Publications

This Test Plan describes laboratory and modeling studies of: the chemistry of brines that could enter Waste Isolation Pilot Plant (WIPP) disposal rooms; the effects of anoxic corrosion of metals in steel containers and the waste on the gas and H{sub 2}O budgets of the repository; the effects of microbial activity, especially microbial degradation of cellulosics in the waste, on the gas and H{sub 2}O budgets of the repository, the Eh and pH of any brine present, and the chemical behavior of radionuclides; the effects of radiolysis on the gas and H{sub 2}O budgets of the repository; the efficacy of backfill additives proposed to remove microbially produced CO{sub 2} or prevent the formation of H{sub 2} from anoxic corrosion, and their effects on repository chemistry; the chemical behavior of Pu, Am, Th, and U in WIPP brines; additional development of the EQ3/6 geochemical software package for use in predicting the behavior of silicates and radionuclides in brines. This Test Plan describes studies of the chemical behavior of the repository as currently designed, and the chemical behavior of radionuclides under these conditions. Addenda will discuss additional studies relevant to design modifications, especially reprocessed waste, and chemically hazardous waste constituents. 165 refs., 7 tabs.

Generally multicomponent mixtures can exhibit a rich collection of phenomena. Thus it is to be expected that they will be described by complicated theories. In this paper we describe a relatively simple theory that is still theoretically correct, and discuss some of the phenomena that it exhibits. 12 refs.

Guest-host poled polymer films have become an active area of research as potential candidates for second-order nonlinear optical and electro-optic devices. This interest derives mainly from their large nonlinear optical coefficients, ease of fabrication, and high optical quality. Progress has been rapid in producing stable, efficient materials, and in building demonstration devices. The second-order nonlinear optical properties arise from the orientational order induced in a collection of highly nonlinear molecules incorporated in a glassy polymer matrix. After reviewing the alignment physics, we present results of nonlinear optical measurements on a methacrylate polymer functionalized with a dicyanovinyl terminated azo dye. Device issues concerning nonlinear optical devices are described with particular attention to phase-matching. We present data on the demonstration of anomalous-dispersion phase matched second harmonic generation in dye solutions. We also present results on electro-optic modulators. © 1989 SPIE.

The Function Point (FP) concept was introduced to define'' a measure for applications development and maintenance functions avoiding the problems inherent in productivity measures in the late 1970s. At that time, Albrecht outlines three essentials elements for software size measurement: the measure must be technology independent; the technique must measure all the application functions delivered to the end customer; and the technique must measure only the application functions as delivered. Using these three attributes of a measurement, further concentrated analysis could be performed for languages, technologies, methodologies, and tools. The characterization of systems and the quality of the product are motives for subscribing to FPs. Since the inception of FPs, attempts have been made to improve the process of quantifying FPs. Some of these attempts have strayed from the intended use of FPs and have diverted valuable energy away from consistent application. The purpose of this article is to describe the process and the quantification of complexity factors for each of the five Unadjusted FPs. 4 refs.

Light ion fusion research has developed ion diodes that have unique properties when compared to other ion diodes. These diodes involve relativistic electrons, ion beam stagnation pressures that compress the magnetic field to the order of 10 Tesla, and large space-charge and particle current effects throughout the accelerating region. These diodes have required new theories and models to account for effects that previously were unimportant. One of the most important effects of the magnetic field compression and large space-charge has been impedance collapse. The impedance collapse can lead to poor energy transfer efficiency, beam debunching, and rapid change of the beam focus. This paper discusses our current understanding of these effects, some of the methods we are using to ameliorate them, and the future directions our theory and modeling will take. 40 refs., 6 figs.

A new scanning electron microscopy imaging technique has been developed to examine the logic state of conductors on passivated CMOS integrated circuits. This technique employs a modified Resistive Contrast Imaging system to acquire image data on powered devices. The image is generated by monitoring subtle shifts in the power supply current of an integrated circuit as an electron beam is scanned over the device surface. The images produced with this new technique resemble voltage contrast data from devices with the passivation removed and the surface topography subtracted. Non-destructive applications of this imaging method to functional and failed integrated circuits are described. Possible irradiation effects and methods to minimize them are also discussed. 2 refs., 1 fig.

