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- High speed data transmission for the SSC solenoidal detector
- High speed data transmission using fiber optics for the Superconducting Super Collider solenoidal detector has been studied. The solenoidal detector system will consist of nine subsystems involving more than a total 10{sup 7} channels of readout electronics. Consequently, a new high performance data acquisition system, incorporating high-speed optical fiber networks, will be required to process this large quantity of data. 15 refs., 3 figs., 1 tab.
- Regulatory compliance issues related to the White Oak Creek Embayment time-critical removal action
- In September 1990, Martin Marietta Energy Systems (Energy Systems) discovered high levels of Cesium-137 ({sup 137}Cs) in surface sedimenus near the mouth of White Oak Creek Embayment (WOCE). White Oak Creek (WOC) receives surface water drainage from Oak Ridge National Laboratory. Since this discovery, the Department of Energy (DOE) and Energy Systems have pursued actions designed to stabilize the contaminated WOCE sediments under provisions of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and the implementing regulations in the National Contingency Plan (NCP) (40 CFR Part 300), as a time-critical removal action. By definition, a time-critical removal is an action where onsite activities are initiated within six months of the determination that a removal action is appropriate. Time-critical removal actions allow comparatively rapid mobilization to protect human health and the environment without going through the lengthy and extensive CERCLA Remedial Investigation/Feasibility Study/Record of Decision process. Many aspects of the project, in terms of compliance with the substantive requirements of the NCP and ARARs, have exceeded the regulatory requirements, despite the fact that there is no apparent authority on conducting removal actions at Federal facilities. Much of the interpretation of the NCP was groundbreaking in nature for both EPA and DOE. 4 refs., 2 figs.
- Heat transfer coefficient in serpentine coolant passage for CCDTL
- A series of heat transfer experiments were conducted to refine the cooling passage design in the drift tubes of a coupled cavity drift tube linac (CCDTL). The experimental data were then compared to numerical models to derive relationships between heat transfer rates, Reynold`s number, and Prandtl number, over a range of flow rates. Data reduction consisted of axisymmetric finite element modeling where the heat transfer coefficients were modified to match the experimental data. Unfortunately, the derived relationship is valid only for this specific geometry of the test drift tube. Fortunately, the heat transfer rates were much better (approximately 2.5 times) than expected.
- Evolution of environmental protection strategies in the Soviet Union
- In performing this work, interviews were conducted with members of the Supreme Soviet Committee for Rational Use of Natural Resources, Moscow, City Council, and St. Petersburg City Council. These officials provided their views on the current status of environmental protection in the former Soviet Union. Literature published in English, although limited, supplemented these discussions. In addition, a literature search was conducted of recent articles about this topic. Although the research for this paper was conducted before and during the August 1991 coup attempt in the Soviet Union, and after the formation of the Commonwealth of Independent States (CIS), many of the observations expressed in this report may be relevant to the new states. This report provides to historical perspective on the barriers encountered while attempting to develop environmental policy in the former Soviet Union and establishes a context for problems facing the new states in developing their environmental policies. Organization changes that have occurred in environmental protection since the August coup are included to the extent they are known.
- Integration of site-specific health information: Agency for Toxic Substances and Disease Registry health assessments
- The Agency for Toxic Substances and Disease Registry is required to conduct a health assessment of any site that is listed on or proposed for the US Environmental Protection Agency's National Priorities List. Sixteen US Department of Energy (DOE) sites currently fall into this category. Health assessments contain a qualitative description of impacts to public health and the environment from hazardous waste sites, as well as recommendations for actions to mitigate or eliminate risk. Because these recommendations may have major impacts on compliance activities at DOE facilities, the health assessments are an important source of information for the monitoring activities of DOE's Office of Environmental Compliance (OEC). This report provides an overview of the activities involved in preparing the health assessment, its role in environmental management, and its key elements.
- Global climate change policy issues related to the movement of industry from developed to rapidly industrializing countries
- Global climate change policies adopted by developed countries may encourage industries to move to countries with less restrictive policies. The purpose of this study is to identify policy-driven issues that may result in such a movement. This report (1) summarizes the conclusions of previous studies that have explored the relationship between environmental regulations and industrial movement, (2) identifies and summarizes existing and proposed US global climate change policy options, and (3) discusses issues and topics relating to possible industrial relocation because of the global climate change policy options. It concludes with recommendations for further research. Although federal global climate change policy options are the primary focus of this report, some international and regional efforts addressing this issue are also included. A potential regional industrial migration issue is highlighted. 14 refs., 2 figs., 3 tabs.
- A review of occupational safety and health issues relevant to the Environmental Restoration Program: Selected case histories and associated issues
- Since the 1940s, US Department of Energy (DOE) sites have been used for nuclear materials processing and production, warhead testing, and weapons research and development. These activities have resulted in extensive environmental contamination. DOE has established a goal to cleanup and restore the groundwater, soils, sediments, and surface water at its facilities across the nation. To achieve this goal, many workers will be needed to conduct the cleanup. These workers will need training and will be required to follow occupational safety and health (OSH) regulations and guidelines. Compliance with the OSH regulations and guidelines will have an anomous influence on the schedule, money, and technology needed for environmental restoration. Therefore, one area that must be considered in the early stages of long-term planning is the impact of OSH issues on the environmental restoration process. The DOE Office of Environmental Restoration and Waste Management has requested that the Pacific Northwest Laboratory (PNL) investigate the impact of these issues on the environmental restoration process.
