HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPE SYSTEMS (open access)

HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPE SYSTEMS

Hydrogen and oxygen generation due to the radiolysis of water is a recognized hazard in pipe systems used in the nuclear industry, where the accumulation of hydrogen and oxygen at high points in the pipe system is expected, and explosive conditions exist. Pipe ruptures at nuclear facilities were attributed to hydrogen explosions inside pipelines, in nuclear facilities, i.e., Hamaoka, Nuclear Power Station in Japan, and Brunsbuettel in Germany. Prior to these accidents an ignition source for hydrogen was questionable, but these accidents, demonstrated that a mechanism was, in fact, available to initiate combustion and explosion. Hydrogen explosions may occur simultaneously with water hammer accidents in nuclear facilities, and a theoretical mechanism to relate water hammer to hydrogen deflagrations and explosions is presented herein.
Date: May 2, 2010
Creator: Leishear, R
Object Type: Article
System: The UNT Digital Library
SIGMA WEB INTERFACE FOR REACTOR DATA APPLICATIONS (open access)

SIGMA WEB INTERFACE FOR REACTOR DATA APPLICATIONS

We present Sigma Web interface which provides user-friendly access for online analysis and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The interface includes advanced browsing and search capabilities, interactive plots of cross sections, angular distributions and spectra, nubars, comparisons between evaluated and experimental data, computations for cross section data sets, pre-calculated integral quantities, neutron cross section uncertainties plots and visualization of covariance matrices. Sigma is publicly available at the National Nuclear Data Center website at http://www.nndc.bnl.gov/sigma.
Date: May 9, 2010
Creator: Pritychenko,B. & Sonzogni, A.A.
Object Type: Report
System: The UNT Digital Library
Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3 (open access)

Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3

None
Date: May 3, 2010
Creator: Moore, R. G.
Object Type: Article
System: The UNT Digital Library
Energy Gaps in the Failed High-Tc Superconductor La_1.875Ba_0.125CuO_4 (open access)

Energy Gaps in the Failed High-Tc Superconductor La_1.875Ba_0.125CuO_4

A central issue on high-T{sub c} superconductivity is the nature of the normal-state gap (pseudogap) in the underdoped regime and its relationship with superconductivity. Despite persistent efforts, theoretical ideas for the pseudogap evolve around fluctuating superconductivity, competing order and spectral weight suppression due to many-body effects. Recently, while some experiments in the superconducting state indicate a distinction between the superconducting gap and pseudogap, others in the normal state, either by extrapolation from high-temperature data or directly from La{sub 1.875}Ba{sub 0.125}CuO{sub 4} (LBCO-1/8) at low temperature, suggest the ground-state pseudogap is a single gap of d-wave form. Here we report angle-resolved photoemission (ARPES) data from LBCO-1/8, collected with improved experimental conditions, that reveal the ground-state pseudogap has a pronounced deviation from the simple d-wave form. It contains two distinct components: a d-wave component within an extended region around the node and the other abruptly enhanced close to the antinode, pointing to a dual nature of the pseudogap in this failed high-T{sub c} superconductor which involves a possible precursor pairing energy scale around the node and another of different but unknown origin near the antinode.
Date: May 4, 2010
Creator: He, R.
Object Type: Article
System: The UNT Digital Library
Heavy Water Components Test Reactor Decommissioning - Major Component Removal (open access)

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
High Density Nano-Electrode Array for Radiation Detection (open access)

High Density Nano-Electrode Array for Radiation Detection

Bulk single crystals of Cd1-xZnxTe (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd1-xZnxTe with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd1-xZnxTe in an electrochemical route. In this investigation, Cd1-xZnxTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 ºC. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd0.9Zn0.1Te nanowires were 4.29x1013 cm-3, 1.56 eV …
Date: May 7, 2010
Creator: Misra, Mano
Object Type: Report
System: The UNT Digital Library
Alternative Enhanced Chemical Cleaning Basic Studies Results FY09 (open access)

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
TANK 7 CHARACTERIZATION AND WASHING STUDIES (open access)

