Broadband diffractive lens (open access)

Broadband diffractive lens

Significant progress has been made toward solving the century-old problem of chromatic aberrations in diffractive optics. Our approach exploits modern materials and microfabrication technology and is very different from the purely diffractive strategy,'' which is commonly employed and which results in multiple diffractive elements separated by a finite distance. We have developed a Fresnel zone plate lens comprised of a serial stack of patterned minus-filters which allows broadband radiation to be focused (or imaged) without longitudinal or transverse chromatic aberrations. 7 refs., 4 figs.
Date: May 28, 1991
Creator: Ceglio, N. M.; Hawryluk, A. M.; London, R. A.; Seppala, L. G. (Lawrence Livermore National Lab., CA (USA)) & Gaines, D. P. (Brigham Young Univ., Provo, UT (USA))
Object Type: Article
System: The UNT Digital Library
Feasibility study: Application of RCM techniques for substation maintenance at the Bonneville Power Administration. [Reliability Centered Maintenance (RCM)] (open access)

Feasibility study: Application of RCM techniques for substation maintenance at the Bonneville Power Administration. [Reliability Centered Maintenance (RCM)]

This feasibility study examines reliability centered maintenance (RCM) as it applies to Bonneville Power Administrations (BPA) substation maintenance program. Reliability techniques are examined in evaluated. Existing BPA equipment maintenance procedures are documented. Equipment failure history is considered. Economic impacts are estimated. Various equipment instrumentation methods are reviewed. Based on this analysis a prototype system is proposed. The prototype will be implemented in two phases. Phase 1 is to be completed in 1992, it includes instrumenting one power transformer and one oil circuit breaker. Software development will focus on displaying data. Phase 2 is to be completed the following year. The remaining transformers and breakers will be instrumented during the second phase. Software development will focus on predictive maintenance techniques and maintenance decision support.
Date: May 28, 1992
Creator: Purucker, S. L.; Tonn, B. E.; Goeltz, R. T.; James, R. D.; Kercel, S.; Rizy, D. T. et al.
Object Type: Report
System: The UNT Digital Library
Photogenerated carrier-induced reactions on uhv semiconductor surfaces (open access)

Photogenerated carrier-induced reactions on uhv semiconductor surfaces

The objective for this experimental work was to examine the reaction mechanisms, half-collision dynamics, and other optically induced chemical effects, that are operable on a well characterized single-crystal semiconductor surface. Of particular interest were reactions induced by charge transfer from the semiconductor surface including hot carrier and thermalized carrier processes. The primary technique to measure the desorbed fragment translational energies was time-of-flight mass-spectroscopy, used in conjunction with a pulsed tunable laser source. The work was carried out in ultrahigh vacuum, thus other surface spectroscopies such as temperature-programmed desorption, (TPD), (LEED), etc. were used as needed. In the project, the photoreactions of several halogen-containing molecules on GaAs(110) surfaces have been investigated. The studies have made the first observations of several new photochemical processes on uhv prepared surfaces including intermolecular charge transfer; desorption by thermal-carrier-induced reactions (including the measurement of coverage-dependent changes in the translational energies of the desorbed products); interferometric oscillation of photoinduced reactions; and self-quenching of thermal carrier reactions on surfaces.
Date: May 28, 1992
Creator: Osgood, R.M. Jr.
Object Type: Report
System: The UNT Digital Library
Cooperative research in coal liquefaction (open access)

Cooperative research in coal liquefaction

Significant progress was made in the May 1990--May 1991 contract period in three primary coal liquefaction research areas: catalysis, structure-reactivity studies, and novel liquefaction processes. A brief summary of the accomplishments in the past year in each of these areas is given.
Date: May 28, 1991
Creator: Huffman, G. P. & Sendlein, L. V. A. (eds.)
Object Type: Report
System: The UNT Digital Library
DC CICC retrofit magnet preliminary design, software development and analysis report (open access)

