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Biotic Processes Regulating the Carbon Balance of Desert Ecosystems - Final Report (open access)

Biotic Processes Regulating the Carbon Balance of Desert Ecosystems - Final Report

Our results from the 10-year elevated atmospheric CO{sub 2} concentration study at the Nevada Desert FACE (Free-air CO{sub 2} Enrichment) Facility (NDFF) indicate that the Mojave Desert is a dynamic ecosystem with the capacity to respond quickly to environmental changes. The Mojave Desert ecosystem is accumulating carbon (C), and over the 10-year experiment, C accumulation was significantly greater under elevated [CO{sub 2}] than under ambient, despite great fluctuations in C inputs from year to year and even apparent reversals in which [CO{sub 2}] treatment had greater C accumulations.
Date: December 13, 2012
Creator: Nowak, Robert S; Smith, Stanley D; Evans, Dave; Ogle, Kiona & Fenstermaker, Lynn
Object Type: Report
System: The UNT Digital Library
A Review of Hygroscopic Data of PBXN-5 (open access)

A Review of Hygroscopic Data of PBXN-5

None
Date: January 13, 2012
Creator: Davis, R W
Object Type: Report
System: The UNT Digital Library
Simplifying Performance Analysis of Large-scale Adaptive Scientific Applications (open access)

Simplifying Performance Analysis of Large-scale Adaptive Scientific Applications

None
Date: January 13, 2012
Creator: Bhatele, A; Gamblin, T; Gunney, B N; Schulz, M & Bremer, P T
Object Type: Report
System: The UNT Digital Library
Hydrogen Corrosion of Plutonium: Evidence for fast grain-boundary reaction and slower intragrain reaction (open access)

Hydrogen Corrosion of Plutonium: Evidence for fast grain-boundary reaction and slower intragrain reaction

None
Date: February 13, 2012
Creator: Saw, C. K.; Haschke, J. M.; Allen, P. G.; McLean, W., II & Dinh, L. N.
Object Type: Article
System: The UNT Digital Library
GLADE Global Liquid Argon Detector Experiment: a letter of intent to FNAL (open access)

GLADE Global Liquid Argon Detector Experiment: a letter of intent to FNAL

The recent measurements of the {theta}{sub 13} mixing angle, which controls the observable size of any CP violation effects, open a window of opportunity to take advantage of the world's most powerful existing neutrino beam together with recent successes in development of the ultimate detector technology for the detection of electron neutrinos : a liquid argon (LAr) time projection chamber. During this proposed project a 5kt LAr detector (GLADE) will be developed by European groups to be put in a cryostat in the NuMI neutrino beam at Fermi National Accelerator Laboratory in the US and will start taking data in 3-5 years time to address the neutrino mass ordering. The successful fruition of this project, along with nominal exposure at NO{nu}A and T2K, together with information from double beta decay experiments could ascertain that neutrinos are Dirac particles in the next decade.
Date: May 13, 2012
Creator: Thomas, Jennifer
Object Type: Report
System: The UNT Digital Library
The UA9 Experimental Layout (open access)

The UA9 Experimental Layout

None
Date: June 13, 2012
Creator: Scandale, W.; Arduini, G.; Assmann, R.; Bracco, C.; Cerutti, F.; Christiansen, J. et al.
Object Type: Article
System: The UNT Digital Library
SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION (open access)

SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION

Active capping involves the use of capping materials that react with sediment contaminants to reduce their toxicity or bioavailability. Although several amendments have been proposed for use in active capping systems, little is known about their long-term ability to sequester metals. Recent research has shown that the active amendment apatite has potential application for metals contaminated sediments. The focus of this study was to evaluate the effectiveness of apatite in the sequestration of metal contaminants through the use of short-term laboratory column studies in conjunction with predictive, numerical modeling. A breakthrough column study was conducted using North Carolina apatite as the active amendment. Under saturated conditions, a spike solution containing elemental As, Cd, Co, Se, Pb, Zn, and a non-reactive tracer was injected into the column. A sand column was tested under similar conditions as a control. Effluent water samples were periodically collected from each column for chemical analysis. Relative to the non-reactive tracer, the breakthrough of each metal was substantially delayed by the apatite. Furthermore, breakthrough of each metal was substantially delayed by the apatite compared to the sand column. Finally, a simple 1-D, numerical model was created to qualitatively predict the long-term performance of apatite based on the …
Date: February 13, 2012
Creator: Dixon, K. & Knox, A.
Object Type: Article
System: The UNT Digital Library
Branching Fraction Measurement of B to omega l nu decays (open access)