TANK 7 CHARACTERIZATION AND WASHING STUDIES

None
Date: May 19, 2010
Creator: Lambert, D.; Pareizs, J. & Click, D.
Object Type: Report
System: The UNT Digital Library
HANFORD TANK CLEANUP UPDATE APRIL 2010 (open access)

HANFORD TANK CLEANUP UPDATE APRIL 2010

None
Date: May 3, 2010
Creator: Berriochoa, M. V.
Object Type: Report
System: The UNT Digital Library
NREL Gearbox Reliability Collaborative Experimental Data Overview and Analysis: Preprint (open access)

NREL Gearbox Reliability Collaborative Experimental Data Overview and Analysis: Preprint

Most turbines in the market today follow a modular configuration comprised of a main shaft, gearbox, high speed shaft, and generator. The gearbox has the important task of increasing the slow rotor speeds to meet the electromechanical requirements of the electromechanical. These gearboxes are commonly composed of a planetary stage and several parallel shaft stages. The planetary, or epicyclical, design of the gearbox is a feature of the design that has many advantages compared to the traditional parallel shaft arrangement. Among these are that higher gear ratios can be achieved in a single stage, they are capable to carrying higher loads, and they require less space than the traditional parallel shaft arrangement. For this reason, planetary gearboxes they are commonly used in the first stage of the wind turbine gearboxes. However, planetary stages are more complex than the typical parallel shaft arrangement, and can be affected by deflection in the planet carrier, annulus deformations and bearing clearances. Unanticipated levels of these motions can reduce their life expectancy. This paper gives a brief overview of a subset of the experimental efforts, data, and analysis of the GRC project focusing on the planet carrier deformation.
Date: May 1, 2010
Creator: Oyague, F.; Gorman, D. & Sheng, S.
Object Type: Article
System: The UNT Digital Library
Summary Report Documenting Status of the Rare Earth Oxide Investigation (open access)

Summary Report Documenting Status of the Rare Earth Oxide Investigation

The goal of this work is to enhance the understanding of ceramic nuclear fuel thermochemistry through a coordinated modeling and experimental approach. This work supports the Advanced Fuels Campaign Feedstock and Fabrication Technology R&D Program and is focused on the following tasks: (1) use existing compound energy formalism-based models to support Los Alamos National Laboratory (LANL) fuel development activities, (2) assess rare earth (RE) oxide systems and begin development of thermochemical representations of U-RE-O systems, and (3) develop a U-Ce-O thermochemical model for the fluorite-structure phase. In support of the experimental efforts at the LANL, an assessment of temperature-oxygen potential conditions for preparing stoichiometric U{sub 1-y}Ce{sub y}O{sub 2} at relatively low values of y (< 0.4) was performed. There is significant agreement in the literature that both the independent urania and ceria phases, and the urania-ceria solution phase are stoichiometric at oxygen-to-metal (O/M) ratios of 2 at 850 C and an oxygen potential of -368 kJ/mol. The oxygen potential value is obtained at a partial pressure of CO/CO{sub 2} ratio of unity at 1 bar total pressure. This information was successfully applied in thermogravimetric analysis experimental efforts at LANL investigating urania, ceria, and blended powders of the two oxides. Data …
Date: May 1, 2010
Creator: Besmann, Theodore M; Voit, Stewart L & Shin, Dongwon
Object Type: Report
System: The UNT Digital Library
Evaluation of Sludge Batch 5 Qualification with ISDP Salt Batch 1 Compliance to DWPF Waste Acceptance Criteria (open access)

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
Multiscale analysis of nonlinear systems using computational homology (open access)

Multiscale analysis of nonlinear systems using computational homology

This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large …
Date: May 19, 2010
Creator: Mischaikow, Konstantin; Schatz, Michael; Kalies, William & Wanner, Thomas
Object Type: Report
System: The UNT Digital Library
Audit Report on "Management Controls over the Department of Energy's American Recovery and Reinvestment Act - Louisiana State Energy Program" (open access)