DC CICC retrofit magnet preliminary design, software development and analysis report

The January 1992 quarterly progress report discusses a two-dimensional finite element analysis (FEA) of the proposed retrofit MHD coil. The superconducting Cable-in-Conduit Conductor (CICC) winding pack has a smooth, semi-elliptical cross section and is supported by a similarly shaped strap which resists the electromagnetic forces tending to separate the coils on each side of the channel. The coils are designed to produce a peak on-axis field of 4.5 tesla with a nominal current density of 13.05{times}10{sup 6} A/m{sup 2}. A sketch of the magnet system and structure is shown in Fig. 1.0-1. The objective of this analysis is to quantify the highly 3-D characteristics of the proposed superconductivity magnet system, and develop an appropriate support concept. A fully paramatized 3-D finite element model of the coil and structure is developed as a means of obtaining the field and stress solutions. The flexibility of FEA and a model built using design parameters allows variations in the coil end turn bend radius, strap thickness, support details and positions to be studied. The preliminary results show the calculated stresses as a result of this iterative design process.
Date: May 28, 1992
Creator: Myatt, R. L. & Marston, P. G.
Object Type: Report
System: The UNT Digital Library
Methods for fabricating arrays of holes using interference lithography (open access)

Methods for fabricating arrays of holes using interference lithography

Optical interference lithography offers a robust patterning technology capable of achieving high spatial resolution over extremely large field sizes ( {approx}1 m ). Here, we compare two different approaches for fabricating arrays of holes using interferometric techniques. We show that by applying an image reversal process to standard two-beam interference lithography, arrays of high aspect ratio holes can be generated. This process scales to submicron periods and allows holes as small as 0.1 micron to be patterned. Next, we present an analysis of the multiple-beam approach for patterning holes. We demonstrate that while the formation of higher contrast intensity patterns is possible by interfering four or more beams, the shape and modulation depth of such patterns are inherently sensitive to relative phase variations.
Date: May 28, 1997
Creator: Fernandez, A.; Decker, J. Y.; Herman, S. M.; Phillion, D. W.; Sweeney, D. W. & Perry, M. D.
Object Type: Article
System: The UNT Digital Library
Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning (open access)

Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning

Nitric acid is used to clean depleted uranium in the form of cast billets, and cast and wrought parts in the processing cycle and is the largest contributor of waste to the West End Treatment Facility (WETF). An estimated 27,000 gallons of liquid and 75 to 95% of all uranium received was sent to the WETF for processing from this facility in our baseline year. Because wrought parts account for the largest throughput at the nitric acid facility, an alternative cleaning method for these parts was examined first. Test results on the first part type from the wrought family showed ultrasonic cleaning to be an effective cleaning method. Since the geometry for this part presented the most difficulty in terms of ultrasonic cleaning, the entire wrought family is expected to be moved from the nitric acid facility to the ultrasonic cleaning facility. As a result, there will be an 83% reduction part throughput at the nitric acid facility which corresponds to a significant decrease in wastes sent to the WETF and a reduction in the generation and associated costs of waste overall. This change also eliminated two building moves involving two RAD areas resulting in a part movement reduction of …
Date: May 28, 1991
Creator: Frye, L.E. & Senviel, C.B.
Object Type: Report
System: The UNT Digital Library
Advective diffusive/dispersive transport in geochemical processes (open access)

