayer films to be made crack free. The multilayer films are studied by optical microscopy, ellipsometry, X-ray diffraction, and N{sub 2} sorption. Preliminary high temperature frequency response measurements to target gases, such as, H{sub 2}, NO, NO{sub 2}, and propylene indicate limited sensitivity for the configurations tested.

The hydrolysis and self- and cross-condensation kinetics of the hybrid sol tetraethoxysilane and ethyltriethoxysilane were investigated by high resolution {sup 29}Si NMR spectroscopy. A kinetic model in which hydrolysis is reversible and condensation is irreversible was developed. The authors found excellent agreement between the product distributions measured by {sup 29}Si NMR spectroscopy and calculated by the model. The cross-condensation rates for each of the sols were intermediate to the condensation rates of the individual components. Calculations show that for these sols, the concentration of cross-condensed species is a weak function of the relative rates of self-condensation.

The Sr-Bi-Ta-O system is of interest for thin-film non-volatile ferroelectric memories. A better understanding of the process by which the perovskite phase forms can provide insight for improved processing of this ferroelectric compound. The authors have prepared thin-films by a chemical method using Sr-acetate, Bi-acetate and Ta-ethoxide; cation ratios were {approximately} 1:2:2 for Sr, Bi, and Ta, respectively. Results of in-situ crystallization studies using High-Temperature Grazing-Incidence X-ray Diffraction (HTGIXRD) have demonstrated that a fluorite structure, forming in the {approximately}600--700 C range, acts as an intermediate phase prior to the crystallization of the perovskite. Additional samples with cation ratios of {approximately} 1:0.8:2 were also investigated. Results for samples prepared with the 0.8 Bi content indicated that a pyrochlor phase forms which contains a substantial deficiency in Bi compared to the composition of the perovskite phase. The structures of the pyrochlore and fluorite phases and their relation to the formation of the perovskite ferroelectric are discussed.

Silicon nitride powders with an average size as low as 7 nm are synthesized in a pulsed radio frequency glow discharge. The as-synthesized silicon nitride powder from a silane/ammonia plasma has a high hydrogen content and is sensitive to oxidation in air. Post-plasma heating of the powder in a vacuum results in nitrogen loss, giving silicon-rich powder. In contrast, heat treatment at 800 C for 20 minutes in an ammonia atmosphere (200 Torr pressure) yields a hydrogen-free powder which is stable with respect to atmospheric oxidation. Several approaches to synthesizing silicon carbide nano-size powders are presented. Experiments using silane/hydrocarbon plasmas produce particles with a high hydrogen content as demonstrated by Fourier transform infrared analysis. The hydrogen is present as both CH and SiH functionality. These powders are extremely air-sensitive. A second approach uses a gas mixture of methyltrichlorosilane and hydrogen. The particles have a low hydrogen content and resist oxidation. Particle morphology of the silicon carbide is more spherical and there is less agglomeration than is observed in the silicon nitride powder.

Development of capillary stress in porous xerogels, although ubiquitous, has not been systematically studied. The authors have used the beam bending technique to measure stress isotherms of microporous thin films prepared by a sol-gel route. The thin films were prepared on deformable silicon substrates which were then placed in a vacuum system. The automated measurement was carried out by monitoring the deflection of a laser reflected off the substrate while changing the overlying relative pressure of various solvents. The magnitude of the macroscopic bending stress was found to reach a value of 180 MPa at a relative pressure of methanol, P/Po = 0.001. The observed stress is determined by the pore size distribution and is an order of magnitude smaller in mesoporous thin films. Density Functional Theory (DFT) indicates that for the microporous materials, the stress at saturation is compressive and drops as the relative pressure is reduced.

Using infrared light scattering microscopy, the authors have directly observed the inhibition of photon propagation in a 2-dimensional photonic lattice fabricated as a hexagonal array of AlGaAs posts. The lattice was formed by reactive ion etching of {approximately}400 nm diameter posts defined by electron beam lithography. The lattice design parameters correspond to a photonic bandgap near 1.5 {micro}m as calculated by Meade et al. This hexagonal array of posts is an improvement over early honeycomb lattices because it is easier to fabricate. The photonic lattice of 1.4 {micro}m high posts was incorporated into waveguide designed for single mode at 1.5 {micro}m. Several waveguide/lattice combinations were fabricated, including M-bar and K-bar lattice orientations aligned parallel to the waveguide and different numbers of lattice periods. The waveguide/lattice structures were fabricated on GaAs substrates that were subsequently thinned and cleaved to couple light into the waveguide facets. Using a specially designed triple infrared microscope system, they simultaneously imaged the input and output facets and the top surface of the waveguide as laser light was focused onto the input facet. Because of internal scattering in the waveguide, light is scattered upward outward and can be imaged with an infrared camera. Images for reflected input, waveguide scattered light, and transmitted output light for the waveguide with (left images) and without the photonic lattice (right images) are shown. The lefthand image shows how the lattice interrupts the transport of light through the waveguide.

