Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions (open access)

Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions

N/A
Date: February 1, 2006
Creator: A., Smolyakov; Fischer, W.; Omet, C. & Spiller, P.
Object Type: Report
System: The UNT Digital Library
Hydrogen Permeability of Mulitphase V-Ti-Ni Metallic Membranes (open access)

Hydrogen Permeability of Mulitphase V-Ti-Ni Metallic Membranes

None
Date: February 14, 2006
Creator: ADAMS, THAD
Object Type: Article
System: The UNT Digital Library
Evaluation of Ultra Clean Fuels from Natural Gas (open access)

Evaluation of Ultra Clean Fuels from Natural Gas

ConocoPhillips, in conjunction with Nexant Inc., Penn State University, and Cummins Engine Co., joined with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) in a cooperative agreement to perform a comprehensive study of new ultra clean fuels (UCFs) produced from remote sources of natural gas. The project study consists of three primary tasks: an environmental Life Cycle Assessment (LCA), a Market Study, and a series of Engine Tests to evaluate the potential markets for Ultra Clean Fuels. The overall objective of DOE's Ultra Clean Transportation Fuels Initiative is to develop and deploy technologies that will produce ultra-clean burning transportation fuels for the 21st century from both petroleum and non-petroleum resources. These fuels will: (1) Enable vehicles to comply with future emission requirements; (2) Be compatible with the existing liquid fuels infrastructure; (3) Enable vehicle efficiencies to be significantly increased, with concomitantly reduced CO{sub 2} emissions; (4) Be obtainable from a fossil resource, alone or in combination with other hydrocarbon materials such as refinery wastes, municipal wastes, biomass, and coal; and (5) Be competitive with current petroleum fuels. The objectives of the ConocoPhillips Ultra Clean Fuels Project are to perform a comprehensive life cycle analysis and to conduct …
Date: February 28, 2006
Creator: Abbott, Robert; Casey, Edward; Esen, Etop; Smith, Douglas; Burke, Bruce; Nguyen, Binh et al.
Object Type: Report
System: The UNT Digital Library
Observation of B0(s) ---> psi(2S)phi and measurement of ratio of branching fractions B(B0(s) ---> psi(2S)phi) / B(B0(s) ---> J/psi phi) (open access)

Observation of B0(s) ---> psi(2S)phi and measurement of ratio of branching fractions B(B0(s) ---> psi(2S)phi) / B(B0(s) ---> J/psi phi)

The authors report the first observation of B{sub s}{sup 0} {yields} {psi}(2S){phi} decay in p{bar p} collisions {radical}s = 1.96 TeV using 360 pb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. They observe 20.2 {+-} 5.0 and 12.3 {+-} 4.1 B{sub s}{sup 0} {yields} {psi}(2S){phi} candidates, in {psi}(2S) {yields} {mu}{sup +}{mu}{sup -} and {psi}(2S) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decay modes, respectively. They present a measurement of the relative branching fraction {Beta}(B{sub s}{sup 0} {yields} {psi}(2S){phi})/{Beta}(B{sub s}{sup 0} {yields} J/{psi}{phi}) = 0.52 {+-} 0.13(stat.) {+-} 0.04(syst.) {+-} 0.06(BR) using the {psi}(2S) {yields} {mu}{sup +}{mu}{sup -} decay mode.
Date: February 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Search for Z' ---> e+ e- using dielectron mass and angular distribution (open access)

Search for Z' ---> e+ e- using dielectron mass and angular distribution

The authors search Z{prime} bosons in dielectron events produced in p{bar p} collisions at {radical}s = 1.96 TeV, using a 0.45 fb{sup -1} dataset accumulated with the CDF II detector at the Fermilab Tevatron. To identify the Z{prime} {yields} e{sup +}e{sup -} signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z{prime} mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z{prime}, as well as on the contact interaction mass scales for different helicity structure scenarios.
Date: February 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the top quark mass using template methods on dilepton events in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of the top quark mass using template methods on dilepton events in p anti-p collisions at s**(1/2) = 1.96-TeV

The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e{nu}, {mu}{nu}, or {tau}{nu}) from a data sample of 360 pb{sup -1}. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 {+-} 6.0(stat.) {+-} 4.1(syst.) GeV/c{sup 2}.
Date: February 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Science-Driven Network Requirements for ESnet (open access)