Advective diffusive/dispersive transport in geochemical processes

Comprehensive understanding of chemical transport in response to fluid flow and diffusion in geologic processes requires thermodynamic and transport properties of a wide variety of aqueous species at the temperature and pressure of interest, as well as mass transfer computer codes that provide simultaneously for fluid flow, diffusion, dispersion, homogeneous chemical reactions, and mineral solubilities. As a result of research carried out with support from DOE in prior years of this grant, considerable progress has been made in developing computer codes to calculate advective-dispersive-diffusional transport at both high and low pressures and temperatures. These codes have become highly sophisticated, but their application to geochemical processes is limited by the availability of thermodynamic and transport data for the major solute species in the aqueous phase. Over the past three years, research has been directed primarily toward characterizing the thermodynamic behavior of concentrated supercritical aqueous electrolyte solutions and predicting the diffusion coefficients of organic species in oil field brines. Related research has been concerned with characterizing the growth rate of hydrothermal alteration zones and assessing the relative importance of aqueous diffusion and heterogeneous reactions at mineral surfaces in geochemical processes. 103 refs., 12 figs.
Date: May 28, 1991
Creator: Helgeson, H. C.
Object Type: Report
System: The UNT Digital Library
Engineering development of advanced coal-fired low-emission boiler system (open access)

Engineering development of advanced coal-fired low-emission boiler system

The Pittsburgh Energy Technology Center of the US Department of Energy (DOE) has contracted with Combustion Engineering, Inc. (ABB CE) to perform work on the Engineering Development of Advanced Coal-Fired Low-Emission Boiler Systems'' Project and has authorized ABB CE to complete Phase I on a cost-reimbursable basis. The overall objective of the Project is the expedited commercialization of advanced coal-fired low-emission boiler systems. The specified primary objectives are: (1) NOx emissions not greater than one-third NSPS. (2) SOx emissions not greater than one-third NSPS. (3) Particulate emissions not greater than one-half NSPS. The specific secondary objectives are: (1) Improved ash disposability and reduced waste generation. (2) Reduced air toxics emissions. (3) Increased generating efficiency. The final deliverables are a design data base that will allow future coal-fired power plants to meet the stated objectives and a preliminary design of a commercial generation unit.
Date: May 28, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Combustion synthesis and engineering of nanoparticles for electronic, structural and superconductor applications (open access)

Combustion synthesis and engineering of nanoparticles for electronic, structural and superconductor applications

Fully dense, nanocrystalline ceramic articles were prepared by the new nanofabrication process. The process consists of two steps: synthesis of ceramic nanoparticles and fabrication of dense, nanocrystalline ceramic parts. The synthesis step produced 10-nanometer-diameter crystallites, and is capable of being scaled up to kilogram/hour production rates. The fabrication step produced dense parts at significantly reduced sintering temperatures and times -- representing a factor of 10--100 reduction in process energy requirements. The process was demonstrated by producing ultrafine-grained yttria-stabilized ZrO[sub 2], an important material with a variety of energy-related applications (solid electrolytes, oxygen sensors, electrode materials, thermal barrier coatings, etc.). Results from this period clearly illustrate the capabilities of this energy-efficient and directly commercializable process for producing dense, nanocrystalline, multicomponent oxide ceramics.
Date: May 28, 1993
Creator: Stangle, G.C.; Amarakoon, V.R.W. & Schulze, W.A.
Object Type: Report
System: The UNT Digital Library
SHMS-E PLC computer software design description (open access)

SHMS-E PLC computer software design description

The Standard Hydrogen Monitoring System (SHMS) is designed to monitor the volume percent hydrogen concentration during potential gas releases from the Hanford underground waste storage tanks. A flexible gas continuous monitoring system was needed that could be expanded to measure gas compositions at both high and low sensitivities. For these reasons, a modified version of the SHMS (entitled SHMS-E) has been developed. The SHMS-E analytical (often referred to as SHMS-E+) measures gas concentrations in selectable ranges of approximately: Hydrogen (3-100,000 ppm); Nitrous Oxide (10-4,000 ppm); Ammonia (10-10,000 ppm) and Methane (10-4,000 ppm). The SHMS-E basic will monitor Hydrogen using electrochemical cells, but will not have the Microsensor Technology Inc. (MTI) dual-column gas chromatograph, B and K photo-acoustic spectrometer, and associated computers installed though they may be installed with minimal hardware changes in the future if needed.
Date: May 28, 1998
Creator: Schneider, T. C.
Object Type: Report
System: The UNT Digital Library
Chemicals and excess materials disposition during facility deactivation as a means of pollution prevention (open access)