The purpose of this contribution is to propose an ``Authentication Information Element`` that can be used to carry authentication information within the ATM signaling protocols. This information may be used by either signaling entity to validate the claimed identity of the other, and to verify the integrity of a portion of a message`s contents. By specifying a generic authentication IE, authentication information can be generated by any signature algorithm, and can be appended to any ATM signaling message. Procedures for the use of this information element are also provided.

Software process improvement has become a popular pastime, for a variety of reasons. The Software Engineering Institute`s summary of experimental data, which resulted in the Capability Maturity Model, has now had considerable corroboration. There are nearly as many software processes as there are combinations of developers, users, and products. Similarly, there are probably as many software process improvement approaches. However, the meta-process for performing process improvement is quite straightforward. Processes can be represented by a small number of abstractions, with variety supplied through implementation details. The scheme for improvement is almost self-evident: figure out where you are now, use a software process maturity guide to identify shortcomings, plot a change in a direction to eliminate a shortcoming, and go for it. This paper won`t dwell on the meta process and its enactment; the authors simply assume one is in place. Rather, they consider some ways to improve the testing aspects of your software process. These may be changes in what you do for testing as well as in how you do it.

GaN is an attractive material for use in high-temperature or high-power electronic devices due to its high bandgap (3.39 eV), high breakdown field ({approximately}5 {times} 10{sup 6} V/cm), high saturation drift velocity (2.7 {times} 10{sup 7} cm/s), and chemical inertness. To this end, Metal Semiconductor FETs (MESFETs), High Electron Mobility Transistors (HEMTs), Heterostructure FETs (HFETs), and Metal Insulator Semiconductor FETs (MISFETs) have all been reported based on epitaxial AlN/GaN structures (Khan 1993a,b; Binari 1994 and 1995). GaN Junction Field Effect Transistors (JFETs), however, had not been reported until recently (Zolper 1996b). JFETs are attractive for high-temperature operation due to the inherently higher thermal stability of the p/n junction gate of a JFET as compared to the Schottky barrier gate of a MESFET or HFET. In this paper the authors present the first results for elevated temperature performance of a GaN JFET. Although the forward gate properties are well behaved at higher temperatures, the reverse characteristics show increased leakage at elevated temperature. However, the increased date leakage alone does not explain the observed increase in drain current with temperature. Therefore, they believe this first device is limited by temperature activated substrate conduction.

Structure and properties of a series of modified polydimethylsiloxane (PDMS) elastomers reinforced by {ital in situ} generated silic particles were investigated. The PDMS elastomer was modified by systematically varying the molecular weight between reactive groups incorporated into the backbone. Tetraethoxysilane (TEOS) and partial hydrolyzate of TEOS were used to generate silic particles. Chemistry and phase structure of the materials were investigated by {sup 29}Si magic angle spinning nuclear magnetic resonance spectroscopy and swelling experiments.

Conventional III-V metallizations chemes such as Au/Ge/Ni, Ti/Pt/Au, and Au/Be were found to display poor thermal stability on both GaN and InGaN, with extensive reaction and contact degradation at {le}500 C. By contrast, W was found to produce low contact resistance ({rho}{sub c}{similar_to}8x10{sup -5}{Omega}cm{sup 2}) to n-GaN. Ga outdiffusion to the surface of thin (500 A) W films was found after annealing at 1,100 C, but not at 1000 C. Interfacial abruptness increased by 300A after 1,100 C annealing. In the case of WSi{sub X} (X=0.45), Ga outdiffusion was absent even at 1,100 C, but again there was interfacial broadening and some phase changes in the WSi{sub X}. On In{sub 0.5}Ga{sub 0.5}N, a minimum specific contact resistivity of 1.5 x10{sup -5}{Omega}cm{sup 2} was obtained for WSi{sub X} annealed at 700 C. These contacts retained a smooth morphology and abrupt interfaces to 800 C. Graded In{sub X}Ga{sub 1-X}N layers have been employed on GaAs/AlGaAs HBTs (heterojunction bipolar transistors), replacing conventional In{sub X}Ga{sub 1-X}As layers. R{sub C} values of 5x10{sup -7}{Omega}cm{sup 2} were obtained for nonalloyed Ti/Pt/Au on the InGaN, and the morphologies were superior to those of InGaAs contact layers. This proves to have significant advantages for fabrication of sub-micron HBTs. Devices with emitter dimensions of 2x5{mu}m{sup 2} displayed gains of 35 for a base doping level of 7x10{sup 19}cm{sup -3} and stable long-term behavior.

Microtags are microscopic computer-generated holograms with 130-nm features and are mass-producible with EUVL. This fabrication method renders microtags difficult to counterfeit. Applications includ tagging and tracking of microprocessors, memory chips, currencey, and credit cards.

