Publications

The cis and trans isomers of bis-(triethoxysilyl)-2-butene were polymerized by the sol-gel method under various conditions. The trans isomer formed gels under all conditions. The cis isomer formed gels only under basic conditions. Under acidic conditions it formed soluble resins of molecular weight ranging from 88,000 to 180,000 Daltons. Solid state and solution {sup 29}Si NMR revealed that the trans isomer formed condensed gels, and that the resins formed by the cis isomer contained cyclic monomers and/or ordered oligomers.

Polymerizations of aryltrialkoxysilanes generally afford soluble oligomeric or polymeric aryl-substituted silsesquioxanes. This is in spite of being based on trifunctional precursors capable of forming highly crosslinked and insoluble network polymers. In this study, soluble phenyl, benzyl, and phenethyl-substituted silsesquioxane oligomers and polymers were prepared by hydrolyzing their respective triethoxysilyl precursor with water or aqueous acid. Additional samples of the polymers were prepared by heating the materials at 100 C or 200 C under vacuum in order to drive the condensation chemistry. One sample of polybenzylsilsesquioxane was heated at 200 C with catalytic NaOH. The resulting materials were characterized using solution {sup 1}H, {sup 13}C, and {sup 29}Si NMR spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Of particular interest was the effect of the aryl substituent, and processing conditions on the molecular weight and glass transition temperatures of the polysilsesquioxanes.

In May of 1998, a technical basis and implementation guidelines document for A Technique for Human Event Analysis (ATHEANA) was issued as a draft report for public comment (NUREG-1624). In conjunction with the release of the draft NUREG, a paper review of the method, its documentation, and the results of an initial test of the method was held over a two-day period in Seattle, Washington, in June of 1998. Four internationally-known and respected experts in human reliability analysis (HRA) were selected to serve as the peer reviewers and were paid for their services. In addition, approximately 20 other individuals with an interest in HRA and ATHEANA also attended the peer review meeting and were invited to provide comments. The peer review team was asked to comment on any aspect of the method or the report in which improvements could be made and to discuss its strengths and weaknesses. All of the reviewers thought the ATEANA method had made significant contributions to the field of PRA/HRA, in particular by addressing the most important open questions and issues in HRA, by attempting to develop an integrated approach, and by developing a framework capable of identifying types of unsafe actions that generally have not been considered using existing methods. The reviewers had many concerns about specific aspects of the methodology and made many recommendations for ways to improve and extend the method, and to make its application more cost effective and useful to PRA in general. Details of the reviewers` comments and the ATHEANA team`s responses to specific criticisms will be discussed.

Gas guns and velocity interferometric techniques have been used to determine the loading behavior of AD995 alumina rods 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.

Technology roadmaps serve as pathways to the future. They call attention to future needs for research and development; provide a structure for organizing technology forecasts and programs; and help communicate technological needs and expectations among end users and the research and development (R and D) community. Critical Technology roadmaps, of which the Robotics and Intelligent Machines (RIM) Roadmap is one example, focus on enabling or cross-cutting technologies that address the needs of multiple US Department of Energy (DOE) offices. Critical Technology roadmaps must be responsive to mission needs of the offices; must clearly indicate how the science and technology can improve DOE capabilities; and must describe an aggressive vision for the future of the technology itself. The RIM Roadmap defines a DOE research and development path for the period beginning today, and continuing through the year 2020. Its purpose is to identify, select and develop objectives that will satisfy near- and long-term challenges posed by DOE`s mission objectives. If implemented, this roadmap will support DOE`s mission needs while simultaneously advancing the state-of-the-art of RIM. For the purposes of this document, RIM refers to systems composed of machines, sensors, computers and software that deliver processes to DOE operations. The RIM Roadmap describes how such systems will revolutionize DOE processes, most notably manufacturing, hazardous and remote operations, and monitoring and surveillance. The advances in DOE operations and RIM discussed in this document will be possible due to the developments in many other areas of science and technology, including computing, communication, electronics and micro-engineering. Modern software engineering techniques will permit the implementation of inherently safe RIM systems that will depend heavily on software.

An electrochemical cell suitable for in-situ XRD analysis is presented. Qualitative information such as phase formation and phase stability can be easily monitored using the in-situ cell design. Quantitative information such as lattice parameters and kinetic behavior is also straightforward. Analysis of the LiMn&sub2;O&sub4; spinel using this cell design shows that the lattice undergoes two major structural shrinkages at approx. 4.0 V and approx. 4.07 V during charging. These shrinkages correlate well with the two electrochemical waves observed and indicate the likelihood of two separate redox processes which charging and discharging.

The rate at which a mine detection system falsely identifies man-made or natural clutter objects as mines is referred to as the system's false alarm rate (FAR). Generally expressed as a rate per unit area or time, the FAR is one of the primary metrics used to gauge system performance. In this report, an overview is given of statistical methods appropriate for the analysis of data relating to FAR. Techniques are presented for determining a suitable size for the clutter collection area, for summarizing the performance of a single sensor, and for comparing different sensors. For readers requiring more thorough coverage of the topics discussed, references to the statistical literature are provided. A companion report addresses statistical issues related to the estimation of mine detection probabilities.