Chemicals and excess materials disposition during facility deactivation as a means of pollution prevention

This paper presents several innovative and common sense approaches to pollution prevention that have been employed during facility deactivation at the Hanford Site in South Central Washington. It also presents several pollution prevention principles applicable to other projects. Innovative pollution prevention ideas employed at the Hanford site during facility deactivation included: (1) Recycling more than 185,000 gallons of radioactively contaminated nitric acid by sending it to an operating nuclear fuels reprocessing facility in England; (2) Recycling millions of pounds of chemicals and excess materials to other industries for reuse; (3) Evaporating flush water at a low rate and discharging it into the facility exhaust air stream to avoid discharging thousands of gallons of liquid to the soil column; and (4) Decontaminating and disposing of thousands of gallons of radioactively contaminated organic solvent waste to a RCRA licensed, power-producing, commercial incinerator. Common sense pollution prevention ideas that were employed include recycling office furniture, recycling paper from office files, and redeploying tools and miscellaneous process equipment. Additional pollution prevention occurred as the facility liquid and gaseous discharge streams were deactivated. From the facilities deactivation experiences at Hanford and the ensuing efforts to disposition excess chemicals and materials, several key pollution prevention principles …
Date: May 28, 1998
Creator: Godfrey, S. D.
Object Type: Article
System: The UNT Digital Library
Postirradiation Testing Laboratory (327 Building) (open access)

Postirradiation Testing Laboratory (327 Building)

A Standards/Requirements Identification Document (S/RID) is the total list of the Environment, Safety and Health (ES and H) requirements to be implemented by a site, facility, or activity. These requirements are appropriate to the life cycle phase to achieve an adequate level of protection for worker and public health and safety, and the environment during design, construction, operation, decontamination and decommissioning, and environmental restoration. S/RlDs are living documents, to be revised appropriately based on change in the site`s or facility`s mission or configuration, a change in the facility`s life cycle phase, or a change to the applicable standards/requirements. S/RIDs encompass health and safety, environmental, and safety related safeguards and security (S and S) standards/requirements related to the functional areas listed in the US Department of Energy (DOE) Environment, Safety and Health Configuration Guide. The Fluor Daniel Hanford (FDH) Contract S/RID contains standards/requirements, applicable to FDH and FDH subcontractors, necessary for safe operation of Project Hanford Management Contract (PHMC) facilities, that are not the direct responsibility of the facility manager (e.g., a site-wide fire department). Facility S/RIDs contain standards/requirements applicable to a specific facility that are the direct responsibility of the facility manager. S/RlDs are prepared by those responsible for managing …
Date: May 28, 1997
Creator: Kammenzind, D. E.
Object Type: Report
System: The UNT Digital Library
Tank characterization report for single-shell tank 241-U-112 (open access)

Tank characterization report for single-shell tank 241-U-112

A major function of the Tank Waste Remediation System (TWRS) is to characterize waste in support of waste management and disposal activities at the Hanford Site. Analytical data from sampling and analysis and other available information about a tank are compiled and maintained in a tank characterization report (TCR). This report and its appendixes serve as the TCR for single-shell tank 241-U-112. The objectives of this report are (1) to use characterization data in response to technical issues associated with tank 241-U-112 waste, and (2) to provide a standard characterization of this waste in terms of a best-basis inventory estimate. Section 2.0 summarizes the response to technical issues, Section 3.0 shows the best-basis inventory estimate, Section 4.0 makes recommendations about the safety status of the tank and additional sampling needs. The appendixes contain supporting data and information. This report supports the requirements of the Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1997), Milestone M-44-15b, change request M-44-97-03 to issue characterization deliverables consistent with the Waste Information Requirements Document developed for 1998.
Date: May 28, 1998
Creator: Field, J. G.
Object Type: Report
System: The UNT Digital Library
Engineering development of advanced coal-fired low-emission boiler system. Technical progress report No. 2, January--March 1993 (open access)