Branching Fraction Measurement of B to omega l nu decays

We present a measurement of the B{sup +} {yields} {omega}{ell}{sup +}{nu} branching fraction based on a sample of 467 million B{bar B} pairs recorded by the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} collider. We observe 1041 {+-} 133 signal decays, corresponding to a branching fraction of {Beta}(B{sup +} {yields} {omega}{ell}{sup +}{nu}) = (1.15 {+-} 0.15 {+-} 0.12) x 10{sup -4}, where the first error is statistical and the second is systematic. The dependence of the decay rate on q{sup 2}, the momentum transfer squared to the lepton system, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.
Date: June 13, 2012
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A. et al.
Object Type: Article
System: The UNT Digital Library
Catalytic Conversion of Biomass to Fuels and Chemicals Using Ionic Liquids (open access)

Catalytic Conversion of Biomass to Fuels and Chemicals Using Ionic Liquids

This project provides critical innovations and fundamental understandings that enable development of an economically-viable process for catalytic conversion of biomass (sugar) to 5-hydroxymethylfurfural (HMF). A low-cost ionic liquid (Cyphos 106) is discovered for fast conversion of fructose into HMF under moderate reaction conditions without any catalyst. HMF yield from fructose is almost 100% on the carbon molar basis. Adsorbent materials and adsorption process are invented and demonstrated for separation of 99% pure HMF product and recovery of the ionic liquid from the reaction mixtures. The adsorbent material appears very stable in repeated adsorption/regeneration cycles. Novel membrane-coated adsorbent particles are made and demonstrated to achieve excellent adsorption separation performances at low pressure drops. This is very important for a practical adsorption process because ionic liquids are known of high viscosity. Nearly 100% conversion (or dissolution) of cellulose in the catalytic ionic liquid into small molecules was observed. It is promising to produce HMF, sugars and other fermentable species directly from cellulose feedstock. However, several gaps were identified and could not be resolved in this project. Reaction and separation tests at larger scales are needed to minimize impacts of incidental errors on the mass balance and to show 99.9% ionic liquid recovery. …
Date: April 13, 2012
Creator: Liu, Wei; Zheng, Richard; Brown, Heather; Li, Joanne; Holladay, John; Cooper, Alan et al.
Object Type: Report
System: The UNT Digital Library
China's Building Energy Use: A Long-Term Perspective based on a Detailed Assessment (open access)

China's Building Energy Use: A Long-Term Perspective based on a Detailed Assessment

We present here a detailed, service-based model of China's building energy use, nested in the GCAM (Global Change Assessment Model) integrated assessment framework. Using the model, we explore long-term pathways of China's building energy use and identify opportunities of reducing greenhouse gas emissions. The inclusion of a structural model of building energy demands within an integrated assessment framework represents a major methodological advance. It allows for a structural understanding of the drivers of building energy consumption while simultaneously considering the other human and natural system interactions that influence changes in the global energy system and climate. We also explore a range of different scenarios to gain insights into how China's building sector might evolve and what the implications might be for improved building energy technology and carbon policies. The analysis suggests that China's building energy growth will not wane anytime soon, although technology improvement will put downward pressure on this growth. Also, regardless of the scenarios represented, the growth will involve the continued, rapid electrification of the buildings sector throughout the century, and this transition will be accelerated by the implementation of carbon policy.
Date: January 13, 2012
Creator: Eom, Jiyong; Clarke, Leon E.; Kim, Son H.; Kyle, G. Page & Patel, Pralit L.
Object Type: Report
System: The UNT Digital Library
Experimental Definition and Validation of Protein Coding Transcripts in Chlamydomonas reinhardtii (open access)

