Laboratory measurements of single-phase, steady-state permeability of porous rock are important for a number of different applications. The oil and gas industry uses permeability data as a key indicator of the producability of a hydrocarbon reservoir; effective containment of large volumes of oil in underground salt caverns is directly dependent upon the permeability of the adjacent cavern walls; and safe, long term underground isolation of radioactive and hazardous waste is contingent upon the flow and transport characteristics of the surrounding geologic formations. An alternative method for measuring single-phase, steady-state permeability of porous rock is presented. The use of troublesome and expensive mass flow meters is eliminated and replaced with a bridge configuration of flow resistors. Permeability values can be determined directly from differential pressures across the bridge network, resulting in potentially significant cost savings and simplification for conducting these types of measurements. Results from the bridge permeameter are compared with results obtained using conventional methods.
The purpose of this NUREG is to provide technical information useful for the development of fiber-optic communications and intrusion detection subsystems relevant to physical protection. There are major sections on fiber-optic technology and applications. Other topics include fiber-optic system components and systems engineering. This document also contains a glossary, a list of standards and specifications, and a list of fiber-optic equipment vendors.
This report discusses the testing and evaluation of four commercially available fiber optic intrusion detection systems. The systems were tested under carpet-type matting and in a vaulted ceiling application. This report will focus on nuisance alarm data and intrusion detection results. Tests were conducted in a mobile office building and in a bunker.
Activities involving regulatory implementation of updated source term information were pursued. These activities include the identification of the source term, the identification of the chemical form of iodine in the source term, and the timing of the source term`s entrance into containment. These activities are intended to support a more realistic source term for licensing nuclear power plants than the current TID-14844 source term and current licensing assumptions. MELCOR calculations were performed to support the technical basis for the updated source term. This report presents the results from three MELCOR calculations of nuclear power plant accident sequences and presents comparisons with Source Term code Package (STCP) calculations for the same sequences. The three low-pressure sequences were analyzed to identify the materials which enter containment (source terms) and are available for release to the environment, and to obtain timing of sequence events. The source terms include fission products and other materials such as those generated by core-concrete interactions. All three calculations, for both MELCOR and STCP, analyzed the Surry plant, a pressurized water reactor (PWR) with a subatmospheric containment design.
Geothermal energy is one of the more promising renewable energy technologies because it is environmentally benign and, unlike most renewable energy sources, can provide base power. This report provides an assessment of the research and development (R&D) work underway in geothermal energy in the following countries: Denmark, France, Germany, Italy, Japan, Russia, and the United Kingdom. While the R&D work underway in the US exceeds the R&D efforts of the other countries, the lead is eroding. This erosion is due to reductions in federal government funding for geothermal energy R&D and the decline of the US petroleum industry. This erosion of R&D leadership is hindering commercialization of US geothermal energy products and services. In comparison, the study countries are promoting the commercialization of their geothermal energy products and services. As a result, some of these countries, in particular Japan, will probably have the largest share of the global market for geothermal energy products and services; these products and services being targeted toward the developing countries (the largest market for geothermal energy).
In the past, many optimization schemes for massively parallel computers have attempted to achieve parallel efficiency using one of two methods. In the case of large and expensive objective function calculations, the optimization itself may be run in serial and the objective function calculations parallelized. In contrast, if the objective function calculations are relatively inexpensive and can be performed on a single processor, then the actual optimization routine, itself may be parallelized. In this paper, a scheme based upon the Parallel Direct Search (PDS) technique is presented which allows the objective function calculations to be done on an arbitrarily large number (p2) of processors. If, p, the number of processors available, is greater than or equal to 2p{sub 2} then the optimization may be parallelized as well. This allows for efficient use of computational resources since the objective function calculations can be performed on the number of processors that allow for peak parallel efficiency and then further speedup may be achieved by parallelizing the optimization. Results are presented for an optimization problem which involves the solution of a PDE using a finite-element algorithm as part of the objective function calculation. The optimum number of processors for the finite-element calculations is less than p/2. Thus, the PDS method is also parallelized. Performance comparisons are given for a nCUBE 2 implementation.
It is inevitable that sealing and abandonment will someday occur in a SPR cavern or caverns. To gain insight into the long-term behavior of a typical SPR cavern following sealing and abandonment, a suite of mechanical finite-element calculations was performed. The initial analyses predict how quickly and to what extent a cavern pressurizes after it is plugged. The analyses also examine the stability of the cavern as it changes shape due to the excessive pressures generated as the salt creeps and the brine in the cavern thermally expands. These large-scale analyses do not include the details of the plug but assume a good seal is established in the cavern wells. In another series of analyses, the potential for forming a leak at the plug is evaluated. A cement plug, emplaced in the casing seat of a cavern well, is loaded using the predicted brine pressures from the cavern analyses. The plugged casing analyses examine the potential for forming a leak path in and along the interfaces of salt, casing, and cement plug. In the last set of analysis, the dimensional scale of the problem is further reduced to examine a preexisting crack along a casing/salt interface. The cracked interface is assumed to be fluid filled and fully pressurized by the cavern fluids. The analyses address the potential for the fluid path to extend upwards along a plugged casing should an open microannulus surround the casing after it is plugged.