We have sputter-deposited aluminum oxide coatings using a dual ion beam system with a mixture of argon plus 10% oxygen as the working gas. Ambient substrate temperatures and substrate temperatures of 360°C were maintained. The coatings were deposited at deposition rates between 7 and 10 nm/min, with and without concurrent ion bombardment from the second ion gun. Substantial variations in the microstructure and the amount of entrained gas in the coatings were observed. The coatings contain a mixture of varying amounts of γ-Al2O3and amorphous aluminum oxide. Relatively large, 0.5 μm islands of γ-Al2O3 crystallites surrounded by an amorphous matrix were observed in coatings deposited onto heated substrates with ion bombardment from the second ion gun during deposition. Coatings bombarded with a second ion beam during deposition contain more argon as determined by energy dispersive x-ray analysis. The Raman spectra exhibited by the coatings suggest a variation in chemical reactivity and/or porosity which depends on the deposition conditions. © 1990, American Vacuum Society. All rights reserved.

Transit time, the time from bridgewire burst until breakout of detonation from the output pellet of an exploding bridgewire detonator, was measured as a function of burst current. From this data, in conjunction with known equations for run distance versus pressure, unreacted explosive Hugoniots, and detonation properties of the initial pressing pellet, the run distance in the initial pressing explosive pellet and shock pressure from the exploding bridgewire were determined, both as a function of burst current.

The author describes a waveform-recorder evaluation system which is controlled by a Microvax II with instrumentation control through the IEEE-488 bus. Evaluation procedures are described with attention to the 'pathological cases' that can lead to significant misestimates of a digitizer's performance. The aim of these evaluation procedures is consistency with the new Trial Waveform Digitizer Standard generated by the Waveform Measurements and Analysis Committee appointed by the Instrumentation and Measurement Society of the IEEE. Methods are discussed for measuring the effective-bits performance of a waveform digitizer and determining differential nonlinearity.

The Primary Standards Laboratory at Sandia National Laboratories (SNL) and the Precision Engineering Division at the National Institute of Standards and Technology (NIST) are in the process of implementing software error correction on two nearly identical high-accuracy coordinate measuring machines (CMMs). Both machines are Moore Special Tool Company M-48 CMMs which are fitted with laser positioning transducers. Although both machines were manufactured to high tolerance levels, the overall volumetric accuracy was insufficient for calibrating standards to the levels both laboratories require. The error mapping procedure was developed at NIST in the mid 1970's on an earlier but similar model. The error mapping procedure was originally very complicated and did not make any assumptions about the rigidness of the machine as it moved, each of the possible error motions was measured at each point of the error map independently. A simpler mapping procedure was developed during the early 1980's which assumed rigid body motion of the machine. This method has been used to calibrate lower accuracy machines with a high degree of success and similar software correction schemes have been implemented by many CMM manufacturers. The rigid body model has not yet been used on highly repeatable CMMs such as the M48. In this report we present early mapping data for the two M48 CMMs. The SNL CMM was manufactured in 1985 and has been in service for approximately four years, whereas the NIST CMM was delivered in early 1989. 4 refs., 5 figs.

Merlin is a memory based, interconnection system designed to provide very high-performance capability in a disturbed multicomputer environment. By using dynamically mapped reflective memory operations, the system creates a virtual memory environment which permits users to utilize both local and shared memory techniques. This mapped virtual memory approach permits selected information to be shared at high speeds and with relatively low latency. There is no software involvement in the actual sharing of information and the system automatically overlaps computation and communication, to the extent possible, on a word-by-word basis. Memory-to-Memory mapping allows Merlin to provide a uniform programming environment which is independent of interconnection topology, processing elements, and languages. 14 refs., 4 figs.

In the most transmissive parts of the Culebra Dolomite, fluid flow is controlled by fractures. Gypsum (CaSO{sub 4} 2H{sub 2}O) and corrensite (a mixed chlorite/smectite) are the most abundant fracture-fill minerals. Radionuclide/clay interactions may be the dominant mechanism for radionuclide retardation. For this reason, the focus of this study is to examine the extent of the sorption of uranium and plutonium onto clays within the Culebra matrix and fractures. This paper describes several coordinated activities which will evaluate the potential retardation of radionuclide migration by sorption onto clays within the Culebras. These include characterization of the compositions of clays and groundwaters along the flow path; studies of the surface properties of simple reference clays and Culebra clays in dilute solutions and saline mixed electrolytes; development of a database of intrinsic equilibrium constants and specific-interaction parameters for calculations of the aqueous speciation of uranium and plutonium in Na-Cl-Ca-SO{sub 4}-CO{sub 3}-EDTA solutions which range in ionic strength from 0.1--4.0 molal; and measurement of surface complexation constants for uranium and plutonium in simple and mixed electrolyte solutions containing clays. 2 refs., 2 figs.

