Publications

Sandia National Laboratories, Albuquerque, manages the Utility Battery Exploratory Technology Development Program, which is sponsored by the US Department of Energy`s Office of Energy Management. In this capacity, Sandia is responsible for the engineering analyses and development of rechargeable batteries for utility-energy-storage applications. This report details the technical achievements realized during fiscal year 1991. Sodium/Sulfur, Zinc/Bromine, Nickel/Hydrogen, Aluminium/Air and Lead/Acid batteries are evaluated.

This report presents the results of single-well hydraulic tests performed in seven wells in the vicinity of the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico in 1988 and 1989. The tests discussed in this report were performed in four of the five members of the Rustler Formation. The tests include: a slug-withdrawal test of the unnamed lower member of the Rustler ate well H-16; slug-withdrawal and slug-injection tests of the Culebra Dolomite Member at well AEC-7; slug-injection tests of the Culebra at well D-268; a pumping test of the Culebra at well H-18; pulse-injection, slug-injection, and slug-withdrawal tests of Magenta Dolomite Member at well H-2b1; pulse-withdrawal, slug-withdrawal, and slug-injection tests of the Magenta at well H-3b1; and pulse-withdrawal and slug-withdrawal tests of the Forty-niner Member at well H-3d. The tests were intended to provide data on the transmissivities of the Rustler members for use in regional-scale modeling of groundwater flow through the Rustler.

The ES&H Training Catalog is a tool to assist managers in determining which training courses they require their employees to complete. The narrative description under ``Who Shall Attend`` describes the characteristics of the employees and contractors under the direction of Sandia who are required by law, regulation, DOE Order, or SNL Directive to complete the training in order to be in compliance. The narrative is ``Who Should Attend`` describes the individuals for which the course is `highly recommended,`` although they are not mandated to attend.

SANET is a computer program intended for use in constructing, evaluating, and printing event trees for safety and reliability studies. SANET allows the user to graphically construct event trees, assign probabilities to the branches on the tree and include a variety of labels. Fast, publication quality printed output can be obtained. SANET requires an IBM compatible PC with a 80286, 80386 or 80486 processor, VGA graphics, a mouse and an HP Laserjet printer.

The technological innovation process comprises a range of stages, steps, and activities extending fro generation of new ideas through successful practical application of those ideas. This process constitutes the larger context within which technology transfer programs must necessarily operate if the goal is to transform new knowledge and technology into products which are competitive in the emerging global marketplace. A basic grasp of the principles and issues involved in the total innovation process is essential for developing and improving programs, prioritizing activities, and making strategic and operational decisions which will be appropriate and effective. This report attempts to provide a relatively brief overview of the total innovation process and related issues. This focus follows from the intent of the federal technology transfer initiative, which is essentially to facilitate the rapid advance of technological progress and to enhance national economic competitiveness. It is important to recognize that the transfer of technology between organizations or individuals is only one part of the complete process, although possibly a critical part in some situations. From an economic standpoint, technology transfer without resulting successful commercialization is meaningless. This report should be useful primer for people from any sector of the economy, even though it is intended to address the context for the transfer of federal laboratory technology in particular.

Two laboratory tests were designed to study the behavior of SnTe and CsOH in steam at {approximately}1230 K with the reactor materials Inconel 600, 304 stainless steel, silver and nickel, a nonoxidizing constituent of Inconels and steels in reactor accident environments. Thermochemical calculations examined the sensitivity of species in the H-O-Cs-Te-Sn system to temperature, to hydrogen and SnTe concentrations and to total system pressure. Test results indicate that should SnTe be formed from fission product tellurium and the tin in zircaloy cladding, it may not remain stable in steam in the presence of unoxidized (or lightly oxidized) metals. Calculations show a small amount of SnTe, in equilibrium with steam, decomposes to primarily Te and SnO. It is felt that these decomposition producets react with the reactor materials since Sn and Te are seen to be deposited separately and not as SnTe. The deposition velocity for SnO vapor in the system was estimated to be 0.57 m/s. The response of CsOH in the system was similar to behavior observed previously: some cesium combined with silicon found in Inconel and stainless steel oxides. At lower temperatures ({le}940 K) CsOH corroded Inconel, stainless steel and nickel providing enhanced surface area for additional trapping of species. There was no experimental evidence for the formation of cesium telluride; vapor equilibrium calculations did not predict formation either. 33 refs., 29 figs, 7 tabs.

