Publications

A new technique, called tethered rocket, has been developed for testing in the penetration and/or impact modes. The technique involves tethering a rocket-motor assembly to an earth-fixed pivot so that the resulting semicircular arc delivers a payload to a precise impact point. Discussions are presented which describe the analytical and experimental activities of the tethered rocket technique. A series of analytical models has been integral to the success of the tethered rocket development. The analytic results were verified by testing. The tests demonstrated the viability of the technique for penetration and/or impact testing. Also included is a discussion of potential applications of the method. 18 refs., 53 figs., 17 tabs.

Cracking, craters, spotty damage (discoloration), and missing chunks of material have been observed on limiters and along the midplane of tokamak inner walls. This damage is assumed to be due to runaway electron discharges. These runaway electrons have been predicted to range in energy from a few MeV to several hundred MeV. The energy density from the runaway electron discharges ranges from 10 to 500 MJ/m{sup 2} over pulse lengths of 5 to 50 msec. The PTA code package is a unique application of PATRAN, the Integrated TIGER Series, and ABAQUS for modeling high energy electron impact on tokamak first wall and limiter materials. The PTA code package provides a three-dimensional, time dependent, computational code package which predicts energy deposition, temperature rise, and damage on relevant fusion materials from runaway electrons. In this benchmark study, three experiments were modeled to validate the PTA code package. The first and third experiment simulated runaway electrons scattering through a plasma facing surface (graphite) into an internal structure (copper), and the second experiment tested the thermal and structural response from high energy electron impact on different fusion relevant materials. The PTA calculations compared favorably with the experimental results. In particular, the PTA models identified gap conductance, thermal contact, x-ray generation in materials, and the placement of high stopping power materials as key factors in the design of plasma facing components that are resistant to runaway electron damage. 13 refs., 40 figs., 3 tabs.

We have determined experimentally the Shielding Effectiveness (SE) at microwave frequencies of various types of single- and double-braided cables and connectors typical of systems that have been hardened to electromagnetic fields. This report describes a laboratory-sized reverberation chamber and the techniques used to measure the SE of several interconnecting components. Graphical results are presented in the report, along with smoothed overlay plots for each category of measurements. The overlay plots indicate the general trends in the raw data and highlight the differences between tested components. 7 refs., 22 figs.

This report describes a statistical model for field amplitudes within a mode-stirred chamber. The parameters of the probability density function for field amplitudes are estimated by means of maximum likelihood. The accuracy of these parameters is specified as a function of the amount of data used. An experimental investigation of the possibility of using an existing electromagnetic shield room as a mode-stirred chamber is described. The physical alterations of the chamber and the instrumentation are summarized. Descriptions of the tests results are reported. The tests were conducted to determine: the unloaded and loaded Q of the chamber, descriptive statistics of the electromagnetic fields, correlation distances of the fields in frequency, tuner angle, and spatial position, and the possibility of using frequency stirring as an alternative to mechanical stirring. 10 refs., 20 figs., 10 tabs.

High-quality recording of an oscilloscope waveform is usually made on photographic film. Achieving high quality, especially in a possible radiation environment and with fast sweep speeds, requires a thorough understanding of all aspects of the imaging and recording processes. This paper represents a compilation of techniques and procedures to achieve optimum oscilloscope imagery under adverse conditions and in an environment where unwanted radiation is a possibility. 10 figs., 1 tab.

Structural system identification methods are analytical techniques for reconciling test data with analytical models. However, for system identification to become a practical tool for engineering analysis, the estimation techniques/codes must communicate with finite element software packages without intensive analyst intervention and supervision. This paper presents a technique used to integrate commercial software packages for finite element modeling (MSC/NASTRAN), mathematical programming techniques (ADS), and linear system analysis (PRO-MATLAB). The parameter estimation techniques and the software for controlling the overall system were programmed in PRO-MATLAB. Two examples of application of this software using measured data are presented. The examples consist of a truss structure in which the model form is well defined, and an electronics package whose model form is ill-defined since it is difficult to model with finite elements. A comparison of the resulting updated models with the experimental data showed significant improvement. 22 refs.

