Publications

Because of the absence of a nearby, well-defined ground plane, performing electrical tests on unshielded cables installed in conduits is difficult. Experiments were run to develop a preionized gas troubleshooting technique to detect localized degradation of unshielded cables in conduits. This was achieved by introducing a readily ionizable gas like helium (or argon) in the conduit air space and then applying a moderately high voltage to the test cable, thus ionizing the gas surrounding the cable. Breakdown testing was performed on various types of damaged and undamaged cables. Other parameters necessary for practical implementation of the technique were also examined, including gas type, position of the cable with respect to the conduit wall, length of cable, conduit configuration, conduit size, and gas propagation in conduits. High potential testing of cables in the presence of preionized helium gas provides essentially the same information as high potential testing in water. A test criterion of 30 kVdc or 10 kVac would detect when 5-mils of insulation remain on one particular tested cable. No undamaged cable was noted to break down at these voltages. A high concentration of helium is required to perform the test, but this is easily attained with straightforward preparations. A cable with through-wall damage can easily be detected with a test criterion of approximately 1.5 kvac.

Finite element simulations modelling impact of the Generic Accident-Resistant Packaging (GAP) have been performed. The GAP is a nuclear weapon shipping container that will be used by accident response groups from both the United States and the United Kingdom. The package is a thin-walled steel structure filled with rigid polyurethane foam and weighs approximately 5100 lbs when loaded. The simulations examined 250 ft/s impacts onto a rigid target at several orientations. The development of the finite element model included studies of modelling assumptions and material parameters. Upon completion of the simulation series, three full-scale impact tests were performed. A comparison of the simulation results to the test data is given. Differences between the results and data are examined, and possible explanations for the differences are discussed.

A tester was developed to evaluate prototype thermal cells and batteries--especially high-voltage units--under a wide range of constant-current and constant-resistance discharge conditions. Programming of the steady-state and pulsing conditions was by software control or by hardware control via an external pulse generator. The tester was assembled from primarily Hewlett-Packard (H-P) instrumentation and was operated under H-P`s Rocky Mountain Basic (RMB). Constant-current electronic loads rated up to 4 kW (400 V at up to 100 A) were successfully used with the setup. For testing under constant-resistance conditions, power metal-oxide field-effect transistors (MOSFETs) controlled by a programmable pulse generator were used to switch between steady-state and pulse loads. The pulses were digitized at up to a 50 kHz rate (20 {mu} s/pt) using high-speed DVMs; steady-state voltages were monitored with standard DVMs. This paper describes several of the test configurations used and discusses the limitations of each. Representative data are presented for a number of the test conditions.

This report discusses matrixed field emission devices which have been fabricated using a modification of standard integrated circuit fabrication techniques. The emitter-to-gate spacing is fixed by the thickness of a deposited oxide and not by photolithographic techniques. Functioning triodes have been fabricated using this deposited oxide spacer approach. Measured emission current to a collector electrically and physically separated from the matrixed emission array follows Fowler-Nordheim behavior. Modeling of the potential field near the emitter and gate structures as well as the emitted electron trajectories with a two-dimensional, Poisson solver, finite-difference code was used to evaluate and improve field emission structures.

Over the past couple of years the Information Technology Department at Sandia Laboratories has developed software to automatically generate database/4gl procedure code and database maintenance scripts based on database table information. With this software developers simply enter table and referential integrity information and the software generates code and scripts as required. The generated procedure code includes simple insert/delete/update procedures, transaction logging procedures as well as referential integrity procedures. The generated database maintenance scripts include scripts to modify structures, update remote databases, create views, and create indexes. Additionally, the software can generate EPSI representations of Binder diagrams for the tables. This paper will discuss the software application and use of it in real world applications. The automated generation of procedure code and maintenance scripts allows the developers to concentrate on the development of user interface code. The technique involves generating database/4 gl procedure code and maintenance scripts automatically from the database table information. The database/4gl procedure code provides standard insert/update/delete interfaces for upper level code as well as enforces the data constraints defined in the information model. The maintenance scripts provide maintenance scripts and migration scripts. This has resulted in fully updated database applications with complete rules enforcement and database maintenance scripts within days of a database modification.