An analytical expression and an integral representation are presented for the contribution, Y{sup (n)} = {Sigma}{sup (n)}{delta}{Omega}{sub n}, of n-event multiple scattering chains to the observed backscattering spectrum in heavy-ion backscattering (HIBS) measurements. The approximations introduced in deriving the results are chosen such that an upper limit is placed on Y{sup (n)} by the expressions. The Rutherford elastic scattering cross section is used to describe individual collisions between incident projectiles and target atoms. Screening of the Rutherford scattering cross section is included in an approximate fashion which maintains the upper limit estimate. Inelastic energy loss between collision events is assumed proportional to the projectile velocity. Specific application of theses expressions is made to HIBS detection of trace amounts of heavy atom impurities on a Si by 200--400 keV C{sup +} beams. The predicted multiple scattering background for this applications is compared with the predicted single scattering signal for 10{sup 10} atoms/cm{sup 2} of Fe, Cu, Zr, Sn, or Au, as surface impurity. The comparison shows that the multiple scattering background poses no barrier to extending the sensitivity of HIBS detection of impurities in this mass range to levels as low as 10{sup 8} atoms/cm{sup 2} for the upper part of the energy range considered. Comparison of calculations with and without screening included show that the screening of the Rutherford cross section by atomic electrons is a significant factor in preventing multiple scattering effects from interfering with HIBS spectrometry at impurity levels in the 10{sup 10} atoms/cm{sup 2} range.

The MELCOR code has been used to simulate the FLECHT SEASET natural circulation experiments done in a scale-model Westinghouse-PWR test facility, with code results compared to experimental data. Sensitivity studies have been done, for both single-phase and two-phase natural circulation conditions, on time step effects and machine dependencies; nodalization studies and studies on several code modelling options were also done. Good agreement is found between prediction and observation for steady-state, single-phase liquid natural circulation. The code could reproduce the major thermal/hydraulic response characteristics in two-phase natural circulation, but only through a number of nonstandard input modelling modifications; MELCOR cannot reproduce the requisite physical phenomena with ``normal`` input models. Because the same response is observed in similar tests at other facilities over a range of scales and is expected to occur in full-scale plants as well, the ability of the user to ``match`` the observed behavior through a small set of nonstandard input modelling changes allows MELCOR to be used in PRA studies in which such physics are expected to be encountered, while awaiting corrections to the code models involved. The time step control algorithm in MELCOR does not run this problem efficiently; a substantial reduction in time step results in significantly less oscillation predicted at only a small increase run time.

The Waste Isolation Pilot Plant (WIPP) is planned as a mined geologic repository for the disposal of transuranic (TRU) radioactive wastes generated by defense programs of the United States Department of Energy. One of the criteria for evaluating the suitability of the WIPP for disposal of TRU wastes is compliance with the United States Environmental Protection Agency`s (EPA) standards for such facilities. The Containment Requirements of those standards require calculating cumulative releases of radionuclides to the accessible environment by all combinations of events and processes (scenarios) that may affect the escape and transport of radionuclides from the repository for 10, 000 years after decommissioning of the facility. Because the release limits established by the EPA are probabilistic, scenario probabilities are also required. A panel of experts was convened to estimate the probabilities of occurrence of the events used in scenario development and to identify additional human-intrusion events for inclusion in a safety assessment of the WIPP. This report documents the background presentations that were made to the panel about the WIPP program, regulatory guidelines, and performance-assessment program, and site-specific and regional geologic and hydrologic characteristics that may affect the WIPP disposal system.

This report is a revision and update of the original geologic site characterization report that was published in 1980. Many of the topics addressed in the earlier report were predictive in nature and it is now possible to reexamine them some 12 years later, using the data from 17 new caverns and more than ten years of SPR storage experience. Revised maps of the salt configuration show on overhand and faults on the north side of the dome, defining more clearly the edge relationships with respect to the SPR caverns. Caprock faults may locally influence the pattern of subsidence, which is occurring primarily as a result of cavern creep closure. The greater subsidence rate occurring at West Hackberry will likely require mitigative action within a few years. Seismicity of low intensity recurs infrequently at West Hackberry, but a small earthquake in 1983 caused dish rattling in the immediate vicinity.

Cementitious materials, together with other materials, are being considered to seal a potential repository at Yucca Mountain. A concern with cementitious materials is the chemical and mineralogic changes that may occur as these materials age while in contact with local ground waters. A combined theoretical and experimental approach was taken to determine the ability to theoretically predict mineralogic changes. The cementitious material selected for study has a relatively low Ca:Si ratio approaching that of the mineral tobermorite. Samples were treated hydrothermally at 200{degrees}C with water similar to that obtained from the J-13 well on the Nevada Test Site. Post-test solutions were analyzed for pH as well as dissolved K, Na, Ca, Al, and Si. Solid phases formed during these experiments were characterized by scanning electron microscopy and X- ray diffraction. These findings were compared with predictions made by the geochemical modeling code EQ3NR/E06. It was generally found that there was good agreement between predicted and experimental results.

