A rapid deployment access delay system (RAPADS) has been designed to provide high security protection of valued assets. The system or vault is transportable, modular, and utilizes a pin connection design. Individual panels are attached together to construct the vault. The pin connection allows for quick assembly and disassembly, and makes it possible to construct vaults of various sizes to meet a specific application. Because of the unique pin connection and overlapping joint arrangement, a sequence of assembly steps are required to assembly the vault. As a result, once the door is closed and locked, all pin connections are concealed and inaccessible. This provides a high level of protection in that no one panel or connection is vulnerable. This paper presents the RAPADS concept, design, fabrication, and construction.
One of the most challenging applications facing the computer community is development of effective adaptive human-computer interface. This challenge stems from the complex nature of the human part of this symbiosis. The application of this discipline to the environmental restoration and waste management is further complicated due to the nature of environmental data. The information that is required to manage environmental impacts of human activity is fundamentally complex. This paper will discuss the efforts at Sandia National Laboratories in developing the adaptive conceptual model manager within the constraint of the environmental decision-making. A computer workstation, that hosts the Conceptual Model Manager and the Sandia Environmental Decision Support System will also be discussed.
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 design site characterization activities with minimal impact on the ability of the site to isolate waste, and on tests performed as part of the characterization process. One activity of site characterization is the construction of an Exploratory Studies Facility, consisting of underground shafts, drifts, and ramps, and the accompanying surface pad facility and roads. The information in this report addresses the following topics: (1) a discussion of the potential effects of surface construction water on repository-performance, and on surface and underground experiments; (2) one-dimensional numerical calculations predicting the maximum allowable amount of water that may infiltrate the surface of the mountain without affecting repository performance; and (3) two-dimensional numerical calculations of the movement of that amount of surface water and how the water may affect repository performance and experiments. The results contained herein should be used with other site data and scientific/engineering judgement in determining controls on water usage at Yucca Mountain. This document contains information that has been used in preparing Appendix I of the Exploratory Studies Facility Design Requirements document for the Yucca Mountain Site Characterization Project.
The focus of this paper is on changes in perceptions of the risks associated with nuclear waste management over time. In particular, we are interested in the kinds of change that take place when the management programs, and those who are charged with implementing them, are subject to intensive public debate over an extended period of time. We are undertaken an over-time study of perceived risks in Colorado and New Mexico by implementing sequential random household surveys in each state, timed at six month intervals. This study employs three of these surveys, spanning the period from summer, 1990 to summer, 1991. Using these data, we examine the dynamics that may underlie variations in perceived risks over time. In particular, our analysis is focused on changes in the roles played by (1) basic political orientations (i.e. political ideology) and (2) trust in those who advocate conflicting policy positions.
Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques.
Sandia National Laboratories (SNL) is a Department of Energy multiprogram engineering and scientific facility with unique design, development, and test capabilities arising from their work in nuclear weapons, energy resources, defense systems, nuclear safeguards, and specialized scientific endeavors. To support these programs, they have developed instrumentation and telemetry expertise not available elsewhere. This technology is applicable to projects in government and industry. Since the 1950s, they have applied our technical competence to meet difficult challenges with innovative solutions to data acquisition and telemetry problems. Sandia - with experience in fields as diverse as parachute design and plasma physics, geology and rocket guidance, human factors and high-speed aerodynamics, non-destructive testing and satellite communications - can use the power of synergism among our many disciplines to solve your complex problems of data and acquisition and analysis. SNL solves difficult data acquisition problems for extreme environments with expertise in advanced telemetry techniques, high data rate telemetry design, specialized electronics packaging, MIL-STD-1553 communications, instrumentation development, real-time data analysis, project management, specialized testers and data encryption.
Pretest analysis of a heated block test, proposed for the Exploratory Studies Facility at Yucca Mountain, Nevada, was conducted in this investigation. Specifically, the study focuses on the evaluation of the various designs to drill holes and cut slots for the block. The thermal/mechanical analysis was based on the finite element method and a compliant-joint rock-mass constitutive model. Based on the calculated results, relative merits of the various test designs are discussed.
