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Experimental determination of contaminant metal mobility as a function of temperature time and solution. 1998 annual progress report

Description: 'The objective of this work is to determine the fundamental data needed to predict the behavior of {sup 90}Sr at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments which track changes in solution composition with direct molecular characterization of Sr in the solid phase using x-ray absorption spectroscopy. These experiments will be used to identify mechanistic geochemical reactions and their thermochemical properties that will be incorporated into geochemical computer codes. As of May 1998, the authors have completed most of the static sorption experiments as a function of temperature (25, 60, and 80 C), solution pH (4 to 10), initial Sr concentrations (10{sup -7} to 10{sup -3} M), and partial pressure of CO 2 (100% N 2 or atmospheric CO 2 ). They chose to study goethite, kaolinite, gibbsite, and amorphous silica because iron and aluminum (oxy)hydroxides, aluminosilicate clays, and quartz are key components in soils, sediments, and aquifers. The authors have completed x-ray absorption analysis of Sr sorption to kaolinite and goethite at 25{sup -}C, initial Sr of 10{sup -}3 M, and pH 9.'
Date: June 1, 1998
Creator: Carroll, S.; Bruton, C.; O'Day, P. & Sahai, N.
Partner: UNT Libraries Government Documents Department

Experimental determination of contaminant metal mobility as a function of temperature, time and solution chemistry. 1997 annual progress report

Description: 'Strontium is significantly more mobile than other hazardous radioactive metals. Its partitioning between aqueous and solid phases is controlled by reactions that occur at the interface between natural waters and minerals. At a groundwater site in Hanford (200-BP-5), the aerial extent of the {sup 90}Sr plume is 100 times larger than the aerial extent of the {sup 137}Cs and the {sup 239}Pu plumes. Similarly, contaminated, perched watertables at INEL have much higher aqueous concentrations of {sup 90}Sr than {sup 137}Cs, presumably because Cs is preferentially sorbed to solids (Duncan 1995). Under high physical flow conditions, such as those in the highly fractured rock at Hanford and INEL, {sup 90}Sr present in plumes may spread off-site and cause contamination of aquifers or other water sources. Geochemical factors that may contribute to the overall mobility of Sr in natural waters are the solubilities of phases such as strontianite (SrCO{sub 3}) and formation of strong complexes with sulfate and nitrate. Although {sup 90}Sr is mobilized in natural waters in these examples, significant concentrations may also be present in solid phases. Sorption experiments using a wide variety of substrates at room temperature have shown that Sr is removed from solution under certain conditions. Additionally, strontianite (SrCO{sub 3}) may precipitate at low Sr concentrations in the pH range of waters in contact with basaltic rocks, which varies between pH 8 and 10. Waters contain variable amounts of carbonate owing to atmospheric interactions; the partial pressure of CO{sub 2} is about 10 x 3.5 atm in air and commonly as high as 10 x 2.5 atm in soils. The objective of this work is to determine the fundamental data needed to predict the behavior of strontium at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments, which ...
Date: January 1, 1997
Creator: Carroll, S.; Bruton, C.; O'Day, P. & Sahai, N.
Partner: UNT Libraries Government Documents Department

Structural aspects of the Chernobyl accident

Description: On April 26, 1986 the world's worst nuclear power plant accident occurred at the Unit 4 of the Chernobyl Nuclear Power Station in the USSR. This paper presents a discussion of the design of the Chernobyl Power Plant, the sequence of events that led to the accident and the damage caused by the resulting explosion. The structural design features that contributed to the accident and resulting damage will be highlighted. Photographs and sketches obtained from various worldwide news agencies will be shown to try and gain a perspective of the extent of the damage. The aftermath, clean-up, and current situation will be discussed and the important lessons learned for the structural engineer will be presented. 15 refs., 10 figs.
Date: September 2, 1988
Creator: Murray, R.C. & Cummings, G.E.
Partner: UNT Libraries Government Documents Department

Radiation imposed limits on superconducting magnets: A data base for copper stabilizers