Experimental Definition and Validation of Protein Coding Transcripts in Chlamydomonas reinhardtii

Algal fuel sources promise unsurpassed yields in a carbon neutral manner that minimizes resource competition between agriculture and fuel crops. Many challenges must be addressed before algal biofuels can be accepted as a component of the fossil fuel replacement strategy. One significant challenge is that the cost of algal fuel production must become competitive with existing fuel alternatives. Algal biofuel production presents the opportunity to fine-tune microbial metabolic machinery for an optimal blend of biomass constituents and desired fuel molecules. Genome-scale model-driven algal metabolic design promises to facilitate both goals by directing the utilization of metabolites in the complex, interconnected metabolic networks to optimize production of the compounds of interest. Using Chlamydomonas reinhardtii as a model, we developed a systems-level methodology bridging metabolic network reconstruction with annotation and experimental verification of enzyme encoding open reading frames. We reconstructed a genome-scale metabolic network for this alga and devised a novel light-modeling approach that enables quantitative growth prediction for a given light source, resolving wavelength and photon flux. We experimentally verified transcripts accounted for in the network and physiologically validated model function through simulation and generation of new experimental growth data, providing high confidence in network contents and predictive applications. The network …
Date: January 13, 2012
Creator: Salehi-Ashtiani, Kourosh & Papin, Jason A.
Object Type: Report
System: The UNT Digital Library
Stability of Horava-Lifshitz Black Holes in the Context of AdS/CFT (open access)

Stability of Horava-Lifshitz Black Holes in the Context of AdS/CFT

The anti-de Sitter/conformal field theory (AdS/CFT) correspondence is a powerful tool that promises to provide new insights toward a full understanding of field theories under extreme conditions, including but not limited to quark-gluon plasma, Fermi liquid, and superconductor. In many such applications, one typically models the field theory with asymptotically AdS black holes. These black holes are subjected to stringy effects that might render them unstable. Horava-Lifshitz gravity, in which space and time undergo different transformations, has attracted attention due to its power-counting renormalizability. In terms of AdS/CFT correspondence, Horava-Lifshitz black holes might be useful to model holographic superconductors with Lifshitz scaling symmetry. It is thus interesting to study the stringy stability of Horava-Lifshitz black holes in the context of AdS/CFT. We find that uncharged topological black holes in {lambda} = 1 Horava-Lifshitz theory are nonperturbatively stable, unlike their counterparts in Einstein gravity, with the possible exceptions of negatively curved black holes with detailed balance parameter {epsilon} close to unity. Sufficiently charged flat black holes for {epsilon} close to unity, and sufficiently charged positively curved black holes with {epsilon} close to zero, are also unstable. The implication to the Horava-Lifshitz holographic superconductor is discussed.
Date: June 13, 2012
Creator: Ong, Yen Chin; /Taiwan, Natl. Taiwan U.; Chen, Pisin & /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC
Object Type: Article
System: The UNT Digital Library
Doppler Lidar (DL) Handbook (open access)

Doppler Lidar (DL) Handbook

The Doppler lidar (DL) is an active remote sensing instrument that provides range- and time-resolved measurements of radial velocity and attenuated backscatter. The principle of operation is similar to radar in that pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is inferred. The radial or line-of-sight velocity of the scatterers is determined from the Doppler frequency shift of the backscattered radiation. The DL uses a heterodyne detection technique in which the return signal is mixed with a reference laser beam (i.e., local oscillator) of known frequency. An onboard signal processing computer then determines the Doppler frequency shift from the spectra of the heterodyne signal. The energy content of the Doppler spectra can also be used to determine attenuated backscatter.
Date: February 13, 2012
Creator: Newsom, RK
Object Type: Report
System: The UNT Digital Library
Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report January 1–March 31, 2012 (open access)

Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report January 1–March 31, 2012

