SUMMARY REPORT FOR ZINC 65 CONTAMINATION CONTROL (open access)

SUMMARY REPORT FOR ZINC 65 CONTAMINATION CONTROL

Radioactive zinc, {sup 65}Zn, was detected after extraction of 215 TPBARs in from TVA reactor fuel cycle 6. A team consisting of Tritium Engineering, Tritium Operations, Tritium Radiation Control, and Savannah River National Laboratory personnel evaluated the risk and response and developed short, medium and long term goals for contamination control. One of the goals was incorporated into site Performance Based Incentive CO 3.4, to optimize the filter geometry and operating conditions for the Tritium Extraction Facility. This goal included a scoping study to determine if the contamination could be contained within the high radiation environment of the furnace module as well. In order to optimize the filters studies were conducted to independently evaluate the effect of pore size on pumping efficiency and zinc trapping efficiency (1). A study was also conducted to evaluate the effect of temperature on the trapping efficiency and adhesion (2). In addition, the potential for chemically trapping zinc in the lithium trap was evaluated using a thermodynamic study (3) followed by preliminary experimental testing (4). Based on the work that was completed it is determined that a 20 {mu}m filter heated to between 120 and 200 C will act as an effective physical trap for …
Date: July 14, 2011
Creator: Korinko, P.
Object Type: Report
System: The UNT Digital Library
A model for improving microbial biofuel production using a synthetic feedback loop (open access)

A model for improving microbial biofuel production using a synthetic feedback loop

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straight forward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates.
Date: July 14, 2011
Creator: Dunlop, Mary; Keasling, Jay & Mukhopadhyay, Aindrila
Object Type: Article
System: The UNT Digital Library
Optimizing Metalloporphyrin-Catalyzed Reduction Reactions for In Situ Remediation of DOE Contaminants (open access)

Optimizing Metalloporphyrin-Catalyzed Reduction Reactions for In Situ Remediation of DOE Contaminants

Past activities have resulted in a legacy of contaminated soil and groundwater at Department of Energy facilities nationwide. Uranium and chromium are among the most frequently encountered and highest-priority metal and radionuclide contaminants at DOE installations. Abiotic chemical reduction of uranium and chromium at contaminated DOE sites can be beneficial because the reduced metal species are less soluble in water, less mobile in the environment, and less toxic to humans and ecosystems. Although direct biological reduction has been reported for U(VI) and Cr(VI) in laboratory studies and at some field sites, the reactions can sometimes be slow or even inhibited due to unfavorable environmental conditions. One promising approach for the in-situ remediation of DOE contaminants is to develop electron shuttle catalysts that can be delivered precisely to the specific subsurface locations where contaminants reside. Previous research has shown that reduction of oxidized organic and inorganic contaminants often can be catalyzed by electron shuttle systems. Metalloporphyrins and their derivatives are well known electron shuttles for many biogeochemical systems, and thus were selected to study their catalytic capabilities for the reduction of chromium and uranium in the presence of reducing agents. Zero valent iron (ZVI) was chosen as the primary electron donor …
Date: July 14, 2013
Creator: Schlautman, Mark A.
Object Type: Report
System: The UNT Digital Library
Fireside Corrosion (open access)

Fireside Corrosion

Oxy-fuel fireside research goals are: (1) determine the effect of oxyfuel combustion on fireside corrosion - flue gas recycle choice, staged combustion ramifications; and (2) develop methods to use chromia solubility in ash as an ash corrosivity measurement - synthetic ashes at first, then boiler and burner rig ashes.
Date: July 14, 2011
Creator: Holcomb, Gordon
Object Type: Article
System: The UNT Digital Library
MicrobesOnline: an integrated portal for comparative and functional genomics (open access)