Science-Driven Network Requirements for ESnet

The Energy Sciences Network (ESnet) is the primary providerof network connectivity for the US Department of Energy Office ofScience, the single largest supporter of basic research in the physicalsciences in the United States. In support of the Office of Scienceprograms, ESnet regularly updates and refreshes its understanding of thenetworking requirements of the instruments, facilities and scientiststhat it serves. This focus has helped ESnet to be a highly successfulenabler of scientific discovery for over 20 years. In August, 2002 theDOE Office of Science organized a workshop to characterize the networkingrequirements for Office of Science programs. Networking and middlewarerequirements were solicited from a representative group of scienceprograms. The workshop was summarized in two documents the workshop finalreport and a set of appendixes. This document updates the networkingrequirements for ESnet as put forward by the science programs listed inthe 2002 workshop report. In addition, three new programs have beenadded. Theinformation was gathered through interviews with knowledgeablescientists in each particular program or field.
Date: February 21, 2006
Creator: Adams, Paul; Canon, Shane; Carter, Steven; Draney, Brent; Greenwald, Martin; Hodges, Jason et al.
Object Type: Report
System: The UNT Digital Library
Fracture, Aging and Disease in Bone (open access)

Fracture, Aging and Disease in Bone

From a public health perspective, developing a detailed mechanistic understanding of the well-known increase in fracture risk of human bone with age is essential. This also represents a challenge from materials science and fracture mechanics viewpoints. Bone has a complex, hierarchical structure with characteristic features ranging from nanometer to macroscopic dimensions; it is therefore significantly more complex than most engineering materials. Nevertheless, by examining the micro-/nano-structural changes accompanying the process of aging using appropriate multiscale experimental methods and relating them to fracture mechanics data, it is possible to obtain a quantitative picture of how bone resists fracture. As human cortical bone exhibits rising ex vivo crack-growth resistance with crack extension, its fracture toughness must be evaluated in terms of resistance-curve (R-curve) behavior. While the crack initiation toughness declines with age, the more striking finding is that the crack-growth toughness declines even more significantly and is essentially absent in bone from donors exceeding 85 years in age. To explain such an age-induced deterioration in the toughness of bone, we evaluate its fracture properties at multiple length scales, specifically at the molecular and nanodimensions using pico-force atomic-force microscopy, nanoindentation and vibrational spectroscopies, at the microscale using electron microscopy and hard/soft x-ray computed …
Date: February 1, 2006
Creator: Ager, Joel; Balooch, G. & Ritchie, R. O.
Object Type: Article
System: The UNT Digital Library
Improved Tubulars for Better Economics in Deep Gas Well Drilling using Microwave Technology Annual Report: 2005 (open access)

Improved Tubulars for Better Economics in Deep Gas Well Drilling using Microwave Technology Annual Report: 2005

The objective of the research program has been to improve the rate-of-penetration in deep hostile environments by improving the life cycle and performance of coiled-tubing, an important component of a deep well drilling system for oil and gas exploration. The current process of the manufacture long tubular steel products consists of shaping the tube from flat strip, welding the seam and sections into lengths that can be miles long, and coiling onto reels. However, the welds, that are a weak point, now limit the performance of the coil tubing. This is not only from a toughness standpoint but also from a corrosion standpoint. By utilizing the latest developments in the sintering of materials with microwave energy and powder metal extrusion technology for the manufacture of seamless coiled tubing and other tubular products, these problems can be eliminated. The project is therefore to develop a continuous microwave process to sinter continuously steel tubulars and butt-join them using microwave/induction process. The program started about three years ago and now we are in the middle of Phase II. In Phase I (which ended in February 2005) a feasibility study of the extrusion process of steel powder and continuously sinter the extruded tubing was …
Date: February 1, 2006
Creator: Agrawal, Dinesh; Gigl, Paul & Dennis, Mahlon
Object Type: Report
System: The UNT Digital Library
Nuclear Energy Research Initiative Project No. 02 103 Innovative Low Cost Approaches to Automating QA/QC of Fuel Particle Production Using On Line Nondestructive Methods for Higher Reliability Final Project Report (open access)

Nuclear Energy Research Initiative Project No. 02 103 Innovative Low Cost Approaches to Automating QA/QC of Fuel Particle Production Using On Line Nondestructive Methods for Higher Reliability Final Project Report

