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Environmental Sciences

2001

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Articles 1 - 13 of 13

Full-Text Articles in Chemistry

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quaterly Report, William Culbreth, Pang Tao Dec 2001

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quaterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first quarter of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the first quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, keff …


Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (September 1 – November 30, 2001) Report, Ajit K. Roy, Brendan O'Toole Nov 2001

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (September 1 – November 30, 2001) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including HT- 9, EP 823 and 422. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these alloys will be evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. The extent and morphology of cracking of these alloys will further be evaluated …


Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report August 16,2001- November 15, 2001, Samir Moujaes, Yitung Chen Nov 2001

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report August 16,2001- November 15, 2001, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application.

Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …


Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Pang Tao Aug 2001

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Pang Tao

Separations Campaign (TRP)

To mitigate the waste created by conventional fission reactors, spent nuclear fuel must be mechanically separated from its cladding. For the development of fuel processing technology to support the Advanced Accelerator Applications (AAA) Program, aqueous and pyrochemical processes will be used to further separate technetium and iodine, uranium and the higher actinides (see Figure 1 for an example of the process layout)1. The higher actinides, including plutonium, americium, curium, and neptunium will be separated from the waste to facilitate their fabrication into new fuel for placement in a transmuter. High-energy neutrons generated by spallation in the transmuter break down these …


Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean Aug 2001

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean

Separations Campaign (TRP)

Two activities are proposed: the development of a Systems Engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model will be the start of an integrated approach to the analysis of the materials separations associated with the national AAA program. A second portion of the project will streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to the systems engineering …


Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen Aug 2001

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes of two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. …


Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy Aug 2001

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the effect of hydrogen on cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The test materials will undergo appropriate thermal treatments prior to being hydrogen-charged by potentiostatic cathodic polarization technique in a simulated aqueous environment at different temperatures of interest. The specimens, upon completion of testing, will be metallographically examined. Further, the scanning electron microscopy (SEM) will be used to determine the extent and nature of cracking in the specimens tested. The thrust of the proposed …


Managing Birds And Controlling Aircraft In The Kennedy Airport–Jamaica Bay Wildlife Refuge Complex: The Need For Hard Data And Soft Opinions, Kevin Brown, R. Michael Erwin, Milo E. Richmond, P A. Buckley, John Tanacredi Ph.D., Dave Avrin Aug 2001

Managing Birds And Controlling Aircraft In The Kennedy Airport–Jamaica Bay Wildlife Refuge Complex: The Need For Hard Data And Soft Opinions, Kevin Brown, R. Michael Erwin, Milo E. Richmond, P A. Buckley, John Tanacredi Ph.D., Dave Avrin

Faculty Works: CERCOM

During the 1980s, the exponential growth of laughing gull (Larus atricilla) colonies, from 15 to about 7600 nests in 1990, in the Jamaica Bay Wildlife Refuge and a correlated increase in the bird-strike rate at nearby John F. Kennedy International Airport (New York City) led to a controversy between wildlife and airport managers over the elimination of the colonies. In this paper, we review data to evaluate if: (1) the colonies have increased the level of risk to the flying public; (2) on-colony population control would reduce the presence of gulls, and subsequently bird strikes, at the airport; …


Optimization Of Palladium-Catalyzed In Situ Destruction Of Trichloroethylene-Contaminated Groundwater Using A Genetic Algorithm, Manuel Fernandez Mar 2001

Optimization Of Palladium-Catalyzed In Situ Destruction Of Trichloroethylene-Contaminated Groundwater Using A Genetic Algorithm, Manuel Fernandez

Theses and Dissertations

Conventional technologies for the treatment of groundwater contaminated with chlorinated solvents have limitations that have motivated development of innovative technologies. One such technology currently under development involves using palladium-on-alumina (Pd/Al) as a catalyst to promote dechlorination. Pd/Al catalyst may be used in-well as part of a re-circulating horizontal flow treatment well (HFTW) system. An HFTW system involves two or more dual-screened wells, with in-well reactors, to capture and treat contaminated groundwater without the need to pump the water to the surface. In this study, objective and fitness functions, based on system costs and TCE concentration requirements, were developed to optimize …


Dissolution Of Chromium From Inhalable Primer Paint Particles Into A Simulated Lung Fluid, David A. Kauth Mar 2001

Dissolution Of Chromium From Inhalable Primer Paint Particles Into A Simulated Lung Fluid, David A. Kauth

Theses and Dissertations

The use of chromate as a corrosion inhibitor in primer paint is an essential component for the protection of aluminum-skinned aircraft and the primary source of hexavalent chromium (Cr (VI)) exposure to USAF aircraft painters. The objective of this research was to quantify the dissolution of chromate from freshly sprayed paint particles into a simulated lung fluid (SLF). Two primer paints were sprayed with a paint spray gun to generate overspray particles for collection into impingers filled with SLF. Particles were allowed to soak in SLF for 24 and 48 hours and then the particles were removed by centrifugation. The …


Report Of The State Nuclear Safety Advisor Submitted To The Governor And 120th Legislature As Of January 15, 2001, Paula M. Craighead Jan 2001

Report Of The State Nuclear Safety Advisor Submitted To The Governor And 120th Legislature As Of January 15, 2001, Paula M. Craighead

Maine Collection

Report of the State Nuclear Safety Advisor submitted to the Governor and 120th Legislature As of January 15, 2001

Paula M. Craighead, State Nuclear Safety Advisor, Executive Department, Maine State Planning Office, Augusta, Maine, 2001.

Contents: Introduction and Executive Summary / I. Maine Yankee Decommissioning / II. Portsmouth Naval Shipyard (PNS) / III. Low-Level Radioactive Waste (LLRW) / IV. High Level Radioactive Waste / V. Transport Routes and Safety Response / VI. Shipments / VII. Status of Federal and State Legal and Administrative Proceedings / References and Resources / Glossary


Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin Jan 2001

Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin

Dissertations, Theses, and Masters Projects

The interactive effects of humic acids (HAs) and salinity on the bioavailability and toxicity of the pesticides chlorpyrifos and 4,4'-dichlorodiphenyltrichloroethane (DDT) were investigated. The effects of various HAs on the toxicity of chlorpyrifos were initially assessed with the chronic MicrotoxRTM test. Environmentally relevant concentrations of Aldrich, Peat, Leonardite and Suwannee River HAs had no significant effect on the toxicity of either chlorpyrifos or copper (Cu), the test's positive control. as reductions in contaminant toxicity had previously been reported for some contaminants by HAs, it appeared that salinity might be a mitigating factor. Thus salinity effects were further investigated with Aldrich …


Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge Jan 2001

Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The increasing practice of industrial-scale agriculture tends to concentrate large masses of animal waste in relatively compact areas, potentially leading to excessive release of polluting nutrients into waterways during major storms. Anaerobic treatment conditions are generally favored to conserve nitrate N as an agricultural commodity. However, overall N contents in waste are often in excess of crop fertilization needs: storing excess N in soluble nitrate form increases pollution potential. Thus the perceived needs of agriculture and society-at-large become at odds. Organic nitrogen forms (e.g., proteins) are more environmentally stable and are less subject to unintentional release. Although U.S. farmers tend …