Publications

Results 94551–94600 of 96,771

Search results

Jump to search filters

An approach to validation of thermomechanical models

Costin, Laurence S.

Thermomechanical models are being developed to support the design of an Exploratory Studies Facility (ESF) and a potential high-level nuclear waste repository at Yucca Mountain, Nevada. These models are used for preclosure design of underground openings, such as access drifts, emplacement drifts, and waste emplacement boreholes; and in support of postclosure issue resolution relating to waste canister performance, disturbance of the hydrological properties of the host rock, and overall system performance assessment. For both design and performance assessment, the purpose of using models in analyses is to better understand and quantify some phenomenon or process. Therefore, validation is an important process that must be pursued in conjunction with the development and application of models. The Site Characterization Plan (SCP) addressed some general aspects of model validation, but no specific approach has, as yet, been developed for either design or performance assessment models. This paper will discuss a proposed process for thermomechanical model validation and will focus on the use of laboratory and in situ experiments as part of the validation process. The process may be generic enough in nature that it could be applied to the validation of other types of models, for example, models of unsaturated hydrologic flow.

More Details

Scenarios constructed for basaltic igneous activity at Yucca Mountain and vicinity; Yucca Mountain Site Characterization Project

Barr, George E.

Basaltic volcanism has been identified as a possible future event initiating a release of radionuclides from a potential repository at the proposed Yucca Mountain high-level waste repository site. The performance assessment method set forth in the Site Characterization Plan (DOE, 1988) requires that a set of scenarios encompassing all significant radionuclide release paths to the accessible environment be described. This report attempts to catalogue the details of the interactions between the features and processes produced by basaltic volcanism in the presence of the presumed groundwater flow system and a repository structure, the engineered barrier system (EBS), and waste. This catalogue is developed in the form of scenarios. We define a scenario as a well-posed problem, starting from an initiating event or process and proceeding through a logically connected and physically possible combination or sequence of features, events, and processes (FEPs) to the release of contaminants.

More Details

Sandia Capabilities

Van Arsdall, Anne; Doran, Linda; Floyd, H.L.; Garber, Reeta A.; Goetsch, Robert S.; Leonard, Jim; Parrott, Lori K.

Sandia National Laboratories—a Department of Energy multiprogram national laboratory—has for over four decades applied its talents, tools, and techniques to solving technological problems of national scale. This publication provides information of interest about Sandia National Laboratories and the work being done there.

More Details

Preclosure radiological safety evaluation: Exploratory Studies Facility; Yucca Mountain Site Characterization Project

Schelling, F.J.; Smith, J.D.

A radiological safety evaluation is performed to determine the impacts of Exploratory Studies Facility (ESF) design changes on the preclosure public radiological safety for a potential nuclear waste repository at Yucca Mountain, Nevada. Although the ESF design has undergone significant modification, incorporation of the modified design requires only modest changes to the conceptual repository configuration. To the extent feasible, the results of earlier safety evaluations presented in SAND84-2641, SAND88-7061, and SAND89-7024, which were based on the original ESF configuration, are compared with the results for the modified configuration. This comparison provides an estimate of the range of analysis uncertainty. This preliminary analysis indicates that there are no Q-scenarios, which are defined as those scenarios with a net occurrence probability of greater than 10{sup {minus}6}/yr and produce a radiological dose at the 5-km controlled area boundary of greater than 0.5 rem. The analysis yielded estimates for an underground accident of a probability of 3.8 {times} 10{sup {minus}15}/yr and a dose of 1.5 rem. For a surface-initiated accident, a probability of 1.5 {times} 10{sup {minus}12}/yr and a dose of 0.6 rem was estimated.

More Details

Use of the iterative solution method for coupled finite element and boundary element modeling; Yucca Mountain Site Characterization Project

Koteras, J.R.

Tunnels buried deep within the earth constitute an important class geomechanics problems. Two numerical techniques used for the analysis of geomechanics problems, the finite element method and the boundary element method, have complementary characteristics for applications to problems of this type. The usefulness of combining these two methods for use as a geomechanics analysis tool has been recognized for some time, and a number of coupling techniques have been proposed. However, not all of them lend themselves to efficient computational implementations for large-scale problems. This report examines a coupling technique that can form the basis for an efficient analysis tool for large scale geomechanics problems through the use of an iterative equation solver.

More Details

Analysis of releases due to drilling at the potential Yucca Mountain repository

Barnard, R.

Human Instrusion into the potential repository at Yucca Mountain, Nevada, was modeled in the Total-System Performance Assessment (``TSPA-91``) recently completed for the Yucca Mountain Site Characterization Project Office of the DOE. The scenario model assumed that the repository would be penetrated at random locations by a number of boreholes drilled using twentieth-century rotary drilling techniques.

More Details

The appropriateness of one-dimensional Yucca Mountain hydrologic calculations; Yucca Mountain Site Characterization Project

Eaton, R.R.

This report brings into focus the results of numerous studies that have addressed issues associated with the validity of assumptions which are used to justify reducing the dimensionality of numerical calculations of water flow through Yucca Mountain, NV. it is shown that, in many cases, one-dimensional modeling is more rigorous than previously assumed.

More Details

Creative solutions for complex developmental testing

Sandia National Laboratories was requested to establish the FAA Aging Aircraft Nondestructive Inspection (NDI) Development and Demonstration Center. The Center is housed in a hangar at the Albuquerque International Airport and owns its own aged transport airplane. The Center`s work encompasses research and development in enhanced structural inspection. The goals of the Center are to: promote NDI technology development and maturation; help transfer new nondevelopment item technology to the hangar floor; validate NDI techniques; assess reliability or probability of detection of NDI processes. An important part of this project will be to make sure that the cost of implementation and operation of any technique is seriously considered and that techniques are usable in the field. Among the initial techniques to be evaluated are: enhanced visual, magneto-optic eddy current; coherent optics; ultrasonics; thermographics; eddy current scanners; experimental modal analysis. This project is a perfect example of how Development Testing draws on its own resources and teams up with others, as necessary, to get the job done. In this case, New Mexico State University and a private company, Science Applications International Corporation, are assisting.