In the present study we are developing an experimental fracture material property test method specific to dynamic fragmentation. Spherical test samples of the metals of interest are subjected to controlled impulsive stress loads by acceleration to high velocities with a light-gas launcher facility and subsequent normal impact on thin plates. Motion, deformation and fragmentation of the test samples are diagnosed with multiple flash radiography methods. The impact plate materials are selected to be transparent to the x-ray method so that only test metal material is imaged. Through a systematic series of such tests, both strain-to-failure and fragmentation resistance properties are determined through this experimental method. Fragmentation property data for several steels, copper, aluminum, tantalum and titanium have been obtained to date. Aspects of the dynamic data have been analyzed with computational methods to achieve a better understanding of the processes leading to failure and fragmentation, and to test an existing computational fragmentation model.

Neutron powder diffraction at pressures to 6 kbar in gaseous Ne has been used to study the pressure-induced phase transition and compressibilities of Na{sub 2}CsC{sub 60}. The pressure-induced phase can be achieved by compression to about 5 kbar at room temperature. If cooled, this phase can be retained below 200 K upon release of the pressure. The structure is orthorhombic as previously reported (but may differ in its detailed crystal structure) with lattice constants near 80 K and ambient pressure of a=9.385 A, b=10.06 A, and c=14.36 A. Corresponding linear compressibilities are 0.0004, 0014, and 0.0017 kbar{sup -1}, respectively. Identical pressure temperature cycling results in a superconductor with an unexpectedly low pressure dependence for {Tc} while in this phase. Models for the superconducting behavior of this compound are discussed.

In order to support advanced manufacturing, Sandia has acquired the capability to produce plastic prototypes using stereolithography. Currently, these prototypes are used mainly to verify part geometry and ``fit and form`` checks. This project investigates methods for rapidly testing these plastic prototypes, and inferring from prototype test data actual metal part performance and behavior. Performances examined include static load/stress response, and structural dynamic (modal) and vibration behavior. The integration of advanced non-contacting measurement techniques including scanning laser velocimetry, laser holography, and thermoelasticity into testing of these prototypes is described. Photoelastic properties of the epoxy prototypes to reveal full field stress/strain fields are also explored.

W, WSi{sub 0.44} and Ti/Al contacts were examined on n{sup +} In{sub 0.65}Ga{sub 0.35}N, InN and In{sub 0.75}Al{sub 0.25}N. W was found to produce low specific contact resistance ({rho}{sub c} {approximately} 10{sup {minus}7} {Omega} {center_dot}cm{sup 2}) ohmic contacts to InGaN, with significant reaction between metal and semiconductor at 900 {degrees}C mainly due to out diffusion of In and N. WSi{sub x} showed an as-deposited {rho}{sub c} of 4{times}10{sup {minus}7} {Omega} {center_dot}cm{sup 2} but this degraded significantly with subsequent annealing. Ti/Al contacts were stable to {approximately} 600 {degrees}C ({rho}{sub c} {approximately} 4{times}10{sup {minus}7} {Omega} {center_dot}cm{sup 2} at {le}600 {degrees}C). The surfaces of these contacts remain smooth to 800 {degrees}C for W and WSi{sub x} and 650 {degrees}C for Ti/Al. InN contacted with W and Ti/Al produced ohmic contacts with {rho}{sub c} {approximately} 10{sup {minus}7} {Omega} {center_dot}cm{sup 2} and for WSi{sub x} {rho}{sub c} {approximately} 10{sup {minus}6} {Omega} {center_dot}cm{sup 2}. All remained smooth to {approximately} 600 {degrees}C, but exhibited significant interdiffusion of In, N, W and Ti respectively at higher temperatures. The contact resistances for all three metalization schemes were {ge} 10{sup {minus}4} {Omega} {center_dot}cm{sup 2} on InAlN, and degrades with subsequent annealing. The Ti/Al was found to react with the InAlN above 400 {degrees}C, causing the contact resistance to increase rapidly. W and WSi{sub x} proved to be more stable with {rho}{sub c} {approximately} 10{sup {minus}2} and 10{sup {minus}3} {Omega} {center_dot}cm{sup 2} up to 650 {degrees}C and 700 {degrees}C respectively.

As photovoltaic (PV) electrical power systems gain increasing acceptance for both off-grid and utility-interactive applications, the safety, durability, and performance of these systems gains in importance. Local and state jurisdictions in many areas of the country require that all electrical power systems be installed in compliance with the requirements of the National Electrical Code{reg_sign} (NEC{reg_sign}). Utilities and governmental agencies are now requiring that PV installations and components also meet a number of Institute of Electrical and Electronic Engineers (IEEE) standards. PV installers are working more closely with licensed electricians and electrical contractors who are familiar with existing local codes and installation practices. PV manufacturers, utilities, balance of systems manufacturers, and standards representatives have come together to address safety and code related issues for future PV installations. This paper addresses why compliance with the accepted codes and standards is needed and how it is being achieved.