Abstract not provided.

There are many potential benefits to be gained from the aeroelastic behavior of a wind-turbine blade with bend-twist coupling. However, the ability to manufacture blades with sufficient coupling to provide the desired benefits has yet to be established. This report investigates the feasible (or practical) range of the coupling coefficient that can be obtained on a uniform cross-section composite D-spar, which could be the backbone of a wind-turbine-blade. The most critical parameters are identified and studied across a range of possible values. Various features, such as the geometry, skin thickness, ply distribution, ply materials, and ply orientations, are evaluated for their effect on twist-bend coupling of a D-spar. It is found that sufficient coupling can be built into the D-spar shape, but that carbon-fiber composite plies angled between 15 and 30 degrees to the longitudinal axis may be required.

Sandia National Laboratories (SNL) operates the Tonopah Test Range for the Department of Energy's (DOE) Weapons Ordnance Program. Thes annual report (calendar year 1997) summarizes the compliance status to environmental regulations applicable at the site including those statutes that govern air and water quality, waste management, cleanup of contaminated areas, control of toxic substances, and adherence to requirements as related to the National Environmental Policy Act. In compliance with DOE orders, SNL also conducts environmental surveillance for radiological and nonradiological contaminants. SNL's responsibility for environmental surveillance extends only to those activities performed by SNL or under its direction. Annual radiological and nonradiological routine releases and unplanned releases (occurrences) are also summarized. This report has been prepared as required by DOE Order 5400.1, General Environmental Protection Program.

We have reviewed ten major public problems challenging our Nation as it enters the new millennium. These are defense, healthcare costs, education, aging population, energy and environment, crime, low productivity growth services, income distribution, regulations, and infrastructure. These problems share several features. First, each is so large, if it were soIved; it would have major impact on the U.S. economy. Second, each is resident in a socioeconomic system containing non-linear feedback loops and an adaptive human element. Third, each can only be solved by our political system, yet these problems are not responsive to piecemeal problem solving, the approach traditionally used by policy makers. However, unless each problem is addressed in the context of the system in which it resides, the solution maybe worse than the problem. Our political system is immersed in reams of disconnected, unintelligible information skewed by various special interests to suggest policies favoring their particular needs. Help is needed, if rational solutions that serve public interests are to be forged for these ten probIems, The simulation and modeIing tools of physical scientists, engineers, economists, social scientists, public policy experts, and others, bolstered by the recent explosive growth in massively parallel computing power, must be blended together to synthesize models of the complex systems in which these problems are resident. These models must simulate the seemingly chaotic human element inherent in these systems and support policymakers in making informed decKlons about the future. We propose altering the policy development process by incorporating more modeling, simulation and analysis to bring about a revolution in policy making that takes advantage of the revolution in engineering emerging from simulation and modeling. While we recommend major research efforts to address each of these problems, we also observe these to be very complex, highly interdependent, multi-disciplinary problems; it will challenge the U.S. community of individual investigator researchers to make the cultural transformation necessary to address these problems in a team environment. Furthermore, models that simulate future behavior of these complex systems will not be exacq therefore, researchers must be prepared to use the modeling and simulation tools they develop to propose experiments to Congress. We recommend that ten laboratories owned by the American public be selected in an interagency competition to each manage and host a $1 billion/yertr National effort, each focused on one of these ten problems. Much of the supporting research and subsystem modeling work will be conducted at U.S. universities and at private firms with relevant expertise. Success of the Manhattan Project at the middle of the 20th century provides evidence this leadership model works.

The problem of combining multi-source information in applications related to automatic target recognition (ATR) is addressed. A mathematical approach is proposed for fusing the (possibly dependent) outputs of multiple ATR systems or algorithms. The method is derived from statistical principles, and the fused decision takes the form of an hypothesis test. The distribution of the test statistic is approximated as gamma, with parameters estimated from available training data. In a brief simulation study, the proposed method outperforms several alternative fusion techniques.

In-situ barrier emplacement techniques and materials for the containment of high-risk contaminants in soils are currently being developed by the Department of Energy (DOE). Because of their relatively high cost, the barriers are intended to be used in cases where the risk is too great to remove the contaminants, the contaminants are too difficult to remove with current technologies, or the potential movement of the contaminants to the water table is so high that immediate action needs to be taken to reduce health risks. Assessing the integrity of the barrier once it is emplaced, and during its anticipated life, is a very difficult but necessary requirement. Science and Engineering Associates, Inc., (SEA) and Sandia National Laboratories (SNL) have developed a quantitative subsurface barrier assessment system using gaseous tracers in support of the Subsurface Contaminants Focus Area barrier technology program. Called SEAtrace{trademark}, this system integrates an autonomous, multi-point soil vapor sampling and analysis system with a global optimization modeling methodology to locate and size barrier breaches in real time. The methodology for the global optimization code was completed and a prototype code written using simplifying assumptions. Preliminary modeling work to validate the code assumptions were performed using the T2VOC numerical code. A multi-point field sampling system was built to take soil gas samples and analyze for tracer gas concentration. The tracer concentration histories were used in the global optimization code to locate and size barrier breaches. SEAtrace{trademark} was consistently able to detect and locate leaks, even under very adverse conditions. The system was able to locate the leak to within 0.75 m of the actual value, and was able to determine the size of the leak to within 0.15 m.