Maintenance Performance Indicators (PI) specify where the maintenance department is and which direction it is going allowing for a quick and accurate assessment of the performance of the Maintenance Management Program (MMP). Establishing PI`s for the maintenance department will allow a measure of productivity and a means of feedback for methods improvement. Effective performance of the maintenance department directly effects plant profitability. Improvements in the quality and productivity of the maintenance work force will significantly reduce maintenance costs. The level of performance attained by the maintenance work force is usually guessed at. Guessing will not identify areas needing improvement or help to initiate a corrective action. Maintenance PI`s are required for maintenance departments whose goal is to control maintenance costs while increasing productivity. The application of basic statistical methods will allow a maintenance department to know where they are and which direction they are going. The data presented in this paper is a representation of indicators used in industry as well as developed indicators to establish a complete maintenance performance indicator program. The methodology used in developing this program can be used as a way to manage a cost effective maintenance management program.

Nuclear reactor-pumped lasers (RPLs) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

Investigations are being performed on a high current (16 kA), mildly relativistic (400kV), L-band klystron source. Experiments are in an early stage, and thus far have progressed to beam modulation studies. This paper discusses general klystron design considerations, beam propagation results, initial modulation results, and various extraction techniques being considered.

Calculational results are presented here for a class of intermediate-velocity penetration problems. The problems of interest involve penetration of moderate-strength target materials by high-strength projectiles. Two series of metal penetration experiments and a series of concrete slab perforation tests were simulated in this study. The computer code used for the calculations was the CTH code, which employs a recently-developed ``boundary layer`` algorithm for treating penetration problems such as these.

This report presents an application of probabilistic models and risk based criteria for determining the risk impact of the Limiting Conditions of Operations (LCOs) in the Technical Specifications (TSs) of a boiling water reactor during shutdown. This analysis studied the risk impact of the current requirements of Allowed Outage Times (AOTs) and Surveillance Test Intervals (STIs) in eight Plant Operational States (POSs) which encompass power operations, shutdown, and refueling. This report also discusses insights concerning TS action statements.

Becoming aware of the significant changes of the past several years and their effect on the expectations to international safeguards, it is necessary to reflect on which direction the development of nuclear safeguards in a new era needs to take. 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. Within such a regime, the associated measures need to be determined and technological support identified. This paper will identify proven techniques which, with appropriate implementation support, could most quickly make available additional measures for a comprehensive, transparent and open implementation regime. In particular, it will examine the future of remote monitoring in International Safeguards, and provide an update on the International Remote Monitoring Project and related implications.

This paper presents an overview of the Nuclear Electric Propulsion Space Test Program (NEPSTP). The program goals, the proposed mission, the spacecraft, and the Topaz II space nuclear power system are described. The subject of flight qualification is examined and the inherent difficulties of qualifying a space reactor are described. The differences between US and Russian flight qualification procedures are explored. A plan is then described that was developed to determine an appropriate flight qualification program for the Topaz II reactor to support a possible NEPSTP launch. Refocusing of the activities of the Ballistic Missile Defense Organization (BMDO), combined with budgetary pressures, forced the cancellation of the NEPSTP at the end of the 1993 fiscal year.

Thin film decoupling capacitors consisting of submicron thick, sol-gel Pb(Zr,Ti)O{sub 3} layers between Pt electrodes on a Si substrate have recently been developed. Because the capacitor structure needs to be only {approximately}3 {mu}m thick, these devices offer advantages such as decreased package volume and ability to integrate so that interconnect inductance is decreased, which allows faster IC processing rates. To fully utilize these devices, techniques of integrating them onto packages such as multi-chip modules and printed wiring boards or onto IC dies must be developed. The results of our efforts at developing integration processes for these capacitors are described here. Specifically, we have demonstrated a process for printing solder on the devices at the Si wafer level and reflowing it to form bumps and have developed a process for fabricating the devices on thin (25 to 75 {mu}m) substrates to facilitate integration onto ICs and printed wiring boards. Finally, we assessed the feasibility of fabricating the devices on rough surfaces to determine whether it would be possible to fabricate these capacitors directly on multi-layer ceramic substrates.

