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The Greensheet (Houston, Tex.), Vol. 41, No. 11, Ed. 1 Friday, February 5, 2010
Free weekly newspaper that includes business and classified advertising.
Date:
February 5, 2010
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Dust-Plasma Interactions
The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.
Date:
January 5, 2010
Creator:
Rosenberg, M.
Object Type:
Report
System:
The UNT Digital Library
Mechanisms underlying cellular responses of cells from haemopoietic tissue to low dose/low LET radiation
To accurately define the risks associated with human exposure to relevant environmental doses of low LET ionizing radiation, it is necessary to completely understand the biological effects at very low doses (i.e., less than 0.1 Gy), including the lowest possible dose, that of a single electron track traversal. At such low doses, a range of studies have shown responses in biological systems which are not related to the direct interaction of radiation tracks with DNA. The role of these “non-targeted” responses in critical tissues is poorly understood and little is known regarding the underlying mechanisms. Although critical for dosimetry and risk assessment, the role of individual genetic susceptibility in radiation risk is not satisfactorily defined at present. The aim of the proposed grant is to critically evaluate radiation-induced genomic instability and bystander responses in key stem cell populations from haemopoietic tissue. Using stem cells from two mouse strains (CBA/H and C57BL/6J) known to differ in their susceptibility to radiation effects, we plan to carefully dissect the role of genetic predisposition on two non-targeted radiation responses in these models; the bystander effect and genomic instability, which we believe are closely related. We will specifically focus on the effects of low doses …
Date:
March 5, 2010
Creator:
Kadhim, Munira A
Object Type:
Report
System:
The UNT Digital Library
Heavy Water Components Test Reactor Decommissioning - Major Component Removal
The Heavy Water Components Test Reactor (HWCTR) facility (Figure 1) was built in 1961, operated from 1962 to 1964, and is located in the northwest quadrant of the Savannah River Site (SRS) approximately three miles from the site boundary. The HWCTR facility is on high, well-drained ground, about 30 meters above the water table. The HWCTR was a pressurized heavy water test reactor used to develop candidate fuel designs for heavy water power reactors. It was not a defense-related facility like the materials production reactors at SRS. The reactor was moderated with heavy water and was rated at 50 megawatts thermal power. In December of 1964, operations were terminated and the facility was placed in a standby condition as a result of the decision by the U.S. Atomic Energy Commission to redirect research and development work on heavy water power reactors to reactors cooled with organic materials. For about one year, site personnel maintained the facility in a standby status, and then retired the reactor in place. In 1965, fuel assemblies were removed, systems that contained heavy water were drained, fluid piping systems were drained, deenergized and disconnected and the spent fuel basin was drained and dried. The doors of …
Date:
May 5, 2010
Creator:
Austin, W. & Brinkley, D.
Object Type:
Article
System:
The UNT Digital Library
Alternative Enhanced Chemical Cleaning Basic Studies Results FY09
This report is about an Alternative Enhanced Chemical Cleaning Basic Studies Results FY09
Date:
May 5, 2010
Creator:
Hay, M. & King, W.
Object Type:
Report
System:
The UNT Digital Library
Task 1.5 Genomic Shift and Drift Trends of Emerging Pathogens
The Lawrence Livermore National Laboratory (LLNL) Bioinformatics group has recently taken on a role in DTRA's Transformation Medical Technologies Initiative (TMTI). The high-level goal of TMTI is to accelerate the development of broad-spectrum countermeasures. To achieve those goals, TMTI has a near term need to conduct analyses of genomic shift and drift trends of emerging pathogens, with a focused eye on select agent pathogens, as well as antibiotic and virulence markers. Most emerging human pathogens are zoonotic viruses with a genome composed of RNA. The high mutation rate of the replication enzymes of RNA viruses contributes to sequence drift and provides one mechanism for these viruses to adapt to diverse hosts (interspecies transmission events) and cause new human and zoonotic diseases. Additionally, new viral pathogens frequently emerge due to genetic shift (recombination and segment reassortment) which allows for dramatic genotypic and phenotypic changes to occur rapidly. Bacterial pathogens also evolve via genetic drift and shift, although sequence drift generally occurs at a much slower rate for bacteria as compared to RNA viruses. However, genetic shift such as lateral gene transfer and inter- and intragenomic recombination enables bacteria to rapidly acquire new mechanisms of survival and antibiotic resistance. New technologies such …
Date:
January 5, 2010
Creator:
Borucki, M
Object Type:
Report
System:
The UNT Digital Library
High-Power Electrostatic Discharges in PETN: Threshold and Scaling Experiments
There is a considerable set of data establishing the safety of PETN-based detonators that are insulted by electrostatic discharge (ESD) from a human body. However, the subject of ESD safety has garnered renewed interest because of the sparse data on high-power, low-impedance discharges that result when the source is a metallic object such as a tool. Experiments on as-built components, using pin-to-cap fault circuits through PETN-based detonators, showed significant evidence of a power dependence but with a very broad energy threshold and some uncertainty in the breakdown path. We have performed a series of experiments using a well-defined arc discharge path and a well-characterized source that is capable of independent variation of energy and power. Studies include threshold variation with power, arc length, powder surface area, and surface vs. bulk discharge paths. We find that an energy threshold variation with power does not appear to exist in the tested range of fractions to tens of MW, and that there are many subtleties to proper energy and power bookkeeping. We also present some test results for PBX 9407.
