Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991.
This paper describes a new project undertaken by Sandia National Laboratories to develop an agile, automated, high-precision edge finishing system. The project has a two-year duration and was initiated in October, 1994. This project involves re-designing and adding additional capabilities to an existing finishing workcell at Sandia; and developing intelligent methods for automating process definition and for controlling finishing processes. The resulting system will serve as a prototype for systems that will be deployed into highly flexible automated production lines. The production systems will be used to produce a wide variety of products with limited production quantities and quick turnaround requirements. The prototype system is designed to allow programming, process definition, fixture re-configuration, and process verification to be performed off-line for new products. CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) models of the part will be used to assist with the automated process development and process control tasks. To achieve Sandia`s performance goals, the system will be employ advanced path planning, burr prediction expert systems, automated process definition, statistical process models in a process database, and a two-level control scheme using hybrid position-force control and fuzzy logic control. In this paper, we discuss the progress and the planned system development under this project.
This document represents a summary of 27 foreign-based environmental restoration and waste management technologies that have been screened and technically evaluated for application to the cleanup problems of the Department of Energy (DOE) nuclear weapons complex. The evaluation of these technologies was initiated in 1992 and completed in 1995 under the DOE`s International Technology Coordination Program of the Office of Technology Development. A methodology was developed for conducting a country-by-country survey of several regions of the world where specific environmental technology capabilities and market potential were investigated. The countries that were selected from a rank-ordering process for the survey included: then West Germany, the Netherlands, France, Japan, Taiwan, the Czech and Slovak Republics, and the Former Soviet Union. The notably innovative foreign technologies included in this document were screened initially from a list of several hundred, and then evaluated based on criteria that examined for level of maturity, suitability to the DOE needs, and for potential cost effective application at a DOE site. Each of the selected foreign technologies that were evaluated in this effort for DOE application were subsequently matched with site-specific environmental problem units across the DOE complex using the Technology Needs Assessment CROSSWALK Report. For ease of tracking these technologies to site problem units, and to facilitate their input into the DOE EnviroTRADE Information System, they were categorized into the following three areas: (1) characterization, monitoring and sensors, (2) waste treatment and separations, and (3) waste containment. Technical data profiles regarding these technologies include title and description, performance information, development status, key regulatory considerations, intellectual property rights, institute and contact personnel, and references.
Experiences as an environmental activist have produced some insights into addressing the current public over-reaction to environmental risks, and in particular to the risks posed by nuclear industry development.
This overview presents current research at Sandia National Laboratories in the Virtual Reality and Intelligent Simulation Lab. Into an existing distributed VR environment which we have been developing, and which provides shared immersion for multiple users, we are adding virtual actor support. The virtual actor support we are adding to this environment is intended to provide semi-autonomous actors, with oversight and high-level guiding control by a director/user, and to allow the overall action to be driven by a scenario. We present an overview of the environment into which our virtual actors will be added in Section 3, and discuss the direction of the Virtual Actor research itself in Section 4. We will briefly review related work in Section 2. First however we need to place the research in the context of what motivates it. The motivation for our construction of this environment, and the line of research associated with it, is based on a long-term program of providing support, through simulation, for situational training, by which we mean a type of training in which students learn to handle multiple situations or scenarios. In these situations, the student may encounter events ranging from the routine occurance to the rare emergency. Indeed, the appeal of such training systems is that they could allow the student to experience and develop effective responses for situations they would otherwise have no opportunity to practice, until they happened to encounter an actual occurance. Examples of the type of students for this kind of training would be security forces or emergency response forces. An example of the type of training scenario we would like to support is given in Section 4.2.
MicroDexterity Systems Inc. and Sandia National Laboratories are collaborating on the design of a six degree-of-freedom surgeon-controlled micropositioner and a six degree-of-freedom surgeon-controlled master for use in microsurgery. A control system will provide the linkage between the force-reflecting master and micropositioner for force scaling, position scaling, and tremor filtering. The technologies developed by this project are expected to enhance the skills of surgeons, improve the success rates for existing microsurgical procedures, make new high-dexterity procedures possible, and ultimately reduce surgical costs by increasing the precision and speed of operations. This paper discusses the motivation, approach, and accomplishments to date.