- A review of occupational safety and health issues relevant to the environmental restoration program: Selected case histories and associated issues
- This report describes a study conducted by Pacific Northwest Laboratory (PNL) to determine the impact of occupational safety and health (OSH) issues on the environmental restoration process at US Department of Energy sites. PNL selected three remediation projects to study: (1) the 618-9 Burial Ground Expedited Removal Action at the Hanford Site, (2) the Chemical Consolidation Interim Response Action at the Weldon Spring Site, (3) and the 200 West Area Carbon Tetrachloride Expedited Removal Action and VOC-Arid Integration Demonstration at the Hanford Site. The first two case studies involve sites where a remediation activity has been complete. The third case study involves a remediation activity in its early stages of development. This study identifies OSH issues related to actual cleanup, time, documentation, training, and technology development. These issues need to be considered by DOE before making long-term planning efforts. Section 4.0 of this report describes recommendations for addressing these issues.
- A review of occupational safety and health issues relevant to the environmental restoration program: Selected case histories and associated issues
- This report describes a study conducted by Pacific Northwest Laboratory (PNL) to determine the impact of occupational safety and health (OSH) issues on the environmental restoration process at US Department of Energy sites. PNL selected three remediation projects to study: (1) the 618-9 Burial Ground Expedited Removal Action at the Hanford Site, (2) the Chemical Consolidation Interim Response Action at the Weldon Spring Site, (3) and the 200 West Area Carbon Tetrachloride Expedited Removal Action and VOC-Arid Integration Demonstration at the Hanford Site. The first two case studies involve sites where a remediation activity has been complete. The third case study involves a remediation activity in its early stages of development. This study identifies OSH issues related to actual cleanup, time, documentation, training, and technology development. These issues need to be considered by DOE before making long-term planning efforts. Section 4.0 of this report describes recommendations for addressing these issues.
- Evolution of environmental protection strategies in the Soviet Union
- In performing this work, interviews were conducted with members of the Supreme Soviet Committee for Rational Use of Natural Resources, Moscow, City Council, and St. Petersburg City Council. These officials provided their views on the current status of environmental protection in the former Soviet Union. Literature published in English, although limited, supplemented these discussions. In addition, a literature search was conducted of recent articles about this topic. Although the research for this paper was conducted before and during the August 1991 coup attempt in the Soviet Union, and after the formation of the Commonwealth of Independent States (CIS), many of the observations expressed in this report may be relevant to the new states. This report provides to historical perspective on the barriers encountered while attempting to develop environmental policy in the former Soviet Union and establishes a context for problems facing the new states in developing their environmental policies. Organization changes that have occurred in environmental protection since the August coup are included to the extent they are known.
- Cost-Effectiveness of Compact Fluorescent Lighting
- Compact fluorescent technologies have been steadily improving. There has been increased interest in utilizing compact fluorescents to provide cost-effective energy savings for electric utilities in the residential sector. Several utilities in the United States have already distributed compact fluorescents to consumers free of charge. This study assesses the cost-effectiveness of compact fluorescents from the perspectives of consumers and utilities in the Pacific Northwest, where electricity rates are, on average, the lowest in the United States. The study also assesses cost-effectiveness from a societal perspective. Secondary hearing impacts and the value of reduced emissions of pollutants are incorporated into the analysis. Results indicate that compact fluorescents are more likely to be cost-effective as the perspective upon which they are assessed is broadened. Thus, they are least likely to be viewed as cost-effective by consumers, more likely to be considered cost-effective from a utility perspective, and almost always cost-effective from a societal perspective. Given these differences, is is suggested that policies be developed to capture the societal benefits of compact fluorescent retrofits through alternative regulatory or market mechanisms.
- Cost-effectiveness of compact fluorescent lighting. Retrofits for residential consumers in the Pacific Northwest
- Compact fluorescent technologies have been steadily improving. There has been increased interest in utilizing compact fluorescents to provide cost-effective energy savings for electric utilities in the residential sector. Several utilities in the United States have already distributed compact fluorescents to consumers free of charge. This study assesses the cost-effectiveness of compact fluorescents from the perspectives of consumers and utilities in the Pacific Northwest, where electricity rates are, on average, the lowest in the United States. The study also assesses cost-effectiveness from a societal perspective. Secondary hearing impacts and the value of reduced emissions of pollutants are incorporated into the analysis. Results indicate that compact fluorescents are more likely to be cost-effective as the perspective upon which they are assessed is broadened. Thus, they are least likely to be viewed as cost-effective by consumers, more likely to be considered cost-effective from a utility perspective, and almost always cost-effective from a societal perspective. Given these differences, is is suggested that policies be developed to capture the societal benefits of compact fluorescent retrofits through alternative regulatory or market mechanisms.
- Geothermal : Economic Impacts of Geothermal Development in Skamania County, Washington.