The nickel/hydrogen battery was developed in the early nineteen-seventies as an energy storage subsystem for commercial communication satellites. The advantages offered by nickel/hydrogen batteries, including long life, low maintenance and high reliability, make it very attractive for terrestrial applications such as stand-alone photovoltaic systems. The major drawback to the wider use of the nickel/hydrogen battery is its high initial cost. Sandia National Laboratories has placed cost-shared contracts with Comsat Laboratories and Johnson Controls, Inc., to reduce the cost, and a battery consisting of prismatic cells in a common pressure vessel has evolved. A 7-kWh battery has been on test at Sandia since January 1988 using a flat-plate photovoltaic array for charging. © 1990 IEEE

The DOE/Sandia 34-m diameter Vertical-Axis Wind Turbine (VAWT) utilizes a step-tapered, multiple-airfoil section blade. One of the airfoil sections is a natural laminar flow profile, the SAND 0018/50, designed specifically for use on VAWTs. The turbine has now been fully operational for more than a year, and extensive turbine aerodynamic performance data have been obtained. This paper reviews the design and fabrication of the rotor blade, with emphasis on the SAND 0018/50 airfoil, and compares the performance measurements to date with the performance predictions. Possible sources of the discrepancies between measured and predicted performance are identified, and plans for additional aerodynamic testing on the turbine are briefly discussed.

In component reliability assessment programs, three major sources of data are available for reliability assessment: a development program, production data, and field test data. In practice, reliability assessments are required at the end of each stages, and a common method of assessment is to simply combine the test data and provide a pooled estimate. The method suggested in this paper is Bayesian in that the uncertainty about the unreliability is expressed by means of a prior distribution with a specified upper limit. The method is hierarchical Bayes in that the uncertainty about the limit of that prior distribution is also expressed by means of a prior distribution. The data from the development program are incorporated with the prior on the unreliability and with the prior on the upper limit of the prior to obtain a new prior on unreliability. The production data are then used to obtain a revised estimate of the unreliability as well as a modified value for the limit of the prior distribution. This same concept will be carried through when the field data are obtained. The result is a final Bayesian reliability assessment that is iterative in nature and incorporates in a sequential fashion data from each of the three stages common to a component development, production, and surveillance program. 4 refs., 2 tabs.

In this paper the concept of a stochastic electron beam is introduced. A stochastic electron beam is one for which the transverse dynamics is chaotic. Utilizing adiabatic orbits, the resonance overlap condition for transition to stochasticity in a particular electron beam system, the "triple-Bennett configuration," is derived. The tangent map is derived and used to state conditions for strong orbit instability and the resulting exponential decay of phase correlations. The dependence of the K entropy on the strength ε of the nonaxisymmetry of the triple-Bennett configuration is investigated numerically. Implications for the suppression of the ion-hose instability in the ion-focused regime are briefly discussed. © 1990 American Institute of Physics.

Power loadings experienced by tokamak plasma-facing components during normal operation and during off-normal events are discussed. A model for power and particle flow in the tokamak boundary layer is presented and model predictions are compared to infrared measurements of component heating. The inclusion of the full three-dimensional geometry of the component and of the magnetic flux surface is very important in the modeling. Experimental measurements show that misalignment of component armour tile surfaces by only a millimeter can lead to significant localized heating. An application to the design of plasma-facing components for future machines is presented. Finally, thermal loads expected during tokamak disruptions are discussed. The primary problems are surface melting and vaporization due to localized intense heating during the disruption thermal quench and volumetric heating of the component armour and structure due to localized impact of runaway electrons. © 1990.

The influence of coal structure on primary conversions and oil yields under different relatively mild liquefaction regimes has been investigated. Pre-soaking of coal/H-donor solvent slurries at 250°C increased conversions and the level of hydrogen transfer at short contact times (SCT <10 min) demonstrating the importance of solvent accessibility. However, contrary to other studies, prior removal of THF-extractable material (mobile phase) from one bituminous coal actually gave rise to higher conversions to pyridine - solubles for non-donor polynuclear aromatic compounds (PAC), such as naphthalene, phenanthrene and pyrene. These findings highlight the difficulties in relating primary conversions to coal characteristics. In contrast, oil yields have been found to broadly increase with decreasing rank in both H-donor solvent extraction with a process solvent and dry catalytic hydrogenation. However, in SCT tetralin extraction where poor physical contact between coal and solvent exists, neither total conversion nor oil yield correlates with rank. © 1990.