MicrobesOnline: an integrated portal for comparative and functional genomics

Since 2003, MicrobesOnline (http://www.microbesonline.org) has been providing a community resource for comparative and functional genome analysis. The portal includes over 1000 complete genomes of bacteria, archaea and fungi and thousands of expression microarrays from diverse organisms ranging from model organisms such as Escherichia coli and Saccharomyces cerevisiae to environmental microbes such as Desulfovibrio vulgaris and Shewanella oneidensis. To assist in annotating genes and in reconstructing their evolutionary history, MicrobesOnline includes a comparative genome browser based on phylogenetic trees for every gene family as well as a species tree. To identify co-regulated genes, MicrobesOnline can search for genes based on their expression profile, and provides tools for identifying regulatory motifs and seeing if they are conserved. MicrobesOnline also includes fast phylogenetic profile searches, comparative views of metabolic pathways, operon predictions, a workbench for sequence analysis and integration with RegTransBase and other microbial genome resources. The next update of MicrobesOnline will contain significant new functionality, including comparative analysis of metagenomic sequence data. Programmatic access to the database, along with source code and documentation, is available at http://microbesonline.org/programmers.html.
Date: July 14, 2011
Creator: Dehal, Paramvir; Joachimiak, Marcin; Price, Morgan; Bates, John; Baumohl, Jason; Chivian, Dylan et al.
Object Type: Article
System: The UNT Digital Library
Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix (open access)

Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix

Screening tests are being conducted to evaluate waste forms for immobilizing secondary liquid wastes from the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Plans are underway to add a stabilization treatment unit to the Effluent Treatment Facility to provide the needed capacity for treating these wastes from WTP. The current baseline is to use a Cast Stone cementitious waste form to solidify the wastes. Through a literature survey, DuraLith alkali-aluminosilicate geopolymer, fluidized-bed steam reformation (FBSR) granular product encapsulated in a geopolymer matrix, and a Ceramicrete phosphate-bonded ceramic were identified both as candidate waste forms and alternatives to the baseline. These waste forms have been shown to meet waste disposal acceptance criteria, including compressive strength and universal treatment standards for Resource Conservation and Recovery Act (RCRA) metals (as measured by the toxicity characteristic leaching procedure [TCLP]). Thus, these non-cementitious waste forms should also be acceptable for land disposal. Information is needed on all four waste forms with respect to their capability to minimize the release of technetium. Technetium is a radionuclide predicted to be in the secondary liquid wastes in small quantities, but the Integrated Disposal Facility (IDF) risk assessment analyses show that technetium, even at low mass, produces the …
Date: July 14, 2011
Creator: Pires, Richard P.; Westsik, Joseph H.; Serne, R. Jeffrey; Mattigod, Shas V.; Golovich, Elizabeth C.; Valenta, Michelle M. et al.
Object Type: Report
System: The UNT Digital Library
SCIX IMPACT ON DWPF CPC (open access)

SCIX IMPACT ON DWPF CPC

A program was conducted to systematically evaluate potential impacts of the proposed Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) Chemical Processing Cell (CPC). The program involved a series of interrelated tasks. Past studies of the impact of crystalline silicotitanate (CST) and monosodium titanate (MST) on DWPF were reviewed. Paper studies and material balance calculations were used to establish reasonable bounding levels of CST and MST in sludge. Following the paper studies, Sludge Batch 10 (SB10) simulant was modified to have both bounding and intermediate levels of MST and ground CST. The SCIX flow sheet includes grinding of the CST which is larger than DWPF frit when not ground. Nominal ground CST was not yet available, therefore a similar CST ground previously in Savannah River National Laboratory (SRNL) was used. It was believed that this CST was over ground and that it would bound the impact of nominal CST on sludge slurry properties. Lab-scale simulations of the DWPF CPC were conducted using SB10 simulants with no, intermediate, and bounding levels of CST and MST. Tests included both the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles. Simulations were performed at high …
Date: July 14, 2011
Creator: Koopman, D.
Object Type: Report
System: The UNT Digital Library
How Many Muons Do We Need to Store in a Ring For Neutrino Cross-Section Measurements? (open access)

How Many Muons Do We Need to Store in a Ring For Neutrino Cross-Section Measurements?