This Nuclear Energy Research Initiative (NERI) project was tasked with exploring, adapting, developing and demonstrating innovative nondestructive test methods to automate nuclear coated particle fuel inspection so as to provide the United States (US) with necessary improved and economical Quality Assurance and Control (QA/QC) that is needed for the fuels for several reactor concepts being proposed for both near term deployment [DOE NE & NERAC, 2001] and Generation IV nuclear systems. Replacing present day QA/QC methods, done manually and in many cases destructively, with higher speed automated nondestructive methods will make fuel production for advanced reactors economically feasible. For successful deployment of next generation reactors that employ particle fuels, or fuels in the form of pebbles based on particles, extremely large numbers of fuel particles will require inspection at throughput rates that do not significantly impact the proposed manufacturing processes. The focus of the project is nondestructive examination (NDE) technologies that can be automated for production speeds and make either: (I) On Process Measurements or (II) In Line Measurements. The inspection technologies selected will enable particle “quality” qualification as a particle or group of particles passes a sensor. A multiple attribute dependent signature will be measured and used for qualification …
Date: February 28, 2006
Creator: Ahmed, Salahuddin; Batishko, Charles R.; Flake, Matthew; Good, Morris S.; Mathews, Royce; Morra, Marino et al.
Object Type: Report
System: The UNT Digital Library
SuperB: a Linear High-Luminosity B Factory (open access)

SuperB: a Linear High-Luminosity B Factory

This paper is based on the outcome of the activity that has taken place during the recent workshop on ''SuperB in Italy'' held in Frascati on November 11-12, 2005. The workshop was opened by a theoretical introduction of Marco Ciuchini and was structured in two working groups. One focused on the machine and the other on the detector and experimental issues.. The present status on CP is mainly based on the results achieved by BABAR and Belle. Establishment of the indirect CP violation in B sector in 2001 and of the direct CP violation in 2004 thanks to the success of PEP-II and KEKB e{sup +}e{sup -} asymmetric B Factories operating at the center of mass energy corresponding to the mass of the {Upsilon}(4S ). With the two B Factories taking data, the Unitarity Triangle is now beginning to be over constrained by improving the measurements of the sides and now also of the angles {alpha}, and {gamma}. We are also in presence of the very intriguing results about the measurements of sin2{beta} in the time dependent analysis of decay channels via penguin loops, where b {yields} s{bar s}s and b {yields} s{bar d}d. {tau} physics, in particular LFV search, …
Date: February 8, 2006
Creator: Albert, J.; Bettarini, S.; Biagini, M.; Bonneaud, G.; Cai, Y.; Calderini, G. et al.
Object Type: Report
System: The UNT Digital Library
Sample Proficiency Test exercise (open access)

Sample Proficiency Test exercise

The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.
Date: February 5, 2006
Creator: Alcaraz, A.; Gregg, H. & Koester, C.
Object Type: Report
System: The UNT Digital Library
Oxygen Isotopes in Chondritic Interplanetary Dust: Parent-Bodies and Nebular Oxygen Reservoirs (open access)

Oxygen Isotopes in Chondritic Interplanetary Dust: Parent-Bodies and Nebular Oxygen Reservoirs

Planetary objects have preserved various amounts of oxygen issued from isotopically different oxygen reservoirs reflecting their origin and physico-chemical history. An {sup 16}O-rich component is preserved in refractory inclusions (CAIs) whereas meteorites matrices are enriched in an {sup 16}O-poor component. The origin of these components is still unclear. The most recent models are based on isotope selective photodissociation of CO in a {sup 16}O-rich nebula/presolr cloud resulting in a {sup 16}O-poor gas in the outer part of the nebula. However because most meteorite components are thought to be formed in the inner 3AU of the solar nebula, the precise isotopic composition of outer solar system components is yet unknown. In that respect, the oxygen isotopic composition of cometary dust is a key to understand the origin of the solar system. The Stardust mission will bring back to the Earth dust samples from comet Wild2, a short period comet from the Jupiter family. A precise determination of the oxygen isotope composition of Wild2 dust grains is essential to decipher the oxygen reservoirs of the outer solar system. However, Stardust samples may be extremely fragmented upon impact in the collector. In addition, interplanetary dust particles (IDPs) collected in the stratosphere are likely …
Date: February 14, 2006
Creator: Aleon, J.; McKeegan, K. D. & Leshin, L.
Object Type: Article
System: The UNT Digital Library
Les Houches physics at TeV colliders 2005 beyond the standard model working group: Summary report (open access)

Les Houches physics at TeV colliders 2005 beyond the standard model working group: Summary report

