61 Matching Results

Search Results

Advanced search parameters have been applied.

Detection and location of leaks in district heating steam systems: Survey and review of current technology and practices

Description: This report presents the results of a survey undertaken to identify and characterize current practices for detecting and locating leaks in district heating systems, particular steam systems. Currently used technology and practices are reviewed. In addition, the survey was used to gather information that may be important for the application of acoustic leak detection. A few examples of attempts to locate leaks in steam and hot water pipes by correlation of acoustic signals generated by the leaks are also discussed.
Date: March 1, 1992
Creator: Kupperman, D.S.; Raptis, A.C. & Lanham, R.N.
Partner: UNT Libraries Government Documents Department

Acoustic Leak Detection for District Heating Systems

Description: An acoustic leak detection facility was completed and used to evaluate the capability of piezoelectric sensors, accelerometers, and capacitance microphones to detect and locate gas and water leaks in underground district heating and cooling (DHC) piping. Leak detection sensitivity and location capabilities for DHC systems were estimated from laboratory data and from data obtained from the underground DH system in Scranton, Pennsylvania, where acoustic background noise levels and acoustic signals from field-induced steam leaks were acquired. Acoustic detection of leaks with flow rates of less than 10 gpm is possible at a distance of several hundred meters, with a location accuracy of a few meters. Although steam leaks of comparable mass loss can be detected over a similar range with transducers mounted on the pipe outer wall, location accuracy of a few meters over this range may only be possible with transducers in direct contract with the steam. Intrusive sensors may also be necessary to detect and locate leaks in plastic pipe.
Date: February 1988
Creator: Kupperman, D. S. & Karvelas, D. E.
Partner: UNT Libraries Government Documents Department

Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubes : Second Annual Report, October 1978-September 1979

Description: This report discusses the development of ultrasonic testing, acoustic microscopy, dye-enhanced radiography, holographic interferometry, and infrared scanning techniques for flaw detection in silicon carbide (SiC) heat-exchanger tubing. Both preservice and in-service testing requirements are discussed. An ultrasonic boreside probe and an acoustic microscope stage have been designed for continuous monitoring of SiC tubing. Preliminary results with these acoustic systems are presented. In addition, a novel technique for detecting small surface flaws using holographic interferometry is discussed. Fracture mechanics analysis suggests that detection of flaws on the order of 100 um is necessary to assure good reliability of ceramic heat exchangers. The acoustic and holographic techniques have been shown to be capable of detecting flaws of this size. However, the sensitivity of ultrasonic flaw detection in SiC is affected by the microstructure of the component. The practical considerations involved in the use of these techniques are discussed.
Date: November 1979
Creator: Kupperman, D. S.; Yuhas, D.; Deininger, W. & Sciammarella, Cesar A.
Partner: UNT Libraries Government Documents Department

An Ultrasonic Scanner for Stainless Steel Weld Inspections

Description: The large grain size and anisotropic nature of stainless steel weld metal make conventional ultrasonic testing very difficult. This paper evaluates a technique for minimizing the coherent noise in stainless steel weld metal. The method involves digitizing conventional A-scan traces and averaging them with a minicomputer. Results are presented for an ultrasonic scanner which interrogates a small volume of the weld metal while averaging the coherent ultrasonic noise.
Date: September 1978
Creator: Kupperman, D. S. & Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Steam generator mock-up for assessment of inservice inspection technology.