Individual raw datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ARM Data Archive, where they are made available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.
Date: April 13, 2012
Creator: Voyles, J. W.
Object Type: Text
System: The UNT Digital Library
Study of Bbar to Xu l nubar Decays in BBbar Events Tagged by a Fully Reconstructed B-meson Decay and Determination of |V_{ub}| (open access)

Study of Bbar to Xu l nubar Decays in BBbar Events Tagged by a Fully Reconstructed B-meson Decay and Determination of |V_{ub}|

We report measurements of partial branching fractions for inclusive charmless semileptonic B decays {bar B} {yields} X{sub u}{ell}{bar {nu}}, and the determination of the CKM matrix element |V{sub ub}|. The analysis is based on a sample of 467 million {Upsilon}(4S) {yields} B{bar B} decays recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions {Delta}{Beta} in several restricted regions of phase space and determine the CKM element |V{sub ub}| based on four different QCD predictions. For decays with a charged lepton momentum p*{sub {ell}} > 1.0 GeV in the B meson rest frame, we obtain {Delta}{Beta} = (1.80 {+-} 0.13{sub stat.} {+-} 0.15{sub sys.} {+-} 0.02{sub theo.}) x 10{sup -3} from a maximum likelihood fit to the two-dimensional M{sub X} - q{sup 2} distribution. Here, M{sub X} refers to the invariant mass of the final state hadron X and q{sup 2} is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V{sub ub}| = (4.31 …
Date: July 13, 2012
Creator: Lees, J.P.
Object Type: Article
System: The UNT Digital Library
A Stability of LCLS Linac Modulators (open access)

A Stability of LCLS Linac Modulators

Information concerning to a stability of LCLS RF linac modulators is allocated in this paper. In general a 'pulse-to-pulse' modulator stability (and RF phase as well) is acceptable for the LCLS commission and FEL programs. Further modulator stability improvements are possible and approaches are discussed based on our experimental results.
Date: June 13, 2012
Creator: Decker, F. -J.; Krasnykh, A.; Morris, B. & Nguyen, M.
Object Type: Article
System: The UNT Digital Library
Axion-Like Particle Imprint in Cosmological Very-High-Energy Sources (open access)

Axion-Like Particle Imprint in Cosmological Very-High-Energy Sources

Discoveries of very high energy (VHE) photons from distant blazars suggest that, after correction by extragalactic background light (EBL) absorption, there is a flatness or even a turn-up in their spectra at the highest energies that cannot be easily explained by the standard framework. Here, it is shown that a possible solution to this problem is achieved by assuming the existence of axion-like particles (ALPs) with masses {approx} 1 neV. The ALP scenario is tested making use of observations of the highest redshift blazars known in the VHE energy regime, namely 3C 279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to the observed spectra are found when including ALPs rather than considering EBL only. Interestingly, quite similar critical energies for photon/ALP conversions are also derived, independently of the source considered.
Date: June 13, 2012
Creator: Dominguez, A.; Sanchez-Conde, M. A. & Prada, F.
Object Type: Article
System: The UNT Digital Library
Laboratory Studies of Processing of Carbonaceous Aerosols by Atmospheric Oxidants/Hygroscopicity and CCN Activity of Secondary & Processed Primary Organic Aerosols (open access)

Laboratory Studies of Processing of Carbonaceous Aerosols by Atmospheric Oxidants/Hygroscopicity and CCN Activity of Secondary & Processed Primary Organic Aerosols

