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20-100 keV K(alpha) X-Ray Source Generation by Short Pulse High Intensity Lasers (open access)

20-100 keV K(alpha) X-Ray Source Generation by Short Pulse High Intensity Lasers

We are studying the feasibility of utilizing K{alpha} x-ray sources in the range of 20 to 100 keV as a backlighters for imaging various stages of implosions and high areal density planar samples driven by the NIF laser facility. The hard x-ray K{alpha} sources are created by relativistic electron plasma interactions in the target material after a radiation by short pulse high intensity lasers. In order to understand K{alpha} source characteristics such as production efficiency and brightness as a function of laser parameters, we have performed experiments using the 10 J, 100 fs JanUSP laser. We utilized single-photon counting spectroscopy and x-ray imaging diagnostics to characterize the K{alpha} source. We find that the K{alpha} conversion efficiency from the laser energy is {approx} 3 x 10{sup -4}.
Date: August 22, 2003
Creator: Park, H. S.; Koch, J. A.; Landen, O. L.; Phillips, T. W. & Goldsack, T.
System: The UNT Digital Library
9th Diesel Engine Emissions Reduction (DEER) Workshop 2003 (open access)

9th Diesel Engine Emissions Reduction (DEER) Workshop 2003

The PowerTrap{trademark} is a non-exhaust temperature dependent system that cannot become blocked and features a controlled regeneration process independent of the vehicle's drive cycle. The system has a low direct-current power source requirement available in both 12-volt and 24-volt configurations. The system is fully programmable, fully automated and includes Euro IV requirements of operation verification. The system has gained European component-type approval and has been tested with both on- road and off-road diesel fuel up to 2000 parts per million. The device is fail-safe: in the event of a device malfunction, it cannot affect the engine's performance. Accumulated mileage testing is in excess of 640,000 miles to date. Vehicles include London-type taxicabs (Euro 1 and 2), emergency service fire engines (Euro 1, 2, and 3), inner city buses, and light-duty locomotives. Independent test results by Shell Global Solutions have consistently demonstrated 85-99 percent reduction of ultrafines across the 7-35 nanometer size range using a scanning mobility particle sizer with both ultra-low sulfur diesel and off-road high-sulfur fuel.
Date: August 24, 2003
Creator: Kukla, Peter; Wright, James; Harris, Georgina; Ball, Andrew & Gu, Fengshou
System: The UNT Digital Library
Accuracy Limitations in Long Trace Profilometry (open access)

Accuracy Limitations in Long Trace Profilometry

As requirements for surface slope error quality of grazing incidence optics approach the 100 nanoradian level, it is necessary to improve the performance of the measuring instruments to achieve accurate and repeatable results at this level. We have identified a number of internal error sources in the Long Trace Profiler (LTP) that affect measurement quality at this level. The LTP is sensitive to phase shifts produced within the millimeter diameter of the pencil beam probe by optical path irregularities with scale lengths of a fraction of a millimeter. We examine the effects of mirror surface ''macroroughness'' and internal glass homogeneity on the accuracy of the LTP through experiment and theoretical modeling. We will place limits on the allowable surface ''macroroughness'' and glass homogeneity required to achieve accurate measurements in the nanoradian range.
Date: August 25, 2003
Creator: Takacs, P. Z. & Qian, S.
System: The UNT Digital Library
The Addition of Noncondensable Gases into RELAP5-3D for Analysis of High Temperature Gas-Cooled Reactors (open access)

The Addition of Noncondensable Gases into RELAP5-3D for Analysis of High Temperature Gas-Cooled Reactors

Oxygen, carbon dioxide, and carbon monoxide have been added to the RELAP5-3D computer code as noncondensable gases to support analysis of high temperature gas-cooled reactors. Models of these gases are required to simulate the effects of air ingress on graphite oxidation following a loss-of-coolant accident. Correlations were developed for specific internal energy, thermal conductivity, and viscosity for each gas at temperatures up to 3000 K. The existing model for internal energy (a quadratic function of temperature) was not sufficiently accurate at these high temperatures and was replaced by a more general, fourth-order polynomial. The maximum deviation between the correlations and the underlying data was 2.2% for the specific internal energy and 7% for the specific heat capacity at constant volume. The maximum deviation in the transport properties was 4% for oxygen and carbon monoxide and 12% for carbon dioxide.
Date: August 1, 2003
Creator: Davis, C. B. & Oh, C. H.
System: The UNT Digital Library
Advanced beam-dynamics simulation tools for the RIA driver linac,Part I: Low energy beam transport and radiofrequency quadrupole (open access)

