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Ignition of Aluminum Particles and Clouds

Description: Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in s… more
Date: April 7, 2010
Creator: Kuhl, A. L. & Boiko, V. M.
Partner: UNT Libraries Government Documents Department
open access

EFFECT OF GLASS-BATCH MAKEUP ON THE MELTING PROCESS

Description: The response of a glass batch to heating is determined by the batch makeup and in turn determines the rate of melting. Batches formulated for a high-alumina nuclear waste to be vitrified in an all-electric melter were heated at a constant temperature-increase rate to determine changes in melting behavior in response to the selection of batch chemicals and silica grain-size as well as the addition of heat-generating reactants. The type of batch materials and the size of silica grains determine h… more
Date: December 7, 2010
Creator: AA, KRUGER & P, HRMA
Partner: UNT Libraries Government Documents Department
open access

Predicting Image Blur in Proton Radiography: Comparisons Between Measurements and Monte Carlo Simulations

Description: Given the cost and lead-times involved in high-energy proton radiography, it is prudent to model proposed radiographic experiments to see if the images predicted would return useful information. We recently modified our raytracing transmission radiography modeling code HADES to perform simplified Monte Carlo simulations of the transport of protons in a proton radiography beamline. Beamline objects include the initial diffuser, vacuum magnetic fields, windows, angle-selecting collimators, and ob… more
Date: May 7, 2010
Creator: Schach von Wittenau, Alexis E.; Aufderheide, Maurice B., III & Henderson, Gary L.
Partner: UNT Libraries Government Documents Department
open access

Dense Heterogeneous Continuum Model of Two-Phase Explosion Fields

Description: A heterogeneous continuum model is proposed to describe the dispersion of a dense Aluminum particle cloud in an explosion. Let {alpha}{sub 1} denote the volume fraction occupied by the gas and {alpha}{sub 2} the fraction occupied by the solid, satisfying the volume conservation relation: {alpha}{sub 1} + {alpha}{sub 2} = 1. When the particle phase occupies a non-negligible volume fraction (i.e., {alpha}{sub 2} > 0), additional terms, proportional to {alpha}{sub 2}, appear in the conservation… more
Date: April 7, 2010
Creator: Kuhl, A L & Bell, J B
Partner: UNT Libraries Government Documents Department
open access

Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine

Description: The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to… more
Date: December 7, 2010
Creator: Latkowski, J. F.; Kramer, K. J.; Abbott, R. P.; Morris, K. R.; DeMuth, J.; Divol, L. et al.
Partner: UNT Libraries Government Documents Department
open access

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

Description: 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 hum… more
Date: November 7, 2010
Creator: Ohara, J. M.; Gunther, B.; Martinez-Guridi, G. (BNL); Xing, J. & Barnes, V. (NRC)
Partner: UNT Libraries Government Documents Department
open access

Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders

Description: Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity … more
Date: January 7, 2010
Creator: Johnson, Matthew; Weyant, J.; Garner, S. & Occhionero, M.
Partner: UNT Libraries Government Documents Department
open access

Cleanroom Energy Efficiency: Metrics and Benchmarks

Description: Cleanrooms are among the most energy-intensive types of facilities. This is primarily due to the cleanliness requirements that result in high airflow rates and system static pressures, as well as process requirements that result in high cooling loads. Various studies have shown that there is a wide range of cleanroom energy efficiencies and that facility managers may not be aware of how energy efficient their cleanroom facility can be relative to other cleanroom facilities with the same cleanli… more
Date: July 7, 2010
Creator: Initiative, International SEMATECH Manufacturing; Mathew, Paul A.; Tschudi, William; Sartor, Dale & Beasley, James
Partner: UNT Libraries Government Documents Department
open access

HANFORDS PUBLIC TOUR PROGRAM - AN EXCELLENT EDUCATIONAL TOOL

Description: Prior to 2001, the Department of Energy (DOE) sponsored limited tours of the Hanford Site for the public, but discontinued the program after the 9/11 terrorist attacks on the U.S. In 2003, DOE's Richland Operations Office (DOE-RL) requested the site's prime contractor to reinstate the public tour program starting in 2004 under strict controls and security requirements. The planning involved a collaborative effort among the security, safety and communications departments of DOE-RL and the site's… more
Date: December 7, 2010
Creator: KM, SINCLAIR
Partner: UNT Libraries Government Documents Department
open access

Probing Ferroelectricity in PbZr0.2Ti0.8O3 with Polarized Soft X-rays

Description: The reduction in symmetry associated with the onset of ferroelectric order in PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT) thin films leads to a pronounced difference at the Ti L{sub 3,2} absorption edges between spectra measured with the x-ray linear polarization perpendicular and parallel to the ferroelectric polarization. We introduce a general method to analyze the observed difference spectra using atomic multiplet calculations. Moreover, we find experimental evidence for structural changes in PZ… more
Date: June 7, 2010
Creator: Arenholz, E.; van der Laan, G.; Fraile-Rodriguez, A.; Yu, P.; He, Q. & Ramesh, R.
Partner: UNT Libraries Government Documents Department
open access