Description: A steam generator mock-up has been assembled for round-robin studies of the effectiveness of currently practiced inservice inspection (ISI) technology for detection of current-day flaws. The mock-up will also be used to evaluate emerging inspection technologies. The 3.66-m (12-ft.)-tall mock-up contains 400 tube openings, each consisting of 9 test sections that can be used to simulate current-day field-induced flaws and artifacts. Included in the mock-up are simulations of tube support plate (TSP) intersections and the tube sheet (TS). Cracks are present at the TSP, TS, and in the free span sections of the mock-up. For initial evaluation of the round-robin results, various eddy current methods, as well as multivariate models for data analysis techniques, are being used to estimate the depth and length of defects in the mock-up. To ensure that the round-robin is carried out with procedures as close as possible to those implemented in the field, input was obtained from industry experts on the protocol and procedures to be used for the exercise. One initial assembly of the mock-up with a limited number of flaws and artifact has been completed and tested. A second completed configuration with additional flaw and artifacts simulations will be used for the round-robin.
Date: September 11, 1999
Creator: Bakhtiari, S.; Kupperman, D. S. & Muscara, J.
Partner: UNT Libraries Government Documents Department

Evaluation of methods for leak detection in reactor primary systems and NDE of cast stainless steel

Description: Six cracks, including two field-induced IGSCC specimens and two thermal-fatigue cracks, have been installed in a laboratory acoustic leak detection facility. The IGSCC specimens produce stronger acoustic signals than the thermal-fatigue cracks at equivalent leak rates. Despite significant differences in crack geometry, the acoustic signals from the two IGSCC specimens, tested at the same leak rate, are virtually identical in the frequency range from 200 to 400 kHz. Thus, the quantitative correlations between the acoustic signals and leak rate in the 300 to 400 kHz band are very similar for the two IGSCC specimens. Also, acoustic background data have been acquired during a hot functional sensitivity of acoustic leak detection techniques. In addition, cross-correlation techniques have been successfully used in the laboratory to locate the source of an electronically simulated leak signal.
Date: January 1, 1984
Creator: Kupperman, D.S.; Claytor, T.N.; Prine, D.W. & Mathieson, T.A.
Partner: UNT Libraries Government Documents Department

Role of internal stresses in fracture behavior of engineering composites

Description: Microstructure and fracture behavior of SiC(f)/Si{sub 3}N{sub 4} matrix composites, and of Ag-particulate/YBa{sub 2}Cu{sub 3}O{sub x}[YBCO] superconductor matrix composites, together with internal residual strains in composite constituents, have been evaluated as a function of reinforcing-fiber, particulate content, and processing variables. Residual strains were measured by neutron diffraction with the Intense Pulsed Neutron Source and Powder Diffractometer at Argonne National Laboratory. Internal radial strains on SiC fibers in SiC(f)/Si{sub 3}N{sub 4} composites decreased from 0.0015 at 8.4 vol.% fibers to 0.0010 at 23.3 vol.% fibers. This decrease in radial strain with increasing fiber volume fraction is expected to reduce frictional and hence interfacial sliding stresses between SiC fibers and Si{sub 3}N{sub 4} matrix; this is in agreement with interfacial shear strengths measured by the fiber pushout technique. Similar relationships between residual strain and interfacial shear strength was observed for composites hot isostatically pressed (HIPed). For YBCO-AG composites, tensile strain in the Ag phase was as high as 0.085%, whereas compressive strain in the YBCO phase reached 0.09%. The presence of compressive strain (stress) improved the strength of YBCO from 200 to 223 MPa. Implications of the effects of residual stresses on interfacial characteristics and resulting composite mechanical properties and fracture behavior will be discussed.
Date: May 1, 1994
Creator: Singh, J. P.; Singh, D.; Kupperman, D. S. & Majumdar, S.
Partner: UNT Libraries Government Documents Department

Application of neutron diffraction technology to the determination of residual strain in engineering composites

Description: Knowledge of fabrication induced residual stresses in the fiber and matrix of advanced engineering composites is important as these stresses can greatly influence the mechanical properties of these composites. In this paper, the application of neutron diffraction technology to the determination of thermal residual strains in the constituents of composites (from which stresses can be calculated) is discussed. Experimental determination of temperature dependent strain in the fiber and matrix of three composites compare favorably with the results of analytical and finite element methods used to predict strain. These composites (two ceramic matrix and one metal matrix) are materials of interest to a variety of industries. In this paper, the benefit of applying a National Laboratory developed technology to a problem of interest to industry, is shown.
Date: January 1, 1992
Creator: Kupperman, D.S.
Partner: UNT Libraries Government Documents Department