- This report estimates the local economic impacts that could be anticipated from the development of a 100 megawatt (MW) geothermal power plant in eastern Skamania County, Washington, near Mt. Adams, as shown in Figure 1. The study was commissioned by the Bonneville Power Administration to quantify such impacts as part of regional confirmation work recommended by the Northwest Power Planning Council. Skamania County was chosen due to both identified geothermal resources and developer interest. The analysis will focus on two phases: a plant construction phase, including well field development, generating plant construction, and transmission line construction; and an operations phase. Economic impacts will occur to the extent that construction and operations affect the local economy. These impacts will depend on the existing structure of the Skamania County economy and estimates of revenues that may accrue to the county as a result of plant construction, operation, and maintenance. Specific impacts may include additional direct employment at the plant, secondary impacts from wage payments being used to purchase locally produced goods and services, and impacts due to expenditures of royalty and tax payments received by the county. The basis for the analysis of economic impacts in this study is the US Forest Service IMPLAN input-output modeling system.
- Geothermal : Economic Impacts of Geothermal Development in Whatcom County, Washington.
- This report estimates the local economic impacts that could be anticipated from the development of a 100 megawatt (MW) geothermal power plant in eastern Whatcom County, Washington, near Mt. Baker, as shown in Figure 1. The study was commissioned by the Bonneville Power Administration to quantify such impacts as part of regional confirmation work recommended by the Northwest Power Planning Council. Whatcom County was chosen due to both identified geotherrnal resources and developer interest. The analysis will focus on two phases: a plant construction phase, including well field development, generating plant construction, and transmission line construction; and an operations phase. Economic impacts will occur to the extent that construction and operations affect the local economy. These impacts will depend on the existing structure of the Whatcom County economy and estimates of revenues that may accrue to the county as a result of plant construction, operation, and maintenance. Specific impacts may include additional direct employment at the plant, secondary impacts from wage payments being used to purchase locally produced goods and services, and impacts due to expenditures of royalty and tax payments received by the county. The basis for the analysis of economic impacts in this study is the US Forest Service IMPLAN input-output modeling system.
- Genomic plasticity and catabolic potential of Pseudomonas cepacia
- The primary goal of this project was to gain information about the size and organization of the genome of Burkholderia cepacia (formerly Pseudomonas cepacia), a microbe which continues to attract attention because of its extraordinary degradative abilities and potential as an agent of bioremediation. This bacterium is no longer considered to be a member of genus Pseudomonas nor does it belong in the gamma-subclass of the proteobacteria, in which the authentic pseudomonads are grouped. It belongs in the less well characterized beta-subclass of the proteobacteria. Technology for manipulation of large DNA fragments developed by Cantor was used to demonstrate that chromosomal multiplicity, a characteristic yet to be observed in a gamma-subclass bacterium, is common among B. cepacia strains. A derivative of Tn5 suitable for determining the chromosomal locations of various B. cepacia genes was also constructed.
- Development of DU-AGG (Depleted Uranium Aggregate)
- Depleted uranium oxide (UO{sub 2} or U0{sub 3}) powder was mixed with fine mineral additives, pressed, and heated to about 1,250{degree}C. The additives were chemically constituted to result in an iron-enriched basalt (IEB). Melting and wetting of the IEB phase caused the urania powder compact to densify (sinter) via a liquid phase sintering mechanism. An inorganic lubricant was found to aid in green-forming of the body. Sintering was successful in oxidizing (air), inert (argon), or reducing (dry hydrogen containing) atmospheres. The use of ground U0{sub 3} powders (93 vol %) followed by sintering in a dry hydrogen-containing atmosphere significantly increased the density of samples (bulk density of 8.40 g/cm{sup 3} and apparent density of 9.48 g/cm{sup 3}, open porosity of 11.43%). An improvement in the microstructure (reduction in open porosity) was achieved when the vol % of U0{sub 3} was decreased to 80%. The bulk density increased to 8.59 g/cm{sup 3}, the apparent density decreased slightly to 8.82 g/cm{sup 3} (due to increase of low density IEB content), while the open porosity decreased to an excellent number of 2.78%. A representative sample derived from 80 vol % U0{sub 3} showed that most pores were closed pores and that, overall, the sample achieved the excellent relative density value of 94.1% of the estimated theoretical density (composite of U0{sub 2} and IEB). It is expected that ground powders of U0{sub 3} could be successfully used to mass produce lowcost aggregate using the green-forming technique of briquetting.
- Development of `DUCRETE`
- This interim report covers theoretical and experimental aspects of a series of scoping tests using depleted uranium oxide pieces as aggregate in portland cement to form concrete (DUCRETE). DUCRETE is expected to provide a high integrity material suitable for shielding in spent nuclear fuel containers or for direct disposal in a low- level waste repository. The uranium oxide would produced by conversion of depleted UF{sub 6} stored by the Department of Energy.
- DU-AGG pilot plant design study
- The Idaho National Engineering Laboratory (INEL) is developing new methods to produce high-density aggregate (artificial rock) primarily consisting of depleted uranium oxide. The objective is to develop a low-cost method whereby uranium oxide powder (UO[sub 2], U[sub 3]O[sub ]8, or UO[sub 3]) can be processed to produce high-density aggregate pieces (DU-AGG) having physical properties suitable for disposal in low-level radioactive disposal facilities or for use as a component of high-density concrete used as shielding for radioactive materials. A commercial company, G-M Systems, conducted a design study for a manufacturing pilot plant to process DU-AGG. The results of that study are included and summarized in this report. Also explained are design considerations, equipment capacities, the equipment list, system operation, layout of equipment in the plant, cost estimates, and the proposed plan and schedule.
