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Status report on the long-term stability of the Advanced Photon Source.

Description: Table 1 summarizes the average elevation changes and standard deviations as well as the points with the largest changes for each year. On average, hardly any settlements can be detected; however, local changes of +2.90 mm to {minus}2.31 mm have been measured. Looking at the low and high points, the settlement process is slowing down over time. Overall, the settlements observed match the expectations for this type of construction. To date no major realignment of the Advanced Photon Source (APS) storage ring has been necessary. The particle beam tracks with the settlements of the floor as long as these changes occur in a smooth fashion and not as sudden discontinuities [5]. From Figures 6 through 8 it is also apparent that settlements affect larger areas in the storage ring and experiment hall that impact the location of the source point as well as the location of the beamline user equipment. The limiting apertures of the insertion device chambers will make realignment of the APS storage ring a necessity at some point in the future. Currently simulations and machine studies we underway to provide an estimate of tolerable settlement limits before a realignment of certain sections of the storage ring would be required. In conclusion, the APS has been constructed on solid ground with an excellent foundation. Only small settlement changes are being observed; so far they are not impacting the operation of the accelerator. We are continuing to monitor deformations of the APS floor in anticipation of a future realignment of the accelerator components.
Date: September 21, 1998
Creator: Friedsam, H.
Partner: UNT Libraries Government Documents Department

Independent Evaluation of Air Filter Media from Chornobyl

Description: An independent evaluation was performed to assess the morphology, pressure drop characteristics, alpha spectroscopy characteristics, and collection efficiency of an air sampling filter media and two types of aerosol face masks provided from Chernobyl by Pacific Northwest National Laboratory. The evaluation included characterizing the filter morphology by scqg electron microscopy; measuring the filter pressure drop as a function of air flowrate; evaluating the spectroscopy characteristics of the filter for alpha-emitting radionuclides by sampling ambient radon progeny aerosols in an Eberline Alpha-6A alpha continuous air monitor; determining the particle collection efficiency of the filter media for 0.3 {micro}m aerodynamic diameter monodisperse particles at 1 and 2 cfm; and comparing the apparent construction, durability, and performance similarities of the filter media to other media commonly used for monitoring airborne alpha-emitting radionuclides.
Date: December 21, 1999
Creator: Hoover, MD; Fencl, AF & Vargo, GJ
Partner: UNT Libraries Government Documents Department

Thermal recovery measurements on multi-segment amplifiers

Description: We present the results of a series of experiments to measure the thermal recovery times of a flashlamp-pumped, Nd:Glass multi-segment laser amplifier. In particular, we investigated the thermal recovery times under the following cooling options: (1) passive cooling; (2) active cooling of the flashlamp cassettes, and (3) active cooling of the flashlamp cassettes and gas flow in the pump cavity.
Date: September 21, 1995
Creator: Rotter, M.D.; McCracken, R.W.; Erlandson, A.C. & Brown, D.
Partner: UNT Libraries Government Documents Department

Measurement techniques in dry-powdered processing of spent nuclear fuels.

Description: High-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICPMS) detection, {alpha}-spectrometry ({alpha}-S), and {gamma}-spectrometry ({gamma}-S) were used for the determination of nuclide content in five samples excised from a high-burnup fuel rod taken from a pressurized water reactor (PWR). The samples were prepared for analysis by dissolution of dry-powdered samples. The measurement techniques required no separation of the plutonium, uranium, and fission products. The sample preparation and analysis techniques showed promise for in-line analysis of highly-irradiated spent fuels in a dry-powdered process. The analytical results allowed the determination of fuel burnup based on {sup 148}Nd, Pu, and U content. A goal of this effort is to develop the HPLC-ICPMS method for direct fissile material accountancy in the dry-powdered processing of spent nuclear fuel.
Date: July 21, 1999
Creator: Bowers, D. L.; Hong, J.-S.; Kim, H.-D.; Persiani, P. J. & Wolf, S. F.
Partner: UNT Libraries Government Documents Department

EVOLVE - an advanced first wall/blanket system.