Two years ago, researchers at Sandia National Laboratories showed that a massively parallel computer with 1024 processors could solve scientific problems more than 1000 times faster than a single processor. Since then, interest in massively parallel processing has increased dramatically. This review paper discusses some of the applications of this emerging technology to important problems at Sandia. Particular attention is given here to the impact of massively parallel systems on applications related to national defense. New concepts in heterogenous programming and load balancing for MIMD computers are drastically increasing synthetic aperture radar (SAR) and SDI modeling capabilities. Also, researchers are showing that the current generation of massively parallel MIMD and SIMD computers are highly competitive with a CRAY on hydrodynamic and structural mechanics codes that are optimized for vector processors.

Two-dimensional Acousto-Optic (AO) correlators differ from the frequency plane correlators in that multiplying, shifting, and adding, rather than Fourier transforming are used to obtain the correlations. Thus, many of the available composite filter design techniques are not aimed at designing filters for use in AO correlators since they yield frequency-domain functions. In this paper, a method is introduced for designing filter impulse responses of arbitrary extent for implementation on AO correlators. These filters are designed to yield sharp correlation peaks. Simulation results are included to illustrate the viability of the proposed approach. Also included are some initial results from the first successful use of grey-scale composite filters on an AO correlator.

Previously, we have (lesigueci 3-level filters (suitable for implementation on magneto-optic spatial light modulators) to maxiiiiize the output signal-to-noise ratio (SNR) and to separately maximize Peak-to-Correlation Energy (PCE) that iieasures the correlation peak sharpness. In practice, we want the correlation peaks to he sharp (i.e., large PCE) as well as noise-tolerant (i.e., large SNR). In this paper, we vill present a new method to optimally coiiibine these two desirable properties into a single optimization procedure. Similar methods to trade off SNR versus Peak Efficiency and PCE versus Peak Efficiency will be presented. Both siiiiulation and experinental results will be included.

The Waste Isolation Pilot Plant (WIPP), in southeastern New Mexico, is a research and development facility to demonstrate safe disposal of defense-generated transuranic waste. The US Department of Energy will designate WIPP as a disposal facility if it meets the US Environmental Protection Agency's standard for disposal of such waste; the standard includes a requirement that estimates of cumulative releases of radioactivity to the accessible environment be incorporated in an overall probability distribution. The WIPP Project has chosen an approach to calculation of an overall probability distribution that employs the concept of scenarios for release and transport of radioactivity to the accessible environment. This report reviews the use of Monte Carlo methods in the calculation of an overall probability distribution and presents a logical and mathematical foundation for use of the scenario concept in such calculations. The report also draws preliminary conclusions regarding the shape of the probability distribution for the WIPP system; preliminary conclusions are based on the possible occurrence of three events and the presence of one feature: namely, the events attempted boreholes over rooms and drifts,'' mining alters ground-water regime,'' water-withdrawal wells provide alternate pathways,'' and the feature brine pocket below room or drift.'' Calculation of the WIPP systems's overall probability distributions for only five of sixteen possible scenario classes that can be obtained by combining the four postulated events or features.

Two active Li/SOCl2 cells for use in artillery-fired atomic projectiles are being developed. Voltage delay is the primary mode of electrochemical failure in these cells at -35°C. To minimize this anode polarization, the anode passivation is inhibited by adding chloromethyl chlorosulfate (CMCS) to the sulfur dioxide complex of lithium tetrachloroaluminate (LiAlCl4-SO2) in the cell electrolyte. One battery powers the telemetry system (TM battery) and the other powers a projectile event timer circuit (PET battery). The authors utilize the PET battery and PET load profile to demonstrate the effect of electrolyte additives on anode passive film growth and associated voltage delay. Similar effects were also observed in the TM battery. A limited number of PET prototypes was available for this study. Therefore, several tests were performed in hermetically sealed prismatic laboratory test cells which were constructed using the same electrochemical components which are used in the PET cells.

