Development of Eddy Current Testing System for Bottom-Mounted Instrumentation Nozzle in Reactor Pressure Vessel
芝 小林 小林 徳康 Noriyasu KOBAYASHI 芝 上野 上野 聡一 Souichi UENO 芝 千田 千田 格 Itaru CHIDA 芝 落合 落合 誠 Makoto OCHIAI 芝 藤田 藤田 友基 Tomoki FUJITA 芝 市川 市川 博也 Hiroya ICHIKAWA
Bottom-mounted instrumentationBWREddy current testingPWRStress corrosion cracking
We confirmed the defect detection performance of the eddy current testing (ECT) system in order to inspect the bottom-Mounted instrumentation (BMI) nozzle in reactor pressure vessel. We developed the small size cross coil type ECT sensor that has the magnetic cores near the coils and the sensor driving unit based on the portable laser peening system. According to the experimental result that measured the relationship between the sensor inclined angle and defect detecting sensitivity on the convex surface specimen, the decrease of sensitivity depend on the sensor inclined angle reduced. From the artificial stress corrosion cracking (SCC) detection test using the developed ECT system, we confirmed that the ECT system has the potential for detecting the defect on the little space. These experimental results indicated that there is the possibility that we can inspect the BMI nozzle using the ECT system.