Description: Two of eight differently prepared copper stabilizer samples, previously irradiated in the RTNS-II at LLNL, the IPNS-1 and the BSR at ORNL, have been irradiated to a fluence of 1.33 /times/ 10/sup 22/ n/m/sup 2/ at RTNS-II. During the course of the irradiation the samples were periodically removed (without warming) for measurements of the transverse magnetoresistance and returned for continued irradiation. This experiment extends the range of neutron-irradiation-induced resistivity by a factor of five over the previous experiments. A simple model is developed which reproduces the magnetoresistance results of all the experiments to an accuracy of 2.5%. 13 refs., 6 figs.
Date: October 28, 1987
Creator: Guinan, M.W.; Hahn, P.A.; Klabunde, C.E. & Coltman, R.R. Jr.
Partner: UNT Libraries Government Documents Department

An information-theoretic look at branch-prediction

Description: Accurate branch-prediction is necessary to utilize deeply pipelined and Very Long Instruction-Word (VLIW) architectures. For a set of program traces we show the upper limits on branch predictability, and hence machine utilization, for important classes of branch-predictors using static (compiletime) and dynamic (runtime) program information. A set of optimal superpredictors'' is derived from these program traces. These optimal predictors compare favorably with other proposed methods of branch-prediction. 3 refs., 5 figs., 12 tabs.
Date: September 11, 1990
Creator: Ponder, C.G. (Lawrence Livermore National Lab., CA (USA)) & Shebanow, M.C. (Motorola, Inc., Austin, TX (USA))
Partner: UNT Libraries Government Documents Department

Evaluation of fiber-optic connectors

Description: Two fiber optic connectors for field use in high efficiency, long distance systems are described and evaluated in this report. The transmission testing arrangement and other considerations are included with the test results. Techniques for optimizing the transmission through these connectors are also described and the results are reported. Many desirable characteristics of connectors for field use are considered and compared to the ITT and Amphenol connectors tested here.
Date: February 24, 1981
Creator: Reedy, R.P.
Partner: UNT Libraries Government Documents Department

Gas chromatographic separation of hydrogen isotopes using metal hydrides

Description: A study was made of the properties of metal hydrides which may be suitable for use in chromatographic separation of hydrogen isotopes. Sixty-five alloys were measured, with the best having a hydrogen-deuterium separation factor of 1.35 at 60/sup 0/C. Chromatographic columns using these alloys produced deuterium enrichments of up to 3.6 in a single pass, using natural abundance hydrogen as starting material. 25 references, 16 figures, 4 tables.
Date: May 9, 1984
Creator: Aldridge, F.T.
Partner: UNT Libraries Government Documents Department

ANALYZE Users' Guide

Description: This report is a reproduction of the visuals that were used in the ANALYZE Users' Guide lectures of the videotaped LLNL Continuing Education Course CE2018-H, State Space Lectures. The course was given in Spring 1982 through the EE Department Education Office. Since ANALYZE is menu-driven, interactive, and has self-explanatory questions (sort of), these visuals and the two 50-minute videotapes are the only documentation which comes with the code. More information about the algorithms contained in ANALYZE can be obtained from the IEEE book on Programs for Digital Signal Processing.
Date: October 1, 1982
Creator: Azevedo, S.
Partner: UNT Libraries Government Documents Department

Relativistic shocks in electron-positron plasmas, and polar cap accretion onto neutron stars: Two non-linear problems in astrophysical plasma physics

Description: I outline particle simulations and theory of relativistic shock waves in an e/sup +-/ plasma. Magnetic reflection of particles is an essential role in the shock structure. Instability of the reflected particles in the shock front produces intense extraordinary mode radiation. Such shocks are candidates for the particle accelerator in plerions and in extragalactic jets only if the upstream Poynting flux composes no more than 10% of the total. I summarize analytical and numerical studies of radiation dominated accretion onto the magnetic poles of neutron stars. The upper limit to the photon luminosity depends upon magnetic confinement, not upon the dragging of photons into the star. Numerical solutions show the plasma forms large scale ''photon bubbles.'' I suggest the percolative loss of radiation controls the pressure and therefore the limits of magnetic confinement. Loss of magnetic confinement through resistive interchange instability is suggested as a means of generating TeV to PeV voltage drops along the magnetic field. 34 refs., 6 figs., 1 tab.
Date: August 15, 1988
Creator: Arons, J.
Partner: UNT Libraries Government Documents Department