Surface damage has been observed on the rails of rocket sled tracks and on the barrels of high-velocity guns. The phenomenon is generally referred to as ``ongoing``. Damage to a stationary surface (guider) is created from the oblique impact of a high-velocity object (slider) moving over its surface. The surface damage (gouge) is typically a shallow crater in the shape of a teardrop with the leading edge characterized by the wider end and a slightly raised lip. For rocket sleds, rail gouging occurs when the sled velocity is greater than 1.5 km/sec; while in guns, barrel gouging occurs when the velocity exceeds 4 km/sec. A model is developed to describe the phenomenon of gouging. An unbalanced slider randomly causes a shallow-angle, oblique impact between the slider and the guider. At sufficiently high velocity, the impact produces a thin, but very hot, layer of soft material at the contact surface. Under the action of a moving load, the soft layer lends itself to an antisymmetric deformation and a gouge is formed when this soft material is over-run by the slider. The model is simulated numerically with a hydrodynamic (CTH) code. The results of the simulations are in good agreement with the observed phenomena. Based on the simulated temperature and pressure profiles at the contact surface, design criteria for gouge mitigation are developed in this study. 45 refs., 29 figs., 1 tab.

A description of the Remote Area Monitoring System utilized on nuclear tests conducted by Sandia National Laboratories and the Defense Nuclear Agency is presented. The configuration of the detectors as used on a test is described, as well as the system hardware. Calibration of the detectors before fielding is also discussed.

The annular Core Research Reactor (ACRR) Source Term (ST) Experiment program was designed to obtain time-resolved data on the release of fission products from irradiated fuels under well-controlled light water reactor severe accident conditions. The ST-1 Experiment was the first of two experiments designed to investigate fission product release. ST-1 was conducted in a highly reducing environment at a system pressure of approximately 0.19 MPa, and at maximum fuel temperatures of about 2490 K. The data will be used for the development and validation of mechanistic fission product release computer codes such as VICTORIA.

There are four papers contained in this report which were presented at the Nuclear Energy Agency (NEA) Gas Workshop to provide information about studies of waste-generated gas being conducted for the Waste Isolation Pilot Plant (WIPP). The paper by Davies et al. provides a general overview of the physical conditions pertinent to waste-generated gas and of the coupling of chemical, hydrologic, and structural processes. The paper by Brush et al. describes specific gas-generation processes and the laboratory- and bin-scale experiments being carried out to characterize these processes. The paper by Mendenhall et al. describes coupled modeling of gas generation and room closure, and provides an analysis of the potential for fracture generation and growth. the paper by Webb describes a series of sensitivity calculations carried out to assess the importance of hydrologic parameters, such as formation permeability and two-phase characteristic curves. Together, these papers provide an overview of the present (September 1991) status of waste-generated gas studies for the WIPP.

A three dimensional pretest finite element analysis of the Intermediate Scale Borehole Test has been performed. In the analysis, the 7.7 years simulation period includes the mining of Rooms C1 and C2, and the N1420 cross drift, at time zero; drilling of the borehole between the two rooms at 5.7 years; and 2 years of post-drilling response. An all salt configuration was used in the calculation. The 1984 Waste Isolation Pilot Plant (WIPP) reference elastic-secondary creep law, with reduced elastic moduli, was used to model the creeping response of the salt. Results show that after mining of the rooms and cross drift a relatively high von Mises stress state exists around the perimeter of the pillar. However, by 5.7 years, or immediately prior to drilling of the borehole, the pillar has relaxed to an almost uniform von Mises stress of about 7--8 MPa. After the borehole is drilled, a relatively high von Mises stress field is once again set up in the immediate vicinity of the hole. This drives the creep closure of the borehole. The hole closes more in the vertical direction than in the horizontal direction, resulting in ovalling of the hole. At the end of the simulation, the von Mises stress around the borehole is still higher than that in the remained of the pillar. Thus, the closure rates are relatively high at the end of the simulation time.

A parametric model for releases of radionuclides from spent-nuclear-fuel containers in a waste repository is presented. The model is appropriate for use in preliminary total-system performance assessments of the potential repository site at Yucca Mountain, Nevada; for this reason it is simpler than the models used for detailed studies of waste-package performance. Terms are included for releases from the spent fuel pellets, from the pellet/cladding gap and the grain boundaries within the fuel pellets, from the cladding of the fuel rods, and from the radioactive fuel-assembly parts. Multiple barriers are considered, including the waste container, the fuel-rod cladding, the thermal ``dry-out``, and the waste form itself. The basic formulas for release from a single fuel rod or container are extended to formulas for expected releases for the whole repository by using analytic expressions for probability distributions of some important parameters. 39 refs., 4 figs., 4 tabs.

The design of the potential Yucca Mountain repository is subject to many thermal goals related to the compliance of the site with federal regulations. This report summarizes a series of sensitivity studies that determined the expected temperatures near the potential repository. These sensitivity studies were used to establish an efficient loading scheme for the spent fuel canisters and a maximum areal power density based strictly on thermal goals. Given the current knowledge of the site, a design-basis areal power density of 80 kW/acre can be justified based on thermal goals only. Further analyses to investigate the impacts of this design-basis APD on mechanical and operational aspects of the potential repository must be undertaken before a final decision is made.