Date:
March 5, 2010
Creator:
Liou, W.; McCarrick, J. F.; Hodgin, R. L. & Phillips, D. F.
Object Type:
Article
System:
The UNT Digital Library
Laser Systems for Orbital Debris Removal
The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying …
Date:
February 5, 2010
Creator:
Rubenchik, A M; Barty, C P; Beach, R J; Erlandson, A C & Caird, J A
Object Type:
Article
System:
The UNT Digital Library
Evaluation of Sludge Batch 5 Qualification with ISDP Salt Batch 1 Compliance to DWPF Waste Acceptance Criteria
The purpose of this report is to document the acceptability of Sludge Batch 5 with the initial macrobatch operation of the Interim Salt Disposition Project (ISDP) waste to the Defense Waste Processing Facility (DWPF). This report was prepared to comply with the requirements listed in the Waste Acceptance Criteria for Sludge, Actinide Removal Process (ARP), and Modular Caustic Side Solvent Extraction Unit (MCU) Process Transfers to 512-S and DWPF. The requirements for transfers to 512-S were evaluated during ISDP Salt Batch 1 qualification. The calculations of sludge concentrations are based entirely on the Tank 51 sample processed at SRNL. This is conservative because Tank 51 is blended with the dilute feed in the DWPF Feed Tank (Tank 40). This report documents the acceptability of sludge only as well as Sludge Batch 5 sludge slurry combined with ARP/MCU products for feed to DWPF. All criteria were met for unblended Tank 51 material.
Date:
May 5, 2010
Creator:
Shafer, A.
Object Type:
Report
System:
The UNT Digital Library
Applying Human Factors during the SIS Life Cycle
Safety Instrumented Systems (SIS) are widely used in U.S. Department of Energy's (DOE) nonreactor nuclear facilities for safety-critical applications. Although use of the SIS technology and computer-based digital controls, can improve performance and safety, it potentially introduces additional complexities, such as failure modes that are not readily detectable. Either automated actions or manual (operator) actions may be required to complete the safety instrumented function to place the process in a safe state or mitigate a hazard in response to an alarm or indication. DOE will issue a new standard, Application of Safety Instrumented Systems Used at DOE Nonreactor Nuclear Facilities, to provide guidance for the design, procurement, installation, testing, maintenance, operation, and quality assurance of SIS used in safety significant functions at DOE nonreactor nuclear facilities. The DOE standard focuses on utilizing the process industry consensus standard, American National Standards Institute/ International Society of Automation (ANSI/ISA) 84.00.01, Functional Safety: Safety Instrumented Systems for the Process Industry Sector, to support reliable SIS design throughout the DOE complex. SIS design must take into account human-machine interfaces and their limitations and follow good human factors engineering (HFE) practices. HFE encompasses many diverse areas (e.g., information display, user-system interaction, alarm management, operator response, control …
Date:
May 5, 2010
Creator:
Avery, K.