Description: A new concept for an advanced fusion first wall and blanket has been identified. The key feature of the concept is the use of the heat of vaporization of lithium (about 10 times higher than water) as the primary means for capturing and removing the fusion power. A reasonable range of boiling temperatures of this alkali metal is 1200 to 1400 C, corresponding with a saturation pressure of 0.035 to 0.2 MPa. Calculations indicate that a evaporative system with Li at {approximately}1200 C can remove a first wall surface heat flux of >2 MW/m2 with an accompanying neutron wall load of >10 MW/m2. Work to date shows that the system provides adequate tritium breeding and shielding, very high thermal conversion efficiency, and low system pressure. Tungsten is used as the structural material, and it is expected to operate at a surface wall load of 2 MW/m2 at temperatures above 1200 C.
Date: July 21, 1999
Creator: Khater, H.; Majumdar, S.; Malang, S.; Mattas, R. F.; Mogahed, E.; Nelson, B. et al.
Partner: UNT Libraries Government Documents Department


Description: Although the Brookhaven AGS will become an injector to RHIC, it will still be available for external proton beam experiments. I discuss a number new K decay experiments which have been proposed for this facility.
Date: June 21, 1999
Partner: UNT Libraries Government Documents Department

Energy Technology Division research summary 1997.

Description: The Energy Technology Division provides materials and engineering technology support to a wide range of programs important to the US Department of Energy. As shown on the preceding page, the Division is organized into ten sections, five with concentrations in the materials area and five in engineering technology. Materials expertise includes fabrication, mechanical properties, corrosion, friction and lubrication, and irradiation effects. Our major engineering strengths are in heat and mass flow, sensors and instrumentation, nondestructive testing, transportation, and electromechanics and superconductivity applications. The Division Safety Coordinator, Environmental Compliance Officers, Quality Assurance Representative, Financial Administrator, and Communication Coordinator report directly to the Division Director. The Division Director is personally responsible for cultural diversity and is a member of the Laboratory-wide Cultural Diversity Advisory Committee. The Division's capabilities are generally applied to issues associated with energy production, transportation, utilization or conservation, or with environmental issues linked to energy. As shown in the organization chart on the next page, the Division reports administratively to the Associate Laboratory Director (ALD) for Energy and Environmental Science and Technology (EEST) through the General Manager for Environmental and Industrial Technologies. While most of our programs are under the purview of the EEST ALD, we also have had programs funded under every one of the ALDs. Some of our research in superconductivity is funded through the Physical Research Program ALD. We also continue to work on a number of nuclear-energy-related programs under the ALD for Engineering Research. Detailed descriptions of our programs on a section-by-section basis are provided in the remainder of this book. This Overview highlights some major trends. Research related to the operational safety of commercial light water nuclear reactors (LWRS) is funded by the US Nuclear Regulatory Commission (NRC). In addition to our ongoing work on environmentally assisted cracking and steam generator integrity, a major ...
Date: October 21, 1997
Partner: UNT Libraries Government Documents Department

Thermal performance of steel-framed walls. Final report

Description: In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.
Date: November 21, 1994
Creator: Barbour, E.; Goodrow, J.; Kosny, J. & Christian, J.E.
Partner: UNT Libraries Government Documents Department

Cosmological parameters and power spectrum from peculiar velocities

Description: The power spectrum of mass density fluctuations is evaluated from the Mark III and the SFI catalogs of peculiar velocities by a maximum likelihood analysis, using parametric models for the power spectrum and for the errors. The applications to the two different data sets, using generalized CDM models with and without COBE normalization, give consistent results. The general result is a relatively high amplitude of the power spectrum, with {sigma}{sub 8}{Omega}{sub m}{sup 0.6} = 0.8 {+-} 0.2 at 90% confidence. Casting the results in the {Omega}{sub m} {minus} {Omega}{sub {Lambda}} plane, yields complementary constraints to those of the high-redshift supernovae, together favoring a nearly flat, unbound and accelerating universe with comparable contributions from {Omega}{sub m} and {Omega}{sub {Lambda}}. Further implications on the cosmological parameters, arising from a joint analysis of the velocities together with small-scale CMB anisotropies and the high-redshift supernovae, are also briefly described.
Date: September 21, 1999
Creator: Zehavi, Idit
Partner: UNT Libraries Government Documents Department