Current and future needs in automative, aircraft, space, military, and well logging industries require operation of electronics at higher temperatures than today's accepted limit of 395 K. Without the availability of high-temperature electronics, many systems must operate under derated conditions or must accept severe mass penalties required by coolant systems to maintain electronic temperatures below critical levels. This paper presents ongoing research and development in the electronics community to bring high-temperature electronics to commercial realization. Much of this work was recently reviewed at the First International High-Temperature Electronics Conference held 16--20 June 1991 in Albuquerque, New Mexico. 4 refs., 1 tab.

C++ is the first object-oriented programming language which produces sufficiently efficient code for consideration in computation-intensive physics and engineering applications. In addition, the increasing availability of massively parallel architectures requires novel programming techniques which may prove to be relatively easy to implement in C++. For these reasons, Division 1541 at Sandia National Laboratories is devoting considerable resources to the development of C++ libraries. This document describes the first of these libraries to be released, PHYSLIB, which defines classes representing Cartesian vectors and (second-order) tensors. This library consists of the header file physlib.h, the inline code file physlib.inl, and the source file physlib.C. The library is applicable to both three-dimensional and two-dimensional problems; the user selects the 2-D version of the library by defining the symbol TWO D in the header file physlib.h and recompiling physlib.C and his own code. Alternately, system managers may wish to provide duplicate header and object modules of each dimensionality. This code was produced under the auspices of Sandia National Laboratories, a federally-funded research center administered for the United States Department of Energy on a non-profit basis by AT T. This code is available to US citizens, and institutions under research, government use and/or commercial license agreements.

This is the user's guide to CEPXS/ONELD Version 1.1, a code package for coupled electron-photon transport in one-dimensional slab geometry. The code package consists of the multigroup cross-section generating code, CEPXS; the preprocessor code, PRE1D; the discrete ordinates code, ONELD; and the postprocessor code, POST1D. In Version 1.1, new features have been implemented through several new keywords. Since Version 1.0 keywords are still applicable, this document should be considered as an addendum to the Version 1.0 User's Guide. 5 refs.

This report presents a precursory examination of a number of issues pertaining to socket contacts in hermetic connectors. The principal issues addressed are high-contact resistance and contact chatter (circuit discontinuities). Efforts examining the characteristics of the existing socket contact design, the possibility of connector/contact rework, quick-fix solutions, and contact redesigns are summarized.

A model that predicts the final velocity of high-power, pulsed-laser-driven thin flyers is described. The required input parameters can either be obtained from standard handbooks or simply extracted from one set of data. The model yields a number of features and scaling laws that are well verified by experiment. Specific comparisons of model predictions with experimental results illustrate excellent agreement for variations of laser fluence and pulse width as well as flyer diameter and thickness.

The goal of the Limited Flight Path (LFP) test series was to investigate the effect of reactor subcompartment flight path length on direct containment heating (DCH). The test series consisted of eight experiments with nominal flight paths of 1, 2, or 8 m. A thermitically generated mixture of iron, chromium, and alumina simulated the corium melt of a severe reactor accident. After thermite ignition, superheated steam forcibly ejected the molten debris into a 1:10 linear scale the model of a dry reactor cavity. The blowdown steam entrained the molten debris and dispersed it into the Surtsey vessel. The vessel pressure, gas temperature, debris temperature, hydrogen produced by steam/metal reactions, debris velocity, mass dispersed into the Surtsey vessel, and debris particle size were measured for each experiment. The measured peak pressure for each experiment was normalized by the total amount of energy introduced into the Surtsey vessel; the normalized pressures increased with lengthened flight path. The debris temperature at the cavity exit was about 2320 K. Gas grab samples indicated that steam in the cavity reacted rapidly to form hydrogen, so the driving gas was a mixture of steam and hydrogen. These experiments indicate that debris may be trapped in reactor subcompartments and thus will not efficiently transfer heat to gas in the upper dome of a containment building. The effect of deentrainment by reactor subcompartments may significantly reduce the peak containment load in a severe reactor accident. 8 refs., 49 figs., 6 tabs.

The Department of Energy's Solar Thermal Program has as one of its program elements the development and evaluation of conversion device technologies applicable to dish-electric systems. The primary research and development combines a conversion device (heat engine), solar receiver, and generator mounted at the focus of a parabolic dish concentrator. The Stirling-cycle heat engine was identified as the conversion device for dish-electric with the most potential for meeting the program's goals for efficiency, reliability, and installed cost. To advance the technology toward commercialization, Sandia National Laboratories has acquired a Stirling Thermal Motors, Inc., kinematic Stirling engine, STM4-120, for evaluation. The engine is being bench-tested at Sandia's Engine Test Facility and will be combined later with a solar receiver for on-sun evaluation. This report presents the engine characteristics, finite element analyses of critical engine components, test system layout, instrumentation, and preliminary performance results from the bench test.