This report presents a comparison of life cycle costs between battery energy storage systems and alternative mature technologies that could serve the same utility-scale applications. Two of the battery energy storage systems presented in this report are located on the supply side, providing spinning reserve and system stability benefits. These systems are compared with the alternative technologies of oil-fired combustion turbines and diesel generators. The other two battery energy storage systems are located on the demand side for use in power quality applications. These are compared with available uninterruptible power supply technologies.

A system based on the metal-binding kidney protein, metallothionein, bound with a trace quantity of radioactive metal, has been shown to be capable of detecting parts-per-million (ppm) to parts-per-billion (ppb) concentrations of some heavy metals in liquid solution. The main objective of this study was to determine if this type of system has adequate sensitivity and selectivity for application in detecting a number of metallic species of concern to DOE, such as mercury, lead, and chromium. An affinity-displacement study is reported here using the heavy metal radiotracers {sup 65}Zn and {sup 109}Cd bound to metallothionein immobilized on an Affi-Gel 10 filter support. When a heavy metal solution with a greater affinity than the tracer for the protein is poured through the filter the radiotracer is displaced by a mechanism similar to ion exchange. The main objective of this study was to verify previous internal experimental parameters and results, and to determine the specific affinities of metallothionein for the metallic species of most concern to DOE.

Accreditation can offer many benefits to a testing or calibration laboratory, including increased marketability of services, reduced number of outside assessments, and improved quality of services. Compared to ISO 9000 registration, the accreditation process includes a review of the entire quality system, but in addition a review of testing or calibration procedures by a technical expert and participation in proficiency testing in the areas of accreditation. Within the DOE, several facilities have recently become accredited in the area of calibration, including Sandia National Laboratories, Oak Ridge, AlliedSignal FM and T; Lockheed Martin Idaho Technologies Co., and Pacific Northwest National Lab. At the national level, a new non-profit organization was recently formed called the National Cooperation for Laboratory Accreditation (NACLA). The goal of NACLA is to develop procedures, following national and international requirements, for the recognition of competent accreditation bodies in the US. NACLA is a voluntary partnership between the public and private sectors with the goal of a test or calibration performed once and accepted world wide. The NACLA accreditation body recognition process is based on the requirements of ISO Guide 25 and Guide 58. A membership drive will begin some time this fall to solicit organizational members and an election of a permanent NACLA Board of Directors will follow later this year or early 1999.

Two piezoresistive micromachined pressure sensors were compared: a commercially available bulk-micromachined (BM) pressure sensor and an experimental surface-micromachined (SM) pressure sensor. While the SM parts had significantly smaller die sizes, they were outperformed in most areas by the BM parts. This was due primarily to the smaller piezoresistive gauge factor in the polysilicon piezoresistors in the SM parts compared to the single crystal strain gauge used in the BM parts.

In this paper the authors present a new method for making shallow p-type junctions in silicon by molecular ion implantation. Unlike current molecular ion implantation methods which use boron and fluorine molecules, this new method uses an element which is completely miscible in silicon. Note that fluorine is an element that saturates at a very low concentration in silicon. The compounds used in this new method are boron silicides and boron germanium molecules. These compounds have several distinct advantages including the facts that the co-element silicon (or germanium) has a very high saturation value in the silicon matrix, the co-element is massive and therefore creates more damage during implantation, and the co-element has a larger projected range than the boron. Note that the Rp for fluorine is shallower than that of Boron for a BF{sub 2} implant. Recent experiments indicate that BSi ion beams can be generated in a sputter ion source with efficiencies of 0.5% with respect to the generated Si beam. A plan to develop a new ion source that is compatible with current ion implantation systems is presented.

The Advanced Hydrotest Facility (AHF) is a facility under consideration by the Department of Energy (DOE) for conducting explosively-driven hydrodynamic experiments. The major diagnostic tool at AHF will be a radiography accelerator having radiation output capable of penetrating very dense dynamic objects on multiple viewing axes with multiple pulses on each axis, each pulse having a time resolution capable of freezing object motion ({approx}50-ns) and achieving a spatial resolution {approx}1 mm at the object. Three accelerator technologies are being considered for AHF by the DOE national laboratories at Los Alamos (LANL), Livermore (LLNL), and Sandia (SNL). Two of these are electron accelerators that will produce intense x-ray pulses from a converter target yielding a dose {approx}1,000--2,000 Rads {at} 1 meter. LLNL has proposed a 16--20 MeV, 3--6 kA linear induction accelerator (LIA) driven by FET-switched modulators driving metglas loaded cavities. SNL has proposed a 12-MeV, 40-kA Inductive Voltage Adder (IVA) accelerator based on HERMES III pulsed power technology. The third option is a 25--50-GeV proton accelerator capable of {approx}10{sup 13} protons/pulse proposed by LANL. This paper will review the current status of the three accelerator concepts for AHF.