More Details

Reconsolidation of salt as applied to permanent seals for the Waste Isolation Pilot Plant

Hansen, Francis D.

Reconsolidated salt is a fundamental component of the permanent seals for the Waste Isolation Pilot Plant. As regulations are currently understood and seal concepts envisioned, emplaced salt is the sole long-term seal component designed to prevent the shafts from becoming preferred pathways for rating gases or liquids. Studies under way in support of the sealing function of emplaced salt include laboratory testing of crushed salt small-scale in situ tests, constitutive modeling of crushed salt, calculations of the opening responses during operation and closure, and design practicalities including emplacement techniques. This paper briefly summarizes aspects of these efforts and key areas of future work.

More Details

Secure authenticated video equipment

Doren, Neall

In the verification technology arena, there is a pressing need for surveillance and monitoring equipment that produces authentic, verifiable records of observed activities. Such a record provides the inspecting party with confidence that observed activities occurred as recorded, without undetected tampering or spoofing having taken place. The secure authenticated video equipment (SAVE) system provides an authenticated series of video images of an observed activity. Being self-contained and portable, it can be installed as a stand-alone surveillance system or used in conjunction with existing monitoring equipment in a non-invasive manner. Security is provided by a tamper-proof camera enclosure containing a private, electronic authentication key. Video data is transferred communication link consisting of a coaxial cable, fiber-optic link or other similar media. A video review station, located remotely from the camera, receives, validates, displays and stores the incoming data. Video data is validated within the review station using a public key, a copy of which is held by authorized panics. This scheme allows the holder of the public key to verify the authenticity of the recorded video data but precludes undetectable modification of the data generated by the tamper-protected private authentication key.

More Details

A mixture model for shock compression of porous multi-component reactive materials

Baer, M.R.

A multiphase mixture model is presented to describe shock compression of highly porous, multi-component powders. Volume fractions are represented as independent kinematic variables and thermodynamically-admissible phase interaction constitutive models are formulated in the context of a three phase system. Numerical solutions of the multiphase flow equations simulated impact on a porous layer of mixed powders of Al and Fe{sub 2}O{sub 3}. The multiphase model predicts dispersive compaction waves which have features similar to observed time-resolved pressure measurements.

More Details

GENSHELL: A genesis database 2D to 3D shell transformation program

Sjaardema, Gregory D.

GENSHELL is a three-dimensional shell mesh generation program. The three-dimensional shell mesh is generated by mapping a two-dimensional quadrilateral mesh into three dimensions according to one of several types of transformations: translation, mapping onto a spherical, ellipsoidal, or cylindrical surface, and mapping onto a user-defined spline surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, revolving about an axis, and scaling the coordinates. GENSHELL can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. The code GJOIN is then used to join the separate sections into a single body. GENSHELL updates the EXODUS quality assurance and information records to help track the codes and files used to generate the mesh. GENSHELL reads and writes two-dimensional and three-dimensional mesh databases in the GENESIS database format; therefore, it is compatible with the preprocessing, postprocessing, and analysis codes in the Sandia National Laboratories Engineering Analysis Code Access System (SEACAS).

More Details

Volatile organic monitor for industrial effluents

Laguna, G.R.

1990 amendments to the Clean Air Act have created the need for instruments capable of monitoring volatile organic compounds (VOCS) in public air space in an unattended and low cost manner. The purpose of the study was to develop and demonstrate the capability to do long term automatic and unattended ambient air monitoring using an inexpensive portable analytic system at a commercial manufacturing plant site. A gas chromatograph system personal computer hardware, meteorology tower & instruments, and custom designed hardware and software were developed. Comparison with an EPA approved method was performed. The system was sited at an aircraft engines manufacturing site and operated in a completely unattended mode for 60 days. Two VOCs were monitored every 30 minutes during the 24hr day. Large variation in the concentration from 800ppb to the limits of detection of about 10ppb were observed. Work to increase the capabilities of the system is ongoing.

More Details

The continuing challenge of electromagnetic launch

Cowan, M.; Cnare, E.C.; Duggin, B.W.; Kaye, R.J.; Marder, B.M.; Shokair, I.R.

Interest in launching payloads through the atmosphere to ever higher velocity is robust. For hundreds of years, guns and rockets have been improved for this purpose until they are now considered to be near to their performance limits. While the potential of electromagnetic technology to increase launch velocity has been known since late in the nineteenth century, it was not until about 1980 that a sustained and large-scale effort was started to exploit it. Electromagnetic launcher technology is restricted here to mean only that technology which establishes both a current density, J, and a magnetic field, B, within a part of the launch package, called the armature, so that J {times} B integrated over the volume of the armature is the launching force. Research and development activity was triggered by the discovery that high velocity can be produced with a simple railgun which uses an arc for its armature. This so called ``plasma-armature railgun`` has been the launcher technology upon which nearly all of the work has focused. Still, a relatively small parallel effort has also been made to explore the potential of electromagnetic launchers which do not use sliding contacts on stationary rails to establish current in the armature. One electromagnetic launcher of this type is called an induction coilgun because armature current is established by electromagnetic induction. In this paper, we first establish terminology which we will use not only to specify requirements for successful endoatmospheric launch but also to compare different launcher types. Then, we summarize the statuses of the railgun and induction coilgun technologies and discuss the issues which must be resolved before either of these launchers can offer substantial advantage for endoatomospheric launch.

More Details

Vulnerability assessment using two complementary analysis tools

Paulus, W.K.