Effect of grain size on strain in YBa{sub 2}CU{sub 3}O{sub 7-x} using neutron diffraction

Description: The anisotropic expansion and contraction of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) grains during fabrication could lead to internal stresses that may be relieved by microcracking resulting in low critical currents. Neutron diffraction techniques have been used to examine the internal strain as a function of grain size in samples of YBCO. The full width at half maximum (FWHM) of the Gaussian shaped diffraction peaks are used for the strain analysis. The FWHM in the strain distribution for the coarse grain material is found to be about 0.05%. The strain variation for the fine grained material on the other hand is significantly larger and is about 0.3%. Results of this study suggests the strains are relieved by microcracking in coarse grained YBCO.
Date: October 1, 1990
Creator: Kupperman, D. S.; Singh, J. P. & Hitterman, R. L.
Partner: UNT Libraries Government Documents Department

Use of neutron diffraction to determine grain-size effects on strain in YBa{sub 2}CU{sub 3}O{sub 7-x}

Description: Anisotropic expansion and contraction of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) grains during fabrication could lead to internal stresses that may be relieved by microcracking, resulting in low strength and critical current density. Neutron diffraction techniques have been used to examine the internal strain distribution as a function of grain size in YBCO samples. The full width at half maximum (FWHM) of the Gaussian shaped diffraction peaks is used for strain distribution analysis. The FWHM of the strain distribution for coarse-grain YBCO is found to be about 0.05%, while that for fine-grain material is significantly higher at about 0.3%. Results of this study suggest that the strains are relieved by microcracking in coarse-grain YBCO.
Date: October 1, 1990
Creator: Kupperman, D. S.; Singh, J. P. & Hitterman, R. L.
Partner: UNT Libraries Government Documents Department

Detection and location of leaks in district heating steam systems: Survey and review of current technology and practices

Description: This report presents the results of a survey undertaken to identify and characterize current practices for detecting and locating leaks in district heating systems, particular steam systems. Currently used technology and practices are reviewed. In addition, the survey was used to gather information that may be important for the application of acoustic leak detection. A few examples of attempts to locate leaks in steam and hot water pipes by correlation of acoustic signals generated by the leaks are also discussed.
Date: March 1, 1992
Creator: Kupperman, D. S.; Raptis, A. C. & Lanham, R. N.
Partner: UNT Libraries Government Documents Department

Ceramic tamper-revealing seals

Description: A tamper resistant seal is made of a brittle material with internal defects internally arranged in a random pattern to form a unique fingerprint characteristic of the seal which may be identified by ultrasonic scanning to determine whether tampering has occurred. It comprises a flexible metal or ceramic cable with composite ceramic ends or a U-shaped ceramic connecting element attached to a binding element plate or block cast from alumina or Zr, and connected to the connecting element by shrink fitting. Part of the binding element is cast with NiO{sub 2} particles, which allows ultrasonic scanning and the resulting fingerprint. 7 figs.
Date: December 31, 1991
Creator: Kupperman, D. S.; Raptis, A. C. & Sheen, Shuh-Haw
Partner: UNT Libraries Government Documents Department

Research perspectives on the evaluation of steam generator tube integrity.

Description: Industry effects have been largely successful in managing degradation of steam generator tubes due to wastage, pitting, and denting, but fretting, SCC and intergranular attack have proved more difficult to manage. Although steam generator replacements are proceeding there is substantial industry interest in operating with degraded steam generators, and significant numbers of plants will continue to do so. In most cases degradation of steam generator tubing by stress corrosion cracking is still managed by plug or repair on detection, because current NDE techniques for characterization of flaws are not accurate enough to permit continued operation. This paper reviews some of the historical background that underlies current steam generator degradation management strategies and outlines some of the additional research that must be done to provide more effective management of degradation in current generators and provide greater assurance of satisfactory performance in replacement steam generators.
Date: February 22, 2001
Creator: Muscara, J.; Diercks, D. R.; Majumdar, S.; Kupperman, D. S.; Bakhtiari, S. & Shack, W. J.
Partner: UNT Libraries Government Documents Department

