Development of Under-sodium Three-dimensional Visual Inspection Technique Using Matrix-arrayed Ultrasonic Transducer

Karasawa, Hirokazu; Izumi, Mamoru; Suzuki, Takehiko; Nagai, Satoshi; Tamura, Masaaki; Fujimori, Shyuuichi

doi:10.1080/18811248.2000.9714955

Cited by 50 publications

(33 citation statements)

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“…According [14] the dimension of one element in matrix array on 36*36 elements at a frequency 5 MHz, had a size of 2.5 × 2.5 mm, and furthermore, elements were located within 5 mm gap from each other. Array was designed for operation at 200˚C.…”

Section: Wettabilitymentioning

confidence: 99%

Ultrasound Imaging in Nuclear Reactors Cooled by Liquid Metals

Svet¹,

Dement'ev²

2015

OJA

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In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the features of the practical realization of ultrasonic imaging systems based on phased arrays and offers an alternative solution of imaging on the basis of the acoustic lenses of refractive and diffraction types. Using lenses eliminates many of the technical and technological problems associated with the development of multi-element phased arrays. It is shown that lens systems allow using traditional methods of transformation of acoustic fields into the visible images by 2D piezo matrix and a more promising way of acoustooptical transformation based on coherent optical interferometry.

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Section: Wettabilitymentioning

confidence: 99%

Ultrasound Imaging in Nuclear Reactors Cooled by Liquid Metals

Svet¹,

Dement'ev²

2015

OJA

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“…Over the past 30 years, a number of countries including Japan, India, Lithuania/Belgium, France, and Germany have pursued the development of ultrasonic ranging and/or imaging systems for liquid-metal cooled fast reactors (Taguchi et al 1980;Hans et al 1984;McKnight et al 1984;McKnight 1988;Swaminathan et al 1990;Wessels 1991;Lennox et al 1993;Rajendran et al 1996;Karasawa et al 2000;Joo and Lee 2005;Kazys et al 2005;Kazys et al 2006;Kazys et al 2007;Mazeika et al 2007). An initial assessment of these activities is given in a paper by Bond et al (2007b) and a more extensive review is provided below.…”

Section: Summary Of International Research and Development Activitiesmentioning

confidence: 99%

“…Because this reactor was never fueled, there are no data on radiation effects. (Hans et al 1984) 4.4 Japan (Takeishi et al 1997;Karasawa et al 2000 Use of a two-dimensional array affords the opportunity to implement synthetic aperture focusing techniques (SAFT) for raster scanning with a minimal spot size due to the increased effective aperture. This imaging system has been commercialized by Toshiba (Matrixeye™) for use in airframe NDE of carbon fiber reinforced plastics.…”

Section: Summary Of International Research and Development Activitiesmentioning

confidence: 99%

“…In the 1-5 MHz frequency range, transducer excitation is straightforward and may be achieved with commercial equipment (Swaminathan et al 1990;Lennox et al 1993;Karasawa et al 2000). The transducer behaves as an undamped mechanical resonator.…”

Section: A Transducer Excitationmentioning

confidence: 99%

“…Digitization permits signal averaging, feature extraction, frequency analysis, and implementation of signal-correlation techniques to better reject noise. Karasawa et al (2000) achieved signal-to-noise improvement of 20 dB by cross-correlating the detected ultrasound signal with a pure sine wave at the resonant frequency of the transducer (5 MHz).…”

Section: Signal Detection and Processingmentioning

confidence: 99%

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Under-Sodium Viewing: A Review of Ultrasonic Imaging Technology for Liquid Metal Fast Reactors

Griffin¹,

Posakony²,

Chien³

et al. 2009

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Executive SummaryThis current report is a summary of information obtained in the "Information Capture" task of the U.S. DOE-funded "Under Sodium Viewing (USV) Project." The goal of the multi-year USV project is to design, build, and demonstrate a state-of-the-art prototype ultrasonic viewing system tailored for periodic reactor core in-service monitoring and maintenance inspections. The study seeks to optimize system parameters, improve performance, and re-establish this key technology area which will be required to support any new U.S. liquid-metal cooled fast reactors.The earliest information presented herein dates from the early 1970s when the DOE Hanford Site and Argonne National Laboratory were supporting instrumentation development for sodium-cooled fast reactors (SFRs). The most recent U.S. advanced liquid metal reactor (ALMR) design was the Power Reactor Innovative Small Module (PRISM). The U.S.-sponsored design effort was discontinued in 1995; however, General Electric (GE) continued development up to year 2000. A number of other countries (especially India, Japan, France, and Great Britain) have built and operated fast, metal-cooled reactors and supporting diagnostic instrumentation for in-service inspections. Piezoelectric transducers have been reported in systems used to: (i) acquire in-core images; (ii) perform ultrasonic NDE inspections; and (iii) measure liquid sodium levels, detect structural anomalies, and detect leaks.This study has served to identify important design parameters and options for an ultrasonic USV system. These include:1. The preferred piezoelectric material for liquid sodium temperatures up to 260°C is lead zirconate titanate (PZT). Higher Curie temperature (T c ) materials such as lithium niobate and lead metaniobate have also been used.2. Most demonstrated USV ultrasonic transducers are of the direct sodium immersion type. Only a few designs use an ultrasonic waveguide to isolate the transducer from the molten sodium.3. Poor sodium wetting of the transducer face has been an issue. Degraded wetting results in inefficient mechanical (acoustic) coupling between the transducer and the liquid sodium working fluid. Solutions have required either coating the transducer face (e.g., with evaporated or sputtered gold) or bonding a metal diaphragm to the transducer face (e.g., stainless steel or nickel).4. Thermal shock damage to the piezoelectric transducer is an important issue. Fracture of piezoelectric ceramics due to high thermal gradients/transients or thermal expansion mismatches at the transducer face or backing layer must be considered early in the design process.5. Cable length between the transducer and ultrasonic transceiver has a major impact on received signal amplitude. The minute electrical charges generated by the piezoelectric transducer dictate use of lowcapacitance, radiation-resistant, high-temperature cables, and cable length must be kept as short as possible. Impedance matching and signal conditioning must be considered.6. To date, most ultrasonic USV systems have ...

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Design, Life-Time and Residual Life

Hoffelner¹

2012

Materials for Nuclear Plants

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Development of Under-sodium Three-dimensional Visual Inspection Technique Using Matrix-arrayed Ultrasonic Transducer

Cited by 50 publications

References 1 publication

Ultrasound Imaging in Nuclear Reactors Cooled by Liquid Metals

Ultrasound Imaging in Nuclear Reactors Cooled by Liquid Metals

Under-Sodium Viewing: A Review of Ultrasonic Imaging Technology for Liquid Metal Fast Reactors

Design, Life-Time and Residual Life

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