Communicating between the Apple and the Wang

Description: This manual covers what the beginner needs to know in order to transfer files between an Apple's Microcomputer and a Wang's OIS Word Processor. We have also tried to indicate where the experienced user might want to look for additional details. We cover the use of Apple Writer )(, VisiTerm, VisiCalc, and EasyWriter Professional. For us, the two most useful connections are from Applewriter to Wang and from Visicalc to Wang. From Wang to Apple Writer via Visiterm may have some value. Files can be transferred by VisiTerm to Wang, but they arrive with RETURNS in the middle of words, which have to be edited out, so we do not recommend it. We describe how to go from EasyWriter to Wang, but we do not know how to go from Wang to EasyWriter. We see no reason to go from Wang to VisiCalc, so we haven't thought about it. All instructions are given for a typical configuration of the Apple, namely the one on which this manual was composed. It is detailed in the section on Hardware and Software.
Date: October 26, 1982
Creator: Barton, G.W., Downey, R.
Partner: UNT Libraries Government Documents Department

Local fields in strongly coupled plasmas

Description: Computer simulation techniques and important static properties of plasma microfields are discussed. The relevant timescales are introduced for dynamical atomic problems, and some time-dependent properties of microfields are discussed. In the last two sections of the paper these results are applied to two problems relevant to the spectroscopy of dense plasmas: (1) broadening of spectral lines, and (2) screening in inelastic electron-ion collisions.
Date: June 1, 1984
Creator: Pollock, E.L. & Weisheit, J.C.
Partner: UNT Libraries Government Documents Department

Technology development for high power induction accelerators

Description: The marriage of Induction Linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 MeV/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator has been constructed at the Lawrence Livermore National Laboratory (LLNL) to demonstrate these concepts and to provide a test facility for high brightness sources. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak power capability, repetition rates exceeding a kilohertz and excellent reliability.
Date: June 11, 1985
Creator: Birx, D.L. & Reginato, L.L.
Partner: UNT Libraries Government Documents Department

Chemical-decomposition models for the thermal explosion of confined HMX, TATB, RDX, and TNT explosives

Description: Chemical decomposition models have been deduced from the available chemical kinetic data on the thermal decomposition of HMX, TATB, RDX, and TNT. A thermal conduction model is used in which the thermal conductivity of the reacting explosive decreases linearly with the mass fraction reacted to that of the gaseous products. These reactive heat flow models are used to predict the time to explosion versus reciprocal temperature curves from several heavily confined explosive tests. Good agreement is obtained between experimental and calculated explosion times for the pure explosives HMX, TATB, RDX, and TNT, mixtures such as RX-26-AF (HMX/TATB), Octol (HMX/TNT), and Comp B (RDX/TNT), and for PBX 9404, an HMX-based explosive containing an energetic nitrocellulose binder.
Date: March 26, 1981
Creator: McGuire, R.R. & Tarver, C.M.
Partner: UNT Libraries Government Documents Department

Distributed computer controls for accelerator systems

Description: A distributed control system has been designed and installed at the Lawrence Livermore National Laboratory Multi-user Tandem Facility using an extremely modular approach in hardware and software. The two tiered, geographically organized design allowed total system implementation with four months with a computer and instrumentation cost of approximately $100K. Since the system structure is modular, application to a variety of facilities is possible. Such a system allows rethinking and operational style of the facilities, making possible highly reproducible and unattended operation. The impact of industry standards, i.e., UNIX, CAMAC, and IEEE-802.3, and the use of a graphics-oriented controls software suite allowed the efficient implementation of the system. The definition, design, implementation, operation and total system performance will be discussed. 3 refs.
Date: September 1, 1988
Creator: Moore, T.L.
Partner: UNT Libraries Government Documents Department

Preliminary limits on the flux of muon neutrinos from extraterrestrial point sources