The atmosphere is composed of a complex mixture of gases and suspended microscopic aerosol particles. The ability of these particles to take up water (hygroscopicity) and to act as nuclei for cloud droplet formation significantly impacts aerosol light scattering and absorption, and cloud formation, thereby influencing air quality, visibility, and climate in important ways. A substantial, yet poorly characterized component of the atmospheric aerosol is organic matter. Its major sources are direct emissions from combustion processes, which are referred to as primary organic aerosol (POA), or in situ processes in which volatile organic compounds (VOCs) are oxidized in the atmosphere to low volatility reaction products that subsequent condense to form particles that are referred to as secondary organic aerosol (SOA). POA and VOCs are emitted to the atmosphere from both anthropogenic and natural (biogenic) sources. The overall goal of this experimental research project was to conduct laboratory studies under simulated atmospheric conditions to investigate the effects of the chemical composition of organic aerosol particles on their hygroscopicity and cloud condensation nucleation (CCN) activity, in order to develop quantitative relationships that could be used to more accurately incorporate aerosol-cloud interactions into regional and global atmospheric models. More specifically, the project aimed …
Date: June 13, 2012
Creator: Ziemann, P. J.; Arey, J.; Atkinson, R.; Kreidenweis, S. M. & Petters, M. D.
Object Type: Report
System: The UNT Digital Library
Proliferation Risks of Magneetic Fusion Energy: Clandestine Production, Covert Production and Breakout (open access)

Proliferation Risks of Magneetic Fusion Energy: Clandestine Production, Covert Production and Breakout

Nuclear proliferation risks from magnetic fusion energy associated with access to weapon-usable materials can be divided into three main categories: (1) clandestine production of weapon-usable material in an undeclared facility, (2) covert production of such material inn a declared facility, and (3) use of a declared facility in a breakout scenario, in which a state begins production of fissile material without concealing the effort. In this paper we address each of these categories of risks from fusion. For each case, we find that the proliferation risk from fusion systems can be much lower than the equivalent risk from fission systems, if the fusion system is designed to accommodate appropriate safeguards.
Date: March 13, 2012
Creator: Glaser, A. & Goldston, R. J.
Object Type: Report
System: The UNT Digital Library
Simulation Of Microtearing Turbulence In NSTX (open access)

Simulation Of Microtearing Turbulence In NSTX

Thermal energy confinement times in NSTX dimensionless parameter scans increase with decreasing collisionality. While ion thermal transport is neoclassical, the source of anomalous electron thermal transport in these discharges remains unclear, leading to considerable uncertainty when extrapolating to future ST devices at much lower collisionality. Linear gyrokinetic simulations find microtearing modes to be unstable in high collisionality discharges. First non-linear gyrokinetic simulations of microtearing turbulence in NSTX show they can yield experimental levels of transport. Magnetic flutter is responsible for almost all the transport ({approx}98%), perturbed field line trajectories are globally stochastic, and a test particle stochastic transport model agrees to within 25% of the simulated transport. Most significantly, microtearing transport is predicted to increase with electron collisionality, consistent with the observed NSTX confinement scaling. While this suggests microtearing modes may be the source of electron thermal transport, the predictions are also very sensitive to electron temperature gradient, indicating the scaling of the instability threshold is important. In addition, microtearing turbulence is susceptible to suppression via sheared E-B flows as experimental values of E-B shear (comparable to the linear growth rates) dramatically reduce the transport below experimental values. Refinements in numerical resolution and physics model assumptions are expected to minimize …
Date: February 13, 2012
Creator: Guttenfelder, W.; Kaye, S. M.; Nevins, W. M.; Wanag, E.; Zhang, J.; Bell, R. E. et al.
Object Type: Report
System: The UNT Digital Library
ALTERNATIVES ANALYSIS FOR SELECTING ET #3 SITE (open access)

ALTERNATIVES ANALYSIS FOR SELECTING ET #3 SITE

Engineered trenches (ETs) are considered to be a cost-effective method for disposing Low Level Waste (LLW). Based on waste forecasts from waste generators, the last engineered trench in operation (ET No.2) is anticipated to close in FY14, requiring development of a new ET. Solid Waste requested that SRNL develop an assessment report that reviews four disposal options for this new ET (ET No.3) and determine which option would provide the 'best' Performance Assessment (PA) disposal limits for LLW (Appendix A). Those four options (see option footprint locations in Figure 1-1) are: (1) Disposal at grade on TRU Pads 7-13 where soil would be mounded over waste packages; (2) Excavation at a slightly modified SLIT No.13 location - near the Used Equipment Storage Area; (3) Excavation at a modified SLIT No.12 location - near the 643-26E Naval Reactor Component Disposal Area; and (4) Excavation east of TRU Pad No.26 that replaces northeast portions of four slit trench (ST) disposal units in the eastern set of STs. The assessment consisted of both quantitative and qualitative analyses. The quantitative analysis captured key aspects that were readily quantifiable and had predictable impacts on limits and doses. A simplified modeling strategy stemming from current Special …
Date: February 13, 2012
Creator: Collard, L. & Hamm, L.
Object Type: Report
System: The UNT Digital Library
A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method (open access)