The Authenticated Tracking and Monitoring System (ATMS) answers the need for global monitoring of the status and location of sensitive items on a worldwide basis, 24 hours a day. ATMS uses wireless sensor packs to monitor the status of the items and environmental conditions. A receiver and processing unit collect a variety of sensor event data. The collected data are transmitted to the INMARSAT satellite communication system, which then sends the data to appropriate ground stations. Authentication and encryption algorithms secure the data during communication activities. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. The resulting tracking, timing, and status information could then be processed to ensure compliance with various agreements. Following discussions between the Australian Safeguards Office (ASO), the US Department of Energy (DOE), and Sandia National Laboratories (SNL) in early 1995, the parties mutually agreed to conduct and evaluate a field trial prototype ATMS to track and monitor shipments of uranium ore concentrate (UOC) from an operating uranium mine in Australia to a final destination in Rotterdam, the Netherlands, with numerous stops along the way. During the months of February and March 1998, the trial was conducted on a worldwide basis, with tracking and monitoring stations located at sites in both Australia and the US. This paper describes ATMS and the trial.

Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper.

The excavation of underground radioactive waste repositories produces conditions where the repository is underpressured relative to the surrounding host rock, resulting in groundwater inflow to the repository. Groundwater has been shown to enhance gas generation from emplaced waste forms, which in turn expedites repository pressurization. Repository pressurization from waste-generated gas 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 geomechanical properties. Within this 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, driven by excavation-related stress redistribution, may cause variations 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 within the DRZ also contribute to enhancing potential release pathways away from the repository. Freeze et al. describe an enhanced version of TOUGH2 (called TOUGH28W) and its application to model the coupled processes of gas generation, multiphase flow and geomechanical deformation at the Waste Isolation Pilot Plant (WIPP) repository. This paper describes a new application of TOUGH28W that couples time-dependent DRZ property changes with multiphase groundwater flow around an underground excavation at WIPP. The results are relevant not only to other salt repositories, but also to repositories in other geologic formations where groundwater inflow and DRZ effects are a concern.

Phase encoding of shot records provides a means of imaging a number of shots within a single migration. This results in a reduction in the required computation for a complete image, a reduction by the number of shots used in each individual migration, trading this increase in speed for additional noise in the resulting image. Some methods for phase encoding have been shown to limit this noise to a tolerable range when combining several shots, enabling speed ups of a factor of a few. In this paper, the authors present a use of phase encoding which allows faster imaging by an order of magnitude or more, with the additional benefit that the individual migrations can be stopped whenever the answer is good enough. This approach may ultimately render 3-D frequency-domain prestack depth migration cost effective.

As part of a Safeguards Agreement between the US and the International Atomic Energy Agency (IAEA), the Portsmouth Gaseous Diffusion Plant, Piketon, Ohio, was added to the list of facilities eligible for the application of IAEA safeguards. Currently, the facility is in the process of downblending excess inventory of HEU to low enriched uranium (LEU) from US defense related programs for commercial use. An agreement was reached between the US and the IAEA that would allow the IAEA to conduct an independent verification experiment at the Portsmouth facility, resulting in the confirmation that the HEU was in fact downblended. The experiment provided an opportunity for the DOE laboratories to recommend solutions/measures for new IAEA safeguards applications. One of the measures recommended by Sandia National Laboratories (SNL), and selected by the IAEA, was a digital video surveillance system for monitoring activity at the HEU feed stations. This paper describes the SNL implementation of the digital video system and its integration with the Load Cell Based Weighing System (LCBWS) from Oak Ridge National Laboratory (ORNL). The implementation was based on commercially available technology that also satisfied IAEA criteria for tamper protection and data authentication. The core of the Portsmouth digital video surveillance system was based on two Digital Camera Modules (DMC-14) from Neumann Consultants, Germany.

A severe accident in a nuclear power plant could result in the relocation of large quantities of molten core material onto the lower head of he reactor pressure vessel (RPV). In the absence of inherent cooling mechanisms, failure of the RPV ultimately becomes possible under the combined effects of system pressure and the thermal heat-up of the lower head. Sandia National Laboratories has performed seven experiments at 1:5th scale simulating creep failure of a RPV lower head. This paper describes a modeling program that complements the experimental program. Analyses have been performed using the general-purpose finite-element code ABAQUS-5.6. In order to make ABAQUS solve the specific problem at hand, a material constitutive model that utilizes temperature dependent properties has been developed and attached to ABAQUS-executable through its UMAT utility. Analyses of the LHF-1 experiment predict instability-type failure. Predicted strains are delayed relative to the observed strain histories. Parametric variations on either the yield stress, creep rate, or both (within the range of material property data) can bring predictions into agreement with experiment. The analysis indicates that it is necessary to conduct material property tests on the actual material used in the experimental program. The constitutive model employed in the present analyses is the subject of a separate publication.

