PARTICLE IMAGE VELOCIMETRY MEASUREMENTS IN A REPRESENTATIVE GAS-COOLED PRISMATIC REACTOR CORE MODEL: FLOW IN THE COOLANT CHANNELS AND INTERSTITIAL BYPASS GAPS (open access)

PARTICLE IMAGE VELOCIMETRY MEASUREMENTS IN A REPRESENTATIVE GAS-COOLED PRISMATIC REACTOR CORE MODEL: FLOW IN THE COOLANT CHANNELS AND INTERSTITIAL BYPASS GAPS

Core bypass flow is one of the key issues with the prismatic Gas Turbine-Modular Helium Reactor, and it refers to the coolant that navigates through the interstitial, non-cooling passages between the graphite fuel blocks instead of traveling through the designated coolant channels. To determine the bypass flow, a double scale representative model was manufactured and installed in the Matched Index-of-Refraction flow facility; after which, stereo Particle Image Velocimetry (PIV) was employed to measure the flow field within. PIV images were analyzed to produce vector maps, and flow rates were calculated by numerically integrating over the velocity field. It was found that the bypass flow varied between 6.9-15.8% for channel Reynolds numbers of 1,746 and 4,618. The results were compared to computational fluid dynamic (CFD) pre-test simulations. When compared to these pretest calculations, the CFD analysis appeared to under predict the flow through the gap.
Date: November 1, 2012
Creator: Conder, Thomas E.; Skifton, Richard & Budwig, Ralph
Object Type: Article
System: The UNT Digital Library
New Tool Quantitatively Maps Minority-Carrier Lifetime of Multicrystalline Silicon Bricks (Fact Sheet) (open access)

New Tool Quantitatively Maps Minority-Carrier Lifetime of Multicrystalline Silicon Bricks (Fact Sheet)

NREL's new imaging tool could provide manufacturers with insight on their processes. Scientists at the National Renewable Energy Laboratory (NREL) have used capabilities within the Process Development and Integration Laboratory (PDIL) to generate quantitative minority-carrier lifetime maps of multicrystalline silicon (mc-Si) bricks. This feat has been accomplished by using the PDIL's photoluminescence (PL) imaging system in conjunction with transient lifetime measurements obtained using a custom NREL-designed resonance-coupled photoconductive decay (RCPCD) system. PL imaging can obtain rapid high-resolution images that provide a qualitative assessment of the material lifetime-with the lifetime proportional to the pixel intensity. In contrast, the RCPCD technique provides a fast quantitative measure of the lifetime with a lower resolution and penetrates millimeters into the mc-Si brick, providing information on bulk lifetimes and material quality. This technique contrasts with commercially available minority-carrier lifetime mapping systems that use microwave conductivity measurements. Such measurements are dominated by surface recombination and lack information on the material quality within the bulk of the brick. By combining these two complementary techniques, we obtain high-resolution lifetime maps at very fast data acquisition times-attributes necessary for a production-based diagnostic tool. These bulk lifetime measurements provide manufacturers with invaluable feedback on their silicon ingot casting processes. NREL …
Date: November 1, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Sandia National Laboratories performance assessment methodology for long-term environmental programs : the history of nuclear waste management. (open access)

Sandia National Laboratories performance assessment methodology for long-term environmental programs : the history of nuclear waste management.

Sandia National Laboratories (SNL) is the world leader in the development of the detailed science underpinning the application of a probabilistic risk assessment methodology, referred to in this report as performance assessment (PA), for (1) understanding and forecasting the long-term behavior of a radioactive waste disposal system, (2) estimating the ability of the disposal system and its various components to isolate the waste, (3) developing regulations, (4) implementing programs to estimate the safety that the system can afford to individuals and to the environment, and (5) demonstrating compliance with the attendant regulatory requirements. This report documents the evolution of the SNL PA methodology from inception in the mid-1970s, summarizing major SNL PA applications including: the Subseabed Disposal Project PAs for high-level radioactive waste; the Waste Isolation Pilot Plant PAs for disposal of defense transuranic waste; the Yucca Mountain Project total system PAs for deep geologic disposal of spent nuclear fuel and high-level radioactive waste; PAs for the Greater Confinement Borehole Disposal boreholes at the Nevada National Security Site; and PA evaluations for disposal of high-level wastes and Department of Energy spent nuclear fuels stored at Idaho National Laboratory. In addition, the report summarizes smaller PA programs for long-term cover systems …
Date: November 1, 2011
Creator: Marietta, Melvin Gary; Anderson, D. Richard; Bonano, Evaristo J. & Meacham, Paul Gregory (Raytheon Ktech, Albuquerque, NM)
Object Type: Report
System: The UNT Digital Library
B physics at CDF - the Beauty of hadron collisions (open access)

