Stress Corrosion Cracking (SCC) on reactor internal components has become one of the most important issues in recent years, and demand for the inspection of reactor internals is increasing. Especially, SCC has detected in shroud support recently so inspection technology for s hroud support has to be developed as soon as possible. We have developed delivery system for shroud support in BWR plant which is availabl e for Visual Testing and Ultrasonic Testing. The specification and positioning capability of th...
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Development of Delivery System for Shroud Support in BWR Plant

The improvement of defect detection and sizing capabilities for nondestructive inspection technique has been required in order to ensure the reliable operation and life extension of nuclear power plant . Immersion phased array UT technique which is not affected the surface geometry of welds has been developed for inspection of BWR internals such as shroud, shroud support, and so on. Furthermore, thin -type array probe was developed and was examined in UT of core spray piping welds in the narrow region betw...
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Application of Phased Array UT on BWR Reactor Internals Piping

The improvement of defect detection and sizing capabilities for nondestructive inspection technique has been required in order to ensure the reliable operation an d life extension of nuclear power plant. Phased array UT technique has superior capabilities for beam steering and focusing to objective regions, and real time B- scan imaging without mechanical scanning. Water gap phased array UT is capable to apply to inspection of welds of BWR internals such as shroud, shroud support, an d so on. Outline of TO...
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Application of Phased Array UT in BWR Internals

Abstract We clarified a defect detecting capability of eddy current testing (ECT) as a surface inspection technique for underwater laser beam welding. An underwater laser beam welding procedure includes groove caving as a preparation, laser beam welding in groove and welding surface grinding as a post treatment. Therefore groove and grinded welding surface inspections are required underwater. We curried out defect detection test s using three kinds of specimens simulated a groove, reactor vessel nozzle dis...
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Applicability Evaluation of Eddy Current Testing for Underwater Laser Beam Welding

Abstract This paper describes development and application of remotely operated vehicles (ROVs) for reactor internals. Stress Corrosion Cracking (SCC) on reactor internal comp onents has become one of the most important issues in recent years, and demand for the inspection of reactor internals is increasing. Toshiba has developed and applied sever al kinds of ROVs, which can inspect and maintain the welds in a narrow space underwater. Particularly, Toshiba succeeded in the development of UT Vehicle, which c...
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Development and Application of In-Vessel Inspection Equipments

The main roles of in-vessel visual inspection (IVVI) are to detect cracks on the surface of internal structures and measure the length of the cracks. For accurately performing those matters by visual inspection, inspectors sometimes need to obtain three-dimensional (3D) measurements of cracks and 3D shape of the surface. We have been developing a prototype system to obtain 3D measurements. This system is based on stereo vision technique and has on ly one measurement head that has an inner movable camera m...
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Three-Dimensional Measurement System for In-Vessel Visual Inspection

The main roles of in-vessel visual inspection (IVVI) are to observe internal structures and crack on the structure surface. For accurately checking those matter s by visual inspection, inspectors sometimes need three-dimensional (3D) recognitions. Therefore, we developed a prototype system that has only one inspection h ead to obtain 3D measurements. This system is based on our 3DVT (3 Dimensional Visual Testing) technique that we have been developing. This report proposes that prototype measurement head a...
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Three-Dimensional Measurement System for In-Vessel Visual Inspection

This paper describes development of the remotely operated device for vacuum cleaning and visual inspection in boiling water reactors to enhance the availability of operating nuclear power plants. Fuel damage can occur if loose debris inside t he reactor vessel flows through the fuel and it can become a serious issue affecting plant reliability and radiation levels, therefore, removing the small debris on the bottom head is significant activities in nuclear power plants. While it i s difficult to remove sma...
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Development of Vacuum Cleaning and Visual Inspection Device in BWR

In-Vessel Visual Inspection (IVVI) is usually conducted as indirect visual inspection with remote TV cameras. We often face the following issues in IVVI. When IVVI is conducted at narrow spa ce in the vessel, it is difficult for inspectors to set the cameras to the best position remotely and manually. When the cameras are quickly moved to reduce hours of IVVI, the visibility be comes poor because of motion blurs. For overcoming these problems, we focused on “Super Resolution (SR)” that is one of image proc...
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In-Vessel Visual Inspection System using Super Resolution Technique

A newly developed in-vessel visual inspection (IVVI) device designed to improve the quality of visual inspection in Boiling Water R eactors (BWRs) while providing significant critical path savings during refueling outages. And Super Resolution Visual Testing (VT) system enhances the inspection image resolution. The system assists the examiners under the condition of relatively faster scanning speed and longer work distance. The effectiveness of the time saving was qualified by the resolution testing with V...
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Maintenance and Inspection Technologies for Shorter Outage