Phase II work for this Laboratory Directed Research and Development project is presented. Historically, high velocity, solid, electrically conducting armatures or projectiles have been utilized to generate or magnify existing electric fields in magnetohydrodynamic (MHD) devices. Useful power can be extracted from high velocity ionized, electrically conductive plasma jets. The MHD device current output can be switched to power other devices. The purpose of this project is to investigate the use of an Explosively-Driven Ionized Plasma Jet Generator (EDMG) to more efficiently obtain velocities much higher than can be achieved with solid armatures or projectiles. The armature velocity is one of the more important parameters in the electric field magnification process. The ionized plasma jet is generated by explosively collapsing a gas (neon, argon, xenon, hydrogen) filled cavity and directing the jet through a shocktube or core of an MHD device. Data are presented for two different size and configuration explosive drivers, one explosive (COMP-C4), one gas (argon), different driver pressures (90-200 psia), different shocktube or test section pressures (0.01-11.7 psia), and for two different shocktube inside dimensions. Measured time-of-arrival, current, voltage, resistance, power and energy data are presented for tests conducted. Measured time-of-arrival and plasma flow velocity data are compared to the predicted CTH hydrocode data. CTH code calculations are also presented to compare EDMG performance of various test gases and various explosive liner materials.

The International Security Program Initiative at Sandia National Laboratories (SNL) is dedicated to achieving a global nuclear security structure that reduces the danger of nuclear and other weapons of mass destruction. SNL is the principle Department of Energy (DOE) laboratory, jointly funded by the DOE and the Department of Defense (DoD), and is responsible for developing technology, concepts, and hardware to protect nuclear weapons and materials at facilities, and during transportation. SNL is working cooperatively with scientists and engineers in various institutes, laboratories, and other organizations within the countries of the Former Soviet Union (FSU) to reduce the risk of nuclear weapons proliferation. One major step toward achieving worldwide protection and control of nuclear materials and weapons proliferation is being accomplished by the DOE National Laboratories on work with the FSU in the area of Material Protection, Control, and Accountability (MPC&A). This report focuses on the accomplishments and status of work under the MPC&A program at Sandia. In addition, brief summaries of other areas of FSU cooperation are included such as Industrial Partnering Program (IPP); Lab-to-Lab; Safe and Secure Dismantlement (SSD); Safety and Security Technology; and Energy and Environment.

This report discusses a novel fabrication process to produce nearly perfect optics. The process utilizes vacuum deposition techniques to optimally modify polished optical substrate surfaces. The surface figure, i.e. contour of a polished optical element, is improved by differentially filling in the low spots on the surface using flux from a physical vapor deposition source through an appropriate mask. The process is expected to enable the manufacture of diffraction-limited optical systems for the UV, extreme UV, and soft X-ray spectral regions, which would have great impact on photolithography and astronomy. This same technique may also reduce the fabrication cost of visible region optics with aspheric surfaces.

Hydrous Metal Oxides (HMOs) are chemically synthesized materials which contain a homogeneous distribution of ion exchangeable alkali cations that provide charge compensation to the metal-oxygen framework. In terms of the major types of inorganic ion exchangers defined by Clearfield, these amorphous HMO materials are similar to both hydrous oxides and layered oxide ion exchangers (e.g., alkali metal titanates). For catalyst applications, the HMO material serves as an ion exchangeable support which facilitates the uniform incorporation of catalyst precursor species. Following catalyst precursor incorporation, an activation step is required to convert the catalyst precursor to the desired active phase. Considerable process development activities at Sandia National Laboratories related to HMO materials have resulted in bulk hydrous titanium oxide (HTO)- and silica-doped hydrous titanium oxide (HTO:Si)-supported NiMo catalysts that are more active in model reactions which simulate direct coal liquefaction (e.g., pyrene hydrogenation) than commercial {gamma}-Al{sub 2}O{sub 3}-supported NiMo catalysts. However, a fundamental explanation does not exist for the enhanced activity of these novel catalyst materials; possible reasons include fundamental differences in support chemistry relative to commercial oxides, high surface area, or catalyst preparation effects (ion exchange vs. incipient wetness impregnation techniques). The goals of this paper are to identify the key factors which control sulfided NiMo catalyst activity, including those characteristics of HTO- and HTO:Si-supported NiMo catalysts which uniquely set them apart from conventional oxide supports.

During April-May, 1995, Sandia National Laboratories, in cooperation with Trans-Pacific Geothermal Corporation, drilled a 5825{prime} exploratory slimhole (3.85 in. diameter) in the Vale Known Geothermal Resource Area (KGRA) near Vale, Oregon. This well was part of Sandia`s program to evaluate slimholes as a geothermal exploration tool. During drilling we performed several temperature logs, and after drilling was complete we performed injection tests, bailing from a zone isolated by a packer, and repeated temperature logs. In addition to these measurements, the well`s data set includes: 2714{prime} of continuous core (with detailed log); daily drilling reports from Sandia and from drilling contractor personnel; daily drilling fluid records; numerous temperature logs; pressure shut-in data from injection tests; and comparative data from other wells drilled in the Vale KGRA. This report contains: (1) a narrative account of the drilling and testing, (2) a description of equipment used, (3) a brief geologic description of the formation drilled, (4) a summary and preliminary interpretation of the data, and (5) recommendations for future work.