Human-system Interfaces for Automatic Systems

Description: Automation is ubiquitous in modern complex systems, and commercial nuclear- power plants are no exception. Automation is applied to a wide range of functions including monitoring and detection, situation assessment, response planning, and response implementation. Automation has become a 'team player' supporting personnel in nearly all aspects of system operation. In light of its increasing use and importance in new- and future-plants, guidance is needed to conduct safety reviews of the operator… more
Date: November 7, 2010
Creator: O'Hara, J. M.; Higgins, James; Fleger, Stephen & Barnes, Valerie
Partner: UNT Libraries Government Documents Department
open access

Uncertainty Analysis Technique for OMEGA Dante Measurements

Description: The Dante is an 18 channel X-ray filtered diode array which records the spectrally and temporally resolved radiation flux from various targets (e.g. hohlraums, etc.) at X-ray energies between 50 eV to 10 keV. It is a main diagnostics installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The absolute flux is determined from the photometric calibration of the X-ray diodes, filters and mirrors and an unfold algorithm. Understanding the errors on thi… more
Date: May 7, 2010
Creator: May, M J; Widmann, K; Sorce, C; Park, H & Schneider, M
Partner: UNT Libraries Government Documents Department
open access

Human Factors Aspects of Operating Small Reactors

Description: The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. They are considering small modular reactors (SMRs) as one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can be designed to generate hydrogen, or to process heat. Many characteristics of SMRs are quite different from t… more
Date: November 7, 2010
Creator: Ohara, J. M.; Higgins, J.; Deem, R. (BNL); Xing, J. & DAgostino, A. (NRC)
Partner: UNT Libraries Government Documents Department
open access

USE OF CEMENTITIOUS MATERIALS FOR SRS REACTOR FACILITY IN-SITU DECOMMISSIONING - 11620

Description: The United States Department of Energy (US DOE) concept for facility in-situ decommissioning (ISD) is to physically stabilize and isolate in tact, structurally sound facilities that are no longer needed for their original purpose of, i.e., producing (reactor facilities), processing (isotope separation facilities) or storing radioactive materials. The Savannah River Site 105-P and 105-R Reactor Facility ISD requires about 250,000 cubic yards of grout to fill the below grade structure. The fills … more
Date: December 7, 2010
Creator: Langton, C.; Stefanko, D.; Serrato, M.; Blankenship, J.; Griffin, W.; Waymer, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Recent Developments in Neutron Detection and Multiplicity Counting with Liquid Scintillator

Description: For many years at LLNL we have been developing time-correlated neutron detection techniques and algorithms for many applications including Arms Control, Threat Detection and Nuclear Material Assaying. Many of our techniques have been developed specifically for relatively low efficiency (a few %) inherent in the man-portable systems. Historically we used thermal neutron detectors (mainly {sup 3}He) taking advantage of the high thermal neutron interaction cross-sections but more recently we have … more
Date: January 7, 2010
Creator: Nakae, L F; Kerr, P L; Newby, R J; Prasad, M K; Rowland, M S; Snyderman, N J et al.
Partner: UNT Libraries Government Documents Department
open access

Reviewing Consensus HFE Standards for NRC Use: A Case Study using the IEEE Standard for Computerized Operating Procedure Systems

Description: The U.S. Nuclear Regulatory Commission’s (NRC’s) endorsement of consensus standards provides a cost-effective means of enhancing the staff’s ability to review state-of-the-art designs. Although the NRC endorsed consensus standards in many technical disciplines, it yet has to do so in human factors engineering (HFE). The purpose of our study was to develop a standardized methodology whereby to evaluate a consensus HFE standard to determine its appropriateness to, and adequacy for using in licens… more
Date: November 7, 2010
Creator: Ohara, J. M.; Higgins, J. & Xing, J., Fleger S. - NRC
Partner: UNT Libraries Government Documents Department
open access

High Pressure - High Temperature Polymorphism in Ta: Resolving an Ongoing Experimental Controversy

Description: Phase diagrams of refractory metals remain essentially unknown. Moreover, there is an ongoing controversy over the high pressure (P) melting temperatures of these metals: results of diamond anvil cell (DAC) and shock wave experiments differ by at least a factor of two. From an extensive ab initio study on tantalum we discovered that the body-centered cubic phase, its physical phase at ambient conditions, transforms to another solid phase, possibly hexagonal omega phase, at high temperature (T).… more
Date: April 7, 2010
Creator: Burkovsky, L.; Chen, S. P.; Preston, D. L.; Belonoshko, A. B.; Rosengren, A.; Mikhaylushkin, A. S. et al.
Partner: UNT Libraries Government Documents Department
open access