Audit Report on "Management Controls over the Department of Energy's American Recovery and Reinvestment Act - Louisiana State Energy Program"

The Department of Energy's (Department) Office of Energy Efficiency and Renewable Energy (EERE) provides grants to states, territories and the District of Columbia (states) to support their energy priorities through the State Energy Program (SEP). Federal funding is based on a grant formula that considers the population and energy consumption in each state, and amounted to $25 million for Fiscal Year (FY) 2009. The American Recovery and Reinvestment Act of 2009 (Recovery Act) expanded the SEP by authorizing an additional $3.1 billion to states using the existing grant formula. EERE made grant awards to states after reviewing plans that summarize the activities states will undertake to achieve SEP Recovery Act objectives, including preserving and creating jobs; saving energy; increasing renewable energy sources; and, reducing greenhouse gas emissions. EERE program guidance emphasizes that states are responsible for administering SEP within each state, and requires each state to implement internal controls over the use of Recovery Act funds. The State of Louisiana received $71.6 million in SEP Recovery Act funds; a 164-fold increase over its FY 2009 SEP grant of $437,000. As part of the Office of Inspector General's strategy for reviewing the Department's implementation of the Recovery Act, we initiated this …
Date: May 1, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Applying Human Factors during the SIS Life Cycle (open access)

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
The Impact of an Oxygen Dopant in an ideal Bi_2Sr_2CaCu_2O_8 delta Crystal (open access)

The Impact of an Oxygen Dopant in an ideal Bi_2Sr_2CaCu_2O_8 delta Crystal

Recent scanning tunneling microscopy studies have shown that local nanoscale pairing inhomogenities are correlated with interstitial oxygen dopants in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. Combining electrostatic and cluster calculations, in this paper the impact of a dopant on the local Madelung and charge transfer energies, magnetic exchange J, Zhang-Rice mobility, and interactions with the lattice is investigated. It is found that electrostatic modifications locally increases the charge transfer energy and slightly suppresses J. It is further shown that coupling to c-axis phonons is strongly modified near the dopant. The combined effects of electrostatic modifications and coupling to the lattice yield broadened spectral features, reduced charge gap energies, and a sizable local increase of J. This implies a strong local interplay between antiferromagnetism, polarons, and superconducting pairing.
Date: May 4, 2010
Creator: Johnston, S.
Object Type: Article
System: The UNT Digital Library
National Agenda for Hydrogen Codes and Standards (open access)

National Agenda for Hydrogen Codes and Standards

This paper provides an overview of hydrogen codes and standards with an emphasis on the national effort supported and managed by the U.S. Department of Energy (DOE). With the help and cooperation of standards and model code development organizations, industry, and other interested parties, DOE has established a coordinated national agenda for hydrogen and fuel cell codes and standards. With the adoption of the Research, Development, and Demonstration Roadmap and with its implementation through the Codes and Standards Technical Team, DOE helps strengthen the scientific basis for requirements incorporated in codes and standards that, in turn, will facilitate international market receptivity for hydrogen and fuel cell technologies.
Date: May 1, 2010
Creator: Blake, C.
Object Type: Article
System: The UNT Digital Library
Alternative Enhanced Chemical Cleaning Basic Studies Results FY09 (open access)

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
Search for scalar bottom quarks and third-generation leptoquarks in p p-bar collisions at sqrt(s) = 1.96 TeV (open access)

Search for scalar bottom quarks and third-generation leptoquarks in p p-bar collisions at sqrt(s) = 1.96 TeV

