Alpha Camera has been developed to check the alpha contamination of solid wastes generated during decommissioning of Fukushima Daiichi Nuclear Power Station (1F). A lot of measurements are needed to reveal the alpha contamination distributions due to the narrow field of view of the Alpha Camera. Therefore, in this paper, we propose a novel approach which reconstructs the divided measurement data in a three-dimensional space to identify the contaminated area easily. In primitive demonstration using new recon...
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Development of 3D reconstruction for remote alpha contamination measurement

Multifunction laser welding head has been developed. The head is able to perform not only underwater laser welding as repair, but also laser peening as preventi ve maintenance and laser ultrasonic testing as inspection. Laser transmission test with multifunction laser welding head and optical fiber was carried out. The result showed that laser power needed for welding was transmitted without any damage to them. Under water laser welding onto EDM slits with this welding head w as carried out. EDM slits were...
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Development of Multifunction Laser Welding Head (1) - Evaluation of Under Water Laser Welding with Multifunction Laser Welding Head -

Multifunction laser welding head has been developed. The head is able to perform not only underwater laser welding as repair, but also laser peening as preventive maintenance and laser ultrasonic testing as inspection. By using the effect of color aberration with optics, laser beam was focused to the ideal spot size on each process. Laser p eening was performed on the material surface with the developed head, and stress improvement ability was confirmed....
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Development of Multifunction Laser Welding Head (2) - Stress Improvement by Laser Peening Technology -

Multifunction laser welding head has been developed. The head is able to perform not only underwater laser welding as repair, but also laser peening as preventive maintenance and laser ultrasonic test ing as inspection. For inspection with multifunction laser welding head, a new method of visualized weld defects in water by laser-ultrasonics has developed. To detect and visualize a surface of weld metal with welding bead, the authors have developed a new detection method by leaky wave induced by interactio...
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Development of Multifunction Laser Welding Head (3) - Surface Inspection Technique by Laser-ultrasonics -

Inspection technique for complex surface profiles has been required in order to ensure the reliable operation and high operating rate of nuclear power plants, because many parts due to inspection have complex geometry. We have developed Pha sed Array (PA) ultrasonic testing with immersion technique which suitable to complex geometry. In this paper, we developed precise inspection technique for curvature surface profile such as a nozzle of pressure vessel. For curved surface pro file, Synthesis Aperture Foc...
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Development of Phased Array Inspection Technique for Nozzle Pipes with Curved Surface

Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surfac...
英字タイトル:
Verification and Application of Beam Steering Phased Array UT Technique for Complex Structures