Photovoltaic energy systems have historically been treated as a bulk power generation source for the future. However, utilities and other agencies involved with electrification throughout the world are beginning to find photovoltaics a least-cost option to meet specific loads both for themselves and their customers, in both off-grid and grid-connected applications. These expanding markets offer the potential of hundreds of megawatts of sales in the coming decade, but a strategy addressing both industrial growth and user acceptance is necessary to capitalize on this opportunity. 11 refs.
Phase mixing of transverse oscillations changes the nature of the ion hose instability from an absolute to a convective instability. The stronger the phase mixing, the faster an electron beam reaches equilibrium with the guiding ion channel. This is important for long distance propagation of relativistic electron beams where it is desired that transverse oscillations phase mix within a few betatron wavelengths of injection and subsequently an equilibrium is reached with no further beam emittance growth. In the linear regime phase mixing is well understood and results in asymptotic decay of transverse oscillations as 1/Z{sup 2} for a Gaussian beam and channel system, Z being the axial distance measured in betatron wavelengths. In the nonlinear regime (which is likely mode of propagation for long pulse beams) results of the spread mass model indicate that phase mixing is considerably weaker than in the regime. In this paper we consider this problem of phase mixing in the nonlinear regime. Results of the spread mass model will be shown along with a simple analysis of phase mixing for multiple oscillator models. Particle simulations also indicate that phase mixing is weaker in nonlinear regime than in the linear regime. These results will also be shown. 3 refs., 4 figs.
Photovoltaic (PV) systems are increasing in popularity in the northern latitudes and in the arctic regions in the state of Alaska. This increased interest and the high cost of providing electric power in these remote areas have prompted the Alaska Energy Authority (AEA) to request assistance from the Photovoltaic Design Assistance Center at Sandia National Laboratories. A project to investigate the feasibility of using PV-Diesel hybrid power systems in small villages in Alaska was started in 1989. Data acquisition systems (DAS) were designed and installed in selected villages to obtain resource and load information. The DAS is described and village electrical and resource data are presented. Simulations were run using the collected village data and actual cost data provided by the AEA. Results of the simulations and the economic analysis are presented. 5 refs., 8 figs.
Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.
The purpose of this paper is to develop an analytical model to convert ballistic limit curves obtained from flat projectile experiments to ballistic limit curves based on equivalent diameter spheres. Results from a test program involving flat plat projectiles conducted at Sandia National Laboratories are compared against the predicted performance of equivalent spherical projectiles as determined from the Wilkinson and Cour-Palais penetration equations. The developed method demonstrates good correlation of the ballistic limit of the shield concept for the flat plate projectiles to the theoretical ballistic limit for equivalent spheres as predicted by the penetration equations. 3 refs.
PRA studies are being extended to include a wider spectrum of reactor plants than was considered in NUREG-1150. There is a need for computationally simple models for Direct Containment Heating (DCH) that could be used for screening studies aimed at identifying potentially significant contributors to risk. This paper discusses two adiabatic equilibrium models that are candidates for the task. The first, a 1-cell model, places a true upper bound on DCH loads. This upper bound, however, often far exceeds reasonable expectations of containment loads based on best estimate CONTAIN calculations or experiment observations. In this paper, a 2-cell model is developed that largely captures the major mitigating features of containment compartmentalization, thus providing more reasonable estimates of the containment load. Predictions of the equilibrium models are compared with experiment data from the Limited Flight Path (LFP) test series conducted at Sandia National Laboratories.
The CONTAIN code is currently being used to predict containment thermal hydraulic conditions during design basis and severe accidents for advanced light water reactor (ALWR) designs such as the Westinghouse AP600. In the AP600 design, a passive containment cooling system (PCCS) is used for reducing long-term overpressure during accidents. CONTAIN models for heat and mass transfer within the AP600 containment and outer air cooling channel are verified by comparing recent CONTAIN calculations to integral test data obtained by Westinghouse in their PCCS Integral Test Facility. The comparison includes test in which the outer containment wall is both dry and wet, that is, the wet tests involve an evaporative water film that enhances heat transfer as will be the case for AP600. The appropriateness of the heat and mass transfer analogy methodology used in the CONTAIN code is demonstrated. Code model limitations are discussed along with model development plans and applications for AP600.