We report a new application of atomic force microscopy (AFM) for process characterization of GaAs integrated circuit fabrication. By using the near atomic-level z-resolution of AFM, we are able to gain information not available by other imaging techniques in a number of steps in the sequence for GaAs IC fabrication. A nondestructive method of determining whether micron-sized vias have been etched to completion is presented. In addition, the AFM has been used to evaluate material removal following several of fabrication steps. Shallow trench formation occurs as a result of GaAs removal during the sidewall etch for a commonly used sidewall spacer process. This effect has been not been observed previously by other techniques. Other examples of unintentional removal of small amounts of GaAs during shallow wet and dry etches are presented. These examples show the utility of AFM as an in-line process characterization tool.
This report evaluates telerobotic and teleoperational arm-based retrieval systems that require advanced robotic controls. These systems will be deployed in waste retrieval activities in Hanford`s Single Shell Tanks (SSTs). The report assumes that arm-based, retrieval systems will combine a teleoperational arm and control system enhanced by a number of advanced and telerobotic controls. The report describes many possible enhancements, spanning the full range of the control spectrum with the potential for technical maturation. The enhancements considered present a variety of choices and factors including: the enhancements to be included in the actual control system, safety, detailed task analyses, human factors, cost-benefit ratios, and availability and maturity of technology. Because the actual system will be designed by an offsite vendor, the procurement specifications must have the flexibility to allow bidders to propose a broad range of ideas, yet build in enough restrictions to filter out infeasible and undesirable approaches. At the same time they must allow selection of a technically promising proposal. Based on a preliminary analysis of the waste retrieval task, and considering factors such as operator limitations and the current state of robotics technology, the authors recommend a set of enhancements that will (1) allow the system to complete its waste retrieval mission, and (2) enable future upgrades in response to changing mission needs and technological advances.
Most neutron spectrum determination methodologies ignore self-shielding effects in dosimetry foils and treat covers with an exponential attenuation model. This work provides a quantitative analysis of the approximations in this approach. It also provides a methodology for improving the fidelity of the treatment of the dosimetry sensor response to a level consistent with the user`s spectrum characterization approach. A library of correction functions for the energy-dependent sensor response has been compiled that addresses dosimetry foils/configurations in use at the Sandia National Laboratories Radiation Metrology Laboratory.
We introduce an up-scaled, buoyant invasion percolation model (UIP) for application to non-wetting, dense, non-aqueous phase liquid (DNAPL) migration at the geologic formation scale within the saturated zone of an aquifer. The UEP model incorporates a gravitational potential to model the displacement of fluids of different densities and can be used for either LNAPLs (lighter than water) or DNAPLs (denser than water). We demonstrate model behavior in a simulated braided stream deposit. Simulations show the influence of textural changes across layers and gravity forces in controlling DNAPL migration. While our results are encouraging, the application of this up-scaled percolation model requires a series of tests both in the laboratory and in the field before judgment of sufficient validity for its intended purpose is achieved.
Initiated in 1991; the Dish/Stirling Joint Venture Program (DSJVP) is a 5-year, $17.2 million joint venture which is funded by Cummins Power Generation, Inc. (CPG) of Columbus, Indiana and the United States Department of Energy`s (DOE) Solar Thermal and Biomass Power Division. Sandia National Laboratories administers and provides technical management for this contract on the DOE`s behalf. In January, 1995; CPG advanced to Phase 3 of this three-phase contract. The objective of the DSJVP is to develop and commercialize a 7-kW. Dish/Stirling System for remote power markets by 1997. In this paper, the technical status of the major subsystems which comprise the CPG 7-kW{sub e} Dish/Stirling System is presented. These subsystems include the solar concentrator, heat pipe receiver, engine/alternator, power conditioning, and automatic controls.