The use of data surety within the International Monitoring System (IMS) is designed to offer increased trust of acquired sensor data at a low cost. The demonstrations discussed in the paper illustrate the feasibility of hardware authentication for sensor data and commands in a retrofit environment and a new system and of the supporting key management system. The individual demonstrations which are summarized in the paper are: (1) demonstration of hardware authentication for communication authentication in a retrofit environment; (2)demonstration of hardware authentication in a new system; and (3) demonstration of key management for sensor data and command authentication.

Sandia is evaluating the performance of various infrasound sensors that could be used as part of the International Monitoring Systems (IMS). Specifications for infrasound stations are outlined in CTBT/PC/II/1/Add.2. This document specifies minimum requirements for sensor, digitizer and system. The infrasound sensors evaluation task has the following objectives: provide an overview of the sensors presently in use; evaluate these sensors with respect to the requirements of the IMS.

The goal of this project is the rapid reduction of risk to truck transportation of SNM in Russia. Enhanced protection is being accomplished by cooperation between the US Department of Energy, MINATOM of Russia, the Russian Ministry of Defense, and various Russian Institutes. This program provides an integrated program of specialized trucks that are equipped with hardened overpack (SNM vault) containers, alarm and communications systems, and armored cabs. Armored escort vehicles are also provided to increase the survivability of the guards escorting convoys. Only indigenous Russian equipment, modified and/or manufactured by Designing Bureau for Motor Vehicle Transport Equipment (KBATO), is provided under this program. The US will not provide assistance in the truck transportation arena without a commitment from the Russian facility to provide heavily armed escorts for SNM movement. Each site conducts a detailed transportation needs assessment study that is used as the basis for prioritizing assistance. The Siberian Chemical Combine (Tomsk-7) was the initial site of cooperation. The designs used at Tomsk-7 are serving as the baseline for all future vehicles modified under this program. In FY98, many vehicles systems have been ordered for various institutes. Many additional systems will be ordered in FY99.

Since its inception in 1996, the purpose of the International Physical Protection Advisory Service (IPPAS) has been to provide advice and assistance to International Atomic Energy Agency (IAEA) Member States on strengthening and enhancing the effectiveness of their state system of physical protection of nuclear materials and facilities. Since the protection of nuclear materials and facilities is a Member State`s responsibility, participation within the IPPAS program is voluntary. At the request of a Member State, the IAEA forms a multinational IPPAS team consisting of physical protection specialists. These specialists have broad experience in physical protection system design, implementation, and regulatory oversight. The exact make-up of the team depends upon the needs of the requesting state. IPPAS missions to participating states strive to compare the domestic procedures and practices of the state against international physical protection guidelines (IAEA Information Circular 225) and internationally accepted practice. The missions utilize a top to bottom approach and begin by reviewing the legal and regulatory structure and conclude with reviews of the implementation of the state regulations and international guidelines at individual facilities. IPPAS findings are treated as IAEA Safeguards Confidential Information. To date, IPPAS missions have been concluded in Slovenia, Bulgaria, Romania, Hungary, and Poland.

During the January 1996 meeting of the Gore-Chernomyrdin Commission, the Beloyarsk Nuclear Power Plant (BNPP) was identified as one of the additional sites for cooperative projects on upgrading Materials Protection, Control and Accounting (MPC and A). Since June 1996, Sandia National Laboratories (SNL), Pacific Northwest National Laboratories (PNNL), and Los Alamos National Laboratory (LANL) have worked with BNPP to upgrade MPC and A at the facility. Some unique challenges were encountered because BNPP has an operating BN-600 600-Megawatt breeder reactor. SNL has been responsible for working with BNPP to implement physical protection upgrades to the Central Alarm Station, Fresh Fuel Storage building, Spent Fuel Storage Area, and Vehicle/Personnel Portal. In addition, improved communication equipment for the Ministry of the Interior (MVD) guards and training of personnel were provided. PNNL has been responsible for coordinating Material Control and Accounting (MC and A) upgrades at BNPP. PNNL, in conjunction with LANL, has implemented such MC and A upgrades as a computerized nuclear materials accounting system, training in MC and A elements, nondestructive assay instrumentation for fresh fuel, installation of a fork detector for measuring spent fuel, and installation of an underwater video camera for verification of spent fuel serial numbers.

As part of the Cooperative Threat Reduction Nuclear Material Protection, Control, and Accounting (MPC and A) Program, the US Department of Energy and Mangyshlak Atomic Energy Complex (MAEC), Aktau, Republic of Kazakstan have cooperated to enhance existing MAEC MPC and A features at the BN-350 liquid-metal fast-breeder reactor. This paper describes the methodology of the enhancement activities and provides representative examples of the MPC and A augmentation implemented at the MAEC.