The Intelligent Manufacturing Systems (IMS) Test Case 6 project (Rapid Product Development) was set up to demonstrate rapid product development and 3D measurement techniques where the agencies performing the work were distributed over different countries. Test Case 6 provided a unique opportunity to examine the process by which an application protocol (AP) of the Standard for Exchange of Product Data is prepared. The test case had a well defined scope, the production of simple parts by means of layered manufacturing techniques. The information concerned with this manufacture was similarly well defined, due to the requirement that the information be transmitted among the organizations participating in the test case. STEP is an international standard specifying the data content and format for storage and exchange of product data throughout the product`s life cycle. STEP has been under development since 1984 and is just now emerging as an International Standard. STEP is specified as a series of information models using the EXPRESS computer language. For purposes of data exchange, a mapping to a physical file format is specified. Informally, product data can be defined as all the data about a product which one might wish to save. This definition implies some variation in the amount of data to be saved in any one instance. In the case of Test Case 6, one would certainly wish to save the IGES files describing the part. One may or may not wish to save the manufacturing parameters. While there are many parts of STEP with different purposes, the important series of parts for the purposes of standardizing product data are those dealing with application protocols. An application protocol specifies the details of product data within the context of a single application (in this case, layered manufacturing). Other APs deal with such subjects as configuration-managed solid parts and associated drafting.
A key feature distinguishing robotics from traditional computer science is its connection to the physical world. Robot planning software may use elegant algorithms supported by ironclad analytic proofs, but ultimately nature will decide whether the software output is correct in the sense of accomplishing the task goal. Thus a chief goal of robotics research is to understand and capture this nature in a way that allows algorithmic analysis to produce robust physical results. This is made particularly difficult by the presence of uncertainty, which arises from the inevitable discrepancy between the real task and its idealized computer model. This paper reviews fundamental sets of states, forces, and actions that exist for a broad class of robot manipulation tasks, and ties these sets to past and future approaches to developing robust manipulation planning and execution systems.
Detailed computational modeling of laser surgery requires treatment of the photoablation of human tissue by high intensity pulses of laser light and the subsequent thermomechanical response of the tissue. Three distinct physical regimes must be considered to accomplish this: (1) the immediate absorption of the laser pulse by the tissue and following tissue ablation, which is dependent upon tissue light absorption characteristics; (2) the near field thermal and mechanical response of the tissue to this laser pulse, and (3) the potential far field (and longer time) mechanical response of witness tissue. Both (2) and (3) are dependent upon accurate constitutive descriptions of the tissue. We will briefly review tissue absorptivity and mechanical behavior, with an emphasis on dynamic loads characteristic of the photoablation process. In this paper our focus will center on the requirements of numerical modeling and the uncertainties of mechanical tissue behavior under photoablation. We will also discuss potential contributions that computational simulations can make in the design of surgical protocols which utilize lasers, for example, in assessing the potential for collateral mechanical damage by laser pulses.
New kinds of semiconductor microcavity lasers are being created by modern semiconductor technologies like molecular beam epitaxy and electron beam lithography. These new microcavities exploit 3-dimensional architectures possible with epitaxial layering and surface patterning. The physical properties of these microcavities are intimately related to the geometry imposed on the semiconductor materials. Among these microcavities are surface-emitting structures which have many useful properties for commercial purposes. This paper reviews the basic physics of these microstructured lasers.
The National Center for Advanced Information Components Manufacturing (NCAICM) Projects focus on manufacturing processes, materials, user facilities, standard tools, and equipment for large area emissive flat panel displays and microelectronics. Two types of projects are funded: (1) precompetitive projects done at the Center, and (2) joint industry/national laboratory projects, which may carry intellectual property rights, where the work will be done at the appropriate industry or laboratory site. A summary of the NCAICM Projects will be presented.
Photonics activities at Sandia National Laboratories (SNL) are founded on a strong materials research program. The advent of the Compound Semiconductor Research Laboratory (CSRL) in 1988, accelerated device and materials research and development. Recently, industrial competitiveness has been added as a major mission of the labs. Photonics projects have expanded towards applications-driven programs requiring device and subsystem prototype deliveries and demonstrations. This evolution has resulted in a full range of photonics programs from materials synthesis and device fabrication to subsystem packaging and test.