To analyze the vulnerability of nuclear materials to theft or sabotage, Department of Energy facilities have been using, since 1989, a computer program called ASSESS, Analytic System and Software for Evaluation of Safeguards and Security. During the past year Sandia National Laboratories has began using an additional program, SEES, Security Exercise Evaluation Simulation, enhancing the picture of vulnerability beyond what either program achieves alone. ASSESS analyzes all possible paths of attack on a target and, assuming that an attack occurs, ranks them by the probability that a response force of adequate size can interrupt the attack before theft or sabotage is accomplished. A Neutralization module pits, collectively, a security force against the interrupted adversary force in a fire fight and calculates the probability that the adversaries are defeated. SEES examines a single scenario and simulates in detail the interactions among all combatants. Its output includes shots fired between shooter and target, and the hits and kills. Whereas ASSESS gives breadth of analysis, expressed statistically and performed relatively quickly, SEES adds depth of detail, modeling tactical behavior. ASSESS finds scenarios that exploit the greatest weaknesses of a facility. SEES explores these scenarios to demonstrate in detail how various tactics to nullify the attack might work out. Without ASSESS to find the facility weaknesses, it is difficult to focus SEES objectively on scenarios worth analyzing. Without SEES to simulate the details of response vs. adversary interaction, it is not possible to test tactical assumptions and hypotheses. Using both programs together, vulnerability analyses achieve both breadth and depth.

More Details

Vulnerability assessment using two complementary analysis tools

Paulus, W.K.

To analyze the vulnerability of nuclear materials to theft or sabotage, Department of Energy facilities have been using, since 1989, a computer program called ASSESS, Analytic System and Software for Evaluation of Safeguards and Security. During the past year Sandia National Laboratories has begun using an additional program, SEES, Security Exercise Evaluation Simulation, enhancing the picture of vulnerability beyond what either program achieves alone. Assess analyzes all possible paths of attack on a target and, assuming that an attack occurs, ranks them by the probability that a response force of adequate size can interrupt the attack before theft or sabotage is accomplished. A Neutralization module pits, collectively, a security force against the interrupted adversary force in a fire fight and calculates the probability that the adversaries are defeated. SEES examines a single scenario and simulates in detail the interactions among all combatants. its output includes shots fired between shooter and target, and the hits and kills. Whereas ASSESS gives breadth of analysis, expressed statistically and performed relatively quickly, SEES adds depth of detail, modeling tactical behavior. ASSESS finds scenarios that exploit the greatest weakness of a facility. SEES explores these scenarios to demonstrate in detail how various tactics to nullify the attack might work out. Without ASSESS to find the facility weakness, it is difficult to focus SEES objectively on scenarios worth analyzing. Without SEES to simulate the details of response vs. adversary interaction, it is not possible to test tactical assumptions and hypotheses. Using both programs together, vulnerability analyses achieve both breadth and depth.

More Details

Anomalous zones in Gulf Coast Salt domes with special reference to Big Hill, TX, and Weeks Island, LA

Neal, J.T.

Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion accumulates other materials: Anhydrite bands which are relatively strong, and other, weaker impurities. Shear zones and fault displacement detected at Big Hill and Weeks Island domes have not yet had any known adverse impacts on SPR oil storage, but new caverns at these sites conceivably may encounter some potentially adverse conditions. Seismic reflection profiles at Big Hill dome have shown numerous fractures and faults in the caprock, and verified the earlier recognition of a major shear zone transecting the entire salt stock and forming a graben in the overlying caprock. Casing that is placed in such zones can be at risk. Knowledge of these zones should create awareness of possible effects rather than preclude the future emplacement of caverns. To the extent possible, major anomalous zones and salt stock boundaries should be avoided. Shear zones along overhangs may be particularly hazardous, and otherwise unknown valleys in the top of salt may occur along shear zones. These zones often can be mapped geophysically, especially with high-resolution seismic techniques.

More Details

Physical protection design approach for the Complex 21/Reconfiguration facilities

Jaeger, Cal

Sandia National Laboratories and Los Alamos National Laboratory have been designated as the technical lead for Security, Safeguards and Computer/Information Security systems for all the DOE Complex 21/Weapons Complex Reconfiguration (WCR) facilities. The physical protection systems in these facilities will be required to meet the most current DOE orders and incorporate the latest physical protection technologies, proven state-of-the-art systems and strategies. The planned approach requires that security assistance and information be provided to the designers (e.g. the Complex 21 Architect & Engineer and the Weapons Complex Lead Laboratories) as early as possible and throughout all design phases. The outcome should avoid the costly retrofits to existing facilities that have occurred in the past and result in effective and comprehensive protection against current and projected threats with minimal impact on operations, safety and costs. This paper discusses the physical protection considerations being promoted for the integrated design effort for the Complex 21/Reconfiguration facilities, such as the tritium, uranium/lithium, plutonium processing and storage, high explosive and assembly and disassembly facilities.

More Details

Equation of state and fragmentation issues in computational lethality analysis

Trucano, Timothy G.

The purpose of this report is to summarize the status of computational analysis of hypervelocity impact lethality in relatively nontechnical terms from the perspective of the author. It is not intended to be a review of the technical literature on the problems of concern. The discussion is focused by concentrating on two phenomenology areas which are of particular concern in computational impact studies. First, the material`s equation of state, specifically the treatment of expanded states of metals undergoing shock vaporization, is discussed. Second, the process of dynamic fragmentation is addressed. In both cases, the context of the discussion deals with inaccuracies and difficulties associated with numerical hypervelocity impact simulations. Laboratory experimental capabilities in hypervelocity impact for impact velocities greater than 10.0 km/s are becoming increasingly viable. This paper also gives recommendations for experimental thrusts which utilize these capabilities that will help to resolve the uncertainties in the numerical lethality studies that are pointed out in the present report.

More Details

Networked MS Windows 3.1 based Classified Document Control System (CDOCS)

Desonier, Lawrence M.

Current classified document management systems require a tremendous amount of space and extensive manpower to account for, inventory, and protect the documents. Comprehensive analysis of current control and accountability procedures reveal the main problem is the actual handling of the paper itself. The purpose of the Networked Microsoft Windows 3.1 based Classified Document Control System (CDOCS) is to eliminate the paper by scanning and storing images of pages on a personal computer using {open_quotes}write once read mostly{close_quotes} (WORM) high density optical media. By saving images on the computer, not only can manpower and space requirements be reduced, but the chance of compromise is diminished. As an added benefit, the information is now more readily available to the authorized user and is provided to the user at the user`s PC. The network target for CDOCS is Microsoft Windows for Workgroups. Thus, the system is also readily applicable to unclassified document imaging uses.