Fifteen years of solar thermal technology development have produced a considerable amount of knowledge relating to the production of electricity from central receiver power plants. This body of knowledge is under examination by researchers from the United States and the Federal Republic of Germany for the purpose of defining the next generation central receiver electricity producers. This second generation power plant is expected to represent a significant step towards commercialization of these systems. During the course of the study, specific activities needed to realize this next-step technology are being defined. The study is an international team effort. Under the International Energy Agency Small Solar Power Systems project, researchers from DLR, Interatom, Sandia National Laboratories, and Bechtel have designed a study in which technologies relating to existing systems are quantified, logical next-step systems are characterized, and future potential advances are identified. The receiver concepts under investigation are: salt-in- tube, volumetric, and direct absorption. Two plant performance levels are examined, 30 and 100 MW{sub e}. Each concept is applied with common capacity factors, solar multiples, and types and sizes of heliostats at each performance level. Availability and uncertainty analyses are also performed. Annual energy production figures are calculated using the SOLERGY computer code. Capital and Operation and Maintenance cost methodologies are mutually agreed upon in order that levelized energy cost calculations will be consistent for each power plant. During the course of this effort, further potential advances in central receiver technology have continued to become apparent. These possible areas for improvement will be described. An additional comparison is being made between central receivers and trough-based systems. 8 refs., 2 figs.

A hierarchical control architecture for telerobotic vehicles intended to yield a modular, flexible, and easily expanded control system is presented. This architecture is proposed for applications where simple teleoperation is required but where additional capabilities might be quickly added without major changes to the control system. Similarities to the NASREM architecture are noted. Results are given from hardware implementation of the control system on a telerobotic vehicle, Raybot, at Sandia National Laboratories.

A systematic study is described which addresses the technical issues associated with launching flier-plates intact to hypervelocitites. First, very high pressures are needed to launch the flier plates to hypervelocitites, and second this high pressure loading must be uniform and nearly shockless. To achieve both these criteria, a graded-density material referred to as a pillow'' is used to impact a flier plate. When this graded-density material is used to impact a flier plate at high velocities on a two-stage light-gas gun, nearly shockless megabar pressure pulses are introduced into the flier plate. Since the loading on the flier plate is shockless, melting of the flier plate is prevented. This technique has been used to launch a 2-mm thick titanium alloy (Ti-6Al-4V) plate to a velocity of 8.1 km/s, and a 1-mm thick aluminum alloy (6061-T6) plate to a velocity of 10.4 km/s. A method is described by which the flier plate velocities could be further augmented to velocities approaching 14 km/s. 18 refs., 16 figs.

A new technique is reported for the rapid determination of interstitial oxygen (O{sub i}) in heavily doped n{sup +} and p{sup +} silicon. This technique includes application of a selective electrochemical thinning (SET) process and FTIR transmittance measurement on a limited area of a silicon wafer. The O{sub i} is calculated using ASTM F1188--88 with the IOC 88 calibration factor. An advantage of SET over mechanical thinning is that the original wafer thickness and diameter are maintained for additional processing. 1 tab.

The Shippable Storage Cask Demonstration Project is intended to demonstrate casks which can be used for both shipping and storing spent nuclear fuel assemblies. The demonstration included the requirement that the casks be certified for shipping by the US Nuclear Regulatory Commission (NRC). After a lengthy review process which resulted in the resolution of several important technical issues, designs for two similar casks have been certified. This paper describes the certification phase of the demonstration. Based on experience gained during certification phase of the demonstration. Based on experience gained during certification, observations and recommendations have been developed which can benefit others seeking NRC approval of transportation cask designs.

Reviews of normal breakdown and current induced avalanche breakdown mechanisms in silicon power transistors are presented. We show the applicability of the current induced avalanche model to heavy ion induced burnouts. Finally, we present solutions to current induced avalanche in silicon power semiconductors. 7 refs., 5 figs.

The electronic properties of heavily and orderly Si-doped nipi structures in GaAs are studied theoretically using the ab-initio self-consistent pseudopotential method within the local density approximation. Two nipi configurations are considered. Besides investigating the nature of the impurity-related band edge states, the xy-planar-averaged local ionic and self-consistent potentials are also analyzed. The screening effect of the host crystal on the doping induced potential is found to be small. The effects of the doping induced electric field and the strain due to dopings are also examined. 13 refs., 9 figs., 2 tabs.