| 摘要 |
PURPOSE:To increase durability through the reduction of a deformation value of bellows inside a drive feature by aligning plural ultrasonic transducers in a scan direction and thus constituting an examination head. CONSTITUTION:An ultrasonic wave from ultrasonic transducers 9a, 9b is reflected by a reflection plate 10 passing through a clearance between a reactor core 3 and a reactor top feature 4. An examination head 6 is turned by means of a drive feature 7, scanning a space between the reactor core 3 and the reactor feature 4 to a floating of a fuel aggregate 11. The examination head 6 is equipped with two pieces of transducer 9a, 9b, so that the scan angle is only half that required when a single transducer is used. In addition, a transmission range can be narrowed. Consequently, the change value of the bellows 8 is low, thus increasing its durability and also enhancing examination accuracy. |