More Details

Understanding requirements via natural language information modeling

Sharp, J.K.; Becker, S.D.

Information system requirements that are expressed as simple English sentences provide a clear understanding of what is needed between system specifiers, administrators, users, and developers of information systems. The approach used to develop the requirements is the Natural-language Information Analysis Methodology (NIAM). NIAM allows the processes, events, and business rules to be modeled using natural language. The natural language presentation enables the people who deal with the business issues that are to be supported by the information system to describe exactly the system requirements that designers and developers will implement. Computer prattle is completely eliminated from the requirements discussion. An example is presented that is based upon a section of a DOE Order involving nuclear materials management. Where possible, the section is analyzed to specify the process(es) to be done, the event(s) that start the process, and the business rules that are to be followed during the process. Examples, including constraints, are developed. The presentation steps through the modeling process and shows where the section of the DOE Order needs clarification, extensions or interpretations that could provide a more complete and accurate specification.

More Details

Authenticated In-Plant Process Monitor

Leahy, P.

Transparent and secure process monitoring systems may become an important tool in the dismantlement schemes in support of bilateral and multi-lateral treaties. A prototype system, using public key cryptography to authenticate compliance data, has been developed by Sandia National Laboratories. The Authenticated In-plant Process Monitor (AIPM) is an embedded process monitoring system capable of accepting up to sixteen industry standard process variables, at sample rates of up to two samples per second. Each AIPM will synchronously sample the process, authenticate, and transmit the data in real-time to the host receiving station. The receiving station will validate the compliance data and then display in real-time while updating a relational database. This new generation of monitoring systems must include protection from a host of possible threat scenarios while providing the user authentic clear text data. Data threats are controlled by the use of a public key Treaty Data Authentication Module (TDAM) utilizing the National Institute of Standards and Technology (NIST) Digital Signature Standard. System threats are minimized by the use of a tamper indicating enclosure that monitors unauthorized entry and environmental attacks. Insider threats will be controlled by the use of an authenticated bi-directional communication link between each remote AIPM and the host receiving station. This security envelope will be monitored on a real-time basis with appropriate action taken if an attack occurs. The employment of these security features allows the inspectorate to distribute unprocessed clear text data and an attached digital signature with confidence that the data cannot be forged.

More Details

Information surety for today and tomorrow

Fletcher, S.K.

Information Surety is the enhancement of the confidentiality, integrity, and availability of information and software systems. It is attained through sequential steps: identification of software reliability requirements and information protection needs, designing for a balanced level of risk throughout the system, and application of appropriate software and hardware technologies and procedures. The ability to apply these steps when developing systems is impaired by a general lack of understanding of surety issues by system developers, and by the fact that there are many separate areas of knowledge involved that are not currently integrated into a disciplined approach (e.g., risk assessment, information access control in computers and networks, secure messaging, trusted software development). Our best systems today are achieved by clever designers who use ad-hoc methods. In the absence of good development tools, technologies may be applied haphazardly and/or retrofitted, without yielding balanced protection. This paper will take the audience through an exploration of the elements of information surety, some common misconceptions about information surety today, and the even greater challenges on the horizon. It will end with some suggestions for research areas which will help evolve the discipline of information surety.

More Details

A laboratory evaluation of color video monitors

Terry, Preston L.

Sandia National Laboratories has considerable experience with monochrome video monitors used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than to identify intruders. There is a growing interest in the identification function of security video systems for both access control and insider protection. Because color video technology is rapidly changing and because color information is useful for identification purposes, Sandia National Laboratories established a program to evaluate the newest relevant color video equipment. This report documents the evaluation of an integral component, color monitors. It briefly discusses a critical parameter, dynamic range, details test procedures, and evaluates the results.

More Details

Sample Vial Secure Container

Baumann, M.J.

International Atomic Energy Agency (IAEA) inspectors must maintain continuity of knowledge on all safeguard samples and, in particular, on those samples drawn from plutonium product and spent fuel input tanks at a nuclear reprocessing plant`s blister sampling station. Integrity of safeguard samples must be guaranteed from the sampling point to the moment of sample analysis at an accepted local laboratory or at the IAEA`s Safeguards Analytical Laboratory (SAL) in Seibersdorf, Austria. The safeguard samples are drawn at a blister sampling station with inspector participation and then transferred via a pneumatic post system to the facility`s analytical laboratory. Transfer of the sample by the pneumatic post system, arrival of the sample in the operator`s analytical laboratory, and storage of the sample awaiting analysis are very time consuming activities for an inspector, particularly if continuous human surveillance is required for all these activities. These activities could be observed by ordinary surveillance methods, such as a video monitoring system, but this would be cumbersome and time consuming for both the inspector and the operator. This paper describes a secure container designed to assure sample vial integrity from the point the sample is drawn to treatment of the sample at a facility`s analytical laboratory.

More Details

Silicon MCM substrates for integration of III-V photonic devices and CMOS IC`s

Seigal, P.

The progress made in advanced packaging development at Sandia National Laboratories for integration of III-V photonic devices and CMOS IC`s on Silicon MCM substrates for planar aid stacked applications will be reported. Studies to characterize precision alignment techniques using solder attach materials compatible with both silicon IC`s and III-V devices will be discussed. Examples of the use of back-side alignment and IR through-wafer inspection will be shown along with the extra processing steps that are used. Under bump metallurgy considerations are also addressed.

More Details

A simple description of flow instability with application to a packed bed

Dobranich, Dean D.

A simplified explanation for gas flow instability in parallel heated channels is presented with specific applications to channels containing packed beds of power-producing particles. The explanation captures the basic governing physics of the viscosity-driven instability and hopefully removes some of the misconceptions surrounding this issue. Simple illustrative calculations, steady-state and transient, using the SAFSIM computer program are included in the explanation. The explanation points out that flow instability is common to any and all gas flow systems with parallel heated channels, that the addition of flow resistance to the entrance of a channel mitigates flow instability, and that instabilities do not occur instantaneously.