X-ray microdiffraction studies to measure strain fields in a metal matrix composite

Description: An x-ray diffraction microscope has been used to map the strain field in a fiber-reinforced composite material. The monochromatic x-ray (11 keV) beam was focused by a phase zone plate to produce a focal spot of 1 x 4 {micro}m{sup 2} on the specimen. The change in the peak position of diffraction patterns due to interatomic spacing change, caused by stress in the sample, was measured by using a two-dimensional CCD detector. The radial residual strain field in the fiber-reinforced composite (SCS-6/Ti-14Al-21Nb) was measured from diffraction patterns with a sensitivity of {approximately} 10{sup {minus}4} and an average standard deviation of 9.4 {times} 10{sup {minus}5}.
Date: October 1, 1997
Creator: Lee, H.R.; Yun, W.; Cai, Z.; Rodrigues, W. & Kupperman, D.S.
Partner: UNT Libraries Government Documents Department

Eddy current analysis round robin using the NRC steam generator mockup.

Description: This paper discusses round-robin exercises to assess inspection reliability using the NRC steam generator (SG) mock-up at Argonne National Laboratory. The purpose of the round robins is to assess the current reliability of SG tubing inservice inspection, determine the probability of detection (POD) as function of flaw size or severity, and assess the capability for sizing of flaws. The mock-up contains hundreds of cracks and simulations of artifacts such as corrosion deposits and tube support plates that make detection and characterization of cracks more difficult in operating steam generators than in most laboratory situations. Eddy current signals from the laboratory-grown cracks used in the mock-up have been reviewed to ensure that they provide reasonable simulations of those obtained in the field. The mock-up contains 400 tube openings. Each tube contains nine 22.2-mm (7/8-in.) diameter, 30.5-cm (1-ft) long, Alloy 600 test sections. The flaws are located in the tube sheet near the roll transition zone (RTZ), in the tube support plate (TSP), and in the freespan. The flaws are primarily intergranular stress corrosion cracks (axial and circumferential, ID and OD). In addition to the simulated tube sheet and TSP the mock-up has simulated sludge and magnetite deposits. A validated multiparameter eddy current algorithm that provided a detailed isometric plot for every flaw was used to establish the reference state of defects in the mock-up. The detection results for the 11 teams were used to develop POD curves as a function of maximum depth, voltage and the parameter m{sub p}, for the various types of flaws. The 95% one-sided confidence limits (OSL), which include errors in maximum depth estimates, are presented along with the POD curves. For the second round robin a reconfigured mock-up is being used to evaluate the effectiveness of eddy current arrays.
Date: February 20, 2002
Creator: Kupperman, D. S.; Muscara, J.; Bakhtiari, S.; Park, J. Y. & Shack, W. J.
Partner: UNT Libraries Government Documents Department

Application of NDE methods to green ceramics: initial results

Description: This paper describes a preliminary investigation to assess the effectiveness of microradiography, ultrasonic methods, nuclear magnetic resonance, and neutron radiography for the nondestructive evaluation of green (unfired), ceramics. Objective is to obtain useful information on defects, cracking, delaminations, agglomerates, inclusions, regions of high porosity, and anisotropy.
Date: March 1, 1984
Creator: Kupperman, D.S.; Karplus, H.B.; Poeppel, R.B.; Ellingson, W.A.; Berger, H.; Robbins, C. et al.
Partner: UNT Libraries Government Documents Department