None
Date: February 1, 2006
Creator: Allanach, B. C.; Grojean, C.; Skands, P.; Accomando, E.; Azuelos, G.; Baer, H. et al.
Object Type: Article
System: The UNT Digital Library
Temperature Study of CdZnTe Coplanar-Grid Detectors (open access)

Temperature Study of CdZnTe Coplanar-Grid Detectors

The coplanar-grid (CPG) and other electron only detection techniques have made possible the use of CdZnTe-based detectors for gamma-ray spectroscopy when high efficiency, good energy resolution, and near room temperature operation are required. Despite the demonstrated potential of the technologies, widespread use remains hampered in part by the limited availability of the highly uniform CdZnTe material required for high-resolution spectroscopy. However, it has been recently shown that mild cooling of CdZnTe CPG detectors can result in a significant improvement in the energy resolution of the detectors thereby allowing a wider range of material to be used for high-resolution applications. In this paper, we show that improved spectroscopic performance can consistently be achieved through a combination of detector cooling and increased detector bias. Energy resolutions of about 1 % FWHM at 662 keV for detector volumes up to 2.3 cm{sup 3} have been obtained at -20 C. With the electronic noise subtracted, this amounts to an intrinsic resolution of 0.76 %. We also show that further cooling of the detectors to -30 C leads to field polarization and a loss of spectroscopic performance.
Date: February 14, 2006
Creator: Amman, Mark; Lee, Julie S. & Luke, Paul N.
Object Type: Article
System: The UNT Digital Library
Smoothing of ultrathin silver films by transition metalseeding (open access)

Smoothing of ultrathin silver films by transition metalseeding

The nucleation and coalescence of silver islands on coated glass was investigated by in-situ measurements of the sheet resistance. Sub-monolayer amounts of transition metals (Nb, Ti, Ni, Cr, Zr, Ta, and Mo) were deposited prior to the deposition of silver. It was found that some, but not all, of the transition metals lead to coalescence of silver at nominally thinner films with smoother topology. The smoothing effect of the transition metal at sub-monolayer thickness can be explained by a thermodynamic model of surface energies.
Date: February 10, 2006
Creator: Anders, Andre; Byon, Eungsun; Kim, Dong-Ho; Fukuda, Kentaro & Lim,Sunnie H.N.
Object Type: Article
System: The UNT Digital Library
MPSA 2004 Final Report (open access)

MPSA 2004 Final Report

This proposal was to support a portion of the costs of Methods in Protein Structure Analysis 2004 (MPSA2004). MPSA2004 was the 15th in the series of MPSA international conferences on protein structure analysis that began in 1974. MPSA2004 was held on the campus of the University of Washington, Seattle, WA August 29 through September 2, 2004. Twenty-four internationally recognized speakers gave invited presentations; additional participants were chosen to present short talks in the 10 topics that were addressed. The aim of MPSA conferences is to communicate the latest, cutting-edge techniques in protein structure analysis and proteomics through science success stories as told by the scientific leaders who developed the technologies. Biotechnology vendors are present to explain currently available commercial technology through workshops and demonstrations booths. The overall aim is to provide a forum for exchanging the latest methods and ideas in protein structure analysis and proteomics to current and future practitioners. The conference supported the missions of the DOE Office of Science and the Office of Biological and Environmental Research (BER) in at least two ways: by enabling the above forum, and by encouraging young researchers who might otherwise not attend to meet leading researchers and to learn about the …
Date: February 18, 2006
Creator: Anderson, Carl W.
Object Type: Text
System: The UNT Digital Library
Advanced Gasification By-Product Utilization (open access)

Advanced Gasification By-Product Utilization

With the recent passing of new legislation designed to permanently cap and reduce mercury emissions from coal-fired utilities, it is more important than ever to develop and improve upon methods of controlling mercury emissions. One promising technique is carbon sorbent injection into the flue gas of the coal-fired power plant. Currently, this technology is very expensive as costly commercially activated carbons are used as sorbents. There is also a significant lack of understanding of the interaction between mercury vapor and the carbon sorbent, which adds to the difficulty of predicting the amount of sorbent needed for specific plant configurations. Due to its inherent porosity and adsorption properties as well as on-site availability, carbons derived from gasifiers are potential mercury sorbent candidates. Furthermore, because of the increasing restricted use of landfilling, the coal industry is very interested in finding uses for these materials as an alternative to the current disposal practice. The results of laboratory investigations and supporting technical assessments conducted under DOE Subcontract No. DE-FG26-03NT41795 are reported for the period September 1, 2004 to August 31, 2005. This contract is with the University of Kentucky Research Foundation, which supports work with the University of Kentucky Center for Applied Energy Research …
Date: February 1, 2006
Creator: Andrews, Rodney; Rubel, Aurora; Groppo, Jack; Geertsema, Ari; Huggins, Frank; Maroto-Valer, M. Mercedes et al.
Object Type: Report
System: The UNT Digital Library
Measurement of Low Energy e+e- Interactions at BABARwith Initial State Radiation (open access)

