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Abiotic immobilization/detoxification of recalcitrant organics

Description: In contrast to many remedial techniques that simply transfer hazardous wastes from one part of the environment to another (e.g., off-site landfilling), in situ restoration may offer a safe and cost-effective solution through transformation (to less hazardous products) or destruction of recalcitrant organics. Currently, the US Environmental Protection Agency and US Department of Energy are encouraging research that addresses the development of innovative alternatives for hazardous-waste control. One such alternative is biotic and abiotic immobilization and detoxification of polynuclear aromatic hydrocarbons (PNAs) as associated with the soil humification process. This paper discusses (1) the possibility of using abiotic catalysis (with manganese dioxide) to polymerize organic substances; (2) aspects associated with the thermodynamics and kinetics of the process, and (3) a simple model upon which analyses may be based. 36 refs., 7 figs., 3 tabs.
Date: November 1, 1990
Creator: Whelan, G. & Sims, R. C.

Abiotic reduction of aquifer materials by dithionite: A promising in-situ remediation technology

Description: Laboratory batch and column experiments were conducted with Hanford sediments to develop the capability to predict (1) the longevity of dithionite in these systems, (2) its efficiency as a reductant of structural iron, and (3) the longevity and reactivity of the reduced iron with soluble inorganic and organic species. After an initial induction period, the loss of dithionite by disproportionation and oxidation could be described by pseudo-first-order (PFO) kinetics. Other than the initial reaction with ferric iron, the primary factor promoting loss of dithionite in this system was disproportion nation via heterogeneous catalysis at mineral surfaces. The efficiency of the reduction of structural iron was nearly 100% for the first fourth of the ferric iron, but declined exponentially with higher degrees of reduction so that 75% of the ferric iron could be reduced. This decrease in reduction efficiency probably was related to differences in the accessibility of ferric iron in the mineral particles, with iron in clay-sized particles being the most accessible and that in silt- and sand-sized particles less accessible. Flow-through column studies showed that a reduced-sediment barrier created in this manner could maintain a reducing environment.
Date: November 1, 1994
Creator: Amonette, J.E.; Szecsody, J.E.; Schaef, H.T.; Gorby, Y.A.; Fruchter, J.S. & Templeton, J.C.

Ablation Front Rayleigh-Taylor Growth Experiments in Spherically Convergent Geometry

Description: Experiments were performed on the Nova laser, using indirectly driven capsules mounted in cylindrical gold hohlraums, to measure the Rayleigh-Taylor growth at the ablation front by time-resolved radiography. Modulations were preformed on the surface of Ge-doped plastic capsules. With initial modulations of 4 {micro}m, growth factors of about 6 in optical depth were seen, in agreement with simulations using the radiation hydrocode FCI2. With initial modulations of 1 {micro}m, growth factors of about 100-150 in optical depth were seen. The Rayleigh-Taylor (RT) instability at the ablation front in an inertial confinement fusion capsule has been the subject of considerable investigation. Much of this research has been concentrated on planar experiments, in which RT growth is inferred from radiography. The evolution is somewhat different in a converging geometry; the spatial wavelength decreases (affecting the onset of nonlinear saturation), and the shell thickens and compresses rather than decompressing as in a planar geometry. In a cylindrically convergent geometry, the latter effect is proportional to the radius, while in spherically convergent geometry, the latter effect is proportional to the radius squared. Experiments were performed on the Nova and Omega lasers in cylindrical geometry (using both direct and indirect drive) and have been performed in spherical geometry using direct drive.
Date: November 3, 1999
Creator: Glendinning, S.G.; Cherfils, C.; Colvin, J.; Divol, L.; Galmiche, D.; Haan, S. et al.