An important future element of International Safeguards instrumentation is expected to be the merging of containment/surveillance and nondestructive assay equipment with domestic physical protection equipment into integrated systems, coupled with remote monitoring. Instrumentation would include interior monitoring and assessment and entry/exit monitoring. Of particular importance is the application of interior monitors in spaces of declared inactivity; for example, in nuclear material storage locations that are entered infrequently. The use of modern interior monitors in International Safeguards offers potential for improving effectiveness and efficiency. Within the context of increased cooperation, one can readily envision increased interaction between International Safeguards and Domestic Safeguards, including increased joint use of State System of Accounting and Control data.

Using a microengine as the primary test vehicle, the authors have examined several aspects of characterization. Parametric measurements provide fabrication process information. Drive signal optimization is necessary for increased microengine performance. Finally, electrical characterization of resonant frequency and quality factor can be more accurate than visual techniques.

A remote monitoring system, designed to monitor spent fuel transfers from wet to dry storage, was installed at the Embalse Nuclear Power Station at Embalse, Argentina. The system consists of 6 gamma and one neutron radiation sensors. Five gamma sensors utilize RF transmission to communicate with Echelon nodes connected to a Local Operating Network (LON). One gamma and one neutron sensor are hardwired to the LON network. Each sensor Echelon node is bound to a single Datalogger that stores data until it receives an acquisition command to download to the Data Acquisition Software (DASW) database. The data from the Datalogger are transferred and stored in the Data Acquisition Software database, which resides on the IAEA MOS-MUX server. At a pre-determined interval, data from the DASW database are converted into Excel files and transferred to the IAEA database every 24 hours. At an predetermined interval all data are transferred to the distribution server located at the ARN laboratory at Ezeiza, Argentina. Remote access to data from the distribution server will be made from IAEA headquarters, Vienna, Austria, from ABACC in Rio de Janeiro, Brazil, from the IAEA field office in Buenos Aires, from ARN, and from Sandia National Laboratories, Albuquerque, New Mexico.

The nuclear detonation safety of modern nuclear weapons depends on a coordinated safety theme incorporating three general safety principles: isolation, inoperability, and incompatibility. The success of this approach has encouraged them to study whether these and/or other principles might be useful in other applications. Not surprisingly, no additional first-principles (based on physical laws) have been identified. However, a more widely applicable definition and application of the principle-based approach has been developed, resulting in a selection of strategies that are basically subsets and varied combinations of the more general principles above. However, identification of principles to be relied on is only one step in providing a safe design. As one other important example, coordinating overall architecture and strategy is essential: the authors term this a safety theme.

A novel stack passivation scheme, in which plasma silicon nitride (SiN) is stacked on top of a rapid thermal SiO{sub 2} (RTO) layer, is developed to attain a surface recombination velocity (S) approaching 10 cm/s at the 1.3 {Omega}-cm p-type (100) silicon surface. Such low S is achieved by the stack even when the RTO and SiN films individually yield considerably poorer surface passivation. Critical to achieving low S by the stack is the use of a short, moderate temperature anneal (in this study 730 C for 30 seconds) after film growth and deposition. This anneal is believed to enhance the release and delivery of atomic hydrogen from the SiN film to the Si-SiO{sub 2} interface, thereby reducing the density of interface traps at the surface. Compatibility with this post-deposition anneal makes the stack passivation scheme attractive for cost-effective solar cell production since a similar anneal is required to fire screen-printed contacts. Application of the stack to passivated rear screen-printed solar cells has resulted in V{sub oc}`s of 641 mV and 633 mV on 0.65 {Omega}-cm and 1.3 {Omega}-cm FZ Si substrates, respectively. These V{sub oc} values are roughly 20 mV higher than for cells with untreated, highly recombinative back surfaces. The stack passivation has also been used to form fully screen-printed bifacial solar cells which exhibit rear-illuminated efficiency as high as 11.6% with a single layer AR coating.

To aid designers, generic physical security objectives and design concepts for cut-and-cover underground facilities are presented. Specific aspects addressing overburdens, entryways, security doors, facility services, emergency egress, security response force, and human elements are discussed.

At Sandia National Laboratories (SNL), the authors are developing the ability to accurately predict motions for arbitrary numbers of bodies of arbitrary shapes experiencing multiple applied forces and intermittent contacts. In particular, the authors are concerned with the simulation of systems such as part feeders or mobile robots operating in realistic environments. Preliminary investigation of commercial dynamics software packages led them to the conclusion that they could use commercial software to provide everything they needed except for the contact model. They found that ADAMS best fit their needs for a simulation package. To simulate intermittent contacts, they need collision detection software that can efficiently compute the distances between non-convex objects and return the associated witness features. They also require a computationally efficient contact model for rapid simulation of impact, sustained contact under load, and transition to and from contact conditions. This paper provides a technical review of a custom hierarchical distance computation engine developed at Sandia, called the C-Space Toolkit (CSTk). In addition, they describe an efficient contact model using a non-linear damping term developed by SNL and Ohio State. Both the CSTk and the non-linear damper have been incorporated in a simplified two-body testbed code, which is used to investigate how to correctly model the contact using these two utilities. They have incorporated this model into the ADAMS software using the callable function interface. An example that illustrates the capabilities of the 9.02 release of ADAMS with their extensions is provided.

