In recent years, the inspection of pipes is being carried out by using inspection techniques which employ ultrasonic and eddy current testing, endoscope (CCD cameras or optical fiber). Currently, the inspection devices can be performed only a visual check of the pipes. In case of a damage, they cannot be repaired. In such case, the damaged portion has to be excluded or the pipe has to be replaced. The authors develop a laser processing head comprising an optical fiberscope. It is capable of inspection...
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Development of a laser processing head for the inspection and repair of damages inside of a half-inch pipe

A prototype of maintenance machine for heat exchanger tubes was developed. It was based on the bench top size device which had been specially designed to have dual functions for fiber inspection and laser cladding in JAEA. A laser processing head was improved mechanically in 2 motions of axial translation and circumferential rotation to insert the heat exchanger tubes. ...
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Development of Maintenance Machine for Heat Exchanger Tubes by Laser Technology

New maintenance technique was proposed using a hand-held laser torch for aging chemical plants and power plants. The hand-held laser torch was specially designed to be able to access limited tubular space in various cases. A composite-type optical fiberscope was composed of a center fiber for beam delivery and surrounded fibers for visible image delivery. Laser irradiation on a work pieces with the best accuracy of filler wire was carried out. And, we found that the optimized wire-feed speed was 2 mm/...
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A Study of Cladding Technology on Tube Wall Surface by a Hand-held Laser Torch

Laser thermal processing was applied to robotic systems. For the narrow limited space like a 1-inch diameter tube, a compact laser processing head successfully observed the heat exchanger tube inner wall and welded a crack gap. A compact air cooled fiber laser was able to heat an inner wall through a delivery optical fiber. A filler wire feeder for laser cladding was also tested. A compact maintenance robot for petrochemical industrial plants was demonstrated....
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Development and Deployment of Maintenance Robot with Laser Thermal Processing

A hybrid optical fiber scope and a laser processing head were combined with an eddy current testing un it for the inspection and repairing for Fast Breeder Reactor's heat exchanger pipes. The project propo ses an effective cost reduction method for maintenance of FBR by extension of the heat exchanger's lif etime. By the end of March 2010, a prototype probing system for heat exchanger pipes will be completed....
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Development of Inspection and Repairing Technology for FBR Heat Exchanger Pipes

In order to maintain FBR heat exchanger tubes, a new probe system was designed. A coupling u nit and operational software are key components in the second year. The coupling unit to com bine a high energy laser beam and optical fiberscope images was developed. The operational s oftware successfully controlled an eddy current testing device and a laser processing head....
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Development of Inspection and Repairing Technology for FBR Heat Exchanger tubes (II)Preparation of Operation Software and Performance Check

We are developing the laser welding and cladding device for the maintenance of heat exchanger pipes. In the We are developing the laser welding and cladding device for the maintenance of heat exchan ger pipes. In the case of flow accelerated corrosion where pipe wall thinning occurred after a long time operation, laser cladding is mostly expected. A laser processing head was proposed in order t o access the pipe wall. A composite-type optical fiber scope was used for real time observation and laser process...
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Development of Laser Cladding Technology for Maintenance ofPipe Wall Thinning

For tank, the evaluation method for influence about top board by fluid sloshing is not defined well. We carried out shaking test about cylindrical tank to investigate behavior of inner fluid . And we conducted simulation analyses about the shaking test, too. In this paper, results of the shaking test and simulation analyses, and evaluation for comparison of those are described....
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Evaluation of Cylindrical Tank Sloshing

After 2002, Stress Corrosion Cracking (SCC) came to be detected in the low carbon stainless steel PLR Piping of BWR plants. However, it worked on the improvement of ultrasonic examination technology for PLR Piping in Japan BWR Owners Group (JBOG) , because the mistake of the evaluation was caused as a rare case. In this study, it introduces the improvement of ultrasonic testing technology and evaluation....
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Know-How for the Ultrasonic Examination Practice & Evaluation of PLR Piping

To ensure integrity of structures and components in nuclear power plants, the demand has been increased for establishing nondestructive method for detection of pre-existing plastic strain. In this study, potentiostatic etch ing method is applied to detect and quantitatively measure plastic strain imposed to austenitic stainless steels by tensile straining. After potentiostatic etching (1N HNO3, -600mVsce, 20min), twin lines and slip lines appe ar as etched lines on the surface of specimen because of the pr...
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Inspection of Temperature / Steel Composition Dependency of Plastic Deformation Mechanismin Austenitic Stainless Steel by potentiostatic etching Detection Method.