Abortion Procedures

Description: The Partial-Birth Abortion Ban Act of 1997, H.R. 1122 was vetoed by President Clinton on October 10, 1997. This legislation would have made it a federal crime, punishable by fine and/or incarceration, for a physician to perform a partial birth abortion unless it was necessary to save the life of a mother whose life is endangered by a physical disorder, illness, or injury. The partial-birth abortion legislation has stimulated a great deal of controversy. This report provides a brief overview of the abortion methods currently in use for which data have been published and some positions on the partial birth abortion legislation.
Date: November 17, 1997
Creator: Stith-Coleman, Irene

Absolute CH radical concentrations in rich low-pressure methane-oxygen-argon flames via cavity ringdown spectroscopy of the A transition

Description: We measure cavity ringdown spectra of the A{sup 2}{Delta}-X{sup 2}II transition of the methylidyne (CH) radical in a series of rich low-pressure methane-oxygen-argon flames and demonstrate that the technique is sensitive, quantitative, and straightforward in its implementation and interpretation. As a line-of-sight technique, it complements imaging techniques, such as planar laser-induced fluorescence. Our results generally agree with chemical kinetic models for methane oxidation that have appeared in the literature, but suggest some refinements are necessary. Additional examination of the CH + O{sub 2} reaction rate as a function of temperature is advised. Our results are consistent with those of Derzy et al. using the C{sup 2}{Sigma}{sup +}-X{sup 2}II transition for stoichiometric, low-pressure flames which include nitrogen. Our results for rich flames, as with earlier experiments for singlet methylene, suggest that flame chemical kinetic models need to be adjusted to account for flame chemistry for stoichiometries richer than {phi} = 1.5.
Date: November 22, 1999
Creator: John W. Thomas, Jr & McIlroy, Andrew

Absolute wavefront measurements of high-energy laser beams in the Beamlet Demonstration Project for the National Ignition Facility

Description: The authors measure the absolute wavefront of Beamlet output pulses and actively correct for slowly varying aberrations present when the power amplifiers are not fired. Provision is also made for active precompensation of pump-induced amplifier aberrations.
Date: November 1, 1994
Creator: Salmon, J.T.; Bliss, E.S.; Kartz, M.W. & Van Wonterghem, B.M.

Absorption of laser light in overdense plasmas by sheath inverse bremsstrahlung

Description: The original sheath inverse bremsstrahlung model [P. J. Catto and R. M. More, 1977] is modified by including the vxB term in the equation of motion. It is shown that the present results axe significantly different from those derived without the vxB term. The vxB term is also important in interpreting the absorption mechanism. If the vxB term were neglected, the absorption of the light would be incorrectly interpreted as an increase in the transverse electron temperature. This would violate the conservation of the transverse components of the canonical momentum, in the case of a normally incident laser light. It is also shown that both the sheath inverse bremsstrahlung and the anomalous skin effect are limiting cases of the same collisionless absorption mechanism. Finally, results from PIC plasma simulations are compared with the absorption coefficient calculated from the linear theory.
Date: November 1, 1994
Creator: Yang, T.Y.B.; Kruer, W.L. & More, R.M.

Absorption of undulator radiation in media

Description: Detailed thermal stress analyses of beamline and optical components subject to high heat loads require an Accurate determination of the absorbed power profile for accurate prediction of the temperature profile and structural parameters. This is particularly important for high power beams from wigglers and undulators at the third generation synchrotron sources because components must, in general, be designed and maintained with strict mechanical tolerances. The spatial distribution of the power density of an undulator is a rapidly varying function of the energy of the photons suggesting that approximative methods based on a smooth spectral variation may not be valid. In this paper, a fast code for calculating undulator spectra is developed and compared with a wiggler code for approximation of the same spectra. Results from numerical simulations, including the emittance of the stored particle beam, are presented for the absorbed power density in a beryllium window. We find markedly different results for the two models for far off-axis radiation indicating the inadequacy of the wiggler model applied to an undulator spectrum in this case. The wiggler model overestimates the total absorbed power by as much as 82% for the beryllium window.
Date: November 1, 1992
Creator: Dejus, R. J.; Lai, B. & Khounsary, A. M.