Description: The STAR experiment at RHIC is a large acceptance detector. The electromagnetic calorimeter (EMC) will provide a sensitive trigger to study high p{sub t} jets and hard photons in AuAu, pp, and pAu collisions. The capability for the EMC to trigger on jets and direct photons was studied for trigger level 0. Trigger efficiencies and expected process rates were obtained for pp reactions. Results from pp interactions will be essential to the interpretation of AuAu results as well as for the spin physics program. These studies were performed with the standard STAR software chain which includes GEANT and EMC simulations. The HIJING event generator was used to provide input for the simulations.
Date: March 21, 1999
Partner: UNT Libraries Government Documents Department

Hanford Site 1998 Environmental Report

Description: This Hanford Site environmental report is prepared annually to summarize environmental data and information, to describe environmental management performance, to demonstrate the status of compliance with environmental regulations, and to highlight major environmental programs and efforts. The report is written to meet requirements and guidelines of the U.S. Department of Energy (DOE) and to meet the needs of the public. This summary has been written with a minimum of technical terminology. Individual sections of the report are designed to: describe the Hanford Site and its mission; summarize the status of compliance with environmental regulations; describe the environmental programs at the Hanford Site; discuss the estimated radionuclide exposure to the public from 1998 Hanford Site activities; present the effluent monitoring, environmental surveillance, and groundwater protection and monitoring information; and discuss the activities to ensure quality.
Date: September 21, 1999
Creator: Dirkes, R. L.; Hanf, R. W. & Poston, T. M.
Partner: UNT Libraries Government Documents Department

Hybrid electric vehicles TOPTEC

Description: This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.
Date: June 21, 1994
Partner: UNT Libraries Government Documents Department

Incorporation of radionuclides from the electrometallurgical treatment of spent fuel into a ceramic waste form.

Description: An electrometallurgical process is being developed at Argonne National Laboratory to treat spent metallic nuclear fuel. In this process, the spent nuclear fuel is electrorefined in a molten salt to separate uranium from the other constituents of the fuel. The treatment process generates a contaminated chloride salt that is incorporated into a ceramic waste form. The ceramic waste form, a composite of socialite and glass, contains the fission products (rare earths, alkalis, alkaline earth metals, and halides) and transuranic radionuclides that accumulated in the electrorefiner salt. These radionuclides are incorporated into zeolite A, which can fully accommodate the salt in its crystal structure. The radionuclides are incorporated into the zeolite by high-temperature blending or by ion exchange. In the blending process the salt and zeolite are simply tumbled together at >450 C (723 K), but in the ion exchange process, which yields a product more highly concentrated in fission products, the molten salt is passed through a bed of the zeolite. In either case, the salt-loaded zeolite A is mixed with glass frit and hot isostatically pressed to produce a monolithic leach resistant waste form. Zeolite is converted to sodalite during hot pressing. This paper presents experimental results on the fission product uptake of the zeolite as a function of time and salt composition.
Date: December 21, 1998
Creator: Pereira, C.
Partner: UNT Libraries Government Documents Department

Laboratory Simulation of Response to a Distributed Pressure Load

Description: Responses to a distributed pressure load are typically predicted through the use of a finite-element model. This procedure depends on the model to represent the actual structure accurately. Another technique that is developed in this work is to predict the response based upon an experi- mentally derived model. This model consists of frequency response functions. The pressure distribution is assumed to be known. In this work, the pressure load will be a blast load. The focus of this work will be to simulate a harsh, shock-like environment. Data from a reverse Hopkinson bar (RHB) test is used to generate the response to a symmetric, distributed load. The reverse Hopkinson bar generates a high ampli- tude, high frequency content pulse that excites components at near-blast levels. The frequency response functions gen- erated from the RHB are used to generate an experimental model of the structure, which is then used in conjunction with the known pressure distribution, to estimate the component response to a blast. This result can then be used with a model correlation technique to adjust a finite element model such that data from a true blast test can be used to only fine tune the model. This work details the estimation response due to the blast.
Date: October 21, 1998
Creator: Mayes, R. & Simmermacher, T.
Partner: UNT Libraries Government Documents Department