This report describes a new flexible technology which is now available to design sensor and control networks based on a protocol embedded in an intelligent communications processor. The flexibility allows a system designer and/or a technical installer to make appropriate tradeoffs among simplicity, functionality, and cost in the design of network nodes and their installation. This is especially important in designing an installation scenario for the safeguards network. The network technology permits several choices of installations with the same basic node hardware. A pre-installed network offers maximum simplicity and no flexibility since it will operate as programmed during manufacture or the pre-installation setup and checkout. At the other end of the spectrum, a network can be installed using network management software and a computer. The combination of the network management software and computer hardware is generally referred to as a Network Management Tool (NMT). The NMT option offers full flexibility to change the network during or after installation. Different NMT can provide different degrees of complexity depending upon the applications and the amount of changes that need to be made during installation.
Simplified expressions for the attenuation of radionuclide releases by sprays and by water pools are devised. These expressions are obtained by correlation of the 10th, 50th and 90th percentiles of uncertainty distributions for the water pool decontamination factor and the spray decontamination coefficient. These uncertainty distributions were obtained by Monte Carlo uncertainty analyses using detailed, mechanistic models of the pools and sprays. Uncertainties considered in the analyses include uncertainties in the phenomena and uncertainties in the initial and boundary conditions during dictated by the progression of the severe accidents. Final results are graphically displayed in terms of the decontamination factor achieved at selected levels of conversatism versus pool depth and water subcooling or, in the case of sprays, versus time.
In an effort to reduce the cycle time for producing prototypical mechanical and electro-mechanical components, Sandia National Laboratories has integrated rapid prototyping processes into the design and manufacturing process. The processes currently in operation within the Rapid Prototyping Laboratory are Stereolithography (SL), Selective Laser Sintering (SLS), and Direct Shell Production Casting (DSPC). These emerging technologies have proven to be valuable tools for reducing lead times and fabrication costs. Sandia uses the SL and SLS processes to support internal product development efforts. Their primary use is to fabricate patterns for investment casting in support of a Sandia-managed program called FASTCAST that integrates computational technologies and experimental data into the investment casting process. These processes are also used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit-check models, visual aids for manufacturing, and functional parts in assemblies. The DSPC process is currently being developed as a method of fabricating ceramic investment casting molds directly from a CAD solid model. Sandia is an Alpha machine test site for this process. This presentation will provide an overview of the SL and SLS processes and an update of our experience and success in integrating these technologies into the product development cycle. It will also provide a lead-in for a tour of the Rapid Prototyping Laboratory, where these processes will be demonstrated.
The objective of this study was to find a material and configuration that could reliably detect the proper functioning of a current slapper detonator. Because of the small size of the slapper geometry (on the order of a 15 mils), most diagnostic techniques are not suitable. This program has the additional requirement that the device could not use any electrical power or output signals. This required that the diagnostic be completely passive. The paper describes the three facets of the development effort: complete characterization of the slapper using VISAR measurements, selection of the diagnostic material and configuration, and testing of the prototype designs. The VISAR testing required the use of a special optical probe to allow the laser light to reach both bridges of the slapper detonator. Results are given in the form of flyer velocity as a function of the initiating voltage level. The selected diagnostic design functions in a manner similar to a dent block except that the impact of the Kapton disk causes a fracture pattern. A quick visual inspection is all that is needed to determine if the flyer velocity exceeded the threshold value. Sub-threshold velocities produce a substantially different appearance.
We identify a general framework for weak planning called bootstrap planning, which is defined as global planning using only a local planner along with some memory for learning intermediate subgoals. We present a family of algorithms for bootstrap planning, and provide some initial theory on their performance. In our theoretical analysis, we develop a random digraph problem model and use it to make some performance predictions and comparisons of these algorithms. We also use it to provide some techniques for approximating the optimal resource bound on the local planner to achieve the best global planner. We validate our theoretical results with empirical demonstration on the 15-puzzle. We show how to reduce the planning cost of a global planner by 2 orders of magnitude using bootstrap planning. We also demonstrate a natural but not widely recognized connection between search costs and the lognormal distribution.
Li/SOCl{sub 2} battery technology is attractive by virtue of its high energy density, low self-discharge rate, and ability to to perform well at a wide variety of discharge rates. However, some of these same attributes also make Li/SOCl{sub 2} cells capable of hightly exothermic events when handled under abnormal conditions. We manage the energy safely and optimize the performance by tailoring the design to the application. We have developed three different ``D`` size cells that target low, moderate, and high rate applications. Each design provides safe and efficient performance, although, in progressing from low to high rate capability, the likelihood of venting under abuse conditions increses. We incorporate a vent mechanism in all designs as the ultimate protection from severe abuse. The details of our battery designs and the benefits of application-specific design are discussed.