At the direction of the US Congress, following the Pan Am 103 and TWA 800 crashes, the Federal Aviation Administration funded development of non-invasive techniques to screen airline passengers for explosives. Such an explosives detection portal, developed at Sandia National Laboratories, was field tested at the Albuquerque International airport in September 1997. During the 2-week field trial, 2,400 passengers were screened and 500 surveyed. Throughput, reliability, maintenance and sensitivity were studied. Follow-up testing at Sandia and at Idaho National Engineering and Environmental Laboratory was conducted. A passenger stands in the portal for five seconds while overhead fans blow air over his body. Any explosive vapors or dislodged particles are collected in vents at the feet. Explosives are removed from the air in a preconcentrator and subsequently directed into an ion mobility spectrometer for detection. Throughput measured 300 passengers per hour. The non-invasive portal can detect subfingerprint levels of explosives residue on clothing. A survey of 500 passengers showed a 97% approval rating, with 99% stating that such portals, if effective, should be installed in airports to improve security. Results of the airport test, as well as operational issues, are discussed.

As part of the on-going DOE/Russian MPC and A activities at the Institute of Physics and Power Engineering (IPPE) and in order to provide a basis for planning MPC and A enhancements, an expedient method to review the effectiveness of the MPC and A system has been adopted. These reviews involve the identification of appropriate and cost-effective enhancements of facilities at IPPE. This effort requires a process that is thorough but far less intensive than a traditional vulnerability assessment. The SER results in a quick assessment of current and needed enhancements. The process requires preparation and coordination between US and Russian analysts before, during, and after information gathering at the facilities in order that the analysis is accurate, effective, and mutually agreeable. The goal of this paper is to discuss the SER process, including the objectives, time scale, and lessons learned at IPPE.

The Ministry of the Russian Federation for Atomic Energy (MINATOM) and the US Department of Energy (DOE) are engaged in joint, cooperative efforts to reduce the likelihood of nuclear proliferation by enhancing Material Protection, Control and Accounting (MPC and A) systems in both countries. Mayak Production Association (Mayak) is a major Russian nuclear enterprise within the nuclear complex that is operated by MINATOM. This paper describes the nature, scope, and status of the joint, cooperative efforts to enhance existing MPC and A systems at Mayak. Current cooperative efforts are focused on enhancements to the existing MPC and A systems at two plants that are operated by Mayak and that produce, process, handle and/or store proliferation-sensitive nuclear materials.

Direct laser metal deposition processing is a promising manufacturing technology which could significantly impact the length of time between initial concept and finished part. For adoption of this technology in the manufacturing environment, further understanding is required to ensure robust components with appropriate properties are routinely fabricated. This requires a complete understanding of the thermal history during part fabrication and control of this behavior. This paper will describe research to understand the thermal behavior for the Laser Engineered Net Shaping (LENS) process, where a component is fabricated by focusing a laser beam onto a substrate to create a molten pool in which powder particles are simultaneously injected to build each layer. The substrate is moved beneath the laser beam to deposit a thin cross section, thereby creating the desired geometry for each layer. After deposition of each layer, the powder delivery nozzle and focusing lens assembly is incremented in the positive Z-direction, thereby building a three dimensional component layer additively. It is important to control the thermal behavior to reproducibly fabricate parts. The ultimate intent is to monitor the thermal signatures and to incorporate sensors and feedback algorithms to control part fabrication. With appropriate control, the geometric properties (accuracy, surface finish, low warpage) as well as the materials` properties (e.g., strength, ductility) of a component can be dialed into the part through the fabrication parameters. Thermal monitoring techniques will be described, and their particular benefits highlighted. Preliminary details in correlating thermal behavior with processing results will be discussed.

Laser Engineered Net Shaping, also known as LENS{trademark}, is an advanced manufacturing technique used to fabricate near-net shaped, fully dense metal components directly from computer solid models without the use of traditional machining processes. The LENS{trademark} process uses a high powered laser to create a molten pool into which powdered metal is injected and solidified. Like many SFF techniques, LENS{trademark} parts are made through a layer additive process. In the current system, for any given layer, the laser is held stationary, while the part and its associated substrate is moved, allowing for the each layer`s geometry to be formed. Individual layers are generated by tracing out the desired border, followed by filling in the remaining volume. Recent research into LENS{trademark} has highlighted the sensitivity of the processes to multiple software controllable parameters such as substrate travel velocity, border representation, and fill patterns. This research is aimed at determining optimal border outlines and fill patterns for LENS{trademark} and at developing the associated software necessary for automating the creation of the desired motion control.