An additive three step process has been developed for patterned deposition of Cu onto poly(tetrafluoroethylene) (PTFE). The first step involves patterned irradiation with X-rays or electrons which is thought to cross link the PTFE surface; step two involves chemical etching with the result that only the non-irradiated areas are etched; and step three involves selective chemical vapor deposition (CVD) of Cu onto the etched surface at 200 C using (hexafluoroacetylacetonato)Cu(I) trimethylphosphine ((hfac)Cu(PMe{sub 3})). The non-irradiated areas of the surface are covered by a continuous, dense Cu film with X-ray photoelectron spectra show to contain only surface impurities that are easily removed by a short Ar ion sputter. The irradiated areas show the presence of only C and F, characteristic of PTFE.
The first experiment of the Integral Effects Test (IET-1) series was conducted to investigate the effects of high pressure melt ejection (HPME) on direct containment heating (DCH). A 1:10 linear scale model of the Zion reactor pressure vessel (RPV), cavity, instrument tunnel, and subcompartment structures were constructed in the Surtsey Test Facility at Sandia National Laboratories (SNL). The RPV was modelled with a melt generator that consisted of a steel pressure barrier, a cast MgO crucible, and a thin steel inner liner. The melt generator/crucible had a semi-hemispherical bottom head containing a graphite limitor plate with a 3.5 cm exit hole to simulate the ablated hole in the RPV bottom head that would be formed by tube ejection in a severe nuclear power plant (NPP) accident. The reactor cavity model contained 3.48 kg of water with a depth of 0.9 cm that corresponded to condensate levels in the Zion plant. A steam driven iron oxide/aluminum/chromium thermite was used to simulate HPME. A relatively small steam explosion occurred in the cavity during IET-1. Steam blowthrough entrained debris into the Surtsey vessel resulting in a peak pressure increase in Surtsey of 98 kPa. The Surtsey vessel had been previously inerted with N{sub 2}. The total debris mass ejected into the Surtsey vessel was 43 kg. The hydrogen concentration was 3.1 mol.% in the vessel at equilibrium. The concentration measured inside the subcompartment structures immediately following HPME transient was 20.7 mol.% H{sub 2}. 4 refs., 17 figs., 5 tabs.
During the RADLAC II open-air beam propagation experiments this last year three separate optical diagnostics were used. (1) Streak cameras were deployed to measure matched beam radius and centroid versus time. (2) Three gated, intensified TV cameras were used to image the beam from the end of the propagation range. They gave beam radius and centroid for three slices of the beam over a five meter propagation length. (3) Open shutter cameras were developed to give the time-averaged beam position over the entire propagation range. Data from all three diagnostics were digitized, stored in files on a computer, and post-processed to give temporally and spatially resolved beam size and position. These diagnostics used beam induced air-fluorescence as the mechanism to provide a prompt signal representative of the beam current density. Previous experiments and analysis have shown that the radiation is prompt with the intensity proportional to the beam current density for high energy, high current electron beams propagating in full density air.
Detailed geometric models have been used within a graphical simulation environment to study transportation cask facility design and to perform design and analyses of robotic systems for handling of nuclear waste. The models form the basis for a robot control environment which provides safety, flexibility, and reliability for operations which span the spectrum from autonomous control to tasks requiring direct human intervention.
We have designed and manufactured a test chip devoted to the study of interconnect voiding. The test chip is suitable for evaluating theoretical models, acceleration recipes, and the effects of process variations. We describe the chip and a simple, stress-free packaging technique that eliminates any stress to the chip from die bonding or packaging thermal cycles. With this test chip, we can perform many necessary and desirable experiments: determining stress, observing or stimulating void growth, profiling hydrogen concentrations, and measuring excess current noise. We report here preliminary measurements of residual stress, observations of voids, and determinations of hydrogen concentrations of hydrogen concentration under variations in aluminum annealing and passivation. In agreement with observations elsewhere, we find that passivations which differ greatly in intrinsic stress do not differ much in the stress they impart to patterned metal; some workers have suggested instead that excess hydrogen in the aluminum contributes to voiding. Following this lead, we have used nuclear reaction analysis to profile the hydrogen concentration in passivation, metallization, barrier metal, and interlevel dielectric and present some preliminary measurements here. We conclude that passivated metallization may contain as much as 0.1 atomic % hydrogen. 10 refs.