New pour-in-place, low density, rigid polyurethane foam kits have been developed to mechanically stabilize damaged explosive ordnance. Although earlier foam systems used chlorofluorocarbons as blowing agents, the current versions rely on carbon dioxide generated by the reaction of isocynates with water. In addition, these kits were developed to manually generate small quantifies of rigid foam in the field with minimal or no protective equipment. The purpose of this study was to evaluate and summarize available hazard information for the components of these rigid foam kits and to provide recommendations for personal protective equipment to be used while performing the manual combination of the components. As with most rigid foam systems, these kits consist of two parts, one a mixture of isocyanates; the other, a combination of polyols, surfactants, and amine catalysts. Once completely deployed, the rigid foam is non-toxic. The components, however, have some important health effects which must be considered when establishing handling procedures.

In this continued study, the microstructural evolution and peel strength as a function of thermal aging were evaluated for four Sn-Ag solders deposited on double layered Ag-Pt metallization. Additionally, activation energies for intermetallic growth over the temperature range of 134 to 190{degrees}C were obtained through thickness measurements of the Ag-Sn intermetallic that formed at the solder-metallization interface. It was found that Bi-containing solders yielded higher activation energies for the intermetallic growth, leading to thicker intermetallic layers at 175 and 190{degrees}C for times of 542 and 20.5 hrs, respectively, than the solders free of Bi. Complete reaction of the solder with the metallization occurred and lower peel strengths were measured on the Bi-containing solders. In all solder systems, a Ag-Sn intermetallic thickness of greater than {approximately}7 {mu}m contributed to lower peel strength values. The Ag-Sn binary eutectic composition and the Ag-Sn-Cu ternary eutectic composition solders yielded lower activation energies for intermetallic formation, less microstructural change with time, and higher peel strengths; these solder systems were resilient to the effects of temperatures up to 175{degrees}C. Accelerated isothermal aging studies provide useful criteria for recommendation of materials systems. The Sn-Ag and Sn-Ag-Cu eutectic compositions should be considered for future service life and reliability studies based upon their performance in this study.

Experimental results and a mathematical model are presented to describe differential evaporation rates in electron beam melting of titanium alloys containing aluminum and vanadium. Experiments characterized the evaporation rate of commercially pure titanium, and vapor composition over titanium with up to 6% Al and 4.5% V content as a function of beam power, scan frequency and background pressure. The model is made up of a steady-state heat and mass transport model of a melting hearth and a model of transient thermal and flow behavior near the surface. Activity coefficients for aluminum and vanadium in titanium are roughly estimated by fitting model parameters to experimental results. Based on the ability to vary evaporation rate by 10-15% using scan frequency alone, we discuss the possibility of on-line composition control by means of intelligent manipulation of the electron beam.

Thermal, electrochemical and transition metal mediated reactions of phosphaacetylene monomers were conducted in attempts to form novel polyphosphaacetylenes as a new class of potentially electrically conducting polymers. Molecular modeling was used to simulate the molecular conformations of optimized, isolated oligomers to identify the proper monomeric repeat units for highly conjugated molecules. Electrodeposition of suitable monomers led to low molecular weight oligomers. Thermal polymerization of phosphaacetylene monomers bearing aromatic substituents ed to the formation of polyhedral cage oligomers. Under metathesis polymerization conditions the phosphaacetylene monomers form unique complexes via an unprecedented sequence of intermediates which suggest that metathesis to linear oligomers is achievable. Conductivity measurements on electrodeposited oligomers indicate modest electrical conductivity.

This study examines, from a systems engineering design perspective, the potential of kinetic energy weapons being used in the role of a conventional strategic weapon. Within the Department of Energy (DOE) complex, strategic weapon experience falls predominantly in the nuclear weapons arena. The techniques developed over the years may not be the most suitable methodologies for use in a new design/development arena. For this reason a more fundamental approach was pursued with the objective of developing an information base from which design decisions might be made concerning the conventional strategic weapon system concepts. The study examined (1) a number of generic missions, (2) the effects of a number of damage mechanisms from a physics perspective, (3) measures of effectiveness (MOE`s), and (4) a design envelope for kinetic energy weapon concepts. With the base of information a cut at developing a set of high-level system requirements was made, and a number of concepts were assessed against these requirements.

We describe measurements, modeling, and mitigation experiments on the effects of anode and cathode plasmas in applied-B ion diodes. We have performed experiments with electrode conditioning and cleaning techniques including RF discharges, anode heating, cryogenic cathode cooling and anode surface coatings that have been successful in mitigating some of the effects of electrode contamination on ion diode performance on both the SABRE and PBFA accelerators. We are developing sophisticated spectroscopic diagnostic techniques that allow us to measure the electric and magnetic fields in the A-K gap, we compare these measured fields with those predicted by our 3-D particle-in-cell (PIC) simulations of ion diodes, and we measure anode and cathode plasma densities and expansion velocities. We are continuing to develop E-M simulation codes with fluid-PIC hybrid models for dense plasmas, in order to understand the role of electrode plasmas in ion diode performance. Our strategy for improving high power ion diode performance is to employ and expand our capabilities in measuring and modeling A-K gap plasmas and leverage our increased knowledge into an increase in total ion beam brightness to High Yield Facility (HYF) levels.