More Details

Six degree of freedom fine motion positioning stage based on magnetic levitation

Arling, R.W.; Kohler, S.M.

The design of a magnetically suspended six degree of freedom positioning system capable of nanometer positioning is presented. The sample holder is controlled in six degrees of freedom (DOF) over 300 micrometers of travel in X, Y and Z directions. A design and control summary, and test results indicating stability and power dissipation are included in the paper. The system is vacuum compatible, uses commercially available materials, and requires minimal assembly and setup.

More Details

Concepts for operational period panel seal design at the Waste Isolation Pilot Plant

Hansen, Francis D.

Concepts for underground panel or drift seals at the Waste Isolation Pilot Plant are developed to satisfy sealing requirements of the operational period. The concepts are divided into two groups. In the ``NOW`` group, design concepts are considered in which a sleeve structure is installed in the panel access immediately after excavation and before waste is emplaced. In the ``LATER`` group, no special measures are taken during excavation or before waste emplacement; the seal is installed at a later date, perhaps up to 35 years after the drift is excavated. Three concepts are presented in both the NOW and LATER groups. A rigid sleeve, a yielding sleeve, and steel rings with inflatable tubes are proposed as NOW concepts. One steel ring concept and two concrete monoliths are proposed for seals emplaced in older drifts. Advantages and disadvantages are listed for each concept. Based on the available information, it appears most feasible to recommend a LATER concept using a concrete monolith as a preferred seal for the operational period. Each concept includes the potential of remedial grout and/or construction of a chamber that could be used for monitoring leakage from a closed panel during the operational period. Supporting in situ demonstrations of elements of the concepts are recommended.

More Details

Shock compression properties of silicon carbide

Grady, D.E.; Kipp, M.E.

An investigation of the shock compression and release properties of silicon carbide ceramic has been performed. A series of planar impact experiments has been completed in which stationary target discs of ceramic were struck by plates of either similar ceramic or other appropriate material at velocities up to 2.2 km/s with a propellant gun facility. The particle velocity history at the interface between the back of the target ceramic and a lithium-fluoride window material was measured with laser velocity interferometry (VISAR). Impact stresses achieved in these experiments range between about 10 and 50 GPa. Numerical solutions and analytic methods were used to determine the dynamic compression and release stress-strain behavior of the ceramic. Further analysis of the data was performed to determine dynamic strength and compressibility properties of silicon carbide.

More Details

The CAESAR project: Experimental and modeling investigations of methane reforming in a CAtalytically Enhanced Solar Absorption Receiver on a parabolic dish

Muir, J.F.; Hogan Jr., R.E.; Skocypec, R.D.; Buck, R.

A joint US/Federal Republic of Germany (FRG) project has successfully tested a unique solar-driven chemical reactor in the CAtalytically Enhanced Solar Absorption Receiver (CAESAR) experiment. The CAESAR test was a {open_quotes}proof-of-concept{close_quotes} demonstration of carbon-dioxide reforming of methane in a commercial-scale, solar, volumetric receiver/reactor on a parabolic dish concentrator. The CAESAR design; test facility and instrumentation; thermal and chemical tests; and analysis of test results are presented in detail. Numerical models for the absorber and the receiver are developed and predicted performance is compared with test data. Post test analyses to assess the structural condition of the absorber and the effectiveness of the rhodium catalyst are presented. Unresolved technical issues are identified and future development efforts are recommended.

More Details

Hydrous metal oxide catalysts for oxidation of hydrocarbons

Miller, James E.

This report describes work performed at Sandia under a CRADA with Shell Development of Houston, Texas aimed at developing hydrous metal oxide (HMO) catalysts for oxidation of hydrocarbons. Autoxidation as well as selective oxidation of 1-octene was studied in the presence of HMO catalysts based on known oxidation catalysts. The desired reactions were the conversion of olefin to epoxides, alcohols, and ketones, HMOs seem to inhibit autoxidation reactions, perhaps by reacting with peroxides or radicals. Attempts to use HMOs and metal loaded HMOs as epoxidation catalysts were unsuccessful, although their utility for this reaction was not entirely ruled out. Likewise, alcohol formation from olefins in the presence of HMO catalysts was not achieved. However, this work led to the discovery that acidified HMOs can lead to carbocation reactions of hydrocarbons such as cracking. An HMO catalyst containing Rh and Cu that promotes the reaction of {alpha}-olefins with oxygen to form methyl ketones was identified. Although the activity of the catalyst is relatively low and isomerization reactions of the olefin simultaneously occur, results indicate that these problems may be addressed by eliminating mass transfer limitations. Other suggestions for improving the catalyst are also made. 57 refs.

More Details

Mission hazard assessment for STARS Mission 1 (M1) in the Marshall Islands area

Outka, D.E.; Lafarge, R.A.

A mission hazard assessment has been performed for the Strategic Target System Mission 1 (known as STARS M1) for hazards due to potential debris impact in the Marshall Islands area. The work was performed at Sandia National Laboratories as a result of discussion with Kwajalein Missile Range (KMR) safety officers. The STARS M1 rocket will be launched from the Kauai Test Facility (KTF), Hawaii, and deliver two payloads to within the viewing range of sensors located on the Kwajalein Atoll. The purpose of this work has been to estimate upper bounds for expected casualty rates and impact probability or the Marshall Islands areas which adjoin the STARS M1 instantaneous impact point (IIP) trace. This report documents the methodology and results of the analysis.

More Details

Fire hazards analysis for the Center for National Security and Arms Control (CNSAC) Facility

Klamerus, Eric W.

This Fire Hazards Analysis is sponsored by Plant Engineering and is prepared to support the Safety Assessment for the CNSAC Facility. This is a preliminary fire hazards analysis of a yet to be constructed facility and is based upon the current building design and the current understanding of the potential occupancy hazards. The governing occupancy for this building is personnel offices. The CNSAC facility will be dedicated primarily to two activities: (1) arms control and verification technology and (2) intelligence. This report supplements the Safety Assessment for the CNSAC facility and follows the guidance of DOE Memorandum EH-31.3 and meets the objectives of paragraph 4 of DOE Order 5480.7A, ``Fire Protection.`` This analysis demonstrates that under ``worst case`` assumptions a fire in the CNSAC facility will result in consequences which are below DOE offsite guidelines for accident conditions. This report is based upon preliminary design information and any major changes to the building design may require additional analyses.

