Phased array ultrasonic testing (PAUT) has performed an important role for plant maintenances. However, many parts of cast austenitic stainless steels are difficult to be inspected by UT owing to their noises from large grains. We have been noticing that depending on the PAUT conditions, (e.g. incident angles and focal depths), the tendency of echoes from defects are different from that of grain noises. Thus we have developed new PAUT system which can analyze the tendency of echoes from comprehensive PA...
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Sizing Accuracy Improvement of Defects in Cast Austenitic Stainless Steel Using Post Processing Phased Array UT

We verified that the eddy current testing (ECT) has the enough detectability for defects on the heat affected zone (HAZ) in welding of in-core monitor (ICM) housing inner surfaces for a special inspection involved in long-term operation. It is presumed that a detectability of ECT is decreased because a HAZ of ICM housing inner surfaces is deformed by welding. We conducted full-scale defect detection tests using the simulated ICM housing specimen with the welded part, the rotational ECT probe and the probe m...
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Verification of Eddy Current Testing for In-Core Monitor Housing

Underwater inspection vehicles for nuclear power plants were selected as the third maintenance heritage. Hitachi- GE Nuclear Energy, Ltd and Toshiba Energy Systems & Solutions Corporation have been working on miniaturization and weight reduction of vehicles for many years, and enabling visual inspection of narrow space and bottom of the nuclear reactors, which were not accessible with the conventional hanging cameras. This article describes the developed vehicles by each company and their contribution to ma...
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The Third Maintenance Heritage Underwater Inspection Vehicles for Nuclear Power Plants

It is necessary to confirm whether the feed water nozzle inside corner has crack by eddy current testing, to enable long-term operation of a plant. Therefore, we performed eddy current testing using various types of specimen to collect basic data (probability and length measurement accuracy) of the eddy current testing methods, complying with JEAG4217. As a result, eddy current testing was effective for the inspection of feed water nozzle inside corner. ...
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Eddy current testing technique for feed water nozzle inside corner of nuclear reactor pressure vessel

山本 智 Satoshi YAMAMOTO Non-Member (Times New Roman 10pt) should be about 150 words. Recently, an application target of the phased array ultrasonic testing (PAUT) has been extended. For the inspection of CASS, low frequency (less than 1 MHz) array probe is required. Low frequency array probe are usually constructed by large pitch element. In the case of linear scanning, the low frequency array probe could not obtain enough number of sound beams which construct a precise B-Scope image owing to non-dense arra...
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Accuracy improvement of the linear scanning phased array UT with a large element array probe

Recently, an application target of the phased array ultrasonic testing (PAUT) has been extended. However, it was known that PAUT was difficult to apply to components with complex and high damping materials such as cast austenitic stainless steel (CASS). The Authors have developed shape adaptive beam forming PAUT system for complicated shape parts and comprehensive PAUT conditions analysis system for CASS. Each PAUT systems based on full matrix capture (FMC) technique. In order to enhance an applicability of...
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UT application examination for complicated shape part of cast austenitic stainless steel