The high peak power, single-pulse technology developed for government programs during the mid-60`s through the mid-80`s is being adapted for use in continuously operating, high average power commercial materials processing applications. A new thermal surface treatment technology, called ion beam surface treatment (BEST), uses repetitive high energy (kJ`s per pulse), pulsed ({le}500 ns) ion beams to directly deposit energy in the top 1-20 micrometers of the surface of any material. A high average power IBEST processing system is made up of a magnetic pulse compressor (MPC) a magnetically confined anode plasma (MAP) ion beam source, an ion beam transport system, a materials handling system and various cooling and reset systems. System issues such as cost, reliability, size, maintainability, and design-for-manufacturability that were of secondary importance behind specific performance requirements for the earlier government applications are now the primary issues in proposed industrial systems. Research systems are now obtaining lifetime, reliability, and design-rules information for high average power short-pulse components. Beam sources are being developed that are suitable for industrial systems operating at 5-100 kW, 0.1-2.0 MeV, and {le}500 ns pulse widths. Capitol equipment costs, operating and financing costs, and sizing issues are being weighed against specific economic benefits obtained in short-pulse ion beam treatment of selected products. Dependable equipment designers and suppliers, facility integrator, and servicing organizations are being combined with development teams from end-user companies for final technology integration into major manufacturing facilities. An BEST prototype commercial system is being designed and fabricated by QM Technologies for initial operation in mid-1997.

The Molina Member of the Wasatch Formation has been cored in order to assess the presence/absence and character of microbial communities in the deep subsurface. Geological study of the Molina Member was undertaken in support of the microbiological tasks of this project, for the purposes of characterizing the host strata and of assessing the potential for post-depositional introduction of microbes into the strata. The Molina Member comprises a sandy fluvial unit within a formation dominated by mudstones. Sandy to conglomeratic deposits of braided and meandering fluvial systems are present on the western and eastern margins of the basin respectively, although the physical and temporal equivalence of these systems cannot be proven. Distal braided facies of planar-horizontal bedded sandstones are recognized on the western margin of the basin. Natural fractures are present in all Molina sandstones, commonly as apparent shear pairs. Core from the 1-M-18 well contains natural fractures similar to those found in outcrops, and has sedimentological affinities to the meandering systems of the eastern margin of the basin. The hydrologic framework of the Molina, and thus any potential post-depositional introduction of microbes into the formation, should have been controlled by approximately east-west flow through the natural fracture system, the geometries and extent of the sandstones in which the fractures occur, and hydraulic gradient. Migration to the well site, from outcropping recharge areas at the edge of the basin, could have started as early as 40 million years ago if the cored strata are connected to the eastern sedimentary system.

This study analyzes findings from a national survey of 2,490 randomly selected members of the US public conducted between September 30 and November 14, 1995. It provides an over time comparison of public perceptions about nuclear weapons risks and benefits and key nuclear policy issues between 1993 and 1995. Other areas of investigation include policy preferences regarding nuclear proliferation, terrorism, US/Russian nuclear cooperation, and personal security. Public perceptions of post-cold war security were found to be evolving in unexpected ways. The perceived threat of nuclear conflict involving the US had not declined, and the threat of nuclear conflict between other countries and fears of nuclear proliferation and terrorism had increased. Perceived risks associated with managing the US nuclear arsenal were also higher. Perceptions of external and domestic benefits from US nuclear weapons were not declining. Support was found for increasing funding for nuclear weapons safety, training, and maintenance, but most respondents favored decreasing funding for developing and testing new nuclear weapons. Strong support was evident for programs and funding to prevent nuclear proliferation and terrorism. Though skeptical that nuclear weapons can be eliminated, most respondents supported reducing the US nuclear arsenal, banning nuclear test explosions, and ending production of fissile materials to make nuclear weapons. Statistically significant relationships were found between perceptions of nuclear weapons risks and benefits and policy and spending preferences. Demographic variables and basic social and political beliefs were systematically related both to risk and benefit perceptions and policy and spending options.

This document provides an overview of the processes used to access the performance of the Waste Isolation Pilot Plant (WIPP). The quantitative metrics used in the performance-assessment (PA) process are those put forward in the Environmental Protection Agency`s Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, HIgh-LEvel and transuranic radioactive Wastes (40 CFR 191).