- ROCTECtm STABILIZATION TREATMENT OF WERF ASH
- The objective of this project is to demonstrate a process to stabilize mixed waste flyash generated by the combustion of mixed waste at the Idaho National Engineering & Environmental Laboratory's (INEEL's) Waste Experimental Reduction Facility (WERF) incinerator such that it will meet Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDRs) Universal Treatment Standards.
- Bremsstrahlung pair-production of positrons with low neutron background.
- Minimization of component activation is highly desirable at accelerator-based positron sources. Electrons in the 8- to 14-MeV energy range impinging on a target produce photons energetic enough to create electron-positron pairs; however, few of the photons are energetic enough to produce photoneutrons. Slow positron production by low-energy electrons impinging on a multilayer tungsten target with and without electromagnetic extraction between the layers was studied by simulation. The neutron background from 14-MeV electrons is expected to be significantly lower than that encountered with higher-energy electron beams. Numerical results are presented and some ideas for a low-activation slow-positron source are discussed.
- Effects of vertical girder realignment in the Argonne APS storage ring.
- The effects of vertical girder misalignments on the vertical orbit of the Advanced Photon Source (APS) storage ring are studied. Partial sector-realignment is prioritized in terms of the closed-orbit distortions due to misalignments of the corresponding girders in the sectors. A virtual girder-displacement (VGD) method is developed that allows the effects of a girder realignment to be tested prior to physically moving the girder. The method can also be used to anticipate the corrector strengths needed to restore the beam orbit after a realignment. Simulation results are compared to experimental results and found to reproduce the latter quite closely. Predicted corrector strengths are also found to be close to the actual local corrector strengths after a proof-of-principle two-sector realignment was performed.
- Studies of slow-positron production using low-energy primary electron beams.
- Slow-positron beams produced from negative-work-function solid-state moderators have found numerous applications in condensed matter physics. There are potential advantages in using low-energy primary electron beams for positron production, including reduced radiation damage to single-crystal moderators and reduced activation of nearby components. We present numerical calculations of positron yields and other beam parameters for various target-moderator configurations using the Argonne Wakefield Accelerator (AWA) [1] and Advanced Photon Source (APS) [2] electron linacs [3] as examples of sources for the primary electron beams. The status of experiments at these facilities is reviewed.
- A tracking code for injection and acceleration studies in synchrotrons
- CAPTURE-SPC is a Monte-Carlo-based tracking program that simulates the injection and acceleration processes in proton synchrotrons. The time evolution of a distribution of charged particles is implemented by a symplectic, second-order-accurate integration algorithm. The recurrence relations follow a time-stepping leap--frog method. The time-step can be varied optionally to reduce computer time. Space-charge forces are calculated by binning the phase-projected particle distribution. The statistical fluctuations introduced by the binning process are reduced by presmoothing the data by the cloud-in-cell method and by filtering. Both the bin size and amount of filtering can be varied during the acceleration cycle so that the bunch fine structure is retained while the short wavelength noise is attenuated. The initial coordinates of each macro particle together with its time of injection are retained throughout the calculations. This information is useful in determining low-loss injection schemes.
- Concepts for a slow-positron target at the advanced photon source
- The Advanced Photon Source (APS) linear accelerator beam could be used to produce slow positrons during the hours between the storage ring injection cycles. Initial concepts for the design of a target that is optimized for slow-positron production are discussed, and simulation results are presented. Some possible ways to increase the nominal linac beam power for improved slow-positron production are also discussed.
- Rf capture studies for injection into a synchrotron
- The capture process for a rapid cycling protron synchrotron is studied by numerical simulation. The rf-programming is optimized to allow efficient capture such that minimum particle losses and reasonable capture voltage are attained. The total capture time is constrained to be less than 700 {mu}seconds. Two methods of trapping the injected beam by the synchrotron rf system are examined: by stationary adiabatic capture and by synchronous injection in a standing bucket of the ring. In the adiabatic method, the non-linear function of Lilliequist and Symon is employed. The simulation allows the ``tracking back`` of the original distribution of any set of particles, in particular of those not captured at a given time, which is useful in studying injection alternatives such as shaping the phase-space density prior to injection. The simulation results will be used to design a chopper system to facilitate loss-free injection.
- Effects of imperfections on the dynamic aperture and closed orbit of the IPNS Upgrade synchrotron
- Magnet imperfections and misalignments are analyzed in terms of their effects on the dynamic aperture and closed orbit of the IPNS Upgrade synchrotron. The dynamic aperture is limited primarily by the presence of chromaticity-correcting sextupoles. With the sextupoles energized to the values required to adjust the chromaticities to zero, further reductions of the dynamic aperture caused by dipole strength and roll errors, quadrupole strength and alignment errors, and higher-order multipole errors are studied by tracking. Design specifications for the dipole corrector magnets are obtained and the dynamic aperture is studied before and after correction of the closed orbit. The use of harmonic-correcting sextupoles to reduce the amplitude-dependent tune shifts driven by the chromaticity-correcting sextupoles is investigated.