B physics at CDF - the Beauty of hadron collisions

The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides an unique, rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B{sub s}{sup 0} mixing, and b {yields} s penguin decays.
Date: November 1, 2010
Creator: Tonelli, Diego
Object Type: Article
System: The UNT Digital Library
On Quantum Integrable Systems (open access)

On Quantum Integrable Systems

Many quantum integrable systems are obtained using an accelerator physics technique known as Ermakov (or normalized variables) transformation. This technique was used to create classical nonlinear integrable lattices for accelerators and nonlinear integrable plasma traps. Now, all classical results are carried over to a nonrelativistic quantum case. In this paper we have described an extension of the Ermakov-like transformation to the Schroedinger and Pauli equations. It is shown that these newly found transformations create a vast variety of time dependent quantum equations that can be solved in analytic functions, or, at least, can be reduced to time-independent ones.
Date: November 1, 2011
Creator: Danilov, Viatcheslav & Nagaitsev, Sergei
Object Type: Report
System: The UNT Digital Library
Geomechanical Simulation of Fluid-Driven Fractures (open access)

Geomechanical Simulation of Fluid-Driven Fractures

The project supported graduate students working on experimental and numerical modeling of rock fracture, with the following objectives: (a) perform laboratory testing of fluid-saturated rock; (b) develop predictive models for simulation of fracture; and (c) establish educational frameworks for geologic sequestration issues related to rock fracture. These objectives were achieved through (i) using a novel apparatus to produce faulting in a fluid-saturated rock; (ii) modeling fracture with a boundary element method; and (iii) developing curricula for training geoengineers in experimental mechanics, numerical modeling of fracture, and poroelasticity.
Date: November 30, 2012
Creator: Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S. & Labuz, J.
Object Type: Report
System: The UNT Digital Library
The Effect of Degraded Digital Instrumentation and Control systems on Human-system Interfaces and Operator Performance (open access)

The Effect of Degraded Digital Instrumentation and Control systems on Human-system Interfaces and Operator Performance

Integrated digital instrumentation and control (I&C) systems in new and advanced nuclear power plants (NPPs) will support operators in monitoring and controlling the plants. Even though digital systems typically are expected to be reliable, their potential for degradation or failure significantly could affect the operators performance and, consequently, jeopardize plant safety. This U.S. Nuclear Regulatory Commission (NRC) research investigated the effects of degraded I&C systems on human performance and on plant operations. The objective was to develop technical basis and guidance for human factors engineering (HFE) reviews addressing the operator's ability to detect and manage degraded digital I&C conditions. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we evaluated the potential effects of selected failure modes of the digital feedwater control system of a currently operating pressurized water reactor (PWR) on human-system interfaces (HSIs) and the operators performance. Our findings indicated that I&C degradations are prevalent in plants employing digital systems, and the overall effects on the plant's behavior can be significant, such as causing a reactor trip or equipment to operate unexpectedly. I&C degradations may affect the HSIs used by operators to monitor and control the plant. For example, deterioration of the sensors …
Date: November 7, 2010
Creator: Ohara, J. M.; Gunther, B.; Martinez-Guridi, G. (BNL); Xing, J. & Barnes, V. (NRC)
Object Type: Article
System: The UNT Digital Library
CLIC RF High Power Production Testing Program (open access)

CLIC RF High Power Production Testing Program

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production ({approx} 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.
Date: November 2, 2011
Creator: Syratchev, I.; Riddone, G. & Tantawi, S. G.
Object Type: Article
System: The UNT Digital Library
Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators (open access)

Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

We are developing new scintillator materials that offer potential for high resolution gamma ray spectroscopy at low cost. Single crystal SrI{sub 2}(Eu) offers {approx}3% resolution at 662 keV, in sizes of {approx}1 in{sup 3}. We have developed ceramics processing technology allowing us to achieve cubic inch scale transparent ceramic scintillators offering gamma spectroscopy performance superior to NaI(Tl). We fabricated a bismuth-loaded plastic scintillator that demonstrates energy resolution of {approx}8% at 662 keV in small sizes. Gamma ray spectroscopy can be used to identify the presence of weak radioactive sources within natural background. The ability to discriminate close-lying spectral lines is strongly dependent upon the energy resolution of the detector. In addition to excellent energy resolution, large volume detectors are needed to acquire sufficient events, for example, to identify a radioactive anomaly moving past a detector. We have employed a 'directed search' methodology for identifying potential scintillator materials candidates, resulting in the discovery of Europium-doped Strontium Iodide, SrI{sub 2}(Eu), Cerium-doped Gadolinium Garnet, GYGAG(Ce), and Bismuth-loaded Polymers. These scintillators possess very low self-radioactivity, offer energy resolution of 3-8% at 662 keV, and have potential to be grown cost-effectively to sizes similar to the most widely deployed gamma spectroscopy scintillator, Thallium-doped Sodium Iodide, …
Date: November 19, 2010
Creator: Cherepy, N J
Object Type: Article
System: The UNT Digital Library
Enabling Greater Penetration of Solar Power via the Use of CSP with Thermal Energy Storage (open access)

Enabling Greater Penetration of Solar Power via the Use of CSP with Thermal Energy Storage

At high penetration of solar generation there are a number of challenges to economically integrating this variable and uncertain resource. These include the limited coincidence between the solar resource and normal demand patterns and limited flexibility of conventional generators to accommodate variable generation resources. Of the large number of technologies that can be used to enable greater penetration of variable generators, concentrating solar power (CSP) with thermal energy storage (TES) presents a number of advantages. The use of storage enables this technology to shift energy production to periods of high demand or reduced solar output. In addition, CSP can provide substantial grid flexibility by rapidly changing output in response to the highly variable net load created by high penetration of solar (and wind) generation. In this work we examine the degree to which CSP may be complementary to PV by performing a set of simulations in the U.S. Southwest to demonstrate the general potential of CSP with TES to enable greater use of solar generation, including additional PV.
Date: November 1, 2011
Creator: Denholm, P. & Mehos, M.
Object Type: Report
System: The UNT Digital Library
Processing Tons of Data with QuickView (open access)

Processing Tons of Data with QuickView

This presentation describes the QuickView software used to process data
Date: November 1, 2011
Creator: Diaz, A. B.
Object Type: Article
System: The UNT Digital Library
DOE 2010 Occupational Radiation Exposure November 2011 (open access)

DOE 2010 Occupational Radiation Exposure November 2011

This report discusses radiation protection and dose reporting requirements, presents the 2010 occupational radiation dose data trended over the past 5 years, and includes instructions to submit successful ALARA projects.
Date: November 11, 2011
Creator: U.S. Department of Energy, Office of Health, Safety and Security, Office of Analysis
Object Type: Report
System: The UNT Digital Library
The Network Completion Problem: Inferring Missing Nodes and Edges in Networks (open access)

The Network Completion Problem: Inferring Missing Nodes and Edges in Networks

Network structures, such as social networks, web graphs and networks from systems biology, play important roles in many areas of science and our everyday lives. In order to study the networks one needs to first collect reliable large scale network data. While the social and information networks have become ubiquitous, the challenge of collecting complete network data still persists. Many times the collected network data is incomplete with nodes and edges missing. Commonly, only a part of the network can be observed and we would like to infer the unobserved part of the network. We address this issue by studying the Network Completion Problem: Given a network with missing nodes and edges, can we complete the missing part? We cast the problem in the Expectation Maximization (EM) framework where we use the observed part of the network to fit a model of network structure, and then we estimate the missing part of the network using the model, re-estimate the parameters and so on. We combine the EM with the Kronecker graphs model and design a scalable Metropolized Gibbs sampling approach that allows for the estimation of the model parameters as well as the inference about missing nodes and edges of …
Date: November 14, 2011
Creator: Kim, M & Leskovec, J
Object Type: Article
System: The UNT Digital Library
A Spectral Verification of the HELIOS-2 Lattice Physics Code (open access)