The US Department of Energy (DOE), in cooperation with the Electric Power Research Institute (EPRI) and US nuclear power plant utilities, is preparing a series of aging management guidelines (AMGs) for commodity types of components (e.g., heat exchangers, electrical cable and terminations, pumps). Commodities are included in this series based on their importance to continued nuclear plant operation and license renewal. The AMGs contain a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance and surveillance practices that can be combined to create an effective aging management program. Each AMG is intended for use by the systems engineers and plant maintenance staff (i.e., an AMG is intended to be a hands-on technical document rather than a licensing document). The heat exchangers AMG, published in June 1994, includes the following information of interest to nondestructive examination (NDE) personnel: aging mechanisms determined to be non-significant for all applications; aging mechanisms determined to be significant for some applications; effective conventional programs for managing aging; and effective unconventional programs for managing aging. Since the AMG on heat exchangers was published four years ago, a brief review has been conducted to identify emerging regulatory issues, if any. The results of this review and lessons learned from the collective set of AMGs are presented.

The Photovoltaic Manufacturing Technology Project (PVMaT) is a government/industry research and development (R and D) partnership between the US federal government (through the US Department of Energy [DOE]) and members of the US PV industry. The goals of PVMaT are to help the US PV industry improve module manufacturing processes and equipment; accelerate manufacturing cost reductions for PV modules, balance-of-systems components, and integrated systems; increase commercial product performance and reliability; and enhance the investment opportunities for substantial scale-ups of US-based PV manufacturing plant capacities. The approach for PVMaT has been to cost-share risk taking by industry as it explores new manufacturing options and ideas for improved PV modules and other components, advances system and product integration, and develops new system designs, all of which will lead to overall reduced system life-cycle costs for reliable PV end products. The PVMaT Phase 4A module manufacturing R and D projects are just being completed and initial results for the work directed primarily to module manufacture are reported in this paper. Fourteen new Phase 5A subcontracts have also just been awarded and planned R and D areas for the ten focused on module manufacture are described. Finally, government funding, subcontractor cost sharing, and a comparison of the relative efforts by PV technology throughout the PVMaT project are presented.

Polymerization of phenyl-, benzyl-, and phenethyltroalkoxysilanes formed soluble oligo- and polysilsesquixanes. No gels of any of the monomers were observed to form. The molecular weights of the materials prepared and dried at room temperature were near 2K, but would continuously increase with heating at 100°C to between 5-15K. The polymers were structurally characterized by 1H, 13C, and 29Si NMR.

This report on National Environmental Policy Act (NEPA) compliance at Sandia National Laboratories/New Mexico (SNL/NM) chronicles past and current compliance activities and includes a recommended strategy that can be implemented for continued improvement. This report provides a list of important references. Attachment 1 contains the table of contents for SAND95-1648, National Environmental Policy Act (NEPA) Compliance Guide Sandia National Laboratories (Hansen, 1995). Attachment 2 contains a list of published environmental assessments (EAs) and environmental impact statements (EISs) prepared by SNL/NM. Attachment 3 contains abstracts of NEPA compliance papers authored by SNL/NM and its contractors.

This paper presents the first part of a comprehensive mechanics approach capable of predicting the integrity and reliability of solder joint material under fatigue loading without viscoplastic damage considerations. A separate report will be made to present a comprehensive damage model describing life prediction of the solder material under thermomechanical fatigue loading. The method is based on a theory of damage mechanics which makes possible a macroscopic description of the successive material deterioration caused by the presence of microcracks/voids in engineering materials. A damage mechanics model based on the thermodynamic theory of irreversible processes with internal state variables is proposed and used to provide a unified approach in characterizing the cyclic behavior of a typical solder material. With the introduction of a damage effect tensor, the constitutive equations are derived to enable the formulation of a fatigue damage dissipative potential function and a fatigue damage criterion. The fatigue evolution is subsequently developed based on the hypothesis that the overall damage is induced by the accumulation of fatigue and plastic damage. This damage mechanics approach offers a systematic and versatile means that is effective in modeling the entire process of material failure ranging from damage initiation and propagation leading eventually to macro-crack initiation and growth. As the model takes into account the load history effect and the interaction between plasticity damage and fatigue damage, with the aid of a modified general purpose finite element program, the method can readily be applied to estimate the fatigue life of solder joints under different loading conditions.

The authors improved a self-aligned emitter etchback technique that requires only a single emitter diffusion and no alignment to form self-aligned, patterned-emitter profiles. Standard commercial screen-printed gridlines mask a plasma-etchback of the emitter. A subsequent PECVD-nitride deposition provides good surface and bulk passivation and an antireflection coating. They used full-size multicrystalline silicon (mc-Si) cells processed in a commercial production line and performed a statistically designed multiparameter experiment to optimize the use of a hydrogenation treatment to increase performance. They obtained an improvement of almost a full percentage point in cell efficiency when the self-aligned emitter etchback was combined with an optimized 3-step PECVD-nitride surface passivation and hydrogenation treatment. They also investigated the inclusion of a plasma-etching process that results in a low-reflectance, textured surface on multicrystalline silicon cells. Preliminary results indicate reflectance can be significantly reduced without etching away the emitter diffusion.

A power management energy storage system was developed for stationary applications such as peak shaving, voltage regulation, and spinning reserve. Project activities included design, manufacture, factory testing, and field installation. The major features that characterize the development are the modularity of the production, its transportability, the power conversion method that aggregates power on the AC side of the converter, and the use of commonly employed technology for system components. 21 figs.