Abstracted model for ceramic coating

Description: Engineers are exploring several mechanisms to delay corrosive attack of the CAM (corrosion allowance material) by dripping water, including drip shields and ceramic coatings. Ceramic coatings deposited with high-velocity oxyfuels (HVOF� s) have exhibited a porosity of only 2% at a thickness of 0.15 cm. The primary goal of this document is to provide a detailed description of an abstracted process-level model for Total System Performance Assessment (TSPA) that has been developed to account for the inhibition of corrosion by protective ceramic coatings. A second goal was to address as many of the issues raised during a recent peer review as possible (direct reaction of liquid water with carbon steel, stress corrosion cracking of the ceramic coating, bending stresses in coatings of finite thickness, limitations of simple correction factors, etc.). During the periods of dry oxidation (T 2 100°C) and humid-air corrosion (T I 100°C & RH < SO%), it is assumed that the growth rate of oxide on the surface is diminished in proportion to the surface covered by solid ceramic. The mass transfer impedance imposed by a ceramic coating with gas-filled pores is assumed to be negligible. During the period of aqueous phase corrosion (T I 100°C & RH > 80%), it is assumed that the overall mass transfer resistance governing the corrosion rate is due to the combined resistance of ceramic coating & interfacial corrosion products. Two porosity models (simple cylinder & cylinder-sphere chain) are considered in estimation of the mass transfer resistance of the ceramic coating. It is evident that substantial impedance to 02 transport is encountered if pores are filled with liquid water. It may be possible to use a sealant to eliminate porosity. Spallation (rupture) of the ceramic coating is assumed to occur if the stress introduced by the expanding corrosion products at the ...
Date: November 14, 1998
Creator: Farmer, J C & Stockman, C

AC microcalorimetry of adsorbates on evaporated metal films: Orientational ordering of H sub 2 multilayers

Description: We have improved and extended a novel ac calorimetric technique for measuring the heat capacity of adsorbates on evaporated metal films. Metallic substrates are of particular interest in current studies of the thermodynamics of adsorbed molecules. The method described in the present work is only calorimetric technique which allows measurements of molecules on simple metallic surfaces. Among other improvements, we have achieved significant progress in the preparation and characterization of the evaporated metal film. We have applied this novel technique to a study of hydrogen multilayers on gold and sapphire substrates. We have shown that samples of normal-hydrogen with a nominal coverage n of approximately 25 monolayers (ML) undergo a bulk-like orientational ordering transition. The transition is suppressed as the coverage is decreased, and no sign of the transition remains above 1.6 K for n {approx} 1 ML. For n {approx lt} 8 ML, the peak in the heat capacity exhibits signs of finite-size effects. At higher coverages, finite-size effects are not observed, and the shape of the peak depends strongly on the substrate. We conclude that the peak is inhomogeneously broadened for n {approx lt} 8 ML. This work represents the first measurements of the heat capacity due to orientational ordering in adsorbed hydrogen. The results of an earlier experiment involving vibrational spectroscopy of adsorbed molecules are included in the Appendix. In this work, we have used infrared emission spectroscopy to study the spectral region in the vicinity of the C=O stretch vibration of bridge-bonded CO on Pt(111).
Date: November 1, 1991
Creator: Phelps, R.B.

AC microcalorimetry of adsorbates on evaporated metal films: Orientational ordering of H{sub 2} multilayers

Description: We have improved and extended a novel ac calorimetric technique for measuring the heat capacity of adsorbates on evaporated metal films. Metallic substrates are of particular interest in current studies of the thermodynamics of adsorbed molecules. The method described in the present work is only calorimetric technique which allows measurements of molecules on simple metallic surfaces. Among other improvements, we have achieved significant progress in the preparation and characterization of the evaporated metal film. We have applied this novel technique to a study of hydrogen multilayers on gold and sapphire substrates. We have shown that samples of normal-hydrogen with a nominal coverage n of approximately 25 monolayers (ML) undergo a bulk-like orientational ordering transition. The transition is suppressed as the coverage is decreased, and no sign of the transition remains above 1.6 K for n {approx} 1 ML. For n {approx_lt} 8 ML, the peak in the heat capacity exhibits signs of finite-size effects. At higher coverages, finite-size effects are not observed, and the shape of the peak depends strongly on the substrate. We conclude that the peak is inhomogeneously broadened for n {approx_lt} 8 ML. This work represents the first measurements of the heat capacity due to orientational ordering in adsorbed hydrogen. The results of an earlier experiment involving vibrational spectroscopy of adsorbed molecules are included in the Appendix. In this work, we have used infrared emission spectroscopy to study the spectral region in the vicinity of the C=O stretch vibration of bridge-bonded CO on Pt(111).
Date: November 1, 1991
Creator: Phelps, R. B.