Advanced beam-dynamics simulation tools for the RIA driver linac,Part I: Low energy beam transport and radiofrequency quadrupole

Advanced Beam-Dynamics Simulation Tools for the RIA Driver Linac; Low Energy Beam Transport and Radiofrequency Quadrupole.
Date: August 26, 2003
Creator: Wangler, Thomas P.; Crandall, Kenneth R.; Garnett, Robert W.; Gorelov, Dmitry; Ostroumov, Petr; Qiang, Ji et al.
System: The UNT Digital Library
Advanced Diesel Engine and Aftertreatment Technology Development for Tier 2 Emissions (open access)

Advanced Diesel Engine and Aftertreatment Technology Development for Tier 2 Emissions

Advanced diesel engine and aftertreatment technologies have been developed for multiple engine and vehicle platforms. Tier 2 (2007 and beyond) emissions levels have been demonstrated for a light truck vehicle over a FTP-75 test cycle on a vehicle chassis dynamometer. These low emissions levels are obtained while retaining the fuel economy advantage characteristic of diesel engines. The performance and emissions results were achieved by integrating advanced combustion strategies (CLEAN Combustion{copyright}) with prototype aftertreatment systems. CLEAN Combustion{copyright} allows partial control of exhaust species for aftertreatment integration in addition to simultaneous NOx and PM reduction. Analytical tools enabled the engine and aftertreatment sub-systems development and system integration. The experimental technology development methodology utilized a range of facilities to streamline development of the eventual solution including utilization of steady state and transient dynamometer test-beds to simulate chassis dynamometer test cycles.
Date: August 24, 2003
Creator: Aneja, Rakesh; Bolton, Brian; Oladipo, Adedejo Bukky; Pavlova-MacKinnon, Zornitza & Radwan, Amr
System: The UNT Digital Library
Advanced Research in Diesel Fuel Sprays Using X-rays From The Advanced Photon Source (open access)

Advanced Research in Diesel Fuel Sprays Using X-rays From The Advanced Photon Source

The fuel distribution and degree of atomization in the combustion chamber is a primary factor in the formation of emissions in diesel engines. A number of diagnostics to study sprays have been developed over the last twenty years; these are primarily based on visible light measurement techniques. However, visible light scatters strongly from fuel droplets surrounding the spray, which prevents penetration of the light. This has made quantitative measurements of the spray core very difficult, particularly in the relatively dense near- nozzle region [1-3]. For this reason we developed the x-ray technique to study the properties of fuel sprays in a quantitative way [4]. The x-ray technique is not limited by scattering, which allows it to be used to make quantitative measurements of the fuel distribution. These measurements are particularly effective in the region near the nozzle where other techniques fail. This technique has led to a number of new insights into the structure of fuel sprays, including the discovery and quantitative measurement of shock waves generated under some conditions by high-pressure diesel sprays [5]. We also performed the first-ever quantitative measurements of the time-resolved mass distribution in the near-nozzle region, which demonstrated that the spray is atomized only a …
Date: August 24, 2003
Creator: Powell, C.
System: The UNT Digital Library
Ambient to high-temperature fracture toughness and cyclic fatigue behavior in Al-containing silicon carbide ceramics (open access)

Ambient to high-temperature fracture toughness and cyclic fatigue behavior in Al-containing silicon carbide ceramics

A series of in situ toughened, A1, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with A1 contents varying from 3 to 7 wt percent. With increasing A1 additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline.
Date: August 1, 2003
Creator: Yuan, R.; Kruzic, J. J.; Zhang, X. F.; De Jonghe, L. C. & Ritchie, R. O.
System: The UNT Digital Library
AMS in Phytonutrition (open access)