A bench-scale experiment was designed and constructed to determine the effective thermal diffusivity of crushed tuff. Crushed tuff particles ranging from 12.5 mm to 37.5 mm (0.5 in. to 1.5 in.) were used to fill a cylindrical volume of 1.58 m{sup 3} at an effective porosity of 0.48. Two iterations of the experiment were completed; the first spanning approximately 502 hours and the second 237 hours. Temperatures near the axial heater reached 700 degrees C, with a significant volume of the test bed exceeding 100 degrees C. Three post-test analysis techniques were used to estimate the thermal diffusivity of the crushed tuff. The first approach used nonlinear parameter estimation linked to a one dimensional radial conduction model to estimate thermal diffusivity from the first 6 hours of test data. The second method used the multiphase TOUGH2 code in conjunction with the first 20 hours of test data not only to estimate the crushed tuffs thermal diffusivity, but also to explore convective behavior within the test bed. Finally, the nonlinear conduction code COYOTE-II was used to determine thermal properties based on 111 hours of cool-down data. The post-test thermal diffusivity estimates of 5.0 x 10-7 m{sup 2}/s to 6.6 x 10-7 m{sup 2}/s were converted to effective thermal conductivities and compared to estimates obtained from published porosity-based relationships. No obvious match between the experimental data and published relationships was found to exist; however, additional data for other particle sizes and porosities are needed.

The `Red Forest` radioactive waste burials created during emergency clean-up activities at Chernobyl Nuclear Power Plant represent a serious source of radioactive contamination of the local ground water system with 9OSr concentration in ground water exceeding the drinking water standard by 3-4 orders of magnitude. In this paper we present results of our hydrogeological and radiological `Red Forest` site characterization studies, which allow us to estimate 9OSr subsurface migration parameters. We use then these parameters to assess long terrain radionuclide transport to groundwater and surface water, and to analyze associated health risks. Our analyses indicate that 9OSr transport via ground water pathway from `Red Forest` burials to the adjacent Pripyat River is relatively insignificant due to slow release of 9OSr from the waste burials (less than 1% of inventory per year) and due to long enough ground water residence time in the subsurface, which allows substantial decay of the radioactive contaminant. Tins result and our previous analyses indicate, that though conditions of radioactive waste storage in burials do not satisfy Ukrainian regulation on radiation protection, health risks caused by radionuclide migration to ground water from `Red Forest` burials do not justify application of expensive countermeasures.

Sandia now has the capability to evaluate stresses during cure of epoxies with finite element codes. Numerous material parameters are needed as input to these codes. I present a relatively quick set of tests which enable evaluation of the required thermophysical properties. Ease and accuracy of the tests improve as the reaction rate of the thermoset slows. Material parameters for common encapsulants at Sandia are presented in tables.

No abstract available.

An analytical and experimental study is conducted to investigate the effect of isolator locations on the effectiveness of vibration isolation systems. The study uses isolators with fixed properties and evaluates potential improvements to the isolation system that can be achieved by optimizing isolator locations. Because the available locations for the isolators are discrete in this application, a Genetic Algorithm (GA) is used as the optimization method. The system is modeled in MATLAB{trademark} and coupled with the GA available in the DAKOTA optimization toolkit under development at Sandia National Laboratories. Design constraints dictated by hardware and experimental limitations are implemented through penalty function techniques. A series of GA runs reveal difficulties in the search on this heavily constrained, multimodal, discrete problem. However, the GA runs provide a variety of optimized designs with predicted performance from 30 to 70 times better than a baseline configuration. An alternate approach is also tested on this problem: it uses continuous optimization, followed by rounding of the solution to neighboring discrete configurations. Results show that this approach leads to either infeasible or poor designs. Finally, a number of optimized designs obtained from the GA searches are tested in the laboratory and compared to the baseline design. These experimental results show a 7 to 46 times improvement in vibration isolation from the baseline configuration.

This work addresses specification and design of reliable safety-critical systems, such as nuclear reactor control systems. Reliability concerns are addressed in complimentary fashion by different fields. Reliability engineers build software reliability models, etc. Safety engineers focus on prevention of potential harmful effects of systems on environment. Software/hardware correctness engineers focus on production of reliable systems on the basis of mathematical proofs. The authors think that correctness may be a crucial guiding issue in the development of reliable safety-critical systems. However, purely formal approaches are not adequate for the task, because they neglect the connection with the informal customer requirements. They alleviate that as follows. First, on the basis of the requirements, they build a model of the system interactions with the environment, where the system is viewed as a black box. They will provide foundations for automated tools which will (a) demonstrate to the customer that all of the scenarios of system behavior are presented in the model, (b) uncover scenarios not present in the requirements, and (c) uncover inconsistent scenarios. The developers will work with the customer until the black box model will not possess scenarios (b) and (c) above. Second, the authors will build a chain of several increasingly detailed models, where the first model is the black box model and the last model serves to automatically generated proved executable code. The behavior of each model will be proved to conform to the behavior of the previous one. They build each model as a cluster of interactive concurrent objects, thus they allow both top-down and bottom-up development.

Effectiveness and efficiency of software development can be greatly increased by writing modularized code using informal (styles) and formal (standards) work approaches. Software development is about connecting pieces into a coherent whole. Thus consistent work approaches provide a structure that allows individuals and teams to minimize the time and thought put into making these connections. These investments in structure return even more benefits in the maintenance phase when old code has to be examined by new programmers, or after time has passed. We present some examples of coding style for Avenue: a simplified form of Hungarian notation (notationHungarian, stringCustomerName, etc.), script naming prefixes and suffixes, and options in script headers. We demonstrate several modular, object-like utility scripts that can be used alone or combined into other utilities. These include developer tools such as a System.Echo substitute for Windows, a Window inspector, and a script for detecting and dealing with multiple display resolutions.

