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Fibrous filter efficiency and pressure drop in the viscous-inertial transition flow regime

Aerosol Science and Technology

Hubbard, Joshua A.; Brockmann, John E.; Dellinger, Jennifer D.; Lucero, Daniel A.; Sanchez, A.L.; Servantes, B.L.

Fibrous filter pressure drop and aerosol collection efficiency were measured at low air pressures (0.2-0.8 atm) and high face velocities (5-19 m/s) to give fiber Reynolds numbers lying in the viscous-inertial transition flow regime (1-15). In this regime, contemporary filtration theory based on Kuwabara's viscous flow through an ensemble of fibers underpredicts single fiber impaction by several orders of magnitude. Streamline curvature increases substantially as air stream inertial forces become significant. Dimensionless pressure drop measurements followed the viscous-inertial theory of Robinson and Franklin (1972) rather than Darcy's linear pressure-velocity relationship. Sodium chloride and iron nano-agglomerate aerosols were tested to provide a comparison between particles of dissimilar densities and shape factors. Total filter efficiency collapsed when plotted against the particle Stokes number and fiber Reynolds number. Efficiencies were then modeled with an impactor type equation where the cutpoint Stokes number and a steepness parameter described data well in the sharply increasing portion of the curve (20%-80% efficiency). A minimum in collection efficiency was observed at small Stokes numbers and attributed to interception and diffusive effects. The cutpoint Stokes number was a linearly decreasing function of fiber Reynolds number. Single fiber efficiencies were calculated from total filter efficiencies and compared to contemporary viscous flow impaction theory (Stechkina et al. 1969), and numerical simulations of single fiber efficiencies from the literature. Existing theories underpredicted measured single fiber efficiencies, although comparison is problematic. The assumption of uniform flow conditions for each successive layer of fibers is questionable; thus, the common exponential relationship between single fiber efficiency and total filter efficiency may not be appropriate in this regime. Copyright © American Association for Aerosol Research.

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A short-standoff bistatic lidar system for aerosol cloud backscatter cross section measurement

CLEO: Applications and Technology, CLEO_AT 2012

Schmitt, Randal L.; Glen, Crystal C.; Sickafoose, Shane S.; Shagam, Richard N.; Santarpia, Joshua S.; Brockmann, John E.; Reichardt, Thomas A.; Pack, Michael P.; Chavez, Victor; Boney, Craig M.; Servantes, B.L.

A short-standoff bistatic lidar system coupled with an aerosol chamber has been built to measure aerosol optical backscatter and laser induced fluorescence cross-sections. Preliminary results show good sensitivity across all channels with high signal-to-noise ratio. © OSA 2012.

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Release mitigation spray safety systems for chemical demilitarization applications

Brockmann, John E.; Lucero, Daniel A.; Tucker, Mark D.

Sandia National Laboratories has conducted proof-of-concept experiments demonstrating effective knockdown and neutralization of aerosolized CBW simulants using charged DF-200 decontaminant sprays. DF-200 is an aqueous decontaminant, developed by Sandia National Laboratories, and procured and fielded by the US Military. Of significance is the potential application of this fundamental technology to numerous applications including mitigation and neutralization of releases arising during chemical demilitarization operations. A release mitigation spray safety system will remove airborne contaminants from an accidental release during operations, to protect personnel and limit contamination. Sandia National Laboratories recently (November, 2008) secured funding from the US Army's Program Manager for Non-Stockpile Chemical Materials Agency (PMNSCMA) to investigate use of mitigation spray systems for chemical demilitarization applications. For non-stockpile processes, mitigation spray systems co-located with the current Explosive Destruction System (EDS) will provide security both as an operational protective measure and in the event of an accidental release. Additionally, 'tented' mitigation spray systems for native or foreign remediation and recovery operations will contain accidental releases arising from removal of underground, unstable CBW munitions. A mitigation spray system for highly controlled stockpile operations will provide defense from accidental spills or leaks during routine procedures.

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Spent fuel sabotage test program, characterization of aerosol dispersal : interim final report

Brockmann, John E.; Gregson, Michael W.; Steyskal, Michele S.; Klennert, Lindsay A.