More Details

Conceptual plan: Two-Phase Flow Laboratory Program for the Waste Isolation Pilot Plant

Kelly, Susan

The Salado Two-Phase Flow Laboratory Program was established to address concerns regarding two-phase flow properties and to provide WIPP-specific, geologically consistent experimental data to develop more appropriate correlations for Salado rock to replace those currently used in Performance Assessment models. Researchers in Sandia`s Fluid Flow and Transport Department originally identified and emphasized the need for laboratory measurements of Salado threshold pressure and relative permeability. The program expanded to include the measurement of capillary pressure, rock compressibility, porosity, and intrinsic permeability and the assessment of core damage. Sensitivity analyses identified the anhydrite interbed layers as the most likely path for the dissipation of waste-generated gas from waste-storage rooms because of their relatively high permeability. Due to this the program will initially focus on the anhydrite interbed material. The program may expand to include similar rock and flow measurements on other WIPP materials including impure halite, pure halite, and backfill and seal materials. This conceptual plan presents the scope, objectives, and historical documentation of the development of the Salado Two-Phase Flow Program through January 1993. Potential laboratory techniques for assessing core damage and measuring porosity, rock compressibility, capillary and threshold pressure, permeability as a function of stress, and relative permeability are discussed. Details of actual test designs, test procedures, and data analysis are not included in this report, but will be included in the Salado Two-Phase Flow Laboratory Program Test Plan pending the results of experimental and other scoping activities in FY93.

More Details

Sandia equation of state data base: seslan File

Kerley, G.I.; Christian-Frear, T.L.

Sandia National Laboratories maintains several libraries of equation of state tables, in a modified Sesame format, for use in hydrocode calculations and other applications. This report discusses one of those libraries, the seslan file, which contains 78 tables from the Los Alamos equation of state library. Minor changes have been made to these tables, making them more convenient for code users and reducing numerical difficulties that occasionally arise in hydrocode calculations.

More Details

Burnup Credit Validation of SCALE-4 Using Light-Water-Reactor Criticals

Bowman, S.M.; Hermann, O.W.; Brady, M.C.

The ANSI/ANS 8.1 criticality safety standard recommends validation and benchmarking of the calculational methods used in evaluating criticality safety limits for away-from-reactor applications. The lack of critical experiments with burned light-water reactor (LWR) fuel in racks or in casks necessitates the validation of burnup credit methods by comparison with LWR core criticals. These benchmarks are relevant because they test a methodology`s ability to predict spent fuel isotopic and to evaluate the reactivity effects of heterogeneities and strong absorbers. Data are available to perform analyses at precise state points. As part of the Burnup Credit Analysis Verification (BCAV) Task, the U.S. Department of Energy has sponsored analysis of selected reactor core critical configurations from commercial pressurized-water-reactors (PWRs). The initial analysis methodology used the SCALE-4 code system to analyze a set of reactor critical configurations from Virginia Power`s Slurry and North Anna reactors. However, the analysis procedure was complex and included the calculation of lumped fission products. The methodology has since been revised to simplify both the data requirements and the calculational procedure for the criticality analyst. This revised methodology is validated here by a comparison with three reactor critical configurations from Tennessee Valley Authority`s Sequoyah Unit 2 Cycle 3 and two from Virginia Power`s Slurry Unit 1 Cycle 2.

More Details

The Mobil Integrated C{sup 3} (command control and communications) and Security System

Eras, A.; Brown, R.D.

The current political and economic situations suggest that significant reductions of nuclear forces outside the US will continue. This implies that in times of crisis the rapid deployment of nuclear weapons into a theater may be required. This paper describes a proposed Mobile Integrated C{sup 3} and Security System (MICSS). The MICSS, together with associated personnel, could satisfy the command and control and security requirements of a deployed nuclear operation. Rapid deployment poses unique nuclear weapon surety difficulties that must be overcome for the operation to be effective and survivable. The MICSS must be portable, reliable, limited in size, and easily emplaced to facilitate movement, reduce the possibility of detection, and minimize manpower requirements. The MICSS will be based on existing technology. Sandia has designed prototype mobile command centers for the military. These command centers are based on an approach that stresses modularity, standards, and the use of an open architecture. Radio, telephone, satellite communications, communication security, and global positioning system equipment has been successfully integrated into the command centers. Sandia is also supporting the development of portable security systems for the military. These systems are rapidly deployable and mission flexible and are capable of intrusion detection, area and alarm display, night assessment, and wireless sensor communications. This paper is organized as follows: Background information about the prototype mobile command centers will be presented first. Background information about portable security systems concepts will then be given. Next, an integrated communications and security system will be presented, and finally, the design and status of a prototype MICSS will be described.

More Details

Micro-radiosurgery: a new concept for radiotherapy based upon low energy, ion-induced nuclear reactions

Nuclear Inst. and Methods in Physics Research, B

Horn, Kevin M.

Traditionally, proton radiotherapy has required the use of high energy proton beams (50-200 MeV) which can penetrate into a patient's body to the site of a tumor that is to be destroyed through irradiation. However, substantial damage is still done to healthy tissue along the path of the incident proton beam, as much as 30% of that done at the tumor site. We propose a new concept for the production and delivery of energetic protons for use in medical radiotherapy, based upon the fact that low energy, ion-induced nuclear reactions can produce radiation products suitable for use in radiotherapy applications. By employing specially fabricated "conduit needles" to deliver beams of energetic ions to selected target materials plugging the end of the needle, ion beam-induced nuclear reactions can be generated at the needle tip, emitting reaction-specific radiation products directly at the tumor site. In this paper, we show that the 13.6 MeV protons produced by the d(3He, p)4He nuclear reaction can deliver a lethal dose (7 krad) of radiation to a 4.4 mm diameter sphere of tissue in only 30 s using a 1 μA, 800 keV 3He ion beam. If also proven clinically feasible, the use of low energy, ion-induced nuclear reactions would allow the utilization of relatively inexpensive, compact, low energy ion accelerators for proton radiotherapy and minimize unintended radiation damage to healthy tissue by providing much greater precision in controlling the irradiated volume. © 1993.