Engineering development of advanced coal-fired low-emission boiler system. Technical progress report No. 2, January--March 1993

The Pittsburgh Energy Technology Center of the US Department of Energy (DOE) has contracted with Combustion Engineering, Inc. (ABB CE) to perform work on the ``Engineering Development of Advanced Coal-Fired Low-Emission Boiler Systems`` Project and has authorized ABB CE to complete Phase I on a cost-reimbursable basis. The overall objective of the Project is the expedited commercialization of advanced coal-fired low-emission boiler systems. The specified primary objectives are: (1) NOx emissions not greater than one-third NSPS. (2) SOx emissions not greater than one-third NSPS. (3) Particulate emissions not greater than one-half NSPS. The specific secondary objectives are: (1) Improved ash disposability and reduced waste generation. (2) Reduced air toxics emissions. (3) Increased generating efficiency. The final deliverables are a design data base that will allow future coal-fired power plants to meet the stated objectives and a preliminary design of a commercial generation unit.
Date: May 28, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Feasibility study: Application of RCM techniques for substation maintenance at the Bonneville Power Administration (open access)

Feasibility study: Application of RCM techniques for substation maintenance at the Bonneville Power Administration

This feasibility study examines reliability centered maintenance (RCM) as it applies to Bonneville Power Administrations (BPA) substation maintenance program. Reliability techniques are examined in evaluated. Existing BPA equipment maintenance procedures are documented. Equipment failure history is considered. Economic impacts are estimated. Various equipment instrumentation methods are reviewed. Based on this analysis a prototype system is proposed. The prototype will be implemented in two phases. Phase 1 is to be completed in 1992, it includes instrumenting one power transformer and one oil circuit breaker. Software development will focus on displaying data. Phase 2 is to be completed the following year. The remaining transformers and breakers will be instrumented during the second phase. Software development will focus on predictive maintenance techniques and maintenance decision support.
Date: May 28, 1992
Creator: Purucker, S. L.; Tonn, B. E.; Goeltz, R. T.; James, R. D.; Kercel, S.; Rizy, D. T. et al.
Object Type: Report
System: The UNT Digital Library
Highly dispersed catalysts for coal liquefaction. Quarterly report No. 6, November 23, 1992--February 22, 1993 (open access)

Highly dispersed catalysts for coal liquefaction. Quarterly report No. 6, November 23, 1992--February 22, 1993

The objectives of this project are to study the effect of pretreatment methods on the two-stage liquefaction process. In particular the effects of dispersed catalysts and carbon monoxide atmospheres on a coal liquefaction process. The project is divided into three technical tasks. Task 1 and 2 deal with the analyses and liquefaction experiments, respectively, whereas Task 3 deals with the economic impact of utilizing the pretreatment methods. This quarter concentrated on Tasks 1 and 2. which are summarized below. The fractionated products from the coal liquefaction experiments conducted in Task 2 exhibited a very low H/C ratio, most likely due to the low H/C ratio of the Black Thunder recycle vehicle used in these liquefaction experiments. Wilsonville has reported the recycle vehicle as approximately 20% distillable material (1100{degree}F at one atmosphere), 20% insoluble material (CI) and 40% resid. We are now in the process of fractionating this material in order to determine its contribution to our liquefaction results. We also analyzed some of the sulfated iron catalysts for surface areas, finding that the calcined catalyst had surface areas of 76 m{sup 2}/g, compared to 6 m{sup 2}/g for the iron oxide used by Wilsonville. We also synthesized two more catalysts, …
Date: May 28, 1993
Creator: Hirschon, A. S. & Wilson, R. B.
Object Type: Report
System: The UNT Digital Library
Tritium in the Savannah River environment addendum to WSRC-RP--90-424-1, Revision 1 (open access)

