DEVELOPMENT OF UNDER SODIUM INSPECTION TECHNIQUES FOR FBR(2)

摘要

A reactor vessel of Fast Breeder Reactor (FBR) is filled with opaque liquid sodium. Ultrasonic inspection techniques are effective and useful to observe in-vessel structures under sodium during shut-down condition Under sodium viewing technique and under sodium volumetric inspection technique are applied to develop inspection equipment for the Demonstration Fast Breeder Reactor ( DFBR ) in Japan. In the development of Under Sodium Viewer (USV) the Synthetic Aperture Focusing Technique (SAFT) and the cross correlation processing have been applied to the ultrasonic 3 dimensional image processing with high resolution. And a 15 15 matrix arrayed transducer was manufactured and tested. The matrix arrayed transducer can realize a clear 3-dimensional ultrasonic image because ultrasonic beams are scanned electronically at high speed without mechanical scanning. Within this fiscal year a full-scale 30 30 matrix arrayed transducer will be manufactured and tested under sodium. In the development of Under Sodium Volumetric inspection a prototype linear arrayed UT sensor for under sodium use had been manufactured. In DFBR under sodium UT inspection is planned to inspect a core support flange whose thickness is 180 mm thickness. The prototype processing device for undersodium use was manufactured. It can realize a real-time Bscope image of defects within the in-vessel structures. A in-water test is being carried out in order to evaluate volumetric performance of this method.