More Details

Propagation of transient signals from a spherical source in a half-space with surface layers

Norwood, F.R.

The title problem is of particular interest for the analysis of seismic signals arising from underground nuclear explosions. Previous attempts at the solution have indicated that, although cylindrical symmetry exists, conventional methods cannot be applied because of the existence of plane and spherical boundaries. The present paper develops a ray-grouping technique for finding the solution to the title problem. This technique allows the separation of the problem into a series of canonical problems. Each such problem deals with a given boundary condition (e.g., continuity conditions at a material interface). Using this technique, one may follow waves along ray paths. It is easy to identify, after n reflections, (a) rays which arrive simultaneously at a given point and (b) the terms in the solution which need to be included at a given time. It is important to note that a cylindrical coordinate system is not employed, even though the problem is axially symmetric. Instead, the equations are carefully transformed making it possible to use a Cartesian coordinate system. This results in a spectral representation of the solution in terms of algebraic expressions in lieu of Bessel functions.

More Details

Thermal coating development for impulse drying

Journal of Thermal Spray Technology

Smith, Mark F.

A plasma-sprayed coating has been developed for the heated surface of rolls used in a new energy-efficient paper drying process, known as"Impulse Drying," which could save the US paper industry an estimated $800 million annually in reduced energy costs. Because impulse drying rolls operate at substantially higher surface temperatures than conventional drying rolls, the thermal properties of the roll surface must be carefully tailored to control energy transfer to the paper and thus prevent sheet delamination or other undesirable effects. To meet this requirement, a plasma-sprayed thermal barrier coating has been developed to control thermal mass, heat transfer, and steam infiltration. A coated test platen significantly outperformed a comparable uncoated steel platen in preliminary experiments with a heavyweight grade of paper on a laboratory-scale impulse drying simulator. Based on these results, the coating was then tested on the roll of a pilot-scale impulse dryer. Compared to conventional wet pressing, linerboard that was impulse dried with the coated test roll showed marked improvements in water removal as well as improved physical properties, such as density and specific elastic modulus. The successful prototype coating design has three plasma-sprayed layers that are deposited sequentially: a nickel alloy bond coat, a thick, 17% porous zirconia thermal barrier, and a thin, 5 to 7% porous zirconia top coat. © 1993 ASM International.

More Details

Some parametric flow analyses of a particle bed fuel element

Dobranich, Dean D.

Parametric calculations are performed, using the SAFSIM computer program, to investigate the fluid mechanics and heat transfer performance of a particle bed fuel element. Both steady-state and transient calculations are included, addressing such issues as flow stability, reduced thrust operation, transpiration drag, coolant conductivity enhancement, flow maldistributions, decay heat removal, flow perturbations, and pulse cooling. The calculations demonstrate the dependence of the predicted results on the modeling assumptions and thus provide guidance as to where further experimental and computational investigations are needed. The calculations also demonstrate that both flow instability and flow maldistribution in the fuel element are important phenomena. Furthermore, results are encouraging that geometric design changes to the element can significantly reduce problems related to these phenomena, allowing improved performance over a wide range of element power densities and flow rates. Such design changes will help to maximize the operational efficiency of space propulsion reactors employing particle bed fuel element technology. Finally, the results demonstrate that SAFSIM is a valuable engineering tool for performing quick and inexpensive parametric simulations addressing complex flow problems.

More Details

Metallurgical evaluation of SRAM II/SRAM A programmer base plates

Damkroger, Brian K.

Ten MC4073/4369 programmer base plates were analyzed. This component, a programmer base plate for the SRAM II (and later the SRAM A), is specified as a Grade C quality casting made of aluminum Alloy A356, heat treated to the T6 condition. A concern was expressed regarding the choice of an A356 casting for this application, given the complexity and severity of the loading environment. Preliminary tests and analyses suggested that the design was adequate, but noted the uncertainty involved in a number of their underlying assumptions. The uncertainty was compounded by the discovery that the casting used in the original series of mechanical tests failed. In this investigation, several production castings were examined and found to be of a quality superior to that required under current specifications. Their defect content and microstructure were studied and compared with published data to establish a mechanical property data base. The data base was supplemented with a series of X-direction static tests, which characterized the loading environment and measured the overall casting performance. It was found that the mechanical properties of the supplied castings were adequate for the anticipated X-direction loading environment, but the component is not over-designed. The established data base further indicates that a reduction in casting quality to the allowable level could result in failure of the component. Recommendations were made including (1) change the component specification to require higher casting quality in highly stressed areas, (2) supplement the inspection procedures to ensure adequate quality in critical regions, (3) alter the component design to reduce the stress levels in the mounting feet, (4) substitute a modified A356 alloy to improve the mechanical properties and their consistency, and (5) more thoroughly establish a data base for the mechanical property consequences of levels and configurations of casting defects.

More Details

Maintenance manual for the Beneficial Uses Shipping System cask. Revision 1

Bronowski, D.R.; Yoshimura, H.R.

This document is the Maintenance Manual for the Beneficial Uses Shipping System (BUSS) cask. These instructions address requirements for maintenance, inspection, testing, and repair, supplementing general information found in the BUSS Safety Analysis Report for Packaging (SARP), SAND 83-0698. Use of the BUSS cask is authorized by the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC) for the shipment of special form cesium chloride or strontium flouride capsules.

More Details

Programmer`s manual for CAMCON: Compliance Assessment Methodology CONtroller

Rechard, Robert P.