- Longitudinal tracking studies for a high intensity proton synchrotron
- Results from longitudinal tracking studies for a high intensity proton synchrotron designed for a 1-MW spallation source are presented. The machine delivers a proton beam of 0.5 mA time-averaged current at a repetition rate of 30 Hz. The accelerator is designed to have radiation levels that allow hands-on-maintenance. However, the high beam intensity causes strong space charge fields whose effects may lead to particle loss and longitudinal instabilities. The space charge fields modify the particle distribution, distort the stable bucket area and reduce the rf linear restoring force. Tracking simulations were conducted to analyze the space charge effects on the dynamics of the injection and acceleration processes and means to circumvent them. The tracking studies led to the establishment of the injected beam parameters and rf voltage program that minimized beam loss and longitudinal instabilities. Similar studies for a 10-GeV synchrotron that uses the 2-GeV synchrotron as its injector are also discussed.
- An overview of an accelerator-based neutron spallation source
- An overview of the feasibility study of a 1-MW pulsed spallation source is presented. The machine delivers 1 MW of proton beam power to spallation targets where slow neutrons are produced. The slow neutrons can be used for isotope production, materials irradiation, and neutron scattering research. The neutron source facility is based on a rapid cycling synchrotron (RCS) and consists of a 400-MeV linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The RCS accelerates an average proton beam current of 0.5 mA, corresponding to 1.04 x 10{sup 14} protons per pulse. This intensity is about two times higher than that of existing machines. A key feature of this accelerator system design is that beam losses are minimized from injection to extraction, reducing activation to levels consistent with hands-on maintenance.
- Compilation of information on modeling of inductively heated cold crucible melters
- The objective of this communication, Phase B of a two-part report, is to present information on modeling capabilities for inductively heated cold crucible melters, a concept applicable to waste immobilization. Inductively heated melters are those in which heat is generated using coils around, rather than electrodes within, the material to be heated. Cold crucible or skull melters are those in which the melted material is confined within unmelted material of the same composition. This phase of the report complements and supplements Phase A by Loren Eyler, specifically by giving additional information on modeling capabilities for the inductively heated melter concept. Eyler discussed electrically heated melter modeling capabilities, emphasizing heating by electrodes within the melt or on crucible walls. Eyler also discussed requirements and resources for the computational fluid dynamics, heat flow, radiation effects, and boundary conditions in melter modeling; the reader is referred to Eyler`s discussion of these. This report is intended for use in the High Level Waste (HLW) melter program at Hanford. We sought any modeling capabilities useful to the HLW program, whether through contracted research, code license for operation by Department of Energy laboratories, or existing codes and modeling expertise within DOE.
- Low energy positron diffraction from Cu(111): Importance of surface loss processes at large angles of incidence
- Intensities of positrons specularly diffracted from Cu(111) were measured at the Brandeis positron beam facility and analyzed in the energy range 8eV<E<134eV for angles of incidence {theta} = 25, 30, 35, 40, 45, 50, 52, 57, and 60 degrees. These intensities were calculated for the known geometry of Cu(111) using a dynamical multiple scattering methodology. Above E = 50eV this methodology gives a useful account of the measured intensities using a constant imaginary optical potential of V{sub i} = 4eV. At lower energies strong energy dependences occur associated both with multiple elastic scattering phenomena within atomic layers of Cu parallel to the surface and with the thresholds of inelastic channels (e.g., plasmon creation). Use of the free electron calculation of V{sub i} shows that energy dependence of inelastic processes is necessary to obtain a satisfactory description of the absolute magnitude of the diffracted intensities below E = 50eV. Detailed comparison of the calculated and observed diffraction intensities reveals the necessity of incorporating surface loss processes explicitly into the model in order to achieve a quantitative description of the measured intensities for E<40eV and {theta}>40{degree}. 30 refs., 5 figs., 1 tab.
- Electrically enhanced fluidized bed heat exchanger
- The experiments have shown that a high level of electrical charging can be achieved in a fluidized bed of two resistive particle types; that bed stabilization rather than increased sensible heat transport dominates low frequency electric field effects on heat transfer with most bed loadings; and, hence, that applying an oscillatory potential difference between tubes or rods in a fluidized bed of two mutual contact-charging particle species gives reduced rather than improved heat transfer. Applying an oscillatory potential difference between rods in a bed of quartz particles fluidized alone did give improved heat transfer, however. With no electric field applied, most fluidized mixes were found to give higher heat transfer rates than the average of the values when each of the two species was fluidized alone. The high level of charging observed in some mixed beds may prove of interest for some air cleanup applications; the results show that simultaneous fluidization of pairs of bipolar charging materials of similar particle size is possible without excessive agglomeration. This would be important for air cleanup.
- Harvest Management and Recovery of Snake River Salmon Stocks : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 7 of 11.