In this paper, I review the significant issues and the development of solar concentrators and thermal receivers for central-receiver power plants and dish/engine systems. Due to the breadth of the topic area, I have arbitrarily narrowed the content of this paper by choosing not to discuss line-focus (trough) systems and energy storage. I will focus my discussion on the development of heliostats, dishes, and receivers since the 1970s with an emphasis on describing the technologies and their evolution, identifying some key observations and lessons learned, and suggesting what the future in component development may be.

A new class of inorganic ion exchangers, called crystalline silicotitanates (CSTs), has been prepared at Sandia National Laboratories and Texas A&M University. CSTs have been determined to have high selectivity for the adsorption of Cs and Sr, and several other radionuclides from highly alkaline, high-sodium supernate solutions such as those found at Westinghouse Hanford (WHC). Continuous flow, ion-exchange columns are expected to be used to remove Cs and other radionuclides from the Hanford tank supernate. The proposed application for the CST would be Cs removal from highly alkaline salt solutions in a single pass process with interim storage of the Cs loaded CST until the glass vitrification plant is operational. This paper presents test results which address material requirements relevant for Hanford radwaste processing. This paper also discusses the integrated experimental and modeling approach being developed to establish the performance of the CST materials for the range of solution compositions and processing conditions which are expected to occur. The status on the commercialization of the CST material is also discussed.

Grid partitioning is the method of choice for decomposing a wide variety of computational problems into naturally parallel pieces. In problems where computational load on the grid or the grid itself changes as the simulation progresses, the ability to repartition dynamically and in parallel is attractive for achieving higher performance. We describe three algorithms suitable for parallel dynamic load-balancing which attempt to partition unstructured grids so that computational load is balanced and communication is minimized. The execution time of algorithms and the quality of the partitions they generate are compared to results from serial partitioners for two large grids. The integration of the algorithms into a parallel particle simulation is also briefly discussed.

This paper describes and evaluates operational experiences with the Accident Response Mobile Manipulation System (ARMMS) during simulated accident site salvage operations which might involve nuclear weapons. The ARMMS is based upon a teleoperated mobility platform with two Schilling Titan 7F Manipulators.

The cost of most photovoltaic (PV) systems is more a function of the balance of system (BOS) components than the collectors. The exception to this rule is the grid-tied system whose cost is related more directly to the collectors, and secondarily to the inverter/controls. In fact, recent procurements throughout the country document that collector costs for roof-mounted, utility-tied systems (Russell, PV Systems Workshop, 7/94) represent 60% to 70% of the system cost. This contrasts with the current market for packaged stand-alone all PV or PV-hybrid systems where collectors represent only 25% to 35% of the total. Not only are the BOS components the cost drivers in the current cost-effective PV system market place, they are also the least reliable components. This paper discusses the impact that BOS issues have on component performance, system performance, and system cost and reliability. We will also look at recent recommended changes in system design based upon performance evaluations of fielded PV systems.

The U.S. Department of Energy (DOE) has supported the development of solar thermal electric (STE) technology since the early 1970s. From its inception, the program has held a long-term goal of nurturing STE technologies from the research and development (R&D) stage through technology development, ultimately leading to commercialization. Within the last few years, the focus of this work -has shifted from R&D to cost-shared cooperative projects with industry. These projects are targeted not just at component development, but at complete systems, marketing approaches, and commercialization plans. This changing emphasis has brought new industry into the program and is significantly accelerating solar thermal`s entry into the marketplace. Projects such as Solar Two in the power tower area, a number of dish/Stirling joint ventures in the modular power area, and operations and maintenance (O&M) cost reduction studies will be discussed as examples of this new focus.

Sandia National Laboratories has designed, constructed and operated bare metal Godiva-type and pool-type pulse reactors since 1961. The reactor facilities were designed to support a wide spectrum of research, development, and testing activities associated with weapon and reactor systems.