Application of NDE methods to green ceramics: initial results

Description: The effectiveness of microradiography, ultrasonic methods, unclear magnetic resonance, and neutron radiography was assessed for the nondestructive evaluation of green (unfired) ceramics. The application of microradiography to ceramics is reviewed, and preliminary experiments with a commercial microradiography unit are described. Conventional ultrasonic techniques are difficult to apply to flaw detection green ceramics because of the high attenuation, fragility, and couplant-absorbing properties of these materials. However, velocity, attenuation, and spectral data were obtained with pressure-coupled transducers and provided useful informaion related to density variations and the presence of agglomerates. Nuclear magnetic resonance (NMR) imaging techniques and neutron radiography were considered for detection of anomalies in the distribution of porosity. With NMR, areas of high porosity might be detected after the samples are doped with water. In the case of neutron radiography, although imaging the binder distribution throughout the sample may not be feasible because of the low overall concentration of binder, regions of high binder concentration (thus high porosity) should be detectable.
Date: January 1, 1983
Creator: Kupperman, D.S.; Karplus, H.B.; Poeppel, R.B.; Ellingson, W.A.; Berger, H.; Robbins, C. et al.
Partner: UNT Libraries Government Documents Department

Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubes : Annual Report, October 1977-September 1978

Description: This report discusses the adequacy of several nondestructive evaluation techniques for the detection of flaws in silicon carbide heat-exchanger tubing. Experimental results have been obtained for conventional ultrasonic testing, acoustic microscopy, conventional and dye-enhanced radiography, holographic interferometry, infrared scanning and internal-friction measurements.
Date: March 1979
Creator: Kupperman, D. S.; Yuhas, D.; Sciammarella, Cesar A.; Lapinski, N. P. & Fiore, N. F.
Partner: UNT Libraries Government Documents Department

Development of Nondestructive Evaluation Techniques for High-Temperature Ceramic Heat Exchanger Components : Third Annual Report, October 1979-September 1980

Description: The goals of the present program are not only to develop hardware and procedures for efficiently inspecting ceramic heat-exchanger components in conventional ways, but also to develop advanced NDE techniques that will allow effective failure prediction. The main objectives in FY 1980 have been to (a) develop a computer-interfaced ultrasonic bore-side probe for pre-service and in-service inspection, (b) develop and assess techniques for inspection of SiC tubing by acoustic microscopy, and (c) carry out preliminary tests to compare ultrasonic, holographic, and infrared techniques with more conventional dye-penetrant and radiographic methods for inspection of butt joints in ceramic tubes. Circumferential notches, 125 microns deep x 250 microns long, on the inner and outer surfaces of sintered and siliconized SiC tubes were successfully detected with an ultrasonic bore-side probe. The acoustic microscope was modified to handle 30- as well as 100-MHz sound waves, since the lower-frequency waves give better penetration of Sic tube walls. The modification decreased the acoustic noise. The ability to detect a notch only 250 x 125 x 75 microns in size was demonstrated. Efforts to examine a butt joint with dye-penetrant, radiographic, ultrasonic, and holographic-interferometry techniques revealed that while holography seemed to identify more clearly the presence of a crack-like inner surface flaw, ultrasonic pulse-echo and pitch-catch techniques at 22 MHz also indicated the presence of an anomaly; the ultrasonic and holographic results agreed with regard to angular location of the flaw.
Date: 1980
Creator: Kupperman, D. S.; Yuhas, D.; Sciammarella, Cesar A.; Caines, M. J. & Winiecki, A.
Partner: UNT Libraries Government Documents Department

Effect of Welding Procedure and Aging on Ultrasonic Wave Propagation in Austenitic Stainless Steel

Description: Various types of austenitic stainless steel (SS) were aged for up to 2500 h at a temperature of 600C to determine whether the resultant microstructural changes would affect the ultrasonic velocity and attenuation and thus the reliability of ultrasonic in-service inspections. Samples of Type 304 and 316 SS as well as 308, 308CRE, and 316 weld metal were examined. Velocity variations were less than 1%, and attenuation variations at frequencies below 10 MHz were not significant except in the anomalous case of one Type 316 SS weldmetal sample. That change may be due to unexpected microstructural changes associated with aging. The variation in the samples attributed to aging is therefore not expected to have a deleterious effect on ultrasonic in-service inspection of stainless steel reactor components.
Date: July 1980
Creator: Kupperman, D. S.; Caines, M. J.; Reimann, K. J. & Fiore, N. F.
Partner: UNT Libraries Government Documents Department