Description: When the Relativistic Heavy Ion Collider (RHIC) at BNL begins operation in the Fall of 1999, heavy ions will be accelerated in collider mode for the first time, and a new energy regime will be entered for Heavy Ion Physics. The Solenoidal Tracker At RHIC (STAR) detector has a near 4{pi} coverage and is dedicated to taking hadronic measurements. A large volume Time Projection Chamber placed in a solenoidal magnet at 0.5T is used to track and identify the many thousands of produced particles. STAR will measure many observables simultaneously on an event-by-event basis to study signatures of a possible QGP phase transition and the space-time evolution of the collision process. The goal is to obtain a fundamental understanding of the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high energy densities. This paper outlines the physics STAR intends to study during the first year of operation.
Date: March 21, 1999
Partner: UNT Libraries Government Documents Department

Experiments on Corium Dispersion after Lower Head Failure at Moderate Pressure

Description: Concerning the mitigation of high pressure core melt scenarios, the design objective for future PWRS is to transfer high pressure core melt to low pressure core melt sequences, by means of pressure relief valves at the primary circuit, with such a discharge capacity to limit the pressure in the reactor coolant system to less than 20 bar. Studies have shown that in late in-vessel reflooding scenarios there may be a time window where the pressure is indeed in this range, at the moment of the reactor vessel rupture. It has to be verified that large quantities of corium released from the vessel after failure at pressures <20 bar cannot be carried out of the reactor pit, because the melt collecting and cooling concept of future PWRs would be rendered useless. Existing experiments investigated the melt dispersal phenomena in the context of the DCH resolution for existing power plants in the USA, most of them having cavities with large instrument tunnels leading into subcompartments. For such designs, breaches with small cross sections at high vessel failure pressures had been studied. However, some present and future European PWRs have an annular cavity design without a large pathway out of the cavity other than through the narrow annular gap between the RPV and the cavity wall. Therefore, an experimental program was launched, focusing on the annular cavity design and low pressure vessel failure. The first part of the program comprises two experiments which were performed with thermite melt steam and a prototypic atmosphere in the containment in a scale 1:10. The initial pressure in the RPV-model was 11 and 15 bars, and the breach was a hole at the center of the lower head with a scaled diameter of 100 cm and 40 cm, respectively. The main results were: 78% of melt mass ...
Date: September 21, 1999
Partner: UNT Libraries Government Documents Department

X-ray and visible light transmission as two-dimensional, full-field moisture-sensing techniques: A preliminary comparison

Description: Two independent high-resolution moisture-sensing techniques, x-ray absorption and light transmission, have been developed for use in two-dimensional, thin-slab experimental systems. The techniques yield full-field measurement capabilities with exceptional resolution of moisture content in time and space. These techniques represent powerful tools for the experimentalist to investigate processes governing unsaturated flow and transport through fractured and nonfractured porous media. Evaluation of these techniques has been accomplished by direct comparison of data obtained by means of the x-ray and light techniques as well as comparison with data collected by gravimetric and gamma-ray densitometry techniques. Results show excellent agreement between data collected by the four moisture-content measurement techniques. This program was established to support the Yucca Mountain Site Characterization Project.
Date: January 21, 1992
Creator: Tidwell, V. C. & Glass, R. J.
Partner: UNT Libraries Government Documents Department

Implementation of U.S. transparency monitoring under the U.S./Russian HEU purchase agreement

Description: During the past three years US monitoring at Russian nuclear facilities, subject to the HEU Purchase Agreement, has evolved as MINATOM and DOE negotiators worked to improve transparency rights and as additional Russian facilities began processing HEU. The number of Russian nuclear facilities subject to US monitoring has increased from two in 1996 to the current four. In that time, physical monitoring, which only permitted visual inspections and access to process forms is being supplemented by instrumentation which detects U-235 enrichment of material in containers and instrumentation which is used to confirm that blending of HEU into LEU at the blending facilities is taking place. This paper summarizes the US HEU Transparency monitoring activities performed in Russian facilities. It then summarizes the process used to certify the Blend Down Monitoring System (BDMS) that is currently in use at one of these facilities.
Date: July 21, 1999
Creator: Benton, J B; Glaser, J W & Mastal, E F
Partner: UNT Libraries Government Documents Department