A Level II/III probabilistic risk assessment (PRA) has been performed for N Reactor, a Department of Energy (DOE) production reactor located on the Hanford reservation in Washington. The accident progression analysis documented in this report determines how core damage accidents identified in the Level I PRA progress from fuel damage to confinement response and potential releases the environment. The objectives of the study are to generate accident progression data for the Level II/III PRA source term model and to identify changes that could improve plant response under accident conditions. The scope of the analysis is comprehensive, excluding only sabotage and operator errors of commission. State-of-the-art methodology is employed based largely on the methods developed by Sandia for the US Nuclear Regulatory Commission in support of the NUREG-1150 study. The accident progression model allows complex interactions and dependencies between systems to be explicitly considered. Latin Hypecube sampling was used to assess the phenomenological and systemic uncertainties associated with the primary and confinement system responses to the core damage accident. The results of the analysis show that the N Reactor confinement concept provides significant radiological protection for most of the accident progression pathways studied.

This report documents the development and testing of the SA3263 high voltage rectifier diode manufactured by Microsemi. 15 refs., 4 tabs.

A new gridless electrostatic field solver which utilities Fourier decomposition in the azimuthal coordinate has been developed and tested. The scaling with the number of simulation particles is N log N. This algorithm has been implemented in the BUCKSHOT code, which originally used a direct summation algorithm with N{sup 2} scaling. The Fourier decomposition in the new algorithm is done about the center of mass of each species, thus nonlinear ion hose physics is included in the m = O mode. Higher order modes describe non-axisymmetric profile changes. The breakeven point between the new solver and the direct summation algorithm is about N = 64 particles per species when up to m = 2 Fourier modes are kept. For a typical ion hose simulation with 256 particles per species the new solver is faster by a factor of about 2.7. 8 refs., 11 figs.

In order to generate a lithium vapor on the anode surface within PBFA II, an electrically insulating, lithium-coated substrate is required. One approach for providing this lithium source is the ceramic-option anode. This anode consists of two halves, equatorially split, each containing an insulating ceramic insert onto which a lithium-bearing film is sputtered. A lithium vapor is generated by ohmically pulse heating this film to 1500 K. The half-anode structure required to produce this vapor consists of a ceramic insulator, steel housing, and disk conductors. This report describes the design and fabrication of these separate components and the procedures required to join them to form the half-anode assembly. In addition, appendices are included which contain detailed drawings and specifications for these operations. 5 refs., 10 figs.

This report describes standard design criteria for and intrabuilding and interbuilding telecommunications wiring system to provide voice and open data services to facilities at Sandia National Laboratories, Albuquerque.

The US Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) must comply with EPA regulation 40 CFR Part 191, Subpart B, which sets environmental standards for radioactive waste disposal. The regulation, Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (hereafter referred to as the Standard), was vacated in 1987 by a Federal Court of Appeals and is underground revision. By agreement with the Sate of New Mexico, the WIPP project is evaluating compliance with the Standard as promulgated, in 1985 until a new regulation is available. This report summarizes the early-1990 status of Sandia National Laboratories' (SNL) understanding of the Project's ability to achieve compliance. The report reviews the qualitative and quantitative requirements for compliance, and identifies unknowns complicating performance assessment. It discusses in relatively nontechnical terms the approaches to resolving those unknowns, and concludes that SNL has reasonable confidence that compliance is achievable with the Standard as first promulgated. 46 refs., 7 figs.

This report provides system designers with basic human factors information and guidelines to help in the selection of manual data input devices. The selection of such devices is important with respect to the environment in which the device with be used, speed of data entry required, error potential, and the user friendliness of the candidate devices. The report reviews several of the most commonly used data input devices and provides a description of each, experimental evaluations, and observations and recommendations based on review of the data. In addition, the appendix presents an input device matrix that gives general guidance concerning input devices and the physical and mission environment in which they might be used. Additional assistance should be requested from Sandia National Laboratories (SNL) Human Factors Personnel. 23 refs., 13 figs.