The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

Different insert (insulator) materials are undergoing evaluation to replace the Fiberite E-3938 BE96 material currently used. Also being evaluated is the reconfiguration of the insert and metal shell-edge geometries for the purpose of reducing the alleged interference principally responsible for insert damage.

The irradiation embrittlement of neutron shield tank (NST) material (A212 Grade B steel) from the Shippingport reactor has been characterized. Irradiation increases the Charpy transition temperature (CTT) by 23--28{degrees}C (41--50{degrees}F) and decreases the upper-shelf energy. The shift in CTT is not as severe as that observed in high-flux isotope reactor (HFIR) surveillance specimens. However, the actual value of the CTT is higher than that for the HFIR data. The increase in yield stress is 51 MPa (7.4 ksi), which is comparable to HFIR data. The NST material is weaker in the transverse orientation than in the longitudinal orientation. Some effects of position across the thickness of the wall are also observed; the CTT shift is slightly greater for specimens from the inner region of the wall. Annealing studies indicate complete recovery from embrittlement after 1 h at 400{degrees}C (752{degrees}F). Although the weld metal is significantly tougher than the base metal, the shifts in CTT are comparable. The shifts in CTT for the Shippingport NST are consistent with the test and Army reactor data for irradiations at <232{degrees}C (<450{degrees}F) and show very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor (ORR). The effects of irradiation temperature, fluence rate, and neutron flux spectrum are discussed. The results indicate that fluence rate has no effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s and at the low operating temperatures of the Shippingport NST, i.e., 55{degrees}C (130{degrees}F). This suggests that the accelerated embrittlement of HFIR surveillance samples is most likely due to the relatively higher proportion of thermal neutrons in the HFIR spectrum compared to that for the test reactors. 28 refs., 25 figs.

An analysis of thermosyphoning in a stream generator model is presented. The model considers the transient development of buoyancy-driven steam flow in the steam generator tubing, secondary side heat transfer and an inlet plenum mixing model. Numerical solutions are obtained for conditions intended to simulate the natural circulation phenomena in a 3-Loop pressurized water reactor in a loss-of-coolant accident scenario. The relation between the circulation rate and the heating rate is determined. The sensitivity of the model to various key parameters is examined. 16 refs.

The drive designed and built by the Solar Power Engineering Company (SPECO) for its large area heliostat failed under high wind loads during a winter storm. This report details the testing and analysis done to verify the load capabilities of the rebuilt heliostat drive. Changes in design and improvements in fabrication resulted in a usable drive. 12 figs., 7 tabs.

Data are presented from the 18 W/m{sup 2} Mockup for Defense High-Level Waste, a very large scale in situ test fielded underground at the Waste Isolation Pilot Plant (WIPP). These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. The results in this report give measured data from the mechanical response gages, i.e., room closure gages, extensometers, and stress meters emplaced in the test. Construction of the test began in June 1984; gage data in this report cover the complete test duration, that is, to June 1990.

Coaxial transmission cells have been developed for testing optical fiber current sensors. Three of these cells are airlines that provide transverse electromagnetic mode operation to 1.0, 2.3, and 13.7 GHz. Standing wave ratios are <1.5 for the unloaded airlines over their given frequency ranges. Solid and liquid dielectric coaxial cells use materials with high relative permittivities, >9.1. A ceramic test cell has a useful frequency range to 2.5 GHz; the liquid cells, filled with propanol, methanol, or water, are good to {approximately}500 MHz. The properties of the liquid cells are described using a model of a multilayer coaxial dielectric system with complex relative permittivities. 15 refs.