AMS in Phytonutrition

As public interest in phytonutrition continues to increase, the result will be an augmented demand for extensive phytochemical research. The fact that foods are inherently phytochemically complex dictates a need to apply scientific techniques, which can detect synergistic interaction among the many active principles and adjuvant substances in the plant, and furthermore, modify the activities of these components. As illustrated by the experiments discussed in this presentation, the advantages of AMS are unique and extensive. These advantages are best summarized by Dr. John Vogel, an originator of biological AMS experimentation: ''AMS brings (at least) three advantages to biochemical tracing: high sensitivity for finding low probability events or for use of physiologic-sized doses; small sample sizes for painless biopsies or highly specific biochemical separations; and reduction of overall radioisotope exposures, inventories, and waste streams.'' AMS opens the door to increased phytochemical tracing in humans to obtain biochemical data concerning human health at dietary relevant levels of exposure. AMS, thus, obviates the need for uncertain extrapolations from animal models, which express marginal relevance to human metabolism. The unparalleled capabilities and benefits of AMS will undoubtedly establish this particular MS technique as an important analytical tool in phytochemical research.
Date: August 26, 2003
Creator: Dueker, S. R. & Buchholz, B. A.
System: The UNT Digital Library
ANALYSIS OF SPACE CHARGE DRIVEN MODULATION IN ELECTRON BUNCH ENERGY SPECTRA. (open access)

ANALYSIS OF SPACE CHARGE DRIVEN MODULATION IN ELECTRON BUNCH ENERGY SPECTRA.

As was discussed earlier [1,2] longitudinal space charge force in initially nonuniform bunch transforms density fluctuations into energy modulation along the bunch. For characterization of the resulted energy modulation one can chirp the bunch using accelerator section, located upstream of beam spectrometer, and record energy spectrum of such chirped bunch. Measured spectrum shows structure with parameters, depending on the bunch properties. In this paper we present analysis of the structure in the bunch energy spectrum and its connection with energy modulation along the bunch.
Date: August 22, 2003
Creator: SHAFTAN,T. YU,L. H.
System: The UNT Digital Library
Analytic ICF Hohlraum Energetics (open access)

Analytic ICF Hohlraum Energetics

We apply recent analytic solutions to the radiation diffusion equation to problems of interest for ICF hohlraums. The solutions provide quantitative values for absorbed energy which are of use for generating a desired radiation temperature vs. time within the hohlraum. Comparison of supersonic and subsonic solutions (heat front velocity faster or slower, respectively, than the speed of sound in the x-ray heated material) suggests that there may be some advantage in using high Z metallic foams as hohlraum wall material to reduce hydrodynamic losses, and hence, net absorbed energy by the walls. Analytic and numerical calculations suggest that the loss per unit area might be reduced {approx} 20% through use of foam hohlraum walls. Reduced hydrodynamic motion of the wall material may also reduce symmetry swings, as found for heavy ion targets.
Date: August 27, 2003
Creator: Rosen, M D & Hammer, J
System: The UNT Digital Library
ANALYTICAL TOOL DEVELOPMENT FOR AFTERTREATMENT SUB-SYSTEMS INTEGRATION (open access)

ANALYTICAL TOOL DEVELOPMENT FOR AFTERTREATMENT SUB-SYSTEMS INTEGRATION

The stringent emissions standards of 2007 and beyond require complex engine, aftertreatment and vehicle systems with a high degree of sub-system interaction and flexible control solutions. This necessitates a system-based approach to technology development, in addition to individual sub-system optimization. Analytical tools can provide an effective means to evaluate and develop such complex technology interactions as well as understand phenomena that is either too expensive or impossible to study with conventional experimental means. The analytical effort can also guide experimental development and thus lead to efficient utilization of available experimental resources.A suite of analytical models has been developed to represent PM and NOx aftertreatment sub-systems. These models range from computationally inexpensive zero-dimensional models for real-time control applications to CFD-based, multi-dimensional models with detailed temporal and spatial resolution. Such models in conjunction with well established engine modeling tools such as engine cycle simulation, engine controls modeling, CFD models of non-combusting and combusting flow, and vehicle models provide a comprehensive analytical toolbox for complete engine, aftertreatment and vehicle sub-systems development and system integration applications. However, the fidelity of aftertreatment models and application going forward is limited by the lack of fundamental kinetic data.
Date: August 24, 2003
Creator: Bolton, B; Fan, A; Goney, K; Pavlova-MacKinnon, Z; Sisken, K & Zhang, H
System: The UNT Digital Library
APBF-DEC NOx Adsorber/DPF Project: Light-Duty Passenger Car Platform (open access)