The report describes a preliminary evaluation of models for transforming regional climate model output from a regional to a local scale for the Yucca Mountain area. Evaluation and analysis of both empirical and numerical modeling are discussed which is aimed at providing site-specific, climate-based information for use by interfacing activities. Two semiempirical approaches are recommended for further analysis.
A mathematical formulation is presented for describing the transport of air, water and energy through porous media. The development follows a continuum mechanics approach. The theory assumes the existence of various average macroscopic variables which describe the state of the system. Balance equations for mass and energy are formulated in terms of these macroscopic variables. The system is supplemented with constitutive equations relating fluxes to the state variables, and with transport property specifications. Specification of various mixing rules and thermodynamic relations completes the system of equations. A numerical simulation scheme, employing the method of lines, is described for one-dimensional flow. The numerical method is demonstrated on sample problems involving nonisothermal flow of air and water. The implementation is verified by comparison with existing numerical solutions.
Measurements of capillary barrier performance have been conducted in above-grade wooden structures (boxes) configured to measure the water balance. The capillary-barrier portion of the boxes is 6.0 m long, 2.0 m wide, and 1.2 m high with a slope of 5%. A coarse-grained material was placed in the bottom 25-cm of the box with a 90-cm deep fine-grained material (local soil) on top. A region for laterally diverted water to accumulate and drain was created in the last 1.0 m of the box. The soil at the top is terraced into five, 1.4 m long, level intervals to prevent runoff when adding water. Water is added uniformly to the entire top of the box at a rate of about 66 l/day, or an infiltration rate of 1.7 m/year. The top of the box is covered with fiber-reinforced plastic to minimize evaporation of water, discourage plant growth, and prevent rainfall from contacting the soil. Five drains are spaced along the bottom of the coarse layer. These drains discretize the coarse layer into five collection regions to provide a means of identifying the breakthrough location into the coarse layer. A drain is also located in the downdip collection region of the box. Soil moisture changes were measured in the fine-grained material with a frequency-domain reflectometry (FDR) probe, which was calibrated using soil from the field site at a known moisture content and density.
The objective of Sandia`s refining of coal-derived liquids project is to determine the relationship between hydrotreating conditions and Product characteristics. The coal-derived liquids used in this work were produced In HTI`s first proof-of-concept run using Illinois No. 8 coal. Samples of the whole coal liquid product, distillate fractions of this liquid, and Criterion HDN-60 catalyst were obtained from Southwest Research Inc. Hydrotreating experiments were performed using a continuous operation, unattended, microflow reactor system. A factorial experimental design with three variables (temperature, (310{degrees}C to 388{degrees}C), liquid hourly space velocity (1 to 3 g/h/cm{sup 3}(cat)), pressure (500 to 1000 psig H{sub 2}) is being used in this project. Sulfur and nitrogen contents of the hydrotreated products were monitored during the hydrotreating experiments to ensure that activity was lined out at each set of reaction conditions. Results of hydrotreating the whole coal liquid showed that nitrogen values in the products ranged from 549 ppM at 320{degrees}C, 3 g/h/cm{sup 3}(cat), 500 psig H{sub 2} to <15 ppM at 400{degrees}C, 1 g/h/ cm{sup 3}(cat), 1000 psig H{sub 2}.
A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 {times} 10{sup 5} seconds and for as long as 1.8 {times} 10{sup 6} seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress.
This report discusses the testing and evaluation of thirteen commercially available exterior digital video motion detection (VMD) systems. The systems were evaluated for use in a specific outdoor application. The report focuses primarily on the testing parameters, each system`s advertised features, and the nuisance alarm and detection test results.
Bridged polysilsesquioxanes represent an interesting family of hybrid organic-inorganic composite materials. It has been shown that manipulation of the organic bridging component offers the potential for the synthesis of a variety of materials with a range of surface areas and porosities. In addition, incorporation of a heteroatom within the bridging organic component allows for further chemical transformation of the polysilsesquioxane material.