Tritium in the Savannah River environment addendum to WSRC-RP--90-424-1, Revision 1

This document is an addendum to ``Tritium in the Savannah River Site Environment,`` WSRC-RP90-424- 1, released in May of 1991. The purpose of this report is to update the information found in WSRC-RP-90-424-1 for the four year period 1987--1990. Some data has also been included from 1991. The report includes summaries of atmospheric and aqueous monitoring of tritium and estimates of the dose to the population surrounding the Savannah River Site.
Date: May 28, 1992
Creator: Murphy, C. E. Jr. & Carlton, W. H.
Object Type: Report
System: The UNT Digital Library
Environmental permits and approvals plan for high-level waste interim storage, Project W-464 (open access)

Environmental permits and approvals plan for high-level waste interim storage, Project W-464

This report discusses the Permitting Plan regarding NEPA, SEPA, RCRA, and other regulatory standards and alternatives, for planning the environmental permitting of the Canister Storage Building, Project W-464.
Date: May 28, 1998
Creator: Deffenbaugh, M. L.
Object Type: Report
System: The UNT Digital Library
DC CICC retrofit magnet preliminary design, software development and analysis report. Quarterly progress report, [January 1, 1992--March 31, 1992] (open access)

DC CICC retrofit magnet preliminary design, software development and analysis report. Quarterly progress report, [January 1, 1992--March 31, 1992]

The January 1992 quarterly progress report discusses a two-dimensional finite element analysis (FEA) of the proposed retrofit MHD coil. The superconducting Cable-in-Conduit Conductor (CICC) winding pack has a smooth, semi-elliptical cross section and is supported by a similarly shaped strap which resists the electromagnetic forces tending to separate the coils on each side of the channel. The coils are designed to produce a peak on-axis field of 4.5 tesla with a nominal current density of 13.05{times}10{sup 6} A/m{sup 2}. A sketch of the magnet system and structure is shown in Fig. 1.0-1. The objective of this analysis is to quantify the highly 3-D characteristics of the proposed superconductivity magnet system, and develop an appropriate support concept. A fully paramatized 3-D finite element model of the coil and structure is developed as a means of obtaining the field and stress solutions. The flexibility of FEA and a model built using design parameters allows variations in the coil end turn bend radius, strap thickness, support details and positions to be studied. The preliminary results show the calculated stresses as a result of this iterative design process.
Date: May 28, 1992
Creator: Myatt, R. L. & Marston, P. G.
Object Type: Report
System: The UNT Digital Library
Development of gamma ray imaging cameras. Progress report for second year (open access)

Development of gamma ray imaging cameras. Progress report for second year

In January 1990, the Department of Energy initiated this project with the objective to develop the technology for general purpose, portable gamma ray imaging cameras useful to the nuclear industry. The ultimate goal of this R&D initiative is to develop the analog to the color television camera where the camera would respond to gamma rays instead of visible photons. The two-dimensional real-time image would be displayed would indicate the geometric location of the radiation relative to the camera`s orientation, while the brightness and ``color`` would indicate the intensity and energy of the radiation (and hence identify the emitting isotope). There is a strong motivation for developing such a device for applications within the nuclear industry, for both high- and low-level waste repositories, for environmental restoration problems, and for space and fusion applications. At present, there are no general purpose radiation cameras capable of producing spectral images for such practical applications. At the time of this writing, work on this project has been underway for almost 18 months. Substantial progress has been made in the project`s two primary areas: mechanically-collimated (MCC) and electronically-collimated camera (ECC) designs. We present developments covering the mechanically-collimated design, and then discuss the efforts on the electronically-collimated …
Date: May 28, 1992
Creator: Wehe, D. K. & Knoll, G. F.
Object Type: Report
System: The UNT Digital Library
Combustion synthesis and engineering of nanoparticles for electronic, structural and superconductor applications. Annual progress report, December 1, 1992--May 31, 1993 (open access)