Hazardous operations which have in the past been completed by technicians are under increased scrutiny due to high costs and low productivity associated with providing protective clothing and environments. As a result, remote systems are needed to accomplish many hazardous materials handling tasks such as the clean-up of waste sites in which the exposure of personnel to radiation, chemical, explosive and other hazardous constituents is unacceptable. Computer models augmented by sensing, and structured, modular computing environments are proving effective in automating many unstructured hazardous tasks. Work at Sandia National Laboratories (SNL) has focused on applying flexible automation (robotics) to meet the needs of the U.S. Department of Energy (USDOE). Dismantling facilities, environmental remediation, and materials handling in changing, hazardous environments lead to many technical challenges. Computer planning, monitoring and operator assistance shorten training cycles, reduce errors, and speed execution of operations. Robotic systems that re-use well-understood generic technologies can be much better characterized than robotic systems developed for a particular application, leading to a more reliable and safer systems. Further safety in robotic operations results from use of environmental sensors and knowledge of the task and environment. Collision detection and avoidance is achieved from such sensor integration and model-based control. This paper discusses selected technologies developed at SNL for use within the USDOE complex that have been or are ready for transfer to government and industrial suppliers. These technologies include sensors, sub-systems, and the design philosophy applied to quickly integrate them into a working robotic system. This paper represents the work of many people at the Intelligent Systems and Robotics Center at SNL, to whom the credit belongs.

The Hypervelocity Experimental Research Database (HERD) described in this paper was developed to aid researchers with code validation for impacts that occur at velocities faster than the testable regime. Codes of concern include both hydrocodes and fast-running analytical or semi-empirical models used to predict the impact phenomenology and damage that results to projectiles and targets. There are several well documented experimental programs that can serve as benchmarks for code validation; these are identified and described. Recommendations for further experimentation (a canonical problem) to provide validation data are also discussed.

Radar imaging and detection of objects buried in soil has potentially important applications in the areas of nonproliferation of weapons, environmental monitoring, hazardous-waste site location and assessment, and even archeology. In order to understand and exploit this potential, it is first necessary to understand how the soil responds to an electromagnetic wave, and how targets buried within the soil scatter the electromagnetic wave. We examine the response of the soil to a short pulse, and illustrate the roll of the complex dielectric permittivity of the soil in determining radar range resolution. This leads to a concept of an optimum frequency and bandwidth for imaging in a particular soil. We then propose a new definition for radar cross section which is consistent with the modified radar equation for use with buried targets. This radar cross section plays the same roll in the modified radar equation as the traditional radar cross section does in the free-space radar equation, and is directly comparable to it. The radar cross section of several canonical objects in lossy media is derived, and examples are given for several object/soil combinations.

The National Solar Thermal Test Facility (NSTTF) at Sandia National Laboratories in Albuquerque, New Mexico, USA conducts testing of solar thermal components and systems, funded primarily by the US Department of Energy. Activities are conducted in support of Central Receiver Technology, Distributed Receiver Technology and Design Assistance projects. All activities are performed in support of various cost-shared government/industry joint ventures and, on a design assistance basis, in support of a number of other industry partners.

The U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), in cooperation with nuclear power plant utilities and the Nuclear Energy Institute, have prepared equipment aging evaluations of nuclear power plant equipment for life extension considerations. Specifically, these evaluations focused on equipment considered important for plant license renewal (U.S. Code of Federal Regulations 10CFR54). {open_quotes}Industry Reports{close_quotes} (IRs), jointly funded by DOE and EPRI, evaluated the aging of major systems, structures, and components (e.g., reactor pressure vessels, Class I structures, PWR and BWR containments, etc.) and contain a mixture of technical and licensing information. {open_quotes}Aging Management Guidelines{close_quotes} (AMGs), funded by DOE, evaluate aging for commodity types of equipment (e.g., pumps, electrical switchgear, heat exchangers, etc.) and concentrate on technical issues only. AMGs are intended for systems engineers and plant maintenance staff. A significant number of technical issues were resolved during IR interactions with the U.S. Nuclear Regulatory Commission (NRC). However, certain technical issues have not been resolved and are considered {open_quotes}open{close_quotes}. Examples include certain issues related to fatigue, neutron irradiation embrittlement, intergranular stress corrosion cracking (IGSCC) and electrical cable equipment qualification. Direct NRC interaction did not take place during preparation of individual AMGs due to their purely technical nature. The eventual use of AMGs in a future license renewal application will likely require NRC interaction at that time. With a few noted exceptions, the AMG process indicated that current aging management practices of U.S. utilities were effective in preventing age-related degradation. This paper briefly describes the IR and AMG processes and summarizes the unresolved technical issues identified through preparation of the documents.