Measurement of Low Energy e+e- Interactions at BABARwith Initial State Radiation

The status of the analysis of e{sup +}e{sup -} annihilation using the radiative return technique at BaBar is presented. Cross sections for the processes e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0}, {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, {pi}{sup +}{pi}{sup -}K{sup +}K{sup -}, K{sup +}K{sup -}K{sup +}K{sup -}, 3({pi}{sup +}{pi}{sup -}), {pi}{sup 0}{pi}{sup 0}2({pi}{sup +}{pi}{sup -}), K{sup +}K{sup -}2({pi}{sup +}{pi}{sup -}) and p{bar p} are measured in the energy range from threshold up to 4.5 GeV. Studies on resonant structures involved in these processes have been performed. We present also new precise measurements of the effective proton form factor and of the ratio of the electric to magnetic proton form factor, |G{sub E}/G{sub M}|. In addition, the J/{psi} and {psi}(2S) branching fractions to all these final states have been measured.
Date: February 22, 2006
Creator: Anulli, F.
Object Type: Article
System: The UNT Digital Library
A Review of Hazardous Chemical Species Associated with CO2 Capture from Coal-Fired Power Plants and Their Potential Fate in CO2 GeologicStorage (open access)

A Review of Hazardous Chemical Species Associated with CO2 Capture from Coal-Fired Power Plants and Their Potential Fate in CO2 GeologicStorage

Conventional coal-burning power plants are major contributors of excess CO2 to the atmospheric inventory. Because such plants are stationary, they are particularly amenable to CO2 capture and disposal by deep injection into confined geologic formations. However, the energy penalty for CO2 separation and compression is steep, and could lead to a 30-40 percent reduction in useable power output. Integrated gas combined cycle (IGCC) plants are thermodynamically more efficient, i.e.,produce less CO2 for a given power output, and are more suitable for CO2 capture. Therefore, if CO2 capture and deep subsurface disposal were to be considered seriously, the preferred approach would be to build replacement IGCC plants with integrated CO2 capture, rather than retrofit existing conventional plants. Coal contains minor quantities of sulfur and nitrogen compounds, which are of concern, as their release into the atmosphere leads to the formation of urban ozone and acid rain, the destruction of stratospheric ozone, and global warming. Coal also contains many trace elements that are potentially hazardous to human health and the environment. During CO2 separation and capture, these constituents could inadvertently contaminate the separated CO2 and be co-injected. The concentrations and speciation of the co-injected contaminants would differ markedly, depending on whether CO2 …
Date: February 23, 2006
Creator: Apps, J. A.
Object Type: Report
System: The UNT Digital Library
Evolution of Ni3X Precipitation Kinetics, Morphology and Spatial Correlations in Binary Ni-X Alloys Aged Under Externally Applied Stress (open access)

Evolution of Ni3X Precipitation Kinetics, Morphology and Spatial Correlations in Binary Ni-X Alloys Aged Under Externally Applied Stress

Coarsening of Ni3Al, Ni3Ga, Ni3Ge and Ni3Si precipitates in aged binary single-crystal Ni-Al, Ni-Ga, Ni-Ge and Ni-Si alloys under applied compressive stress was measured experimentally over the temperature range 600 to 700 °C. Experiments were also performed on binary Ni-Al single crystals deformed in tension at 640 °C. The orientation of the crystals was [100] in all the experiments. Compared to the kinetics of coarsening in unstressed alloys, coarsening was slightly slower in specimens aged under compression and slightly faster in specimens aged in tension. The effect of applied stress on morphology and spatial correlation was also measured and found to be small. Ni3Al precipitates of a given size generally tended to become more non-equiaxed and their interfaces more planar, with increasing compressive stress. Ni3Ge precipitates behaved differently, becoming more spherical in specimens aged under compression. The effect of applied stress on kinetics is attributed to the influence of elastic deformation on diffusion. A model was developed that predicts slightly slower diffusion under compression and slightly faster diffusion in tension. The elastic constants of single crystals of Ni-Al, Ni-Si, Ni-Ga and Ni-Ge solid solutions were measured from room temperature to about 1100 K using resonant ultrasound spectroscopy.
Date: February 7, 2006
Creator: Ardell, Alan J.
Object Type: Report
System: The UNT Digital Library
IMPACTS OF REDUCING CONDITIONS IN THE SATURATED ZONE AT YUCCA MOUNTAIN (open access)