Surfactant studies for bench-scale operation; Sixth quarterly technical progress report, October 1, 1993--December 31, 1993

Description: A phase II study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the sixth quarter of work. The major accomplishments were (1) Completion of the distillation of the liquid product from coal liquefaction autoclave reactor runs with Illinois No. 6 coal at 400{degree}C, with and without surfactant and/or catalyst at pressures of 1700 psig, (2) Batch autoclave runs at 375 and 400{degree}C with 1 wt % lignin to Illinois No. 6 coal to further define the surfactant effect of sodium lignosulfonate, and (3) a preliminary economic evaluation of the application of the lignosulfonate surfactant in an industrial liquefaction process and a proposed conceptual plant design.
Date: January 21, 1994
Creator: Hickey, G.S. & Sharma, P.K.
Partner: UNT Libraries Government Documents Department

Development and application of NDE methods for monolithic and continuous fiber ceramic matrix composites.

Description: Monolithic structural ceramics and continuous fiber ceramic matrix composites (CMCs) are being developed for application in many thermally and chemically aggressive environments where structural reliability is paramount. We have recently developed advanced nondestructive evaluation (NDE) methods that can detect distributed ''defects'' such as density gradients and machining-induced damage in monolithic materials, as well as delamination, porosity, and throughwall cracks, in CMC materials. These advanced NDE methods utilize (a) high-resolution, high-sensitivity thermal imaging; (b) high-resolution X-ray imaging; (c) laser-based elastic optical scattering; (d) acoustic resonance; (e) air-coupled ultrasonic methods; and (f) high-sensitivity fluorescent penetrant technology. This paper discusses the development and application of these NDE methods relative to ceramic processing and ceramic components used in large-scale industrial gas turbines and hot gas filters for gas stream particulate cleanup.
Date: May 21, 1999
Creator: Ellingson, W. A.
Partner: UNT Libraries Government Documents Department

Investigation of the potential impacts from tritium soil contamination in the CP-5 yard.

Description: Based on a review of available data, significant contributions to low-level tritium soil contamination in the CP-5 yard have been made by airborne tritium fallout and rainout from the CP-5 ventilation system stack. Based on the distribution of tritium in the yard, it is also likely that leaks in secondary system piping which lead to the cooling towers were a significant contributor to tritium in CP-5 yard subsurface soil. Based on the foregoing analysis, low-level tritium contamination will not prohibit the release of the yard for unrestricted use in the future. Worst case dose estimates based on very conservative assumptions indicate that a 25 rmem annual effective dose equivalent limit will not be exceeded under the most restrictive residential-use family farm scenario. Given the impermeable nature of the glacial till under CP-5, low-level concentrations of tritium may be occasionally detected in the deep well (3300 12D), but the peak concentration will not approach the levels calculated by RESRAD; however, continued monitoring of the deep well is recommended. To ensure that all sources of potential tritium release have been removed from the CP-5 complex, removal of tritiated water from each rod-out hole and an evaluation of the physical integrity of the rod-out holes is recommended. This will also allow for an evaluation of tritium concentrations in shallow groundwater under CP-5 by sampling groundwater that is currently being forced into the drain tile system. Additional surface and subsurface soil sampling and analysis will be required to determine the final release status of soils around the Building 330 complex relative to elevated concentrations of CS-137, CO-60,Co-57, and Eu-152 identified during the 1993 IT Corporation characterization. The potential radiological impact from isolated elevations of the latter radionuclides is relatively low and can be evaluated as part of the final status survey of outdoor areas ...
Date: December 21, 1998
Creator: Hysong, R. J.
Partner: UNT Libraries Government Documents Department

Simulation of edge-plasma profiles and turbulence related to L-H transitions in tokamaks

Description: Understanding plasma profile evolution and plasma turbulence are two important aspects of developing a predictive model for edge-plasma in tokamaks and other fusion-related devices. Here they describe results relevant to the L-H transition phenomena observed in tokamaks obtained from two simulations codes which emphasize the two aspects of the problem. UEDGE solves for the two-dimensional (2-D) profiles of a multi-species plasma and neutrals given some anomalous cross-field diffusion coefficients, and BOUT solves for the three-dimensional (3-D) turbulence that gives rise to the anomalous diffusion. These two codes are thus complementary in solving different aspects of the edge-plasma transport problem; ultimately, they want to couple the codes so that UEDGE uses BOUT's turbulence transport results, and BOUT uses UEDGE's plasma profiles with a fully automated iteration procedure. This goal is beyond the present paper; here they show how each aspect of the problem, i.e., profiles and turbulent transport, can contribute to L-H type transitions.
Date: September 21, 1999
Creator: Cohen, R H; Rognlien, T D & Xu, X Q
Partner: UNT Libraries Government Documents Department