We report the results of a search for pair production of scalar bottom quarks ({tilde b}{sub 1}) and scalar third-generation leptoquarks (LQ{sub 3}) in 5.2 fb{sup -1} of p{bar p} collisions at the D0 experiment of the Fermilab Tevatron Collider. Scalar bottom quarks are assumed to decay to a neutralino ({tilde {chi}}{sub 1}{sup 0}) and a b quark, and we set 95% C.L. lower limits on their production in the (m{sub {tilde b}{sub 1}}, m{sub {tilde {chi}}{sub 1}{sup 0}}) mass plane such as m{sub {tilde b}{sub 1}} > 247 GeV for m{sub {tilde {chi}}{sub 1}{sup 0}} = 0 and m{sub {tilde {chi}}{sub 1}{sup 0}} > 110 GeV for 160 < m{sub {tilde b}{sub 1}} < 200 GeV. The leptoquarks are assumed to decay to a tau neutrino and a b quark, and we set a 95% C.L. lower limit of 247 GeV on the mass of a charge-1/3 third-generation scalar leptoquark.
Date: May 1, 2010
Creator: Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd et al.
Object Type: Article
System: The UNT Digital Library
The hierarchy of multiple many-body interaction scales in high-temperature superconductors (open access)

The hierarchy of multiple many-body interaction scales in high-temperature superconductors

To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few hundred meV below the Fermi energy. Here, at higher energy scale, we present improved experimental data from four families of high-T{sub c} superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low energy anomaly ('kink') of 0.03-0.09eV, a high energy anomaly of 0.3-0.5eV, and an anomalous enhancement of the width of the LDA-based CuO{sub 2} band extending to energies of {approx} 2 eV. Besides their universal behavior over the families, we find that all of these three dispersion anomalies also show clear doping dependence over the doping range presented.
Date: May 3, 2010
Creator: Meevasana, W.
Object Type: Article
System: The UNT Digital Library
Evaluation of ISDP Batch 2 Qualification Compliance to 512-S, DWPF, Tank Farm, and Saltstone Waste Acceptance Criteria (open access)

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
Glass Composition Constraint Recommendations for Use in Life-Cycle Mission Modeling (open access)

Glass Composition Constraint Recommendations for Use in Life-Cycle Mission Modeling

The component concentration limits that most influence the predicted Hanford life-cycle HLW glass volume by HTWOS were re-evaluated. It was assumed that additional research and development work in glass formulation and melter testing would be performed to improve the understanding of component effects on the processability and product quality of these HLW glasses. Recommendations were made to better estimate the potential component concentration limits that could be applied today while technology development is underway to best estimate the volume of HLW glass that will eventually be produced at Hanford. The limits for concentrations of P2O5, Bi2O3, and SO3 were evaluated along with the constraint used to avoid nepheline formation in glass. Recommended concentration limits were made based on the current HLW glass property models being used by HTWOS (Vienna et al. 2009). These revised limits are: 1) The current ND should be augmented by the OB limit of OB ≤ 0.575 so that either the normalized silica (NSi) is less that the 62% limit or the OB is below the 0.575 limit. 2) The mass fraction of P2O5 limit should be revised to allow for up to 4.5 wt%, depending on CaO concentrations. 3) A Bi2O3 concentration limit of 7 …
Date: May 3, 2010
Creator: McCloy, John S. & Vienna, John D.
Object Type: Report
System: The UNT Digital Library
Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester with KIVA-3V (open access)

Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester with KIVA-3V

Discusses the use of KIVA-3V to develop a model that reproduces ignition behavior inside the Ignition Quality Tester, which measures the ignition delay of low-volatility fuels.
Date: May 1, 2010
Creator: Bogin, G. E., Jr.; DeFilippo, A.; Chen, J. Y.; Chin, G.; Luecke, J.; Ratcliff, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Wind Turbine Generator System Duration Test Report for the ARE 442 Wind Turbine (open access)

Wind Turbine Generator System Duration Test Report for the ARE 442 Wind Turbine

This test is being conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines are being tested at the NWTC as a part of this project. Duration testing is one of up to 5 tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a grid connected ARE 442 wind turbine mounted on a 30.5 meter (100 ft) lattice tower manufactured by Abundant Renewable Energy. The system was installed by the NWTC Site Operations group with guidance and assistance from Abundant Renewable Energy.
Date: May 1, 2010
Creator: van Dam, J.; Baker, D. & Jager, D.
Object Type: Report
System: The UNT Digital Library