This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program provides source-term data that are relevant to plausible sabotage scenarios in relation to spent fuel transport and storage casks and associated risk assessments. We present details and significant results obtained from this program from 2001 through 2007. Measured aerosol results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; measurements of volatile fission product species enhanced sorption--enrichment factors onto respirable particles; and, status on determination of the spent fuel ratio, SFR, needed for scaling studies. Emphasis is provided on recent Phase 3 tests using depleted uranium oxide pellets plus non-radioactive fission product dopants in surrogate spent fuel test rodlets, plus the latest surrogate cerium oxide results and aerosol laboratory supporting calibration work. The DUO{sub 2}, CeO{sub 2}, plus fission product dopant aerosol particle results are compared with available historical data. We also provide a status review on continuing preparations for the final Phase 4 in this program, tests using individual short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. The source-term data, aerosol results, and program design have been tailored to support and guide follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage, aerosol test program was performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission. This program has significant input from, and is cooperatively supported and coordinated by both the U.S. and international program participants in Germany, France, and others, as part of the International Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC).

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Spent fuel sabotage aerosol test program :FY 2005-06 testing and aerosol data summary

Brockmann, John E.; Lucero, Daniel A.; Steyskal, Michele S.; Gregson, Michael W.

This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO{sub 2}, test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage--aerosol test program, performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission, had significant inputs from, and is strongly supported and coordinated by both the U.S. and international program participants in Germany, France, and the U.K., as part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC.

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Biological restoration of major transportation facilities domestic demonstration and application project (DDAP): technology development at Sandia National Laboratories

Griffith, Richard O.; Brown, Gary S.; Betty, Rita B.; Tucker, Mark D.; Ramsey, James L.; Brockmann, John E.; Lucero, Daniel A.; Mckenna, Sean A.; Peyton, Chad E.; Einfeld, Wayne E.; Ho, Pauline H.

The Bio-Restoration of Major Transportation Facilities Domestic Demonstration and Application Program (DDAP) is a designed to accelerate the restoration of transportation nodes following an attack with a biological warfare agent. This report documents the technology development work done at SNL for this DDAP, which include development of the BROOM tool, an investigation of surface sample collection efficiency, and a flow cytometry study of chlorine dioxide effects on Bacillus anthracis spore viability.

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Joint Sandia/NIOSH exercise on aerosol contamination using the BROOM tool

Griffith, Richard O.; Brown, Gary S.; Tucker, Mark D.; Ramsey, James L.; Brockmann, John E.; Lucero, Daniel A.; Mckenna, Sean A.; Peyton, Chad E.; Einfeld, Wayne E.; Ho, Pauline H.

In February of 2005, a joint exercise involving Sandia National Laboratories (SNL) and the National Institute for Occupational Safety and Health (NIOSH) was conducted in Albuquerque, NM. The SNL participants included the team developing the Building Restoration Operations and Optimization Model (BROOM), a software product developed to expedite sampling and data management activities applicable to facility restoration following a biological contamination event. Integrated data-collection, data-management, and visualization software improve the efficiency of cleanup, minimize facility downtime, and provide a transparent basis for reopening. The exercise was held at an SNL facility, the Coronado Club, a now-closed social club for Sandia employees located on Kirtland Air Force Base. Both NIOSH and SNL had specific objectives for the exercise, and all objectives were met.

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Spent fuel sabotage aerosol ratio program : FY 2004 test and data summary

Sorenson, Ken B.; Borek, Theodore T.; Dickey, Roy R.; Brockmann, John E.; Lucero, Daniel A.; Gregson, Michael W.; Coats, Richard L.

This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC) and supported by both the U.S. Department of Energy and the Nuclear Regulatory Commission.

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LDRD report: Smoke effects on electrical equipment

Martin, Tina T.; Baynes, Edward E.; Nowlen, Steven P.; Brockmann, John E.; Gritzo, Louis A.; Shaddix, Christopher R.

Smoke is known to cause electrical equipment failure, but the likelihood of immediate failure during a fire is unknown. Traditional failure assessment techniques measure the density of ionic contaminants deposited on surfaces to determine the need for cleaning or replacement of electronic equipment exposed to smoke. Such techniques focus on long-term effects, such as corrosion, but do not address the immediate effects of the fire. This document reports the results of tests on the immediate effects of smoke on electronic equipment. Various circuits and components were exposed to smoke from different fields in a static smoke exposure chamber and were monitored throughout the exposure. Electrically, the loss of insulation resistance was the most important change caused by smoke. For direct current circuits, soot collected on high-voltage surfaces sometimes formed semi-conductive soot bridges that shorted the circuit. For high voltage alternating current circuits, the smoke also tended to increase the likelihood of arcing, but did not accumulate on the surfaces. Static random access memory chips failed for high levels of smoke, but hard disk drives did not. High humidity increased the conductive properties of the smoke. The conductivity does not increase linearly with smoke density as first proposed; however, it does increase with quantity. The data can be used to give a rough estimate of the amount of smoke that will cause failures in CMOS memory chips, dc and ac circuits. Comparisons of this data to other fire tests can be made through the optical and mass density measurements of the smoke.

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34 Results
34 Results