Evaluation of Flygt Mixers for Application in Savannah River Site Tank Summary of Test Results from Phase A, B, and C Testing

Description: Staff from the Savannah River Site (SRS), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), and ITT Flygt Corporation in Trumbull, Connecticut, are conducting a joint mixer testing program to evaluate the applicability of Flygt mixers to SRS Tank 19 waste retrieval and waste retrieval in other U.S. Department of Energy (DOE) tanks. This report provides the results of the Phase C Flygt mixer testing and summarizes the key findings from the Phase A and B tests. Phase C Flygt mixer testing used full-scale, Model 4680 Flygt mixers (37 kW, 51-cm propeller) installed in a fall-scale tank (25.9-m diameter) at SRS. Phase A testing used a 0.45-m tank and Flygt mixers with 7.8-cm diameter propellers. Phase B testing used Model 4640 Flygt mixers (3 kW, 37-cm propeller) installed in 1.8-m and 5.7-m tanks. Powell et al. (1999z4 1999b) provide detailed descriptions of the Phase A and B tests. In Phase C, stationary submerged jet mixers manufactured by ITT Flygt Corporation were tested in the 25.9-m diameter tank at the SRS TNX facility. The Model 4680 mixers used in Phase C have 37-kW (50-hp) electric motors that drive 51-cm (20-in.) diameter propellers at 860 rpm. Fluid velocity was measured at selected locations with as many as four Model 4680 mixers operating simultaneously in the 25.9-m tank, which was filled with water to selected levels. Phase C involved no solids suspension or sludge mobilization tests.
Date: October 21, 1999
Creator: Hatchell, B. K.; Gladki, H.; Farmer, J. R.; Johnson, M. A.; Poirier, M. R.; Powell, M. R. et al.
Partner: UNT Libraries Government Documents Department

Development of NDE methods for hot gas filters.

Description: Ceramic hot gas candle filters are currently under development for hot gas particulate cleanup in advanced coal-based power systems. The ceramic materials for these filters include nonoxide monolithic, nonoxide-fiber-reinforced composites, and nonoxide reticulated foam. A concern is the lack of reliable data on which to base decisions for reusing or replacing hot gas filters during plant shutdowns. The work in this project is aimed at developing nondestructive evaluation (FIDE) technology to allow detection, and determination of extent, of life-limiting characteristics such as thermal fatigue, oxidation, damage from ash bridging such as localized cracking, damage from local burning, and elongation at elevated temperature. Although in-situ NDE methods are desirable in order to avoid disassembly of the candle filter vessels, the current vessel designs, the presence of filter cakes and possible ash bridging, and the state of NDE technology prevent this. Candle filter producers use a variety of NDE methods to ensure as-produced quality. While impact acoustic resonance offers initial promise for examining new as-produced filters and for detecting damage in some monolithic filters when removed from service, it presents difficulties in data interpretation, it lacks localization capability, and its applicability to composites has yet to be demonstrated. Additional NDE technologies being developed and evaluated in this program and whose applicability to both monolithics and composites has been demonstrated include (a) full-scale thermal imaging for analyzing thermal property variations; (b) fret, high-spatial-resolution X-ray imaging for detecting density variations and dimensional changes; (c) air-coupled ultrasonic methods for determining through-thickness compositional variations; and (d) acoustic emission technology with mechanical loading for detecting localized bulk damage. New and exposed clay-bonded SiC filters and CVI-SiC composite filters have been tested with these additional NDE methods.
Date: July 21, 1999
Creator: Deemer, C.; Ellingson, W. A.; Koehl, E. R.; Lee, H.; Spohnholtz, T. & Sun, J. G.
Partner: UNT Libraries Government Documents Department