CAMCON, the Compliance Assessment Methodology CONtroller, is an analysis system that assists in assessing the compliance of the Waste Isolation Pilot Plant (WIPP) with applicable long-term regulations of the US Environmental Protection Agency, including Subpart B of the Environmental Standards for the Management and Disposal of spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191 and 40CFR268.6, which is the portion of the Land Disposal Restrictions implementing the Resource, Conservative, and Recovery Act of 1976, as amended that states the conditions for disposal of hazardous chemical wastes. This manual provides an architectural overview of the CAMCON system. Furthermore this manual presents guidelines and presents suggestions for programmers developing the many different types of software necessary to investigate various events and physical processes of the WIPP. These guidelines include user interface requirements, minimum quality assurance requirements, coding style suggestions, and the use of numerous software libraries developed specifically for or adapted for the CAMCON system.

More Details

Initial field testing definition of subsurface sealing and backfilling tests in unsaturated tuff; Yucca Mountain Site Characterization Project

Fernandez, J.A.; Case, J.B.; Tyburski, J.R.

This report contains an initial definition of the field tests proposed for the Yucca Mountain Project repository sealing program. The tests are intended to resolve various performance and emplacement concerns. Examples of concerns to be addressed include achieving selected hydrologic and structural requirements for seals, removing portions of the shaft liner, excavating keyways, emplacing cementitious and earthen seals, reducing the impact of fines on the hydraulic conductivity of fractures, efficient grouting of fracture zones, sealing of exploratory boreholes, and controlling the flow of water by using engineered designs. Ten discrete tests are proposed to address these and other concerns. These tests are divided into two groups: Seal component tests and performance confirmation tests. The seal component tests are thorough small-scale in situ tests, the intermediate-scale borehole seal tests, the fracture grouting tests, the surface backfill tests, and the grouted rock mass tests. The seal system tests are the seepage control tests, the backfill tests, the bulkhead test in the Calico Hills unit, the large-scale shaft seal and shaft fill tests, and the remote borehole sealing tests. The tests are proposed to be performed in six discrete areas, including welded and non-welded environments, primarily located outside the potential repository area. The final selection of sealing tests will depend on the nature of the geologic and hydrologic conditions encountered during the development of the Exploratory Studies Facility and detailed numerical analyses. Tests are likely to be performed both before and after License Application.

More Details

Waste component recycle, treatment, and disposal integrated demonstration (WeDID) nuclear weapon dismantlement activities

Wheelis, W.T.

One of the drivers in the dismantlement and disposal of nuclear weapon components is Envirorunental Protection Agency (EPA) guidelines. The primary regulatory driver for these components is the Resource Conservation Recovery Act (RCRA). Nuclear weapon components are heterogeneous and contain a number of hazardous materials including heavy metals, PCB`S, selfcontained explosives, radioactive materials, gas-filled tubes, etc. The Waste Component Recycle, Treatment, Disposal and Integrated Demonstration (WeDID) is a Department of Energy (DOE) Environmental Restoration and Waste Management (ERWM) sponsored program. It also supports DOE Defense Program (DP) dismantlement activities. The goal of WeDID is to demonstrate the end-to-end disposal process for Sandia National Laboratories designed nuclear weapon components. One of the primary objectives of WeDID is to develop and demonstrate advanced system treatment technologies that will allow DOE to continue dismantlement and disposal unhindered even as environmental regulations become more stringent. WeDID is also demonstrating waste minimization techniques by recycling a significant weight percentage of the bulk/precious metals found in weapon components and by destroying the organic materials typically found in these components. WeDID is concentrating on demonstrating technologies that are regulatory compliant, are cost effective, technologically robust, and are near-term to ensure the support of DOE dismantlement time lines. The waste minimization technologies being demonstrated by WeDID are cross cutting and should be able to support a number of ERWM programs.

More Details

Interactive Collaborative Environments (ICE) in the design to manufacturing process

Ashby, Rodema

Interactive Collaborative Environments (ICE) technologies allow teames at separate locations to work concurrently on joint problem solving. Examples of ICE use include engineers simultaneously viewing and manipulating the same CAD application to discuss design/production changes and trade-offs. This concept was demonstrated in March of 1992 between AT&T, Shreveport Works and Holmdel. In May 1992, Sandia National Laboratories demonstrated a platform independent version of application sharing code using the workstations and application software available at AT&T, Shreveport Works. AT&T and Sandia are currently negotiating future work agreements. In addition, Sandia has provided demonstrations and created pilot project links for internal Sandia use, and for communication with other facilities, e.g. Los Alamos National Laboratories and Sandia, California location. ICE can also be used to link up suppliers and customers, even in different companies. Anywhere team members are separated geographically, or even between building and facilities at a particular site, ICE can improve remote problem solving, cutting down on delays and miscommunication flascoes.

More Details

The detection of organosphosphonates by polymer films on a surface acoustic wave device and a micromirror fiberoptic sensor

Applied Biochemistry and Biotechnology

Hughes, R.C.

There is a need for sensitive detection of organophosphonates by inexpensive, portable instruments. Two kinds of chemical sensors, based on surface acoustic wave (SAW) devices and fiberoptic micromirrors, show promise for such sensing systems. Chemically sensitive coatings are required for detection, and data for thin films of the polymer polysiloxane are reported for both kinds of physical transducers. Both kinds of sensors are shown to be capable of detecting concentrations of diisopropylmethylphosphonate (DIMP) down to 1 ppm. © 1993 Humana Press Inc.

More Details

Energy dispersive x-ray spectrometers in ultrahigh vacuum environments

Michael, Joseph R.

The combination of an energy dispersive x-ray spectrometer (EDS) with the ultrahigh vacuum environment of many modern electron microscopes requires the spectrometer designer to take extra precautions and presents the microscopist with the additional option of utilizing windowless spectrometers for light element detection while not worrying about contamination of the detector. UHV is generally defined as a pressure of better than 10{sup {minus}7} Pa and is necessary to prevent specimen modification by the components of the vacuum. UHV may also be defined as an environment in which the time to form a monolayer on the specimen is equal to or longer than the usual time for a laboratory measurement. This report examines performance of energy dispersion x-ray spectrometers in UHV.

More Details
Results 94551–94600 of 96,771
Results 94551–94600 of 96,771