APBF-DEC NOx Adsorber/DPF Project: Light-Duty Passenger Car Platform

A 1.9L turbo direct injection (TDI) diesel engine was modified to achieve the upcoming Tier 2 Bin 5 emission standard in combination with a NOx adsorber catalyst (NAC) and a diesel particulate filter (DPF). The primary objective for developing this test bed is to investigating the effects of different fuel sulfur contents on the performance of an advanced emission control system (ECS) in a light-duty application. During the development process, the engine-out emissions were minimized by applying a state-of-the-art combustion system in combination with cooled exhaust gas recirculation (EGR). The subsequent calibration effort resulted in emission levels requiring 80-90 percent nitrogen-oxide (NOx) and particulate matter (PM) conversion rates by the corresponding ECS. The strategy development included ean/rich modulation for NAC regeneration, as well as, the desulfurization of the NAC and the regeneration of the DPF. Two slightly different ECS were investigated and calibrated. The initial vehicle results in an Audi A4 station wagon over the federal test procedure (FTP), US 06, and the highway fuel economy test (HFET) cycle indicate the potential of these configuration to meet the future Tier 2 emission standard.
Date: August 24, 2003
Creator: Tomazic, D; Tatur, M & Thornton, M
System: The UNT Digital Library
APBF-DEC NOx Adsorber/DPF Project: SUV / Pick-up Truck Platform (open access)

APBF-DEC NOx Adsorber/DPF Project: SUV / Pick-up Truck Platform

The objective of this project is to determine the influence of diesel fuel composition on the ability of NOX adsorber catalyst (NAC) technology, in conjunction with diesel particle filters (DPFs), to achieve stringent emissions levels with a minimal fuel economy impact. The test bed for this project was intended to be a light-duty sport utility vehicle (SUV) with a goal of achieving light-duty Tier 2-Bin 5 tail pipe emission levels (0.07 g/mi. NOX and 0.01 g/mi. PM). However, with the current US market share of light-duty diesel applications being so low, no US 2002 model year (MY) light-duty truck (LDT) or SUV platforms equipped with a diesel engine and having a gross vehicle weight rating (GVWR) less than 8500 lb exist. While the current level of diesel engine use is relatively small in the light-duty class, there exists considerable potential for the diesel engine to gain a much larger market share in the future as manufacturers of heavy light-duty trucks (HLDTs) attempt to offset the negative impact on cooperate average fuel economy (CAFE) that the recent rise in market share of the SUVs and LDTs has caused. The US EPA Tier 2 emission standards also contain regulation to prevent the …
Date: August 24, 2003
Creator: Webb, C.; Weber, P. & Thornton, M.
System: The UNT Digital Library
APIVT Epitaxial Growth on Zone-Melt Recrystallized Silicon: Preprint (open access)

APIVT Epitaxial Growth on Zone-Melt Recrystallized Silicon: Preprint

Single-junction thin-film silicon solar cells require large grain sizes to ensure adequate photovoltaic performance. Using 2D silicon solar cell simulations on the quantitative effects of grain-boundary recombination on device performance, we have found that the acceptable value of effective grain boundary recombination velocity is almost inversely proportional to grain size. For example, in a polycrystalline silicon thin film with an intragrain bulk minority-carrier lifetime of 1 s, a recombination velocity of 104 cm/s is adequate if the grain is 20 m across, whereas a very low recombination velocity of 103 cm/s must be accomplished to achieve reasonable performance for a 2-m grain. For this reason, large grain size on the order of hundreds of m is currently a prerequisite for efficient solar cells, although a more effective grain-boundary passivation technique may be developed in the future.
Date: August 1, 2003
Creator: Wang, T. H.; Sims, P. E.; Page, M. R.; Bauer, R. E.; Landry, M. D.; Reedy, R. et al.
System: The UNT Digital Library
The appreciation of stochastic motion in particle accelerators (open access)

The appreciation of stochastic motion in particle accelerators

A description is given of the analytic and numerical work, performed from July 1955 through August 1956, so as to develop, and then study, the process of making intense proton beams, suitable for colliding beams. It is shown how this investigation led, in a most natural way, to the realization that stochasticity can arise in a simple Hamiltonian system. Furthermore, the criterion for the onset of stochasticity was understood, and carefully studied, in two different situations. The first situation was the proposed (and subsequently used) ''stacking process'' for developing an intense beam, where stochasticity occurs as additional particles are added to the intense circulating beam. The second situation occurs when one seeks to develop ''stochastic accelerators'' in which particles are accelerated (continuously) by a collection of radio frequency systems. It was in the last connection that the well-known criterion for stochasticity, resonance overlap, was obtained.
Date: August 3, 2003
Creator: Symon, Keith & Sessler, Andrew
System: The UNT Digital Library
Are both symmetric and buckled dimers on Si(100) minima? Density functional and multireference perturbation theory calculations (open access)

Are both symmetric and buckled dimers on Si(100) minima? Density functional and multireference perturbation theory calculations