This paper presents the relations that describe thermodynamic equilibrium in a three-phase system. Multiple components, including air, water, and oil components, are considered in three phases: (1) aqueous, (2) oil, and (3) gas. Primary variables are specified for each of seven possible phase combinations. These primary variables are then used to determine the necessary secondary variables to completely describe the system. Criteria are also developed to check the stability of each phase configuration and determine possible transitions from one phase configuration to another phase configuration via phase appearances and disappearances.
The authors analyze the problem of radiation trapping (imprisonment) by the method of Holstein. The process is described by an integrodifferential equation which shows that the effective radiative decay rate of the system depends on the size and the shape of the active medium. Holstein obtains a global decay rate for a particular geometry by assuming that the radiating excited species evolves into a steady state spatial mode. The authors derive a new approximation for the trapped decay which has a space dependent decay rate and is easy to implement in a detailed computer simulation of a plasma confined within an arbitrary geometry. They analyze the line shapes that are relevant to a near-atmospheric-pressure mixture of He and Xe. This line-shape analysis can be utilized in either the Holstein formulae or the space-dependent decay approximation.
Polyelectrolyte (PE) gels are swollen polymer/solvent networks that undergo a reversible volume collapse/expansion through various types of stimulation. Applications that could exploit this large deformation and solvent expulsion/absorption characteristics include robotic {open_quotes}fingers{close_quotes} and drug delivery systems. The goals of the research were to first explore the feasibility of using the PE gels as {open_quotes}smart materials{close_quotes} - materials whose response can be controlled by an external stimulus through a feedback mechanism. Then develop a predictive capability to simulate the dynamic behavior of these gels. This involved experimentally characterizing the response of well-characterized gels to an applied electric field and other stimuli to develop an understanding of the underlying mechanisms which cause the volume collapse. Lastly, the numerical analysis tool was used to simulate various potential engineering devices based on PE gels. This report discusses the pursuit of those goals through experimental and computational means.
Reactor-scale ex-vessel boiling experiments were performed in the CYBL facility at Sandia National Laboratories. The boiling flow pattern outside the RPV bottom head shows a center pulsating region and an outer steady two-phase boundary layer region. The local heat transfer data can be correlated in terms of a modified Rohsenow correlation.
In some nuclear reactor core melt accidents, a potential exists for molten core debris to be dispersed into the containment under high pressure. Resulting energy transfer to the containment atmosphere can pressurize the containment. This process, known as direct containment heating (DCH), has been the subject of extensive experimental and analytical programs sponsored by the US Nuclear Regulatory Commission (NRC). DCH modeling has been a major focus for the development of the CONTAIN code. In support of the peer review, extensive analyses of DCH experiments were performed in order to assess the CONTAIN code`s DCH models and improve understanding of DCH phenomenology. The present paper summarizes this assessment effort.
This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.
The Environmental Restoration (ER) Project has been tasked with the characterization, assessment, remediation and long-term monitoring of contaminated waste sites at Sandia National Laboratories/New Mexico (SNL/NM). Many of these sites will require remediation which will involve the use of baseline technologies, innovative technologies that are currently under development, and new methods which will be developed in the near future. The Technology Applications Program (TAP) supports the ER Project and is responsible for development of new technologies for use at the contaminated waste sites, including technologies that will be used for remediation and restoration of these sites. The purpose of this report is to define the remediation needs of the ER Project and to identify those remediation needs for which the baseline technologies and the current development efforts are inadequate. The area between the remediation needs and the existing baseline/innovative technology base represents a technology gap which must be filled in order to remediate contaminated waste sites at SNL/NM economically and efficiently. In the first part of this report, the remediation needs of the ER Project are defined by both the ER Project task leaders and by TAP personnel. The next section outlines the baseline technologies, including EPA defined Best Demonstrated Available Technologies (BDATs), that are applicable at SNL/NM ER sites. This is followed by recommendations of innovative technologies that are currently being developed that may also be applicable at SNL/NM ER sites. Finally, the gap between the existing baseline/innovative technology base and the remediation needs is identified. This technology gap will help define the future direction of technology development for the ER Project.