Object Type:
Article
System:
The UNT Digital Library
Alternative Enhanced Chemical Cleaning Basic Studies Results FY09
Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids …
Date:
May 5, 2010
Creator:
Hay, M. & King, W.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of ISDP Batch 2 Qualification Compliance to 512-S, DWPF, Tank Farm, and Saltstone Waste Acceptance Criteria
The purpose of this report is to document the acceptability of the second macrobatch (Salt Batch 2) of Tank 49H waste to H Tank Farm, DWPF, and Saltstone for operation of the Interim Salt Disposition Project (ISDP). Tank 49 feed meets the Waste Acceptance Criteria (WAC) requirements specified by References 11, 12, and 13. Salt Batch 2 material is qualified and ready to be processed through ARP/MCU to the final disposal facilities.
Date:
May 5, 2010
Creator:
Shafer, A.
Object Type:
Report
System:
The UNT Digital Library
NEUTRON MULTIPLICITY AND ACTIVE WELL NEUTRON COINCIDENCE VERIFICATION MEASUREMENTS PERFORMED FOR MARCH 2009 SEMI-ANNUAL DOE INVENTORY
The Analytical Development (AD) Section field nuclear measurement group performed six 'best available technique' verification measurements to satisfy a DOE requirement instituted for the March 2009 semi-annual inventory. The requirement of (1) yielded the need for SRNL Research Operations Department Material Control & Accountability (MC&A) group to measure the Pu content of five items and the highly enrich uranium (HEU) content of two. No 14Q-qualified measurement equipment was available to satisfy the requirement. The AD field nuclear group has routinely performed the required Confirmatory Measurements for the semi-annual inventories for fifteen years using sodium iodide and high purity germanium (HpGe) {gamma}-ray pulse height analysis nondestructive assay (NDA) instruments. With appropriate {gamma}-ray acquisition modeling, the HpGe spectrometers can be used to perform verification-type quantitative assay for Pu-isotopics and HEU content. The AD nuclear NDA group is widely experienced with this type of measurement and reports content for these species in requested process control, MC&A booking, and holdup measurements assays Site-wide. However none of the AD HpGe {gamma}-ray spectrometers have been 14Q-qualified, and the requirement of reference 1 specifically excluded a {gamma}-ray PHA measurement from those it would accept for the required verification measurements. The requirement of reference 1 was a new …
Date:
February 5, 2010
Creator:
Dewberry, R.; Ayers, J.; Tietze, F. & Klapper, K.
Object Type:
Article
System:
The UNT Digital Library
POST-FIRE REVEGETATION AT HANFORD
Range fires on the Hanford Site can have a long lasting effect on native plant communities. Wind erosion following removal of protective vegetation from fragile soils compound the damaging effect of fires. Dust storms caused by erosion create health and safety hazards to personnel, and damage facilities and equipment. The Integrated Biological Control Program (IBC) revegetates burned areas to control erosion and consequent dust. Use of native, perennial vegetation in revegetation moves the resulting plant community away from fire-prone annual weeds, and toward the native shrub-steppe that is much less likely to burn in the future. Over the past 10 years, IBC has revegetated major fire areas with good success. IBC staff is monitoring the success of these efforts, and using lessons learned to improve future efforts.
Date:
January 5, 2010
Creator:
Roos, R. C.; Johnson, A. R.; Caudill, J. G.; Rodriguez, J. M. & Wilde, J. W.
Object Type:
Article
System:
The UNT Digital Library
Tank 12 Sludge Characterization and Aluminum Dissolution Demonstration
A 3-L sludge slurry sample from Tank 12 was characterized and then processed through an aluminum dissolution demonstration. The dominant constituent of the sludge was found to be aluminum in the form of boehmite. The iron content was minor, about one-tenth that of the aluminum. The salt content of the supernatant was relatively high, with a sodium concentration of {approx}7 M. Due to these characteristics, the yield stress and plastic viscosity of the unprocessed slurry were relatively high (19 Pa and 27 cP), and the settling rate of the sludge was relatively low ({approx}20% settling over a two and a half week period). Prior to performing aluminum dissolution, plutonium and gadolinium were added to the slurry to simulate receipt of plutonium waste from H-Canyon. Aluminum dissolution was performed over a 26 day period at a temperature of 65 C. Approximately 60% of the insoluble aluminum dissolved during the demonstration, with the rate of dissolution slowing significantly by the end of the demonstration period. In contrast, approximately 20% of the plutonium and less than 1% of the gadolinium partitioned to the liquid phase. However, about a third of the liquid phase plutonium became solubilized prior to the dissolution period, when the …
Date:
May 5, 2010
Creator:
Reboul, S.; Hay, M.; Zeigler, K & Stone, M.