We report a spin-unrestricted density functional theory (DFT) solution at the symmetric dimer structure for cluster models of Si(100). With this solution, it is shown that the symmetric structure is a minimum on the DFT potential energy surface, although higher in energy than the buckled structure. In restricted DFT calculations the symmetric structure is a saddle point connecting the two buckled minima. To further assess the effects of electron correlation on the relative energies of symmetric versus buckled dimers on Si(100), multireference second order perturbation theory (MRMP2) calculations are performed on these DFT optimized minima. The symmetric structure is predicted to be lower in energy than the buckled structure via MRMP2, while the reverse order is found by DFT. The implications for recent experimental interpretations are discussed.
Date: August 29, 2003
Creator: Jung, Yousung; Shao, Yihan; Gordon, Mark S.; Doren, Douglas J. & Head-Gordon, Martin
System: The UNT Digital Library
At-wavelength interferometry of high-NA diffraction-limited EUV optics (open access)

At-wavelength interferometry of high-NA diffraction-limited EUV optics

Recent advances in all-reflective diffraction-limited optical systems designed for extreme ultraviolet (EUV) lithography have pushed numerical aperture (NA) values from 0.1 to 0.3, providing Rayleigh resolutions of 27-nm. Worldwide, several high-NA EUV optics are being deployed to serve in the development of advanced lithographic techniques required for EUV lithography, including the creation and testing of new, high-resolution photoresists. One such system is installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. Sub{angstrom}-accuracy optical testing and alignment techniques, developed for use with the previous generations of EUV lithographic optical systems, are being extended for use at high NA. Considerations for interferometer design and use are discussed.
Date: August 1, 2003
Creator: Goldberg, Kenneth A.; Naulleau, Patrick; Rekawa, Senajith; Denham, Paul; Liddle, J. Alexander; Anderson, Erik et al.
System: The UNT Digital Library
B Physics in CDF (open access)

B Physics in CDF

The upgraded CDF detector is now collecting data with the aim of integrating 2 fb{sup -1} by year 2006. The pursued B physics program is very appealing. CDF will provide measurements of various CP violating and B mixing parameters which both complement and extend B-factories measurements. In addition there is a variety of spectroscopy measurements on B{sub s} and heavier B hadrons which are currently accessible only at the Tevatron. In this talk we give a description of the new CDF tools available for B physics, we discuss the preliminary results obtained with the first 70 pb{sup -1} of data, and we highlight Run II B physics prospects.
Date: August 12, 2003
Creator: Fiori, Irene
System: The UNT Digital Library
Beam collimation at hadron colliders (open access)

Beam collimation at hadron colliders

Operational and accidental beam losses in hadron colliders can have a serious impact on machine and detector performance, resulting in effects ranging from minor to catastrophic. Principles and realization are described for a reliable beam collimation system required to sustain favorable background conditions in the collider detectors, provide quench stability of superconducting magnets, minimize irradiation of accelerator equipment, maintain operational reliability over the life of the machine, and reduce the impact of radiation on personnel and the environment. Based on detailed Monte-Carlo simulations, such a system has been designed and incorporated in the Tevatron collider. Its performance, comparison to measurements and possible ways to further improve the collimation efficiency are described in detail. Specifics of the collimation systems designed for the SSC, LHC, VLHC, and HERA colliders are discussed.
Date: August 12, 2003
Creator: Mokhov, Nikolai V.
System: The UNT Digital Library
BIFUNCTIONAL CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NO BY HYDROCARBONS (open access)

BIFUNCTIONAL CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NO BY HYDROCARBONS

Novel bifunctional catalysts combining two active phases, typically Cu-ZSM-5 and a modifier, were prepared and tested for the selective catalytic reduction of nitrogen oxides using propylene in order to overcome the hindering effects of water typically seen for single-phase catalysts such as Cu-ZSM-5. The catalysts were made by typical preparation techniques, but parameters could be varied to influence the catalyst. The physical characterization of the materials showed that the modification phase was added strictly to the external surface of the zeolite without hindering any internal surface area. Chemical characterization by temperature programmed reactions, DRIFTS and x-ray absorption spectroscopy indicated strong interaction between the two phases, primarily producing materials that exhibited lower reduction temperatures. Two improvements in NOx reduction activity (1000 ppm NO, 1000 ppm C3H6, 2% O2, 30,000 hr-1 GHSV) were seen for these catalysts compared with Cu- ZSM-5: a lower temperature of maximum NOx conversion activity (as low at 250 C), and an enhancement of activity when water was present in the system. The use of a second phase provides a way to further tune the properties of the catalyst in order to achieve mechanistic conditions necessary to maximize NOx remediation.
Date: August 24, 2003
Creator: Neylon, M.; Castagnola, M.; Kropf, A. & Marshall, C.
System: The UNT Digital Library
Blue and Green Light? Wavelength Scaling for NIF (open access)