Combustion synthesis and engineering of nanoparticles for electronic, structural and superconductor applications. Annual progress report, December 1, 1992--May 31, 1993

Fully dense, nanocrystalline ceramic articles were prepared by the new nanofabrication process. The process consists of two steps: synthesis of ceramic nanoparticles and fabrication of dense, nanocrystalline ceramic parts. The synthesis step produced 10-nanometer-diameter crystallites, and is capable of being scaled up to kilogram/hour production rates. The fabrication step produced dense parts at significantly reduced sintering temperatures and times -- representing a factor of 10--100 reduction in process energy requirements. The process was demonstrated by producing ultrafine-grained yttria-stabilized ZrO{sub 2}, an important material with a variety of energy-related applications (solid electrolytes, oxygen sensors, electrode materials, thermal barrier coatings, etc.). Results from this period clearly illustrate the capabilities of this energy-efficient and directly commercializable process for producing dense, nanocrystalline, multicomponent oxide ceramics.
Date: May 28, 1993
Creator: Stangle, G. C.; Amarakoon, V. R. W. & Schulze, W. A.
Object Type: Report
System: The UNT Digital Library
Liquid metal reactor deactivation as applied to the experimental breeder reactor - II. (open access)

Liquid metal reactor deactivation as applied to the experimental breeder reactor - II.

The Experimental Breeder Reactor-II (EBR-II) at Argonne National Laboratory-West (ANL-W) was shutdown in September, 1994. This sodium cooled reactor had been in service since 1964, and by the US Department of Energy (DOE) mandate, was to be placed in an industrially and radiologically safe condition for ultimate decommissioning. The deactivation of a liquid metal reactor presents unique concerns. The first major task associated with the project was the removal of all fueled assemblies. In addition, sodium must be drained from systems and processed for ultimate disposal. Residual quantities of sodium remaining in systems must be deactivated or inerted to preclude future hazards associated with pyrophoricity and generation of potentially explosive hydrogen gas. A Sodium Process Facility (SPF) was designed and constructed to react the elemental sodium from the EBR-II primary and secondary systems to sodium hydroxide for disposal. This facility has a design capacity to allow the reaction of the complete inventory of sodium at ANL-W in less than two years. Additional quantities of sodium from the Fermi-1 reactor are also being treated at the SPF.
Date: May 28, 1999
Creator: Earle, O. K.; Michelbacher, J. A.; Pfannenstiel, D. F. & Wells, P. B.
Object Type: Article
System: The UNT Digital Library
A general protocol for restoration of entire river catchments (open access)

A general protocol for restoration of entire river catchments

Large catchment basins may be viewed as ecosystems with interactive natural and cultural attributes. Stream regulation severs ecological connectivity between channels and flood plains by reducing the range of natural flow and temperature variation, reduces the capacity of the ecosystem to sustain native biodiversity and bioproduction and promotes proliferation of non-native biota. However, regulated rivers regain normative attributes, which promote recovery of native biota, as distance from the dam increases and in relation to the mode of regulation. Therefore, reregulation of flow and temperature to normative pattern, coupled with elimination of pollutants and constrainment of nonnative biota, can naturally restore damaged habitats from headwaters to mouth. The expectation is rapid recovery of depressed populations of native species. The protocol requires: restoration of seasonal temperature patterns; restoration of peak flows needed to reconnect and periodically reconfigure channel and floodplain habitats; stabilization of base flows to revitalize the shallow water habitats; maximization of dam passage to allow restoration of metapopulation structure; change in the management belief system to rely on natural habitat restoration as opposed to artificial propagation, installation of artificial instream structures (river engineering) and artificial food web control; and, practice of adaptive ecosystem management.
Date: May 28, 1996
Creator: Stanford, Jack A.; Frissell, Christopher A.; Ward, J. V.; Liss, William J.; Coutant, Charles C.; Williams, Richard N. et al.
Object Type: Article
System: The UNT Digital Library