The capability of eddy current testing (ECT) for the bottom mounted instrumentation (BMI) weld area of reactor vessel in a pressurized water reactor was demonstrated by the developed ECT system and procedure. | Eddy current testing system for bottom mounted instrumentation welds EPJ Nuclear Sci. Technol. 1 4 2015 Nuclear Sciences N. Kobayashi et al. published by EDP Sciences 2015 amp Technologies DOI epjn e2015-50043-1 Available online at http REGULAR ARTICLE Eddy current testing system for bottom mounted instrumentation welds Noriyasu Kobayashi1 Souichi Ueno1 Naotaka Suganuma1 Tatsuya Oodake2 Takeshi Maehara3 Takashi Kasuya3 and Hiroya Ichikawa4 1 Power and Industrial Systems Research and Development Center Toshiba Corporation 8 Shinsugita-cho Isogo-ku Yokohama 235-8523 Japan 2 Power and Industrial Systems Research and Development Center Toshiba Corporation 1 Komukaitoshiba-cho Saiwai-ku Kawasaki 212-8581 Japan 3 Keihin Product Operations Toshiba Corporation 2-4 Suehiro-cho Tsurumi-ku Yokohama 230-0045 Japan 4 Isogo Nuclear Engineering Center Toshiba Corporation 8 Shinsugita-cho Isogo-ku Yokohama 235-8523 Japan Received 19 June 2015 Received in final form 18 August 2015 Accepted 27 August 2015 Published online 05 December 2015 Abstract. The capability of eddy current testing ECT for the bottom mounted instrumentation BMI weld area of reactor vessel in a pressurized water reactor was demonstrated by the developed ECT system and procedure. It is difficult to position and move the probe on the BMI weld area because the area has complexly curved surfaces. The space coordinates and the normal vectors at the scanning points were calculated as the scanning trajectory of probe based on the measured results of surface shape on the BMI mock-up. The multi-axis robot was used to move the probe on the mock-up. Each motion-axis position of the robot corresponding to each scanning point was calculated by the inverse kinematic algorithm. In the mock-up test the probe was properly contacted with most of the weld surfaces. The artificial stress corrosion cracking of approximately 6 mm in length and the electrical-discharge machining slit of mm in length 1 mm in .