Description: We present the arrival directions of 117 upward-going muon events collected with the IMB proton lifetime detector during 317 days of live detector operation. The rate of upward-going muons observed in our detector was found to be consistent with the rate expected from atmospheric neutrino production. The upper limit on the total flux of extraterrestrial neutrinos >1 GeV is <0.06 neutrinos/cm/sup 2/-sec. Using our data and a Monte Carlo simulation of high energy muon production in the earth surrounding the detector, we place limits on the flux of neutrinos from a point source in the Vela X-2 system of <0.009 neutrinos/cm/sup 2/-sec with E > 1 GeV. 6 refs., 5 figs.
Date: July 3, 1985
Creator: Bionta, R.M.; Blewitt, G.; Bratton, C.B.; Casper, D.; Cortez, B.G.; Chrysicopoulou, P. et al.
Partner: UNT Libraries Government Documents Department

Status of beam transport with the ETA and ATA accelerators

Description: Both the Experimental Test Accelerator (ETA) and the Advanced Test Accelerator (ATA) are 10 kA electron induction linacs. The ETA produces a 4.5 MeV, 30 ns pulse, and the ATA a 50 MeV, 70 ns pulse. The ETA has been operational since 1979, having produced over 6 million pulses. Both the beam breakup instability and lower frequency transverse motions of the beam have been suppressed by accelerator cavity damping and with a wire damping zone. These efforts will be summarized. The ATA has become operational within this last year. Full beam current operation has not yet been achieved because of low-frequency transverse motion and centroid drift of the beam. The beam breakup instability has also been observed but does not disrupt the beam. Efforts at finding the source of the drift and low frequency motion, as well as wire damping of these motions will be reported. 6 references, 6 figures.
Date: May 1, 1984
Creator: Struve, K.W.; Caporaso, G.J.; Chong, Y.P.; Clark, J.C.; Fessenden, T.J.; Lauer, E.J. et al.
Partner: UNT Libraries Government Documents Department

Control of information as an element of nuclear safeguards

Description: Control of information as an element of physical protection has a long history in the field of national security. The nuclear industry is familiar with the constraints on proprietary information; and, with an effective date of October 1, 1980 for Parts 25 and 95 in Title 10 of the code of Federal Regulations, certain activities had to cope with rules for safeguarding of classified information. In applying the rules it is important to understand the differences between national security information and restricted data, and how guidance is promulgated both by the Nuclear Regulatory Commission (NRC) and by the Department of Energy. More recently, with a fully effective date of January 20, 1982, the NRC published rules for the protection of unclassified safeguards information. The scope is much broader than for the classified information. For example, the rules are applicable to power reactors. In this paper the directives which provide the details for compliance with all these rules are identified, and their application is discussed. NRC inspectors will be checking for compliance with the rules. Once problems of compliance are resolved, the more difficult question of evaluating the impact of information control procedures on the effectiveness of a physical protection system can be addressed.
Date: March 1, 1982
Creator: Green, J.N.
Partner: UNT Libraries Government Documents Department

The international magnetic fusion energy program

Description: In May of 1988, the long tradition of international cooperation in magnetic fusion energy research culminated in the initiation of design work on the International Thermonuclear Experimental Reactor (ITER). If eventually constructed in the 1990s, ITER would be the world's first magnetic fusion reactor. This paper discusses the background events that led to ITER and the present status of the ITER activity. This paper presents a brief summary of the technical, political, and organizational activities that have led to the creation of the ITER design activity. The ITER activity is now the main focus of international cooperation in magnetic fusion research and one of the largest international cooperative efforts in all of science. 2 refs., 12 figs.
Date: October 6, 1988
Creator: Fowler, T.K.
Partner: UNT Libraries Government Documents Department

Alternate laser fusion drivers

Description: One objective of research on inertial confinement fusion is the development of a power generating system based on this concept. Realization of this goal will depend on the availability of a suitable laser or other system to drive the power plant. The primary laser systems used for laser fusion research, Nd/sup 3 +/: Glass and CO/sub 2/, have characteristics which may preclude their use for this application. Glass lasers are presently perceived to be incapable of sufficiently high average power operation and the CO/sub 2/ laser may be limited by and issues associated with target coupling. These general perceptions have encouraged a search for alternatives to the present systems. The search for new lasers has been directed generally towards shorter wavelengths; most of the new lasers discovered in the past few years have been in the visible and ultraviolet region of the spectrum. Virtually all of them have been advocated as the most promising candidate for a fusion driver at one time or another.
Date: November 1, 1979
Creator: Pleasance, L.D.
Partner: UNT Libraries Government Documents Department