As a crosslinking polymer cures, dramatic changes in molecular architecture occur. These structural changes in turn affect the viscoelastic behavior of the material. At a critical extent of reaction (the gel point), the polymer undergoes a transition from a viscous liquid to an elastic solid. We have monitored the evolution of structure and viscoelasticity in the most common epoxy encapsulant used at Sandia, diethanolamine-cured Epon 828. The structure evolves according to percolation theory, and the viscoelasticity evolves according to our dynamic scaling theory for branched polymers. 9 refs., 12 figs.

Calculations are performed to predict the distribution of the (5p){sup 5}(5d)--(5p){sup 5}(6p)emission cross section in Xe in a strong magnetic field. For isotopes with no nuclear magnetic moment, the question is the calculation of Lande g factors. This is done with wavefunctions obtained by diagonalizing the electrostatic interaction in jj coupling, leading to reasonable accurate Lande g factors. For levels described by quantum numbers J and M, the Zeeman interaction is always diagonal in M, and with a 6 kG magnetic field the Zeeman interaction is effectively diagonal in J (the non-diagonal matrix elements are negligible), so the resulting cross section calculations are simple. For the isotopes with non-zero magnetic moments, one must determine the dipole and quadrupole hyperfine splitting coefficients. To do this and to improve the overall fit of the calculated and measured energy levels, it was necessary to include configuration interaction between terms of the (5p){sup 5}(5d) and (5p){sup 5}(6s) configurations. Comparisons are made between these calculated hyperfine parameters and experiment. Hyperfine splittings are tabulated as are the cross sections and energy shifts due to hyperfine interaction in each transition. When hyperfine interaction is included and levels are characterized by the quantum numbers F and M{sub F}, the Zeeman interaction is diagonal in M{sub F} but different F. All these effects were included in the calculations leading to a particularly rich spectrum for Xe(131) with I = 3/2. For example, the (5p){sup 5}(5d){sub J} = 4{minus}(5p){sup 5}(6p){sub J} = 3 transition is split into approximately 336 components. 21 refs., 3 figs., 12 tabs.

This annual report summarizes progress which has been made in Fiscal Year 1989 on this program of geotechnology for tight gas reservoirs. Most of the studies are an outgrowth of the results and experience from the Multiwell Experiment -- an unprecedented investigation of western gas reservoirs typical of the Mesaverde Formation. Results are presented in the following study areas: (1) tectonism, subsidence and fracturing of these reservoirs, (2) mechanism for the formation of regional fractures in flat-lying basins, (3) the case against natural hydraulic fracturing, (4) characterization and implications of dickite-mineralized fractures, (5) significance of coring-induced fractures, (6) determination of an effective stress law for permeability in tight sandstones, and (7) stress azimuths for two well sites in the Piceance Basin. In addition, technology transfer aspects and impact of the Multiwell Experiment are summarized. 27 refs., 28 figs., 1 tab.

This study was performed under FUTURE LOOK, a joint Defense Nuclear Agency/Department of Energy (DNA/DOE) sponsored study. The intent of FUTURE LOOK is to identify and develop means of providing requisite security and survivability to the Non-Strategic Nuclear Forces (NSNF) in the Twenty-First Century. Our current thinking about the future world in Europe is summarized. In this report we develop four scenarios/stockpile cases to cover the spectrum of potential happenings in Europe; we also develop general security and survivability implications and recommendations for each case. The four cases are: (1) a substantially reduced (factor of 2--10) European stockpile; (2) a near-zero stockpile, with no Army weapons remaining in Europe; (3) current stockpile in Europe remains; and (4) current stockpile numbers remain, but aggressive modernization is allowed. We plan to use the information in this report to assist in developing detailed security and survivability options as part of our follow-on to FUTURE LOOK studies. 8 refs., 6 tabs.

The purpose of this computer program is to serve as a tool in the daily operation of the R D storage function. This menu-driven, interactive program was written in DBase III+ for use on an IBM PC-XT computer to efficiently store items in a minimum space, inventory, locate, report, withdraw and record the activities in a history file. A drive path is utilized in numbering each storage location to minimize the distance and time required to store and retrieve an item. An empty-space listing is available for a limited inventory.