We present an in situ technique for monitoring metal-organic vapor phase epitaxy growth by normal-incidence reflectance. This technique is used to calibrate the growth rate periodically and to monitor the growth process routinely. It is not only a precise tool to measure the growth rate, but also very useful in identifying unusal problems during a growth run, such as depletion of source material, deterioration of surface morphology, and problems associated with an improper growht procedure. We will also present an excellent reproducibility ({+-}0.3% over a course of more than 100 runs) of the cavity wavelength of vertical-cavity surface emitting laser structures with periodic calibration by this in situ technique.

Electronic and electrical system protection design can be used to eliminate deleterious effects from lightning, electromagnetic interference, and electrostatic discharges. Evaluation of conventional lightning protection systems using advanced computational modeling in conjunction with rocket-triggered lightning tests suggests that currently used lightning protection system design rules are inadequate and that significant improvements in best practices used for electronic and electrical system protection designs are possible. A case study of lightning induced upset and failure of a railway signal and control system is sketched.

How can the public play a role in decisions involving complicated scientific arguments? This paper describes a public participation exercise in which stakeholders used multiattribute utility analysis to select a site for a hazardous waste facility. Key to success was the ability to separate and address the two types of judgements inherent in environmental decisions: technical judgements on the likely consequences of alternative choices and value judgements on the importance or seriousness of those consequences. This enabled technical specialists to communicate the essential technical considerations and allowed stakeholders to establish the value judgements for the decision. Although rarely used in public participation, the multiattribute utility approach appears to provide a useful framework for the collaborative resolution of many complex environmental decision problems.

Two polyurethane systems, EN-7 and L-100, have a long history as encapsulants and coatings in Sandia programs. These materials contain significant amounts of toluene diisocyanate (TDI), a suspect human carcinogen. As part of efforts to reduce the use of hazardous materials in the workplace, PET-90A, a polyurethane with less than 0.1% free TDI, was identified as a candidate for new applications and as a replacement for the more hazardous polyurethanes in selected programs. This report documents the results of a two-year accelerated aging study of PET-90A, EN-7, and L-100 polyurethane elastomers to characterize the effect of 135{degrees}F isothermal aging on selected physical, electrical, mechanical and thermal properties. In general, there was very little change in properties over the two year period for the three elastomers. The largest changes occurred in EN-7, which is the polyurethane with the longest service history in Sandia applications.

Vector network analyzers provide a convenient way to measure scattering parameters of a variety of microwave devices. However, these instruments, unlike oscilloscopes, require a high degree of user knowledge and expertise. Measurement calibration or error correction must be done prior to use. There are many ways to make poor measurement or measurement. Check standards have been used to verify that the network analyzer is operating properly. A computer program was developed to automatically measure a check standard and compare the new measurements with an historical database of measurements of the check standard device. The program can acquire new measurement data from selected check standards, plot the new data against the mean and standard deviation of prior data for the check standard, and update the database files for the check standard. This paper describes the function of the software including a discussion of its capabilities. The way in which the software is used in our lab is also described. Finally, examples are given of how the software can detect potential measurement problems.

Fe/KClO{sub 4} pyrotechnic mixtures are used in thermal batteries to provide the heat necessary to bring the battery stack to operating temperatures of 550 to 600 C. This heat source is normally used as discs pressed from bulk powder. To evaluate the consequences associated with unexpected ignition of large amounts of heat powder, combustion of 84% Fe/16% KClO{sub 4} heat powders was conducted for various scenarios under controlled conditions and the response documented. Increasing amounts of heat powder--up to 8 lbs--were ignited in both unconfined and confined (sealed) containers in a remote area. The containers were thermocoupled and the resulting burning filmed with a standard video camera, high-speed (1,000 frames/s) film and video cameras, and an infrared video camera. A 20- minute video of the burning under the various conditions is presented.

Sandia`s Risk Management and NEPA Department recognized the need for hazard and environmental data analysis and management to support the line managers` need to know, understand, manage and document the hazards inherent in their facilities and activities. ISEEMS (Integrated Safety, Environmental, & Emergency Management System) was developed in response to this need. ISEEMS takes advantage of the fact that there is some information needed for the NEPA process that is also needed for the safety documentation process. The ISEEMS process enables Sandia to identify and manage hazards and environmental concerns at a level of effort commensurate with the hazards themselves by adopting a necessary and sufficient (graded) approach to compliance. The Preliminary Hazard Screening module of ISEEMS determines the facility or project activity hazard classification and facility designation. ISEEMS` geo-referenced icon allows immediate, visual integration of hazard information across geographic boundaries resulting in significant information compression. At Sandia, ISEEMS runs on the Sandia Internal Restricted Network, in an MS-Windows environment on standard PC hardware. The possibility of transporting ISEEMS to a ``WEB-like`` environment is being explored.