Detection and Location of Leaks in District Heating Steam Systems: Survey and Review of Current Technology and Practices

Description: This report presents the results of a survey undertaken to identify and characterize current practices for detecting and locating leaks in district heating systems, particular steam systems. Currently used technology and practices are reviewed. In addition, the survey was used to gather information that may be important for the application of acoustic leak detection. A few examples of attempts to locate leaks in steam and hot water pipes by correlation of acoustic signals generated by the leaks are also discussed.
Date: March 1992
Creator: Kupperman, D. S.; Raptis, A. C. & Lanham, R. N.
Partner: UNT Libraries Government Documents Department

Steam generator tube integrity program: Annual report, August 1995--September 1996. Volume 2

Description: This report summarizes work performed by Argonne National Laboratory on the Steam Generator Tube Integrity Program from the inception of the program in August 1995 through September 1996. The program is divided into five tasks: (1) assessment of inspection reliability, (2) research on ISI (inservice-inspection) technology, (3) research on degradation modes and integrity, (4) tube removals from steam generators, and (5) program management. Under Task 1, progress is reported on the preparation of facilities and evaluation of nondestructive evaluation techniques for inspecting a mock-up steam generator for round-robin testing, the development of better ways to correlate failure pressure and leak rate with eddy current (EC) signals, the inspection of sleeved tubes, workshop and training activities, and the evaluation of emerging NDE technology. Results are reported in Task 2 on closed-form solutions and finite-element electromagnetic modeling of EC probe responses for various probe designs and flaw characteristics. In Task 3, facilities are being designed and built for the production of cracked tubes under aggressive and near-prototypical conditions and for the testing of flawed and unflawed tubes under normal operating, accident, and severe-accident conditions. Crack behavior and stability are also being modeled to provide guidance for test facility design, develop an improved understanding of the expected rupture behavior of tubes with circumferential cracks, and predict the behavior of flawed and unflawed tubes under severe accident conditions. Task 4 is concerned with the acquisition of tubes and tube sections from retired steam generators for use in the other research tasks. Progress on the acquisition of tubes from the Salem and McGuire 1 nuclear plants is reported.
Date: February 1998
Creator: Diercks, D. R.; Bakhtiari, S.; Kasza, K. E.; Kupperman, D. S.; Majumdar, S.; Park, J. Y. et al.
Partner: UNT Libraries Government Documents Department

Thermal strains in titanium aluminide and nickel aluminide composites

Description: Neutron diffraction was used to measure residual thermal strains developed during postfabrication cooling in titanium aluminide and nickel aluminide intermetallic matrix composites. Silicon carbide /Ti 14Al-21Nb, tungsten and sapphire/NiAl, and sapphire and SiC-coated sapphire/NiAl{sub 25}Fe{sub 10} composites were investigated. The thermal expansion coefficient of the matrix is usually greater than that of the fibers. As such, during cooldown, compressive residual strains are generated in the fibers and tensile residual strains are generated in the matrix, parallel to the fibers. Liquid-nitrogen dipping and thermal cycling tend to reduce the fabrication-induced residual strains in silicon carbide-fiber-reinforced titanium aluminide matrix composites. However, matrix cracking can occur as a result of these processes. The axial residual strains in the matrix were lower in the nickel aluminide matrix than in the titanium aluminide matrix. As the matrix undergoes plastic deformation, residual thermal strains are related to the yield stress of the matrix.
Date: January 1, 1992
Creator: Saigal, A. (Tufts Univ., Medford, MA (United States). Dept. of Mechanical Engineering) & Kupperman, D.S. (Argonne National Lab., IL (United States))
Partner: UNT Libraries Government Documents Department