The structural properties of spent nuclear fuel shipping containers vary as a function of the cask wall temperature. An analysis is performed to determine the effect of a realistic, though bounding, hot day environment on the thermal behavior of spent fuel shipping casks. These results are compared to those which develop under a steady-state application of the prescribed normal thermal conditions of 10CFR71. The completed analysis revealed that the majority of wall temperatures, for a wide variety of spent fuel shipping cask configurations, fall well below those predicted by using the steady-state application of the regulatory boundary conditions. It was found that maximum temperatures at the cask surface occasionally lie above temperatures predicted under the regulatory condition. This is due to the conservative assumptions present in the ambient conditions used. The analysis demonstrates that diurnal temperature variations which penetrate the cask wall have maxima substantially less than the corresponding temperatures obtained when applying the steady-state regulatory boundary conditions. Therefore, it is certain that vital cask components and the spent fuel itself will not exceed the temperatures calculated by use of the steady-state interpretation of the 10CFR71 normal conditions.
The increasing complexity of integrated circuits demands that software tools, in addition to hardware tools, be used for successful diagnosis of failure. A series of customizable software tools have been developed that organize failure analysis information and provide expert level help to failure analysts to increase their productivity and success.
An Integrated Demonstration (ID) Program, hosted by the Fernald Environmental Restoration Management Company, has been established for investigating technologies applicable to the characterization and remediation of soils contaminated with uranium. Chemical and physical characterization of Fernald soils and the uranium wastes contained therein is being accomplished by means of standard analytical techniques as well as a suite of non-standard microscopy and spectroscopy techniques. Likewise, a suite of physical and chemical extraction technologies are being designed and tested for accomplishing soil decontamination. However, the main theme of this paper is not the technologies being tested but the approach taken to integrate characterization, decontamination, and risk assessment efforts. It is the authors intent to outline the critical components of an integrated approach for characterizing and remediating uranium contaminated soils as well as provide a real-world example based on the lessons learned in the ID program.
Pyroshock is a potentially severe environment produced by the detonation of explosively actuated components and stage separation hardware. Electronic components exposed to pyroshock events during flight or deployment can be damaged by this high frequency, high G shock. Flight qualification of these components may be accomplished using one of many existing techniques to simulate the pyroshock environment in the laboratory. Two new techniques developed at Sandia National Laboratories allow larger components to be tested to a wide variety of pyroshock environments. The frequency content and amplitude of the simulated pyroshock can be easily controlled in a predictable manner. The pyroshock environment is produced by the resonant response of a test fixture that has been excited by a mechanical impact. The resonant fixture has a dominant frequency that can be continuously adjusted over a frequency range that is typically found in most pyroshock environments. The test apparatus and techniques utilized by each method will be described in this paper. Experimental results will be presented which illustrate the capabilities of each method.
From the beginning, equipment to support IAEA Safeguards could be characterized as that which is used to measure nuclear material, Destructive Assay (DA) and Non Destructive Assay (NDA), and that which is used to provide continuity of knowledge between inspection intervals, Containment & Surveillance (C/S). C/S equipment has often been thought of as Cameras and Seals, with a limited number of monitors being employed as they became available. In recent years, technology has advanced at an extremely rapid rate, and continues to do so. The traditional film cameras are being replaced by video equipment, and fiber optic and electronic seals have come into rather widespread use. Perhaps the most interesting aspect of this evolution, and that which indicates the wave of the future without much question, is the integration of video surveillance and electronic seals with a variety of monitors. This is demonstrated by safeguards systems which are installed in several nuclear facilities in France, Germany, Japan, the UK, the USA, and elsewhere. The terminology of Integrated Monitoring Systems (IMS) has emerged, with the employment of network technology capable of interconnecting all desired elements in a very flexible manner. Also, the technology for transmission of a wide variety of information to off-site locations, termed Remote Monitoring, is in widespread industrial use, requiring very little adaptation for safeguards use. This paper examines the future of the Integrated Monitoring Systems and Remote Monitoring in International Safeguards, including technical and other related factors.
It is well known that two phase titanium alloy systems suffer from an abrupt drop in ductility at elevated temperatures in the range of 1,000 to 1,150 K. This loss of ductility is manifested by easy decohesion of polycrystalline aggregates along the grain boundaries of the high temperature beta phase. If the alloy is in a state of tensile stress at the aforementioned temperatures, cracks initiate at the grain boundaries and propagate readily through the alloy, leading to premature failure. This phenomenon is a cause of major concern in titanium alloy fabrication and welding. Several mechanisms have been proposed to explain high temperature crack nucleation and growth along the boundaries. A critical review of the phenomenon and possible mechanisms responsible for the observed behavior will be discussed.