Analytical estimate of the number of muons that must decay in the straight section of a storage ring to produce a neutrino & anti-neutrino beam of sufficient intensity to facilitate cross-section measurements with a statistical precision of 1%. As we move into the era of precision long-baseline {nu}{sub {mu}} {yields} {nu}{sub e} and {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} measurements there is a growing need to precisely determine the {nu}{sub e} and {bar {nu}}{sub e} cross-sections in the relevant energy range, from a fraction of 1 GeV to a few GeV. This will require {nu}{sub e} and {bar {nu}}{sub e} beams with precisely known fluxes and spectra. One way to produce these beams is to use a storage ring with long straight sections in which muon decays ({mu}{sup -} {yields} e{sup -}{nu}{sub {mu}}{bar {nu}}{sub e} if negative muons are stored, and {nu}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {mu}} if positive muons are stored) produce the desired beam. The challenge is to capture enough muons in the ring to obtain useful neutrino and anti-neutrino fluxes. Early proposals to use a muon storage ring for neutrino oscillation experiments were based upon injecting 'high energy' charged pions into the ring which …
Date: July 14, 2011
Creator: Geer, Steve
Object Type: Report
System: The UNT Digital Library
Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil (open access)

Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. …
Date: July 14, 2011
Creator: DeAngelis, Kristen; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian; Hugenholtz, Phillip; Simmons, Blake et al.
Object Type: Article
System: The UNT Digital Library
Surge Nozzle NDE Specimen Mechanical Stress Improvement Analysis (open access)

Surge Nozzle NDE Specimen Mechanical Stress Improvement Analysis

The purpose of this project was to perform a finite element analysis of a pressurized water reactor pressurizer surge nozzle mock-up to predict both the weld residual stresses created in its construction and the final stress state after the application of the Mechanical Stress Improvement Process (MSIP). Strain gages were applied to the inner diameter of the mock-up to record strain changes during the MSIP. These strain readings were used in an attempt to calculate the final stress state of the mock-up as well.
Date: July 14, 2011
Creator: Fredette, Lee F.
Object Type: Report
System: The UNT Digital Library
Using Nuclear Resonance Fluorescence for Nondestructive Isotopic Analysis (open access)

Using Nuclear Resonance Fluorescence for Nondestructive Isotopic Analysis

Nuclear resonance fluorescence (NRF) has been studied as one of the nondestructive analysis (NDA) techniques currently being investigated by a multi-laboratory collaboration for the determination of Pu mass in spent fuel. In NRF measurements specific isotopes are identified by their characteristic lines in recorded gamma spectra. The concentration of an isotope in a material can be determined from measured NRF signal intensities if NRF cross sections and assay geometries are known. The potential of NRF to quantify isotopic content and Pu mass in spent fuel has been studied. The addition of NRF data to MCNPX and an improved treatment of the elastic photon scattering at backward angles has enabled us to more accurately simulate NRF measurements on spent fuel assemblies. Using assembly models from the spent fuel assembly library generated at LANL, NRF measurements are simulated to find the best measurement configurations, and to determine measurement sensitivities and times, and photon source and gamma detector requirements. A first proof-of-principal measurement on a mock-up assembly with a bremsstrahlung photon source demonstrated isotopic sensitivity to approximately 1% limited by counting statistics. Data collection rates are likely a limiting factor of NRF-based measurements of fuel assemblies but new technological advances may lead to …
Date: July 14, 2010
Creator: Ludewigt, Bernhard A.; Mozin, Vladimir; Haefner, Andrew & Quiter, Brian
Object Type: Article
System: The UNT Digital Library
IDENTIFYING IMPURITIES IN SURPLUS NON PIT PLUTONIUM FEEDS FOR MOX OR ALTERNATIVE DISPOSITION (open access)

IDENTIFYING IMPURITIES IN SURPLUS NON PIT PLUTONIUM FEEDS FOR MOX OR ALTERNATIVE DISPOSITION

This report provides a technical basis for estimating the level of corrosion products in materials stored in DOE-STD-3013 containers based on extrapolating available chemical sample results. The primary focus is to estimate the levels of nickel, iron, and chromium impurities in plutonium-bearing materials identified for disposition in the United States Mixed Oxide fuel process.
Date: July 14, 2010
Creator: Allender, J & Moore, E
Object Type: Article
System: The UNT Digital Library
High Resolution Photon Timing with MCP-PMTs: A Comparison of a Commercial Constant Fraction Discriminator (CFD) with the ASIC-based Waveform Digitizers TARGET and WaveCatcher (open access)