- Management measures to regulate salmon fishing harvest have grown increasingly complex over the past decade in response to the needs for improved protection for some salmon runs and to alter harvest sharing between fisheries. The development of management plans that adequately address both needs is an immensely complicated task, one that involves a multitude of stocks, each with its own migration patterns and capacity to sustain exploitation. The fishing industry that relies on these fish populations is also highly diverse. The management task is made especially difficult because the stocks are often intermingled on the fishing grounds, creating highly mixed aggregates of stocks and species on which the fisheries operate. This situation is the one confronting harvest managers attempting to protect Snake River salmon. This report provides an overview of some of the factors that will need to be addressed in assessing the potential for using harvest management measures in the recovery of Snake River salmon stocks. The major sections of the report include the following: perspectives on harvest impacts; ocean distribution and in-river adult migration timing; description of management processes and associated fisheries of interest; and altemative harvest strategies.
- Ecosystem Diagnosis and Treatment Planning Model as Applied to Supplementation : Model Description, User Guide, and Theoretical Documentation for the Model Introduced in the Summary Report Series on Supplementation in the Columbia Basin.
- This document describes the formulation and operation of a model designed to assist in planning supplementation projects. It also has application in examining a broader array of questions related to natural fish production and stock restoration. The model is referred to as the Ecosystem Diagnosis and Treatment (EDT) Model because of its utility in helping to diagnose and identify possible treatments to be applied to natural production problems for salmonids. It was developed through the Regional Assessment of Supplementation Project (RASP), which was an initiative to help coordinate supplementation planning in the Columbia Basin. The model is operated within the spreadsheet environment of Quattro Pro using a system of customized menus. No experience with spreadsheet macros is required to operate it. As currently configured, the model should only be applied to spring chinook; modifications are required to apply it to fall chinook and other species. The purpose of the model is to enable managers to consider possible outcomes of supplementation under different sets of assumptions about the natural production system and the integration of supplementation fish into that system. It was designed to help assess uncertainty and the relative risks and benefits of alternative supplementation strategies. The model is a tool to facilitate both planning and learning; it is not a predictive model. This document consists of three principal parts. Part I provides a description of the model. Part II is a guide to running the model. Part III provides theoretical documentation. In addition, a sensitivity analysis of many of the model's parameters is provided in the appendix. This analysis was used to test whether the model produces consistent and reasonable results and to assess the relative effects of specific parameter inputs on outcome.
- Spectroscopy and reaction dynamics of collision complexes containing hydroxyl radicals. Progress report, June 1, 1991--May 31, 1992
- The intermolecular bending and stretching vibrations supported by the OH (X {sup 2}{Pi}) + Ar ({sup 1}S{sub 0}) potential energy surfaces have been accessed by stimulated emission pumping (SEP) of the weakly bound OH-Ar (X {sup 2}{Pi}) complex. Virtually all of the bound vibrational levels of the complex, from the zero-point level to the dissociation limit, have been identified. OH-Ar complexes prepared in these levels undergo predissociation by using OH rotational or spin-orbit excitation to break the weak OH-Ar intermolecular bond. Perturbation theory calculations have been carried out to understand the physical origin of the dynamical processes occurring on the OH (X {sup 2}{Pi}) + Ar ({sup 1}S{sub 0}) potential energy surfaces.
- Decision-aids for enhancing intergovernmental interactions: The Pre-notification Analysis Support System (PASS)
- The Department of Energy (DOE) plans to honor its commitment to government-to-government interactions by providing advance notice of DOE spent fuel and high-level waste shipments to Indian tribes whose jurisdictions are crossed by or adjacent to transportation routes. The tribes are important contributors to a regional response network, and providing tribes with advance notice of DOE shipping plans marks the start -- not the end -- of direct, government-to-government interactions with DOE. The Tribal Prenotification Analysis Support System (PASS) is being developed for the Office of Special Programs within the Department`s Office of Environmental Restoration and Waste Management. PASS will help DOE-Headquarters to coordinate field office activities and provide technical and institutional support to the DOE field offices. PASS is designed to be used by anyone with minimum computer literacy and having contemporary computer hardware and software. It uses on-screen maps to choose and display a shipment route, and to display the tribal jurisdictions. With forms that are easy to understand, it provides information about each jurisdiction and points of contact. PASS records all contacts, commitments made, and actions taken.
- Spectroscopy and reaction dynamics of collision complexes containing hydroxyl radicals
- The intermolecular bending and stretching vibrations supported by the OH (X {sup 2}{Pi}) + Ar ({sup 1}S{sub 0}) potential energy surfaces have been accessed by stimulated emission pumping (SEP) of the weakly bound OH-Ar (X {sup 2}{Pi}) complex. Virtually all of the bound vibrational levels of the complex, from the zero-point level to the dissociation limit, have been identified. OH-Ar complexes prepared in these levels undergo predissociation by using OH rotational or spin-orbit excitation to break the weak OH-Ar intermolecular bond. Perturbation theory calculations have been carried out to understand the physical origin of the dynamical processes occurring on the OH (X {sup 2}{Pi}) + Ar ({sup 1}S{sub 0}) potential energy surfaces.
- Neutron induced fission of U isotopes up to 100 MeV
- We have developed a statistical model description of the neutron induced fission of U isotopes using densities of intrinsic states and spin cut off parameters obtained directly from appropriate Nilsson model single particle levels. The first chance fission cross sections are well reproduced when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second chance fission, we need to: (1) assume that the triaxial level density enhancement is washed out at an excitation energy of {approximately}7 MeV above the triaxial barriers with a width of {approximately}1 MeV, implying a {gamma} deformation for the first barriers of 10{degree} < {gamma} < 20{degree}; and (2) include pre-equilibrium particle emission in the calculations. Above an incoming neutron kinetic energy of {approximately}17 MeV our statistical model U(n,f) cross sections increasingly overestimate the experimental data when so called ``good`` optical model potentials are used to calculate the compound nucleus formation cross sections. This is not surprising since at these high energies little data exists on the scattering of neutrons to help guide the choice of optical model parameters. A satisfactory reproduction of all the available U(n,f) cross sections above 17 MeV is obtained by a simple scaling of our calculated compound nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV.