Object Type:
Report
System:
The UNT Digital Library
SOLAR PUMPED LASER MICROTHRUSTER
The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.
Date:
February 5, 2010
Creator:
Rubenchik, A M; Beach, R; Dawson, J & Siders, C W
Object Type:
Article
System:
The UNT Digital Library
Nano Vacancy Clusters and Trap Limited Diffusion of Si Interstitials in Silicon
The objective of this project is to develop a method to characterize nano vacancy clusters and the dynamics of their formation in ion-irradiated silicon. It will impact (1) semiconductor device processing involving ion implantation, and (2) device design concerning irradiation hardness in harsh environments. It also aims to enhance minority participation in research and curricula on emerging materials and ion beam science. Vacancy defects are of scientific and technological importance since they are ubiquitous when the host materials are exposed to particle irradiation. Studies on vacancy clustering in the past decades were mainly theoretical and the approach heavily relied on the total-energy calculation methods. The lack of experimental data is mainly due to the formidable task in measuring the cluster size and density using modern metrological techniques, including transmission electron microscopy and positron annihilation spectroscopy. To surmount these challenges, we proposed a novel approach to tackle the metrological problems on the nano vacancy clusters, especially in determining densities and sizes of the nano vacancies based on the premise that the vacancy-clusters act as diffusion-trapping centers. For a silicon substrate containing vacancyclusters, the diffusion of interstitials (from the surface) can be classified into three phases: (1) an ultrafast phase-I in which …
Date:
May 5, 2010
Creator:
Chu, Prof. Wei-Kan
Object Type:
Report
System:
The UNT Digital Library
Holdup Measures on an SRNL Mossbauer Spectroscopy Instrument
None
Date:
May 5, 2010
Creator:
Dewberry, R.; Brown, T. & Salaymeh, S.
Object Type:
Article
System:
The UNT Digital Library
Exceeding Expectations: Learnings from the FCV Learning Demo
This presentation summarizes findings of the fuel cell vehicle learning demonstration of the Fuel Cell Technologies Program.
Date:
May 5, 2010
Creator:
Wipke, K.; Sprik, S.; Kurtz, J. & Ramsden, T.
Object Type:
Presentation
System:
The UNT Digital Library
Layed Perovskite PRBA0.5SR0.5CO205 as High Performance Cathode for Solid Oxide Fuels Using Photon Conducting Electrolyte
The layered perovskite PrBa{sub 0.5}Sr{sub 0.5}Co{sub 2}O{sub 5+{delta}} (PBSC) was investigated as a cathode material for a solid oxide fuel cell using a proton-conducting electrolyte based on BaCe{sub 0.7}Y{sub 0.2}Zr{sub 0.1}O{sub 3-{delta}} (BCYZ). The sintering conditions for the PBSC-BCYZ composite cathode were optimized resulting in the lowest area-specific resistance and apparent activation energy obtained with the cathode sintered at 1200 C for 2h. The maximum power densities of the PBSC-BCYZ/BZCY/NiO-BCYZ cell were 0.179, 0.274, 0.395, and 0.522 Wcm{sup -2} at 550, 600, 650, and 700 C, respectively with a 15{micro}m thick electrolyte. A relatively low cell interfacial polarization resistance of 0.132 {Omega}cm{sup 2} at 700 C indicated that the PBSC-BCYZ could be a good cathode candidate for intermediate temperature SOFCs with proton-conducting electrolyte.
Date:
May 5, 2010
Creator:
Brinkman, K.