Accelerated alpha radiation damage in a ceramic waste form, interim results

Description: Interim results are presented on the alpha-decay damage study of a {sup 238}Pu-loaded ceramic waste form (CWF). The waste form was developed to immobilize fission products and transuranic species accumulated from the electrometallurgical treatment of spent nuclear fuel. To evaluate the effects of {alpha}-decay damage on the waste form the {sup 238}Pu-loaded material was analyzed by (1) x-ray diffraction (XRD), (2) microstructure characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy and wavelength dispersive spectroscopy (EDS/WDS) and electron diffraction, (3) bulk density measurements and (4) waste form durability, performed by the product consistency test (PCT). While the predominate phase of plutonium in the CWF, PuO{sub 2}, shows the expected unit cell expansion due to {alpha}-decay damage, currently no significant change has occurred to the macro- or microstructure of the material. The major phase of the waste form is sodalite and contains very little Pu, although the exact amount is unknown. Interestingly, measurement of the sodalite phase unit cell is also showing very slight expansion; again, presumably from {alpha}-decay damage.
Date: November 11, 1999
Creator: Frank, S. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T. P.; Sinkler, W.; Esh, D. et al.

Accelerated Leach Test Development Program Annual Report: 1990

Description: In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs.
Date: November 1990
Creator: Fuhrmann, M.; Pietrzak, R. F.; Heiser, J.; Franz, E. M. & Colombo, P.

Accelerated line-by-line calculations for the radiative transfer of trace gases related to climate studies. Progress report No. 1, 15 September 1993--14 September 1994

Description: In the present study we are studying the effects of including carbon dioxide, ozone, methane, and the halocarbons in addition to water vapor in the radiating atmosphere. The study has focused on two principal issues: the effect on the spectral fluxes and cooling rates of carbon dioxide, ozone and the halocarbons at 1990 concentration levels and the change in fluxes and cooling rates as a consequence of the anticipated ten year change in the profiles of these species. For the latter study the water vapor profiles have been taken as invariant in time. The radiative line-by-line calculations using LBLRTM (Line-By-Line Radiative Transfer Model) have been performed for tropical (TRP), mid-latitude winter (MLW) and mid-latitude summer (MLS) model atmospheres. The halocarbons considered in the present study are CCl{sub 4}, CFC-11, CFC-12 and CFC-22. In addition to considering the radiative effects of carbon dioxide at 355 ppM, the assumed current level, we have also obtained results for doubled carbon dioxide at 710 ppM. An important focus of the current research effort is the effect of the ozone depletion profile on atmospheric radiative effects.
Date: November 15, 1993
Creator: Clough, S. A.

Accelerated safety analyses - structural analyses Phase I - structural sensitivity evaluation of single- and double-shell waste storage tanks

Description: Accelerated Safety Analyses - Phase I (ASA-Phase I) have been conducted to assess the appropriateness of existing tank farm operational controls and/or limits as now stipulated in the Operational Safety Requirements (OSRs) and Operating Specification Documents, and to establish a technical basis for the waste tank operating safety envelope. Structural sensitivity analyses were performed to assess the response of the different waste tank configurations to variations in loading conditions, uncertainties in loading parameters, and uncertainties in material characteristics. Extensive documentation of the sensitivity analyses conducted and results obtained are provided in the detailed ASA-Phase I report, Structural Sensitivity Evaluation of Single- and Double-Shell Waste Tanks for Accelerated Safety Analysis - Phase I. This document provides a summary of the accelerated safety analyses sensitivity evaluations and the resulting findings.
Date: November 1, 1994
Creator: Becker, D. L.

Accelerated screening methods for predicting lubricant performance in refrigerant compressors: Final report

Description: The tribological characteristics of various lubricant/refrigerant mixtures have been experimentally investigated by means of a unique high pressure tribometer (HPT). In order to identify more effective bench testers for screening lubricants for compressors, a comparison is made between data obtained from the HPT, Four Ball and Falex{trademark} testers, and those obtained from accelerated component (compressor) tests. Part 1 of this study is geared toward a comparison between data obtained from a Falex specimen tester and those obtained by the HPT. The main purpose of this comparison was to determine if the controlled environment and the lower loads used with the HPT produce different rankings than those obtained from the Falex tests. The results obtained from the HPT gave a consistent ranking a different loads and speeds and this ranking did not always correlate with that obtained from the Falex tester. In Part 2, the HPT is used to approximately simulate specific critical contacts in compressors to determine the degree to which it could predict lubricant performance. A comparison is made between data obtained from component tests and those obtained from the HPT. For comparison purposes, each lubricant is also tested and ranked based on results obtained in an air environment with both the HPT and a Four Ball machine. Based on wear data, the rankings of the lubricants obtained from the various testers are compared to the lubricant rankings obtained from the component tests. Assuming that the component data are correct, this comparison shows that approximately a 65% accuracy is obtained by means of the HPT operating in a pressurized refrigerant environment and that this accuracy is essentially the same as the accuracy with the HPT operating in an air environment, the Falex tester and the Four Ball tester.
Date: November 1, 1994
Creator: Cusano, C.; Yoon, H. & Poppe, C.