- A Set of Monte Carlo Subroutines for Treating the Physics of Compton Scattering
- A set of portable Monte Carlo subroutines is presented to treat the physics of Compton scattering. Electron binding energies are included by the modification of the Klein-Nishina probability distribution by the incoherent scattering function. In addition the scattered photon's energy is calculated by taking into account the momentum distribution of the electron. These subroutines have been verified and validated by calculating the total cross section over incident photon energies of 10 keV to 100 MeV for elements of Z=l to Z=l 00 and are within 1.08% of published values.
- Materials science and engineering
- During FY-97, work within the Materials Science and Engineering thrust area was focused on material modeling. Their motivation for this work is to develop the capability to study the structural response of materials as well as materials processing. These capabilities have been applied to a broad range of problems, which support many programs at Lawrence Livermore National Laboratory. Recent examples of structural response problems studied include material fracture (such as interface failure), damage in laser optics, the response of weapons components (such as high explosives) and the failure of composite materials. For materials processing, typical problems studied include metal forming, laser processing, casting, and heat treating. To improve our ability to model material behavior, much of the work involves developing new material models and failure models, as well as applying the codes to new problems. Most investigations involve experimental studies to gather basic information on material response and to validate codes or material models. Projects are inherently multi-disciplinary, involving several investigators with expertise in materials and mechanics. The thrust area studies for FY-97 are described in the following three articles: (1) Evolution of Anisotropic Yield Behavior; (2) Modeling of She Localization in Materials; and (3) Modeling of Casting Microstructures and Defects.
- Materials science and engineering
- During FY-96, work within the Materials Science and Engineering Thrust Area was focused on material modeling. Our motivation for this work is to develop the capability to study the structural response of materials as well as material processing. These capabilities have been applied to a broad range of problems, in support of many programs at Lawrence Livermore National Laboratory. These studies are described in (1) Strength and Fracture Toughness of Material Interfaces; (2) Damage Evolution in Fiber Composite Materials; (3) Flashlamp Envelope Optical Properties and Failure Analysis; (4) Synthesis and Processing of Nanocrystalline Hydroxyapatite; and (5) Room Temperature Creep Compliance of Bulk Kel-E.
- Evolution of grain size distribution during deformation of superplastic materials
- Grain size distribution and its evolution during superplastic deformation has been studied for two materials- ultrahigh carbon steel, which has a two phase microstructure, and a copper alloy, which has a quasi-single phase microstructure. For both materials the distribution of initial grain size is very accurately represented by a lognormal throughout the deformation history. The evolution of the parameters characterizing the log normal distribution have also been studied and found to vary in a systematic manner results. Results can be used to specify the grain size distribution as a function of strain during superplastic deformation and thus should prove useful for computational studies in which grain size distribution is evaluated.
- Superplastic deformation in two microduplex stainless steels
- The deformation behavior and mechanisms of superplastic flow in two microduplex stainless steels (SuperDux64 and Nitronic 19D) were studied at {similar_to}0.7T{sub m}. The two steels differed in initial grain size by a factor of 3. Both steels exhibited solute-drag-controlled grain boundary sliding in a high temperature {gamma}+{delta} phase field. In a lower temperature {gamma}+{sigma} phase field, the fine-grained steel ({bar L}=5{mu}m) exhibited climb-controlled grain boundary sliding and the coarser- grained steel ({bar L}=15{mu}m) exhibited solute-drag-controlled slip creep.
- An Evaluation of Power Law Breakdown in Metals, Alloys, Dispersion Hardened Materials and Compounds
- Creep at high stresses often produces strain rates that exceed those that would be predicted by a power law relationship. In this paper, we examine available high stress creep data for pure metals, solid solution alloys, dispersion strengthened powder metallurgy materials and compounds for power law breakdown (PLB). The results show that, if PLB is observed, then the onset of PLB is generally observed at about {epsilon}/D{sub eff} = 10{sup 13} m{sup -2}, where D{sub eff} is the effective diffusion coefficient incorporating lattice and dislocation pipe diffusion. The common origins of PLB for the various systems studied can be found in the production of excess vacancies by plastic deformation. Anomalous behavior in two pure metals (nickel and tungsten) and a solid solution alloy (Fe-25Cr and Fe-26Cr-1Mo) has been analyzed and provides insight into this excess vacancy mechanism. In metal systems, the onset of PLB is related to a change in the nature of the subgrain structure developed. In the PLB region, subgrains become imperfect containing dislocation tangles adjacent to the sub-boundary, and dislocation cells are evident. The dislocation tangles and cells are the source of excess vacancies and increase the creep rate above that predicted from power law creep. If subgrains do not form then PLB is not observed. In solid solution alloys, in which the dominant deformation resistance results from the interaction of solute atoms with moving dislocations, excess vacancies influence the diffusion of these solute atoms. PLB is not observed in many systems. This is attributed either to the presence of a high equilibrium vacancy concentration (because of a low activation energy for vacancy formation) or to the inability to form subgrains.