IMPACTS OF REDUCING CONDITIONS IN THE SATURATED ZONE AT YUCCA MOUNTAIN

Variations in groundwater redox chemistry in the saturated zone near Yucca Mountain could have significant repository to the accessible environment. This study examines geochemical data relevant to the distribution of redox impacts on processes associated with the potential transport of redox-sensitive radionuclides from the proposed conditions in the saturated zone, the relationships between redox state and solubility and sorption coefficients for technetium and neptunium, and sensitivity in transport model simulations. Results indicate evidence for a zone of reducing conditions in the volcanic rocks of the saturated zone located to the east and south of the repository and along the inferred flow paths from the repository. A working hypothesis is that these reducing conditions are related to the presence of minor pyrite in the matrix of some volcanic units. Chemical equilibrium modeling of technetium solubility using EQ3/6 software codes is used to estimate the value of solubility limits as a function of Eh. Surface complexation modeling with the EQ3 code is used to estimate neptunium sorption coefficient values as a function of Eh. A general analytical approach, one-dimensional reactive transport modeling, and the three-dimensional saturated zone site-scale transport model using the FEHM software code are used to evaluate the impacts of …
Date: February 28, 2006
Creator: Arnold, B.W.; Meijer, A.; Kalinina, E.; Robinson, B.; Kelkar, S.; Jove-Colon, C. et al.
Object Type: Report
System: The UNT Digital Library
Summary of NR Program Prometheus Efforts (open access)

Summary of NR Program Prometheus Efforts

The Naval Reactors Program led work on the development of a reactor plant system for the Prometheus space reactor program. The work centered on a 200 kWe electric reactor plant with a 15-20 year mission applicable to nuclear electric propulsion (NEP). After a review of all reactor and energy conversion alternatives, a direct gas Brayton reactor plant was selected for further development. The work performed subsequent to this selection included preliminary nuclear reactor and reactor plant design, development of instrumentation and control techniques, modeling reactor plant operational features, development and testing of core and plant material options, and development of an overall project plan. Prior to restructuring of the program, substantial progress had been made on defining reference plant operating conditions, defining reactor mechanical, thermal and nuclear performance, understanding the capabilities and uncertainties provided by material alternatives, and planning non-nuclear and nuclear system testing. The mission requirements for the envisioned NEP missions cannot be accommodated with existing reactor technologies. Therefore concurrent design, development and testing would be needed to deliver a functional reactor system. Fuel and material performance beyond the current state of the art is needed. There is very little national infrastructure available for fast reactor nuclear testing and …
Date: February 8, 2006
Creator: Ashcroft, J. & Eshelman, C.
Object Type: Report
System: The UNT Digital Library
Wanaket Wildlife Area 2005 HEP Report (open access)

Wanaket Wildlife Area 2005 HEP Report

The Regional HEP Team (RHT) and Confederated Tribes of the Umatilla Indian Reservation (CTUIR) Wildlife Program staff conducted a follow-up habitat evaluation procedures (HEP) analysis on the Wanaket Wildlife Management Area in June 2005. The 2005 HEP investigation generated 3,084.48 habitat units (HUs) for a net increase of 752.18 HUs above 1990/1995 baseline survey results. The HU to acre ratio also increased from 0.84:1.0 to 1.16:1.0. The largest increase in habitat units occurred in the shrubsteppe/grassland cover type (California quail and western meadowlark models), which increased from 1,544 HUs to 2,777 HUs (+43%), while agriculture cover type HUs were eliminated because agricultural lands (managed pasture) were converted to shrubsteppe/grassland. In addition to the agriculture cover type, major changes in habitat structure occurred in the shrubsteppe/grassland cover type due to the 2001 wildfire which removed the shrub component from well over 95% of its former range. The number of acres of all other cover types remained relatively stable; however, habitat quality improved in the riparian herb and riparian shrub cover types. The number and type of HEP species models used during the 2005 HEP analysis were identical to those used in the 1990/1995 baseline HEP surveys. The number of species models …
Date: February 2006
Creator: Ashley, Paul R.
Object Type: Report
System: The UNT Digital Library