This paper provides a summary and status report for two ongoing experimental programs. The purpose of each program is to determine the behavior of certain components of the containment pressure boundary when subjected to severe accident conditions. The first program is investigating the effect of various parameters on tearing of the steel liner in reinforced concrete containments. The second will attempt to determine if worst-case containment loading conditions are capable of causing leakage through piping penetration bellows. The liner test program is almost complete; however, the bellows tests have not yet begun. Therefore, the emphasis of the paper is on the liner experiments. The research activities described herein are a part of the Containment Integrity Programs, which are managed by Sandia National Laboratories for the US Nuclear Regulatory Commission.
A Science Advisor Program has been established at Sandia National Laboratories (SNL) for the long term augmentation of math and science instruction in New Mexico schools. Volunteer SNL engineers and scientists team with the faculty of participating schools to enhance the teachers` abilities to capture and hold the student`s scientific imagination and develop their scientific skills. This is done primarily through providing laboratory resources, training the teachers how to use those resources, and advising how to obtain them in the future. In its first year, over 140 advisors teamed with 132 schools, for average weekly contact with 500 teachers and 10,000 students. Surveys indicate a general rise in frequency and quality of hands-on science instruction, as well as teacher and student attitudes. An expanded evaluation is planned for subsequent years.
The syntheses and physical properties of {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]X (X=Br and Cl) are summarized. The {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Br salt is the highest {Tc} radical-cation based ambient pressure organic superconductor ({Tc}=11.6 K), and the {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Cl salt becomes a superconductor at even higher {Tc} under 0.3 kbar hydrostatic pressure ({Tc}=12.8 K). The similarities and differences between {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Br and {kappa}-(ET){sub 2}Cu(NCS){sub 2} ({Tc}=10.4 K) are presented. The X-ray structures at 127 K reveal that the the S{hor_ellipsis}S contacts shorten between ET dimers in the former compound while the S{hor_ellipsis}S contacts shorten within dimers in the latter. The difference in their ESR linewidth behavior is also explained in terms of the structural differences. A semiconducting compound, (ET)Cu[N(CN){sub 2}]{sub 2}, isolated during {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Cl synthesis is also reported. The ESR measurements of the {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Cl salt indicate that the phase transition near 40 K is similar to the spin density wave transition in (TMTSF){sub 2}SbF{sub 6}. A new class of organic superconductors, {kappa}-(ET){sub 2}Cu{sub 2}(CN){sub 3} and {kappa}-(ET){sub 2}Cu{sub 2}(CN){sub 3}-{delta}Br{delta}, is reported with {Tc}`s of 2.8 K (1.5 kbar) and 2.6 K (1 kbar), respectively.
We describe a new electrochemical processing technique based on porous silicon formation that can produce surface and buried insulators, conductors, and sacrificial layers required for silicon micromachining to fabricate micromechanical devices and sensors. Porosity and thickness of porous silicon layers for micromachining can be controlled to a relative precision better than 0.3% for porosities ranging from 20--80% and thicknesses ranging from sub- micron to hundreds of microns. The technique of using porous silicon has important implications for microfabrication of silicon electromechanical devices and sensors. The high relative precision in realizing a given thickness is superior to that obtained with conventional chemical etches. 8 refs.
This paper discusses the development of the software for Source Term Analyses for Containment Evaluations (STACE). This software is being developed for the Source Term Technical Issue Resolution Program at Sandia National Laboratories (SNL) in support of the Cask Systems Development Program (CSDP) that is sponsored by the US Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM). STACE is a system of computer codes operating under a graphics-based controller that performs source term analysis of spent fuel transport casks. Output from STACE includes the cladding breach probability, the releasable radionuclide concentrations, and maximum permissible gas flow rates past the closure seals. STACE is anticipated being used for on- and off-site situations related to the handling and transport of spent fuel casks.
This paper presents a methodology for determining the response of spent fuel assembly spacer grids subjected to transport cask impact loading. The spacer grids and their interaction with rod-to-rod loading are the most critical components governing the structural response of spent fuel assemblies. The purpose of calculating the assembly response is to determine the resistance to failure of spent fuel during regulatory transport. The failure frequency computed from these analyses is used in calculating category B spent fuel cask containment source term leakage rates for licensing calculations. Without defensible fuel rod failure frequency prediction calculations, assumptions of 100% fuel failure must be made, leading to leak tight cask design requirements.