The United States Department of energy, after considering a number of alternative disposal methods for radioactive wastes in the United States, Proposed that these wastes should be disposed of in deep geologic repositories. This alternative is currently being developed at the Waste Isolation Pilot Plant (WIPP), for transuranic waste, and investigated at Yucca Mountain, for spent power-reactor fuel and vitrified high-level waste, the latter resulting principally from defense activities. In addition, a research program on subseabed disposal was active from 1973 until 1987 but is currently suspended. The two deep-geologic disposal projects are discussed in detail and the subseabed-disposal research project is briefly summarized. 28 refs., 39 figs., 4 tabs.

Thermal and mechanical models for intact and jointed rock mass behavior are being developed, verified, and validated at Sandia National Laboratories for the Yucca Mountain Project. Benchmarking is an essential part of this effort and is the primary tool for verifying engineering software used to solve thermomechanical problems. This report presents the results of the second phase of the first thermomechanical benchmark exercise. In the first phase of this exercise, three finite element codes for nonlinear heat conduction and one coupled thermoelastic boundary element code (HEFF) were used to solve the thermal portion of the benchmark problem. The boundary element code HEFF was used in this exercise because it calculates a solution to the coupled thermal/elastic problem using an approximate analytical method and, thus, provides a means of comparing the finite element solutions with a solution obtained by an independent method. The results from the thermal analysis were then used as input to the second phase of the analysis, which consisted of solving the structural portion of the benchmark problem using a linear elastic rock mass model. Five different structural codes, JAC, SPECTROM-31, VISCOT, and HEFF, were used by the participants in this portion of the study. The problem solved by each code was a two-dimensional idealization of a series of drifts with the approximate dimensions of the proposed design for vertical emplacement of nuclear waste at Yucca Mountain. 6 refs., 74 figs., 4 tabs.

This report documents the development and testing of the SA3262, a high voltage rectifier diode, manufactured by Microsemi. 13 figs., 4 tabs.

Dual focus laser velocimetry (L2F), photographic techniques, and pressure measurements were used to investigate particle and flame characteristics of a high velocity oxygen/fuel (HVOF) flame spray gun known as CDS''. Velocities of alumina, tungsten carbide, and Triballoy particles within the HVOF effluent stream have been measured using L2F techniques. Photographs of the exiting gases were used to determine the local Mach numbers within the gas stream. Measurements of Mach angles in the photographs were used to determine the actual gas velocity in the free jet of the device. Pressure measurements were made on the HVOF device which enabled calculations of the gas content, R, and the specific heat ratio, {kappa}. These calculations combined with estimates of gas temperature are used to calculate gas velocities at Mach 1 (nozzle exit). The HVOF device was used to produce dense WC/12 wt. % Co and Triballoy T-400 coatings. For the two gas flow conditions examined, higher hardness values and densities were observed for coatings deposited at the higher gas flow rates.

This report documents the characterization and development of the 381558 (2N6193JTXV), a medium power PNP silicon transistor designed for switching and wide band amplifier applications. The 2N6193JTXV is manufactured by Motorola. 50 figs., 6 tabs.

This report documents the characterization and development of the 381568 (2N5339JTXV), a medium power NPN silicon transistor designed for switching and wide band amplifier applications. The 2N5339JTXV is manufactured by Motorola. 50 figs., 6 tabs.

This report describes the major hardware and software components of the HERMES III Control and Monitor System at the Simulation Technology Laboratory (STL) at Sandia National Laboratories. The HERMES III Control and Monitor System is a computer controlled system that controls and monitors the charging, arming, and firing of the HERMES III accelerator. This documentation is intended to be a general introduction to the system for engineers and technicians involved in the maintenance and modification of the system. It may also be useful to persons interested in designing and constructing a similar control system. This report collects many of the documents produced throughout the project and directs the reader toward other documents written for this project.