Structural calculations were performed to evaluate the source-term nuclear fuels transport cask (ST Cask) under various hypothetical accident scenarios. (1) Three-dimensional transient dynamic analyses were performed to evaluate the strength of the cask`s end-closure clamp mechanism. The calculations were performed for two impact orientations: a side impact and a 20{degrees} corner impact. The calculations identified three weaknesses in the clamp design: a gap designed between the clamp and the cask provides a deformation mode which loosens the clamp, two unconstrained swing bolts used to fasten the clamp can lose preload and come free; and insufficient stiffness of the clamp in torsion. (2) An axisymmetric finite element model was used to evaluate the dynamics of end-drops from 5 and 10 ft. The calculations show that loads generated in the end-drops could break the payload support cable and damage the payload winch. Lead slump resulted in both end-drop calculations. The stresses generated in the cask wall during the end-drops was insufficient to cause buckling. (3) To determine the factor of safety to yield, calculations in which the cask was treated as a beam loaded under its own weight were performed for two support configurations: simply supported at both ends and simply supported at the center (trunnion loading). (4) The survival of the cask from a 1-m drop onto a mild steel punch was evaluated based on equations derived from empirical data. The calculations showed that the ST Cask could survive such an event. (5) Finally, the bolt configuration for the upper-closure was analyzed and determined to be inadequate because it does not prevent the closure from sliding relative to the cask body. Specific recommendations for design changes are made in the report to eliminate identified problems.

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 Site Characterization Project. Benchmarking is an essential part of this effort and is one of the tools used to demonstrate verification of engineering software used to solve thermomechanical problems. This report presents the results of the third (and final) phase of the first thermomechanical benchmark exercise. In the first phase of this exercise, nonlinear heat conduction code were used to solve the thermal portion of the benchmark problem. The results from the thermal analysis were then used as input to the second and third phases of the exercise, which consisted of solving the structural portion of the benchmark problem. In the second phase of the exercise, a linear elastic rock mass model was used. In the third phase of the exercise, two different nonlinear jointed rock mass models were used to solve the thermostructural problem. Both models, the Sandia compliant joint model and the RE/SPEC joint empirical model, explicitly incorporate the effect of the joints on the response of the continuum. Three different structural codes, JAC, SANCHO, and SPECTROM-31, were used with the above models in the third phase of the study. Each model was implemented in two different codes so that direct comparisons of results from each model could be made. The results submitted by the participants showed that the finite element solutions using each model were in reasonable agreement. Some consistent differences between the solutions using the two different models were noted but are not considered important to verification of the codes. 9 refs., 18 figs., 8 tabs.

Licensing of the potential nuclear-waste repository at Yucca Mountain by the Nuclear Regulatory Commission would require, among other things, demonstrations of the long term usability of the underground facilities. Such a demonstration involves analysis of the mechanical response of the rock to the presence of underground openings and heat-producing waste, which in turn requires data on the mechanical properties of the rock. This document describes the experimental results from a scoping study which led to the development of procedures for performing quality-affecting rock-mechanics experiments on intact rock. The future experiments performed with these procedures will produce information on the time-dependent deformation of welded tuff and represent one aspect of the overall effort to characterize the rheology of the rock mass. 3 refs., 42 figs., 6 tabs.

This report describes a joint shear model used in conjunction with a computational model for jointed media with orthogonal joint sets. The joint shear model allows nonlinear behavior for both joint sets. Because nonlinear behavior is allowed for both joint sets, a great many cases must be considered to fully describe the joint shear behavior of the jointed medium. An extensive set of equations is required to describe the joint shear stress and slip displacements that can occur for all the various cases. This report examines possible methods for simplifying this set of equations so that the model can be implemented efficiently form a computational standpoint. The shear model must be examined carefully to obtain a computationally efficient implementation that does not lead to numerical problems. The application to fractures in rock is discussed. 5 refs., 4 figs.

Ground water flow in unsaturated, fractured rock is often assumed to be dominated by the porous matrix component. This is frequently based on the argument that water flowing in the fractures is rapidly imbibed into the rock matrix by capillary suction forces with negligible resistance to uptake at the matrix-fracture interface. However, the existence of a low-permeability mineralized layer or coating at this interface may substantially reduce matrix imbibition and consequently result in fracture-dominated flow. To test this concept, four tuff samples containing natural fractures were obtained from tuff formations in southern Nevada. By performing imbibition experiments into the matrix rock, across a mineralized fracture face and then across a fresh uncoated fracture face, water uptake as a function of time and coating was measured. A relatively simple model has been developed to describe the imbibition behavior. 6 refs.

The Network File System (NFS) is used in UNIX-based networks to provide transparent file sharing between heterogeneous systems. Although NFS is well-known for being weak in security, it is widely used and has become a de facto standard. This paper examines the user authentication shortcomings of NFS and the approach Sandia National Laboratories has taken to strengthen it with Kerberos. The implementation on a Cray Y-MP8/864 running UNICOS is described and resource/performance issues are discussed. 4 refs., 4 figs.

The current status of lifetime prediction under conditions of thermomechanical creep/fatigue is reviewed. Each method is summarized and the results of the application to solder joints is shown. While each method has been applied with some success, a predictive, phenomenological approach has not been developed and validated. A method which captures the response of a crack to steady-state and cycling environments appears to hold most the most promise to provide a useful design tool.