A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method

A wide variety of plasma waves play an important role in the energization and loss of particles in the inner magnetosphere. Our ability to understand and model wave-particle interactions in this region requires improved knowledge of the spatial distribution and properties of these waves as well as improved understanding of how the waves depend on changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a two-dimensional, finite element code that solves the full wave equations in global magnetospheric geometry. The code describes three-dimensional wave structure including mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional axisymmetric background plasma with general magnetic field topology. We illustrate the capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from external, solar wind compressions; and wave structure and mode conversion of electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which propagate along the magnetic field lines toward the ionosphere. We also discuss advantages of the finite element method for resolving resonant structures, and how the model may be adapted to include nonlocal kinetic effects.
Date: March 13, 2012
Creator: Valeo, Ernest; Johnson, Jay R.; Eun-Hwa & Phillips, Cynthia
Object Type: Article
System: The UNT Digital Library
Calibrating Accelerometers Using an Electromagnetic Launcher (open access)

Calibrating Accelerometers Using an Electromagnetic Launcher

A Pulse Forming Network (PFN), Helical Electromagnetic Launcher (HEML), Command Module (CM), and Calibration Table (CT) were built and evaluated for the combined ability to calibrate an accelerometer. The PFN has a maximum stored energy of 19.25 kJ bank and is fired by a silicon controlled rectifier (SCR), with appropriate safety precautions. The HEML is constructed out of G-10 fiberglass and is designed to accelerate 600 grams to 10 meters per second. The CM is microcontroller based running Arduino Software. The CM has a keypad input and 7 segment outputs of the bank voltage and desired voltage. After entering a desired bank voltage, the CM controls the charge of the PFN. When the two voltages are equal it allows the fire button to send a pulse to the SCR to fire the PFN and in turn, the HEML. The HEML projectile's tip hits a target that is held by the CT. The CT consists of a table to hold the PFN and HEML, a vacuum chuck, air bearing, velocity meter and catch pot. The Target is held with the vacuum chuck awaiting impact. After impact, the air bearing allows the target to fall freely for the velocity meter to get …
Date: May 13, 2012
Creator: Timpson, Erik
Object Type: Article
System: The UNT Digital Library
AGING BEHAVIOR OF VITON O-RING SEALS IN THE 9975 SHIPPING PACKAGE (open access)

AGING BEHAVIOR OF VITON O-RING SEALS IN THE 9975 SHIPPING PACKAGE

The Savannah River Site (SRS) is storing plutonium (Pu) materials in the K-Area Materials Storage (KAMS) facility. The Pu materials were packaged according to the DOE-STD-3013 standard and shipped to the SRS in Type B 9975 packages. The robust 9975 shipping package was not designed for long-term product storage, but it is a specified part of the storage configuration and the KAMS facility safety basis credits the 9975 design with containment. Within the 9975 package, nested stainless steel containment vessels are closed with dual O-ring seals based on Viton{reg_sign} GLT or GLT-S fluoroelastomer. The aging behavior of the O-ring compounds is being studied to provide the facility with advanced notice of nonconformance and to develop life prediction models. A combination of field surveillance, leak testing of surrogate fixtures aged at bounding service temperatures, and accelerated-aging methodologies based on compression stress-relaxation and oxygen consumption analysis is being used to evaluate seal performance. A summary of the surveillance program relative to seal aging behavior is presented.
Date: January 13, 2012
Creator: Skidmore, E.; Daugherty, W.; Hoffman, E.; Dunn, K. & Bellamy, S.
Object Type: Article
System: The UNT Digital Library