Inclusive pi^0, eta, and direct photon production at high transverse momentum in p+p and d+Au collisions at sqrt(s_NN) = 200 GeV

Description: We report a measurement of high-p{sub T} inclusive {pi}{sup 0}, {eta}, and direct photon production in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV at midrapidity (0 < {eta} < 1). Photons from the decay {pi}{sup 0} {yields} {gamma}{gamma} were detected in the Barrel Electromagnetic Calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The {eta} {yields} {gamma}{gamma} decay was also observed and constituted the first {eta} measurement by STAR. The first… more
Date: July 7, 2010
Creator: STAR Collaboration
Partner: UNT Libraries Government Documents Department
open access

R- AND P- REACTOR VESSEL IN-SITU DECOMISSIONING VISUALIZATION

Description: The R- & P- Reactor facilities were constructed in the early 1950's in response to Cold War efforts. The mission of the facilities was to produce materials for use in the nation's nuclear weapons stockpile. R-Reactor was removed from service in 1964 when President Johnson announced a slowdown of he nuclear arms race. PReactor continued operation until 1988 until the facility was taken off-line to modernize the facility with new safeguards. Efforts to restart the reactor ended in 1990 at the end… more
Date: June 7, 2010
Creator: Vrettos, N.; Bobbitt, J. & Howard, M.
Partner: UNT Libraries Government Documents Department
open access

Proton-Nucleus Scattering Approximations and Implications for LHC Crystal Collimation

Description: In particle accelerators, scattered protons with energies close to the incident particles may travel considerable distances with the beam before impacting on accelerator components downstream. To analyze such problems, angular deflection and energy loss of scattered particles are the main quantities to be simulated since these lead to changes in the beam's phase space distribution and particle loss. Simple approximations for nuclear scattering processes causing limited energy loss to high-energ… more
Date: June 7, 2010
Creator: Noble, Robert
Partner: UNT Libraries Government Documents Department
open access

A Moving Window Technique in Parallel Finite Element Time Domain Electromagnetic Simulation

Description: A moving window technique for the finite element time domain (FETD) method is developed to simulate the propagation of electromagnetic waves induced by the transit of a charged particle beam inside large and long structures. The window moving along with the beam in the computational domain adopts high-order finite-element basis functions through p refinement and/or a high-resolution mesh through h refinement so that a sufficient accuracy is attained with substantially reduced computational cost… more
Date: June 7, 2010
Creator: Lee, Lie-Quan; Candel, Arno; Ng, Cho & Ko, Kwok
Partner: UNT Libraries Government Documents Department
open access

Development of Controlled Pitch Nano Arrays for Application in Nano Scale Based Proportional Counters

Description: Proportional counters (PCs) are a type of gas-filled radiation detection device capable of distinguishing between a wide range of radiation types and energies. In this application, however, these devices are limited by high power consumption and high bias potentials required to operate in the proportional detection regime. Previous work performed with a single carbon nanotube (CNT) anode has shown that nanoscale-based PCs can operate at bias potentials of 10V rather than the 1000V range require… more
Date: June 7, 2010
Creator: Sexton, L.; Serkiz, S. & Siegfried, M.
Partner: UNT Libraries Government Documents Department
open access

Compact, Intelligent, Digitally Controlled IGBT Gate Drivers for a PEBB-Based ILC Marx Modulator

Description: SLAC National Accelerator Laboratory has built and is currently operating a first generation prototype Marx klystron modulator to meet ILC specifications. Under development is a second generation prototype, aimed at improving overall performance, serviceability, and manufacturability as compared to its predecessor. It is designed around 32 cells, each operating at 3.75 kV and correcting for its own capacitor droop. Due to the uniqueness of this application, high voltage gate drivers needed to b… more
Date: June 7, 2010
Creator: Nguyen, M. N.; Burkhart, C.; Olsen, J. J. & Macken, K.
Partner: UNT Libraries Government Documents Department
open access

Lifetime Tests on a High Ohms/Square Metalized High Crystalline Polypropylene Film Capacitor with Application to a Marx Modulator

Description: This paper presents accelerated lifetime tests on a polypropylene film capacitor. Experimental parameters (20% droop, 5 Hz repetition rate) simulate anticipated operating conditions encountered in the SLAC P2 Marx. Elevated film electric field stress is utilized as the acceleration parameter. Results indicate that, for the particular film of interest, a film stress of {approx}290 V/{mu}m corresponds to a 10{sup 5} hour lifetime. In addition, the voltage scaling exponent for this film is 13.1.
Date: June 7, 2010
Creator: Kemp, Mark A.; Burkhart, Craig & Tang, Tao
Partner: UNT Libraries Government Documents Department
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