We present a simple and effective path planning algorithm, an essential component in facilitating robot programming, based on a series of plausible task restriction. It is designed to solve realistic'' problems very quickly, at the expense of not being able to solve every problem. First, the notion of realistic'' problems is motivated with heuristic arguments and formalized through task restrictions. Next, an algorithm solving the resulting tasks of interest is provided. We prove its corrections and theoretical efficiency, and demonstrate empirically its effectiveness and speed. We expect our algorithm to be of practical significance based on its simplicity and predicted performance. 9 refs., 7 figs.

To address the need of a practical motion planner for manipulators, we present an efficient and resolution-complete algorithm that has performance commensurate with task difficulty. The algorithm uses SANDROS, a new search strategy that combines hierarchical, nonuniform-multi-resolution, and best-fit search to find a near-optimal solution in the configuration space. This algorithm can be applied to any manipulator, and has been tested with 5 and 6-degree-of-freedom robots, with execution time ranging from 20 seconds to 10 minutes on a 16 MIPS workstation. 14 refs., 3 figs., 1 tab.

HISPLT is a graphics postprocessor designed to plot time histories for wave propagation codes. HISPLT is available for CRAY UNICOS, CRAY CTSS, VAX VMS computer systems, and a variety of UNIX workstations. The original HISPLT code employs a database structure that allows the program to be used without modification to process data generated by many wave propagation codes. HISPLT has recently been modified to process time histories for the reactor safety analysis code, MELCOR. This report provides a complete set of input instructions for HISPLT and provides examples of the types of plotted output that can be generated using HISPLT. 6 refs., 8 figs., 5 tabs.

The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing closed-circuit television systems for video alarm assessment. There is a section on each of the major components in a video system: camera, lens, lighting, transmission, synchronization, switcher, monitor, and recorder. Each section includes information on component selection, procurement, installation, test, and maintenance. Considerations for system integration of the components are contained in each section. System emphasis is focused on perimeter intrusion detection and assessment systems. A glossary of video terms is included. 13 figs., 9 tabs.

Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This report describes the theoretical background of the VAWT Stochastic Aerodynamic Loads (VAWT-SAL) computer code, whose purpose is to numerically simulate these random loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Stream Tube (DMST) analysis is employed to model the rotor's aerodynamic response. The analysis includes the effects of Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. The mean ambient wind is assumed to have a shear profile which is described by either a power law or a logarithmic variation with height above ground. Superimposed on this is a full 3-D field of turbulence: i.e., in addition to random fluctuations in time, the turbulence is allowed to vary randomly in planes perpendicular to the mean wind. The influence of flow retardation on the convection of turbulence through the turbine is also modeled. Calculations are presented for the VAWT 34-m Test Bed currently in operation at Bushland, Texas. Predicted time histories of the loads, as well as their Fourier spectra, are presented and discussed. Particular emphasis is placed on the differences between so-called steady-state'' (mean wind only) predictions, and those produced with turbulence present. Somewhat surprisingly, turbulence is found to be capable of either increasing or decreasing the average output power, depending on the turbine's tip-speed ratio. A heuristic explanation for such behavior is postulated, and a simple formula is derived for predicting the magnitude of this effect without the need for a full stochastic simulation. 41 refs., 32 figs., 1 tab.

Division 2525 Battery Test Laboratory is a fully automated battery testing facility used in evaluating various battery technologies. The results of these tests are used to verify developers' claims, characterize prototypes, and assist in identifying the strengths and weaknesses of each technology. The Test Facility consists of a central computer and nine remote computer controlled battery test systems. Data acquired during the battery testing process is sent to the central computer system. The test data is then stored in a large database for future analysis. The central computer system is also used in configuring battery tests. These test configurations are then sent to their appropriate remote battery test sites. The Battery Test Facility can perform a variety of battery tests, which include the following: Life Cycle Testing; Parametric Testing at various temperature levels, cutoff parameters, charge rates, and discharge rates; Constant Power Testing at various power levels; Peak Power Testing at various State-of-Charge levels; Simplified Federal Urban Driving Schedule Tests (SFUDS79). The Battery Test Facility is capable of charging a battery either by constant current, constant voltage, step current levels, or any combination of them. Discharge cycles can be by constant current, constant resistance, constant power, step current levels, or also any combination of them. The Battery Test Facility has been configured to provide the flexibility to evaluate a large variety of battery technologies. These technologies include Lead-Acid, Sodium/Sulfur, Zinc/Bromine, Nickel/Hydrogen, Aluminum/Air, and Nickel/Cadmium batteries.