Acceleration amplifications in nif structures subjected to earthquake base motions

Description: NIF technical staff have questioned the possibility of obtaining acceleration amplifications (i.e. amplification of the ground acceleration values) in a structure which are significantly higher than the acceleration amplification exhibited across the period range in the input response spectrum. This note utilizes a simple example to illustrate that the acceleration amplification resulting from the dynamic response of a structural system can indeed be significantly higher than the amplifications indicated in the response spectrum, and that the GEMINI program is computing the appropriate acceleration levels for a simple MDOF system.
Date: November 29, 1999
Creator: McCallen, D

Acceleration of the remediation process through interim action

Description: During the Remedial Investigation and Feasibility Study (RI/FS) phase of a CERCLA cleanup, it is possible to implement interim actions at a site ``to respond to an immediate site threat or take advantage of an opportunity to significantly reduce risk quickly.`` An interim action is a short term action that addresses threats to public health and safety and is generally followed by the RI/FS process to achieve complete long term protection of human health and the environment. Typically, an interim action is small in scope and can be implemented quickly to reduce risks, such as the addition of a security fence around a known or suspected hazard, or construction of a temporary cap to reduce run-on/run-off from a contaminant source. For more specialized situations, however, the possibility exists to apply the intent of the interim action guidance to a much larger project scope. The primary focus of this paper is the discussion of the interim action approach for streamlined remedial action and presentation of an example large-scale project utilizing this approach at the Fernald Environmental Management Project (FEMP).
Date: November 1, 1993
Creator: Clark, T. R.; Throckmorton, J. D.; Hampshire, L. H.; Dalga, D. G. & Janke, R. J.

Accelerator-driven assembly for plutonium transformation (ADAPT)

Description: A particle accelerator-driven spallation target and corresponding blanket region are proposed for the ultimate disposition of weapons-grade plutonium being retired from excess nuclear weapons in the US and Russia. The highly fissile plutonium is contained within .25 to .5 cm diameter silicon-carbide coated graphite beads, which are cooled by helium, within the slightly subcritical blanket region. Major advantages include very high one-pass burnup (over 90 %), a high integrity waste form (the coated beads), and operation in a subcritical mode, thereby minimizing the vulnerability to the positive reactivity feedbacks often associated with plutonium fuel.
Date: November 1, 1994
Creator: Van Tuyle, G. J.; Todosow, M.; Powell, J. & Schweitzer, D.

Accelerator production of tritium plant design and supporting engineering development and demonstration work

Description: Tritium is an isotope of hydrogen with a half life of 12.3 years. Because it is essential for US thermonuclear weapons to function, tritium must be periodically replenished. Since K reactor at Savannah River Site stopped operating in 1988, tritium has been recycled from dismantled nuclear weapons. This process is possible only as long as many weapons are being retired. Maintaining the stockpile at the level called for in the present Strategic Arms Reduction Treaty (START-I) will require the Department of Energy to have an operational tritium production capability in the 2005--2007 time frame. To make the required amount of tritium using an accelerator based system (APT), neutrons will be produced through high energy proton reactions with tungsten and lead. Those neutrons will be moderated and captured in {sup 3}He to make tritium. The APT plant design will use a 1,700 MeV linear accelerator operated at 100 mA. In preparation for engineering design, starting in October 1997 and subsequent construction, a program of engineering development and demonstration is underway. That work includes assembly and testing of the first 20 MeV of the low energy plant linac at 100 mA, high-energy linac accelerating structure prototyping, radiofrequency power system improvements, neutronic efficiency measurements, and materials qualifications.
Date: November 1, 1997
Creator: Lisowski, P.W.