Abstract
It is necessary to point out leakage positions in a nuclear reactor containment toward a decommission of the Fukusima Dai-chi Nuclear Power Plant's severe accident. To detect those leakage, two sectorial array sensors are applied for ultrasonic velocity profiler (UVP) method. Two UVP profiles from different positions and angles can produce two-dimensional flow vector map. An experiment with an outlet (and an inlet) was executed to confirm the 2-D flow vector mapping method. As a result, the outlet position was obtained using this method and it agreed with the real outlet position. Applicability of this method was confirmed.