Blue and Green Light? Wavelength Scaling for NIF

Use of the National Ignition Facility to also output frequency-doubled (.53{micro}m) laser light would allow significantly more energy to be delivered to targets as well as significantly greater bandwidth for beam smoothing. This green light option could provide access to new ICF target designs and a wider range of plasma conditions for other applications. The wavelength scaling of the interaction physics is a key issue in assessing this green light option. Wavelength scaling theory based on the collisionless plasma approximation is explored, and some limitations associated with plasma collisionality are examined. Important features of the wavelength scaling are tested using the current data base, which is growing. It appears that, with modest restrictions, .53{micro}m light couples with targets as well as .35{micro}m light does. A more quantitative understanding of the beneficial effects of SSD on the interaction physics is needed for both .53{micro}m and .35{micro}m light.
Date: August 21, 2003
Creator: Suter, L.; Miller, M.; Moody, J. & Kruer, W.
System: The UNT Digital Library
BNL NONLINEAR PRE TEST SEISMIC ANALYSIS FOR THE NUPEC ULTIMATE STRENGTH PIPING TEST PROGRAM. (open access)

BNL NONLINEAR PRE TEST SEISMIC ANALYSIS FOR THE NUPEC ULTIMATE STRENGTH PIPING TEST PROGRAM.

The Nuclear Power Engineering Corporation (NUPEC) of Japan has been conducting a multi-year research program to investigate the behavior of nuclear power plant piping systems under large seismic loads. The objectives of the program are: to develop a better understanding of the elasto-plastic response and ultimate strength of nuclear piping; to ascertain the seismic safety margin of current piping design codes; and to assess new piping code allowable stress rules. Under this program, NUPEC has performed a large-scale seismic proving test of a representative nuclear power plant piping system. In support of the proving test, a series of materials tests, static and dynamic piping component tests, and seismic tests of simplified piping systems have also been performed. As part of collaborative efforts between the United States and Japan on seismic issues, the US Nuclear Regulatory Commission (USNRC) and its contractor, the Brookhaven National Laboratory (BNL), are participating in this research program by performing pre-test and post-test analyses, and by evaluating the significance of the program results with regard to safety margins. This paper describes BNL's pre-test analysis to predict the elasto-plastic response for one of NUPEC's simplified piping system seismic tests. The capability to simulate the anticipated ratcheting response of …
Date: August 17, 2003
Creator: Degrassi, G.; Hofmayer, C.; Murphy, C.; Suzuki, K. & Namita, Y.
System: The UNT Digital Library
BNL NONLINEAR PRE TEST SEISMIC ANALYSIS FOR THE NUPEC ULTIMATE STRENGTH PIPING TEST PROGRAM. (open access)

BNL NONLINEAR PRE TEST SEISMIC ANALYSIS FOR THE NUPEC ULTIMATE STRENGTH PIPING TEST PROGRAM.

The Nuclear Power Engineering Corporation (NUPEC) of Japan has been conducting a multi-year research program to investigate the behavior of nuclear power plant piping systems under large seismic loads. The objectives of the program are: to develop a better understanding of the elasto-plastic response and ultimate strength of nuclear piping; to ascertain the seismic safety margin of current piping design codes; and to assess new piping code allowable stress rules. Under this program, NUPEC has performed a large-scale seismic proving test of a representative nuclear power plant piping system. In support of the proving test, a series of materials tests, static and dynamic piping component tests, and seismic tests of simplified piping systems have also been performed. As part of collaborative efforts between the United States and Japan on seismic issues, the US Nuclear Regulatory Commission (USNRC) and its contractor, the Brookhaven National Laboratory (BNL), are participating in this research program by performing pre-test and post-test analyses, and by evaluating the significance of the program results with regard to safety margins. This paper describes BNL's pre-test analysis to predict the elasto-plastic response for one of NUPEC's simplified piping system seismic tests. The capability to simulate the anticipated ratcheting response of …
Date: August 17, 2003
Creator: Degrassi, G.; Hofmayer, C.; Murphy, C.; Suzuki, K. & Namita, Y.
System: The UNT Digital Library