Final report for the tunable driver for the LLNL FEL experiment

Description: This section of the report covers the recent operation of the prototype backward-wave oscillator (BWO) gyrotron. The tube was mounted in its fixture on the superconducting magnet, the beam aligned, and microwaves generated. Initial alignment and operation was performed at low wiggler magnet strength (B{sub w} = 9 G) and thus low {alpha} = {upsilon} {perpendicular}/{upsilon}{parallel}. The microwaves observed under these conditions were at a frequency just above the electron cyclotron frequency of the interaction region. Identification of these waves is tentatively that of forward waves generated in what is a very long gyrotron cavity. By increasing the wiggler field to {approx} 18 G, the backward wave could then be observed. Voltage tunability of the backward wave was demonstrated and frequencies from 13 GHz to 143 GHz were observed.
Date: June 1, 1990
Creator: Guss, W.C.; Basten, M.A.; Kreischer, K.E. & Temkin, R.J.
Partner: UNT Libraries Government Documents Department

Multiple-energy techniques in industrial computerized tomography

Description: Considerable effort is being applied to develop multiple-energy industrial CT techniques for materials characterization. Multiple-energy CT can provide reliable estimates of effective Z (Z{sub eff}), weight fraction, and rigorous calculations of absolute density, all at the spatial resolution of the scanner. Currently, a wide variety of techniques exist for CT scanners, but each has certain problems and limitations. Ultimately, the best multi-energy CT technique would combine the qualities of accuracy, reliability, and wide range of application, and would require the smallest number of additional measurements. We have developed techniques for calculating material properties of industrial objects that differ somewhat from currently used methods. In this paper, we present our methods for calculating Z{sub eff}, weight fraction, and density. We begin with the simplest case -- methods for multiple-energy CT using isotopic sources -- and proceed to multiple-energy work with x-ray machine sources. The methods discussed here are illustrated on CT scans of PBX-9502 high explosives, a lexan-aluminum phantom, and a cylinder of glass beads used in a preliminary study to determine if CT can resolve three phases: air, water, and a high-Z oil. In the CT project at LLNL, we have constructed several CT scanners of varying scanning geometries using {gamma}- and x-ray sources. In our research, we employed two of these scanners: pencil-beam CAT for CT data using isotopic sources and video-CAT equipped with an IRT micro-focal x-ray machine source.
Date: August 1, 1990
Creator: Schneberk, D.; Martz, H. & Azevedo, S.
Partner: UNT Libraries Government Documents Department

Neutron spectra as a function of angle at two meters from the Little Boy assembly

Description: Measurements of neutron spectra produced by the Los Alamos National Laboratory (LANL) Little Boy replica assembly (Comet) were made with a combined multisphere and liquid scintillator system, that has been widely used at the Lawrence Livermore National Laboratory. The combined system was used for measurements at the side (90/sup 0/) and nose (0/sup 0/) of the assembly; additional measurements were made at 45/sup 0/ using only the liquid scintillator. Data were obtained at two meters from the center of the reactive region of the assembly, with good agreement between the multisphere and scintillator results. Comparison with liquid scintillator measurements performed by experimenters from the Canadian Defence Research Establishment, Ottawa (DREO) and calculations from LANL depended on the specific angle, obtaining the best agreement at 90/sup 0/. 32 references, 11 figures, 4 tables.
Date: July 2, 1984
Creator: Griffith, R.V.; Huntzinger, C.J. & Thorngate, J.H.
Partner: UNT Libraries Government Documents Department

Development of a multimaterial, two-dimensional, arbitrary Lagrangian-Eulerian mesh computer program

Description: We have developed a large, multimaterial, two-dimensional Arbitrary Lagrangian-Eulerian (ALE) computer program. The special feature of an ALE mesh is that it can be either an embedded Lagrangian mesh, a fixed Eulerian mesh, or a partially embedded, partially remapped mesh. Remapping is used to remove Lagrangian mesh distortion. This general purpose program has been used for astrophysical modeling, under the guidance of James R. Wilson. The rationale behind the development of this program will be used to highlight several important issues in program design.
Date: October 11, 1982
Creator: Barton, R.T.
Partner: UNT Libraries Government Documents Department