High Resolution Photon Timing with MCP-PMTs: A Comparison of a Commercial Constant Fraction Discriminator (CFD) with the ASIC-based Waveform Digitizers TARGET and WaveCatcher

There is a considerable interest to develop new time-of-flight detectors using, for example, micro-channel-plate photodetectors (MCP-PMTs). The question we pose in this paper is if new waveform digitizer ASICs, such as the WaveCatcher and TARGET, operating with a sampling rate of 2-3 GSa/s can compete with 1GHz BW CFD/TDC/ADC electronics. We have performed a series of measurements with these waveform digitizers coupled to MCP-PMTs operating at low gain and with a signal equivalent to {approx}40 photoelectrons. The tests were done with a laser diode on detectors operating under the same condition used previously in SLAC and Fermilab beam tests. Our test results indicate that one can achieve similar resolution with both methods. Although the commercial CFD-based electronics does exist and performs very well, it is difficult to implement on a very large scale, and therefore the custom electronics is needed. In addition, the analog delay line requirement makes it very difficult to incorporate CFD discriminators in ASIC designs.
Date: July 14, 2011
Creator: Breton, D.; /Orsay, LAL; Delagnes, E.; /DAPNIA, Saclay; Maalmi, J.; /Orsay, LAL et al.
Object Type: Article
System: The UNT Digital Library
A Midsize Tokamak As Fast Track To Burning Plasmas (open access)

A Midsize Tokamak As Fast Track To Burning Plasmas

This paper presents a midsize tokamak as a fast track to the investigation of burning plasmas. It is shown that it could reach large values of energy gain (≥10) with only a modest improvement in confinement over the scaling that was used for designing the International Thermonuclear Experimental Reactor (ITER). This could be achieved by operating in a low plasma recycling regime that experiments indicate can lead to improved plasma confinement. The possibility of reaching the necessary conditions of low recycling using a more efficient magnetic divertor than those of present tokamaks is discussed.
Date: July 14, 2010
Creator: Mazzucato, E.
Object Type: Report
System: The UNT Digital Library
CO2-driven Enhanced Oil Recovery as a Stepping Stone to What? (open access)

CO2-driven Enhanced Oil Recovery as a Stepping Stone to What?

This paper draws heavily on the authors’ previously published research to explore the extent to which near term carbon dioxide-driven enhanced oil recovery (CO2-EOR) can be “a stepping stone to a long term sequestration program of a scale to be material in climate change risk mitigation.” The paper examines the historical evolution of CO2-EOR in the United States and concludes that estimates of the cost of CO2-EOR production or the extent of CO2 pipeline networks based upon this energy security-driven promotion of CO2-EOR do not provide a robust platform for spurring the commercial deployment of carbon dioxide capture and storage technologies (CCS) as a means of reducing greenhouse gas emissions. The paper notes that the evolving regulatory framework for CCS makes a clear distinction between CO2-EOR and CCS and the authors examine arguments in the technical literature about the ability for CO2-EOR to generate offsetting revenue to accelerate the commercial deployment of CCS systems in the electric power and industrial sectors of the economy. The authors conclude that the past 35 years of CO2-EOR in the U.S. have been important for boosting domestic oil production and delivering proven system components for future CCS systems. However, though there is no reason …
Date: July 14, 2010
Creator: Dooley, James J.; Dahowski, Robert T. & Davidson, Casie L.
Object Type: Report
System: The UNT Digital Library
Hurricane Intensity, Sea Surface Temperature, and Stochastic Variation (open access)

Hurricane Intensity, Sea Surface Temperature, and Stochastic Variation

None
Date: July 14, 2010
Creator: Bogen, K. T.; Fischer, L. E. & Jones, E. D.
Object Type: Article
System: The UNT Digital Library
Test Results for the Electron Lens Superconducting Magnets at RHIC (open access)

Test Results for the Electron Lens Superconducting Magnets at RHIC

N/A
Date: July 14, 2013
Creator: J., Muratore; Bruno, D.; Escallier, J.; Fischer, W.; Ganetis, G.; Gupta, R. et al.
Object Type: Article
System: The UNT Digital Library
Secondary Waste Form Development and Optimization—Cast Stone (open access)