A Spectral Verification of the HELIOS-2 Lattice Physics Code

Core modeling of the Advanced Test Reactor (ATR) at INL is currently undergoing a significant update through the Core Modeling Update Project1. The intent of the project is to bring ATR core modeling in line with today’s standard of computational efficiency and verification and validation practices. The HELIOS-2 lattice physics code2 is the lead code of several reactor physics codes to be dedicated to modernize ATR core analysis. This presentation is concerned with an independent verification of the HELIOS-2 spectral representation including the slowing down and thermalization algorithm and its data dependency. Here, we will describe and demonstrate a recently developed simple cross section generation algorithm based entirely on analytical multigroup parameters for both the slowing down and thermal spectrum. The new capability features fine group detail to assess the flux and multiplication factor dependencies on cross section data sets using the fundamental infinite medium as an example.
Date: November 1, 2012
Creator: Crawford, D. S.; Ganapol, B. D. & Nigg, D. W.
Object Type: Article
System: The UNT Digital Library
Extending MC-SURE to Denoise Sensor Data Streams (open access)

Extending MC-SURE to Denoise Sensor Data Streams

None
Date: November 15, 2012
Creator: Ndoye, M. & Kamath, C.
Object Type: Article
System: The UNT Digital Library
Empowering Minority Communities with Health Information - UDC (open access)

Empowering Minority Communities with Health Information - UDC

Training update with Environmental a health focus. Training conducted as part of the United Negro College Fund Special Programs Corporation/National Library of Medicine - HBCU ACCESS Project at the University of the District of Columbia, Washington, DC on November 2, 2010.
Date: November 2, 2010
Creator: McMurray, L.; Foster, R. & Womble, and R.
Object Type: Book
System: The UNT Digital Library
Preliminary results from the MINERvA experiment (open access)

Preliminary results from the MINERvA experiment

The MINERvA experiment, operating since 2009 in the NuMI neutrino beam line at Fermilab, has collected neutrino and antineutrino scattering data on a variety of nuclear targets. The detector is designed to identify events originating in plastic scintillator, lead, carbon, iron, water, and liquid helium. The goal of the experiment is to measure inclusive and exclusive cross sections for neutrino and antineutrino with much greater precision than previous experiments. We present preliminary kinematic distributions for charged current quasi-elastic scattering and other processes.
Date: November 1, 2011
Creator: Harris, Deborah A.
Object Type: Article
System: The UNT Digital Library
Hydrogen Storage Needs for Early Motive Fuel Cell Markets (open access)

Hydrogen Storage Needs for Early Motive Fuel Cell Markets

The National Renewable Energy Laboratory's (NREL) objective for this project is to identify performance needs for onboard energy storage of early motive fuel cell markets by working with end users, manufacturers, and experts. The performance needs analysis is combined with a hydrogen storage technology gap analysis to provide the U.S. Department of Energy (DOE) Fuel Cell Technologies Program with information about the needs and gaps that can be used to focus research and development activities that are capable of supporting market growth.
Date: November 1, 2012
Creator: Kurtz, J.; Ainscough, C.; Simpson, L. & Caton, M.
Object Type: Report
System: The UNT Digital Library
Life extension program for the modular caustic side solvent extraction unit at Savannah River Site (open access)

Life extension program for the modular caustic side solvent extraction unit at Savannah River Site

Caustic Side Solvent Extraction (CSSX) is currently used at the U.S. Department of Energy (DOE) Savannah River Site (SRS) for removal of cesium from the high-level salt-wastes stored in underground tanks. At SRS, the CSSX process is deployed in the Modular CSSX Unit (MCU). The CSSX technology utilizes a multi-component organic solvent and annular centrifugal contactors to extract cesium from alkaline salt waste. Coalescers and decanters process the Decontaminated Salt Solution (DSS) and Strip Effluent (SE) streams to allow recovery and reuse of the organic solvent and to limit the quantity of solvent transferred to the downstream facilities. MCU is operated in series with the Actinide Removal Process (ARP) which removes strontium and actinides from salt waste utilizing monosodium titanate. ARP and MCU were developed and implemented as interim salt processing until future processing technology, the CSSX-based Salt Waste Processing Facility (SWPF), is operational. SWPF is slated to come on-line in October 2014. The three year design life of the ARP/MCU process, however, was reached in April 2011. Nevertheless, most of the individual process components are capable of operating longer. An evaluation determined ARP/MCU can operate until 2015 before major equipment failure is expected. The three year design life of …
Date: November 14, 2012
Creator: Samadi-Dezfouli, Azadeh
Object Type: Article
System: The UNT Digital Library
Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development (open access)

Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.
Date: November 23, 2010
Creator: Aker, Pamela M.; Jones, Anthony M. & Copping, Andrea E.
Object Type: Report
System: The UNT Digital Library
Long-Term Colloid Mobilization And Colloid-Facilitated Transport Of Radionuclides In A Semi-Arid Vadose Zone (open access)

Long-Term Colloid Mobilization And Colloid-Facilitated Transport Of Radionuclides In A Semi-Arid Vadose Zone

The main purpose of this project was to improve the fundamental mechanistic understanding and quantification of long-term colloid mobilization and colloid-facilitated transport of radionuclides in the vadose zone, with special emphasis on the semi-arid Hanford site. While we focused some of the experiments on hydrogeological and geochemical conditions of the Hanford site, many of our results apply to colloid and colloid-facilitated transport in general. Specific objectives were (1) to determine the mechanisms of colloid mobilization and colloid-facilitated radionuclide transport in undisturbed Hanford sediments under unsaturated flow, (2) to quantify in situ colloid mobilization and colloid-facilitated radionuclide transport from Hanford sediments under field conditions, and (3) to develop a field-scale conceptual and numerical model for colloid mobilization and transport at the Hanford vadose zone, and use that model to predict long-term colloid and colloid- facilitated radionuclide transport. To achieve these goals and objectives, we have used a combination of experimental, theoretical, and numerical methods at different spatial scales, ranging from microscopic investigations of single particle attachment and detachment to larger-scale field experiments using outdoor lysimeters at the Hanford site. Microscopic and single particle investigations provided fundamental insight into mechanisms of colloid interactions with the air-water interface. We could show that a …
Date: November 5, 2012
Creator: Flury, Markus; Harsh, James B; Zhang, Fred; Gee, Glendon W; Mattson, Earl D & Lichtner, Peter C
Object Type: Text
System: The UNT Digital Library
Crab Cavities for Linear Colliders (open access)

Crab Cavities for Linear Colliders

Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.
Date: November 8, 2011
Creator: Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; U., /Cockcroft Inst. Accel. Sci. Tech. /Lancaster et al.
Object Type: Article
System: The UNT Digital Library
The Development of Open Water-lubricated Polycrystalline Diamond (PCD) Thrust Bearings for Use in Marine Hydrokinetic (MHK) Energy Machines (open access)

The Development of Open Water-lubricated Polycrystalline Diamond (PCD) Thrust Bearings for Use in Marine Hydrokinetic (MHK) Energy Machines

Polycrstalline diamond (PCD) bearings were designed, fabricated and tested for marine-hydro-kinetic (MHK) application. Bearing efficiency and life were evaluated using the US Synthetic bearing test facility. Three iterations of design, build and test were conducted to arrive at the best bearing design. In addition life testing that simulated the starting and stopping and the loading of real MHK applications were performed. Results showed polycrystalline diamond bearings are well suited for MHK applications and that diamond bearing technology is TRL4 ready. Based on life tests results bearing life is estimated to be at least 11.5 years. A calculation method for evaluating the performance of diamond bearings of round geometry was also investigated and developed. Finally, as part of this effort test bearings were supplied free of charge to the University of Alaska for further evaluation. The University of Alaska test program will subject the diamond bearings to sediment laden lubricating fluid.
Date: November 28, 2012
Creator: Cooley, Craig, H.; Khonsari, Michael,, M & Lingwall, Brent
Object Type: Report
System: The UNT Digital Library
A New Approach to Quantify Level 2 SPAR Models in SAPHIRE 8 (open access)

A New Approach to Quantify Level 2 SPAR Models in SAPHIRE 8

The U.S. Nuclear Regulatory Commission’s (USNRC) Standardized Plant Analysis Risk (SPAR) Level 2 models for U.S. commercial nuclear power plants has historically used a partitioning approach for plant damage state (PDS) binning and model quantification since late 1990s [1]. While this approach has the advantage to be able to identify the details of the severe accident sequences with one or more individual PDS vector characters, the Level 2 model quantification process is tedious and error-prone with multiple steps involved. A new approach to quantify Level 2 SPAR models was recently developed and implemented in the latest SAPHIRE Version 8 [2]. The new approach removes the partition rules and greatly simplifies the quantification process.
Date: November 1, 2012
Creator: Ma, Zhegang; Schroeder, John; Smith, Curtis; Wood, Ted & Sattison, Martin
Object Type: Article
System: The UNT Digital Library