Object Type:
Article
System:
The UNT Digital Library
Relative Humidity and the Susceptibility of Austenitic Stainless Steel to Stress Corrosion Cracking in an impure Plutonium Oxide Environment
Laboratory tests to investigate the corrosivity of moist plutonium oxide/chloride salt mixtures on 304L and 316L stainless steel coupons showed that corrosion occurred in selected samples. The tests exposed flat coupons for pitting evaluation and 'teardrop' stressed coupons for stress corrosion cracking (SCC) evaluation at room temperature to various mixtures of PuO{sub 2} and chloride-bearing salts for periods up to 500 days. The exposures were conducted in sealed containers in which the oxide-salt mixtures were loaded with about 0.6 wt % water from a humidified helium atmosphere. Observations of corrosion ranged from superficial staining to pitting and SCC. The extent of corrosion depended on the total salt concentration, the composition of the salt and the moisture present in the test environment. The most significant corrosion was found in coupons that were exposed to 98 wt % PuO{sub 2}, 2 wt % chloride salt mixtures that contained calcium chloride and 0.6 wt% water. SCC was observed in two 304L stainless steel teardrop coupons exposed in solid contact to a mixture of 98 wt % PuO{sub 2}, 0.9 wt % NaCl, 0.9 wt % KCl, and 0.2 wt % CaCl{sub 2}. The cracking was associated with the heat-affected zone of an autogenous …
Date:
May 5, 2010
Creator:
Zapp, P.; Duffey, J.; Lam, P. & Dunn, K.
Object Type:
Article
System:
The UNT Digital Library
Packaging and Transportation of Additional Neptunium Oxide
The Savannah River Site's HB-Line Facility completed a second neptunium oxide production campaign in which nine (9) additional cans of neptunium oxide were produced and shipped to the Idaho National Laboratory and Oak Ridge National Laboratory in the 9975 shipping container. These additional cans were from a different feed solution than the first fifty (50) cans of neptunium oxide that were previously produced and shipped via a Letter of Amendment to the 9975 Safety Analysis Report for Packaging (SARP) content table. This paper will address the challenges associated with demonstrating the neptunium oxide produced from the additional feed solution was equivalent to the original neptunium oxide and within the content description of the Letter of Amendment.
Date:
May 5, 2010
Creator:
Watkins, R.; Jordan, J. & Hensel, S.
Object Type:
Article
System:
The UNT Digital Library
CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT
The ore pitchblende was discovered in the 1750's near Joachimstal in what is now the Czech Republic. Used as a colorant in glazes, uranium was identified in 1789 as the active ingredient by chemist Martin Klaproth. In 1896, French physicist Henri Becquerel studied uranium minerals as part of his investigations into the phenomenon of fluorescence. He discovered a strange energy emanating from the material which he dubbed 'rayons uranique.' Unable to explain the origins of this energy, he set the problem aside. About two years later, a young Polish graduate student was looking for a project for her dissertation. Marie Sklodowska Curie, working with her husband Pierre, picked up on Becquerel's work and, in the course of seeking out more information on uranium, discovered two new elements (polonium and radium) which exhibited the same phenomenon, but were even more powerful. The Curies recognized the energy, which they now called 'radioactivity,' as something very new, requiring a new interpretation, new science. This discovery led to what some view as the 'golden age of nuclear science' (1895-1945) when countries throughout Europe devoted large resources to understand the properties and potential of this material. By World War II, the potential to harness this …
Date:
May 5, 2010
Creator:
Marra, J.
Object Type:
Book
System:
The UNT Digital Library
COMPARISON OF OXALIC ACID CLEANING RESULTS AT SRS AND HANFORD AND THE IMPACT ON ENHANCED CHEMICAL CLEANING DEPLOYMENT
Waste tanks must be rendered clean enough to satisfy very rigorous tank closure requirements. During bulk waste removal, most of the radioactive sludge and salt waste is removed from the waste tank. The waste residue on the tank walls and interior components and the waste heel at the bottom of the tank must be removed prior to tank closure to render the tank clean enough to meet the regulatory requirement for tank closure. Oxalic acid has been used within the DOE complex to clean residual materials from carbon steel tanks with varying degrees of success. Oxalic acid cleaning will be implemented at both the Savannah River Site and Hanford to clean tanks and serves as the core cleaning technology in the process known as Enhanced Chemical Cleaning. Enhanced Chemical Cleaning also employs a process that decomposes the spent oxalic acid solutions. The oxalic acid cleaning campaigns that have been performed at the two sites dating back to the 1980's are compared. The differences in the waste characteristics, oxalic acid concentrations, flushing, available infrastructure and execution of the campaigns are discussed along with the impact on the effectiveness of the process. The lessons learned from these campaigns that are being incorporated …
Date:
January 5, 2010
Creator:
Spires, R. & Ketusky, E.
Object Type:
Article
System:
The UNT Digital Library