Secondary Waste Form Development and Optimization—Cast Stone

Washington River Protection Services is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF is a Resource Conservation and Recovery Act-permitted, multi-waste, treatment and storage unit and can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid wastes generated during operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The STU to ETF will provide the additional capacity needed for ETF to process the increased volume of secondary wastes expected to be produced by WTP.
Date: July 14, 2011
Creator: Sundaram, S. K.; Parker, Kent E.; Valenta, Michelle M.; Pitman, Stan G.; Chun, Jaehun; Chung, Chul-Woo et al.
Object Type: Report
System: The UNT Digital Library
Lessons Learned and Potential Paths Forward in Virtual Reality Developments for the International Atomic Energy Agency (open access)

Lessons Learned and Potential Paths Forward in Virtual Reality Developments for the International Atomic Energy Agency

N/A
Date: July 14, 2013
Creator: Tackentien, J. K.; Owens, C. & Brown, B.
Object Type: Article
System: The UNT Digital Library
Development of Physical Protection Regulations for Rosatom State Corporation Sites under the U.S.-Russian MPC&A Program (open access)

Development of Physical Protection Regulations for Rosatom State Corporation Sites under the U.S.-Russian MPC&A Program

This paper describes issues related to upgrading the physical protection regulatory basis for Rosatom State Corporation sites. It is underlined that most of the regulatory and methodological documents for this subject area have been developed under the U.S.-Russian MPC&A Program. According to the joint management plan developed and agreed upon by the parties in 2005, nearly 50 physical protection documents were identified to be developed, approved and implemented at Rosatom sites by 2012. It is also noted that, on the whole, the plans have been fulfilled.
Date: July 14, 2012
Creator: Izmaylov, Alexander; Babkin, Vladimir; Shemigon, Nikolai N.; O'Brien, Patricia; Wright, Troy L.; Hazel, Michael J. et al.
Object Type: Report
System: The UNT Digital Library
OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES (open access)

OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES

Two detailed, unit-cell models, a transverse fin design and a longitudinal fin design, of a combined hydride bed and heat exchanger are developed in COMSOL{reg_sign} Multiphysics incorporating and accounting for heat transfer and reaction kinetic limitations. MatLab{reg_sign} scripts for autonomous model generation are developed and incorporated into (1) a grid-based and (2) a systematic optimization routine based on the Nelder-Mead downhill simplex method to determine the geometrical parameters that lead to the optimal structure for each fin design that maximizes the hydrogen stored within the hydride. The optimal designs for both the transverse and longitudinal fin designs point toward closely-spaced, small cooling fluid tubes. Under the hydrogen feed conditions studied (50 bar), a 25 times improvement or better in the hydrogen storage kinetics will be required to simultaneously meet the Department of Energy technical targets for gravimetric capacity and fill time. These models and methodology can be rapidly applied to other hydrogen storage materials, such as other metal hydrides or to cryoadsorbents, in future work.
Date: July 14, 2011
Creator: Garrison, S.; Tamburello, D.; Hardy, B.; Anton, D.; Gorbounov, M.; Cognale, C. et al.
Object Type: Article
System: The UNT Digital Library
Thick Nano-Crystalline Diamond films for fusion applications (open access)

Thick Nano-Crystalline Diamond films for fusion applications

None
Date: July 14, 2010
Creator: Dawedeit, C
Object Type: Thesis or Dissertation
System: The UNT Digital Library
PROGRESS IN THREE-DIMENSIONAL SIMULATIONS OF EXPLOSIONS AND EARTHQUAKES (open access)

PROGRESS IN THREE-DIMENSIONAL SIMULATIONS OF EXPLOSIONS AND EARTHQUAKES

None
Date: July 14, 2010
Creator: Rodgers, A J; Vorobiev, O; Petersson, N A; Sjogreen, B & Foxall, B
Object Type: Article
System: The UNT Digital Library
Minimizing MPI Resource Contention in Multithreaded Multicore Environments (open access)

Minimizing MPI Resource Contention in Multithreaded Multicore Environments

None
Date: July 14, 2010
Creator: Goodell, D; Balaji, P; Buntinas, D; Dozsa, G; Gropp, W; Kumar, S et al.
Object Type: Article
System: The UNT Digital Library