In Japan, the preventive maintenance task of the 600 series nickel basis alloy weld of the reactor vessel (RV) and the steam generator (S/G) safe end weld are pushed forward sequentially, and a defect sizing using the ultrasonic testing (UT) from the inside of the safe end is carried out when the defect was dete cted by surface inspection prior to the work. Some defects are recognized on the S/G safe end and the R/V safe end in Japan, and these defects have occurred in the axial direction of the safe end w...
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Development of Advanced Defect Sizing Technique Using Ultrasonic Testing for Nozzle Welding

1.緒言 現在,原子炉補機冷却水系統などの一次系関連系統設備における各種熱交換器(以下,補機と称す)では,チューブに対しボビンプローブを用いた ECT[1]が実施されている。検査手法をさらに高度化(例として,ボビンプローブでは原理的に困難である周方向欠陥の検出性向上)しつつ, 必要十分の機能を実装することを目的として,熱交換器向けにパンケーキコイルを用いて独自に工夫したコイル 配置にすることで、比較的低コストで良好な検出性を持つアレイECTプローブを開発した。 本論文では,アレイECTプローブの基幹技術で......
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Development of high performance array ECT technique by using pancake coils

Intelligent ECT system for 7/8 inch tubes has been qualified as official method for inspection of Steam Generator tubes in Japan since 2003. We have developed Intelligent ECT system for 3/4 inch outer diameter tubes, which is applicable for full length inspection of all tubes in Steam Generator. We have carried out the verification test on passage, scanning speed, detectability of various defects, performance of auto screening, effectiveness of filtering, and accuracy of depth sizing of wears. Totally...
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Development of Intelligent ECT System for 3/4 inch SG Tubes

In order to solve the problems of the thickness measurement, we have developed a thin-film UT sensor having excellent high-temperature durability and conformability in thin film form. In this paper, it was confirmed that the accuracy of thickness measurement for both complex geometries and plates at high-temperature was equivalent to the accuracy of conventional thickness measurement methods. It was also confirmed that the durability at high temperature and for temperature change in the actual equipmen...
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technology using high-temperature thin-film UT sensor

Eddy Current testing (ECT) for detecting stress corrosion cracks (SCCs) in the vessel's dissimilar metal weld of PWR plants was carried out. Appropriate ECT with a single cross-coil can detect shallow artificial SCCs with depth of 0.5mm or over. And magnetic saturation method is very effective for decreasing noise signals come from permeability change in the boundary region between overlay and buttering of safe-end....
英字タイトル:
Development of Eddy Current Testing Method for PWR Vessel’s Dissimilar Metal Weld