- Ultrahigh carbon steel for automotive applications
- Ultrahigh carbon steels (UHCSs), which contain 1--2.1% carbon, have remarkable structural properties for automotive application when processed to achieve fine ferrite grains with fine spheroidized carbides. When processed for high room temperature ductility, UHCS can have good tensile ductility but significantly higher strength than current automotive high strength steels. The material can also be made superplastic at intermediate temperatures and exhibits excellent die fill capability. Furthermore, they can be made hard with high compression ductility. In wire form it is projected that UHCS can exhibit extremely high strengths (5,000 MPa) for tire cord applications. Examples of structural components that have been formed from fine-grained spheroidized UHCSs are illustrated.
- Modeling microstructural evolution and the mechanical response of superplastic materials
- A model has been developed that accounts for grain growth during, superplastic flow and its subsequent influence on stress-strain-strain rate behavior. These studies are experimentally based and have involved two different types of superplastic materials -- a quasi-single phase metal (Coronze 638) and a microduplex metal (ultrahigh-carbon steel - UHCS). In both materials the kinetics of strain-enhanced grain growth have been studied as a function of strain, strain rate and temperature. An equation for the rate of grain growth has been developed that incorporates the influence of temperature. The evolution of the grain size distribution during superplastic deformation has also been investigated. Our model integrates grain growth laws derived from these studies with two mechanism based, rate dependent constitutive laws to predict the stress-strainstrain rate behavior of materials during superplastic deformation. The influence of crain size distribution and its evolution with strain and strain rate on the stress-strain-strain rate behavior has been represented through the use of distributed parameters. The model can capture the stress-strain-strain rate behavior over a wide range of strains and strain rates with a single set of parameters. Many subtle features of the mechanical response of these materials can be adequately predicted.
- Mechanical behavior of ultrahigh strength ultrahigh carbon steel wire and rod
- Ultrahigh-carbon steels (UHCSS) can achieve very high strengths in wire or rod form. These high strengths result from the mechanical work introduced during wire and rod processing. These strengths have been observed to increase with carbon content. In wire form, tensile strengths approaching 6000 MPa are predicted for UHCS containing 1. 8%C. In this paper, we will discuss the influence of processing (including rapid transformation during wire patenting) and micros ct- ure on the mechanical behavior of UHCS wire. The tensile properties of as- extruded rods are described as a function of extrusion temperature and composition. For spheroidized steels, yield and ultimate tensile strength are a function of grain size, interparticle spacing and particle size. For pearlitic steels, yield and ultimate strength were found to be functions of colony size, carbide size and plate spacing and orientation. Alloying additions (such as C, Cr, Si, Al and Co) can influence the effect of processing on these microstructural features. For spheroidized steels, fracture was found to be a function of the size of coarse carbides and of composition.
- Processing and mechanical behavior of hypereutectoid steel wires
- Hypereutectoid steels have the potential for dramatically increasing the strength of wire used in tire cord and in other high strength wire applications. The basis for this possible breakthrough is the elimination of a brittle proeutectoid network that can form along grain boundaries if appropriate processing procedures and alloy additions are used. A review is made of work done by Japanese and other researchers on eutectoid and mildly hypereutectoid wires. A linear extrapolation of the tensile strength of fine wires predicts higher strengths at higher carbon contents. The influence of processing, alloy additions and carbon content in optimizing the strength, ductility and fracture behavior of hypereutectoid steels is presented. It is proposed that the tensile strength of pearlitic wires is dictated by the fracture strength of the carbide lamella at grain boundary locations in the carbide. Methods to improve the strength of carbide grain boundaries and to decrease the carbide plate thickness will contribute to enhancing the ultrahigh strength obtainable in hypereutectoid steel wires. 23 refs., 13 figs., 1 tab.
- Laminated metals composites fracture and ballistic impact behavior
- Recent advances in the fracture and ballistic impact response of laminated metal composites (LMCs) are reviewed. The laminate structure can provide significant improvements to these properties relative to the component materials. Typical fracture and ballistic impact properties in LMCs are illustrated for systems containing Al alloys and Al matrix composites. The unique mechanisms operating in a layered structure that contribute to fracture or ballistic impact resistance are discussed. The influence of laminate architecture, component material properties and interface strength on mechanisms and properties are briefly reviewed for these Al-based LMCs.
- Forming of superplastic ceramics
- Superplasticity in ceramics has now advanced to the stage that technologically viable superplastic deformation processing can be performed. In this paper, examples of superplastic forming and diffusion bonding of ceramic components are given. Recent work in biaxial gas-pressure forming of several ceramics is provided. These include yttria-stabilized, tetragonal zirconia (YTZP), a 20% alumina/YTZP composite, and silicon. In addition, the concurrent superplastic forming and diffusion bonding of a hybrid ceramic-metal structure are presented. These forming processes offer technological advantages of greater dimensional control and increased variety and complexity of shapes than is possible with conventional ceramic shaping technology.
- Isothermal fatigue
- No Description Available.