Stainless steel is used in various nuclear installations as a major structural material. Tritium is produced by several nuclear reactions in these facilities. It is considered that the hydrogen isotope included tritium permeated for stainless steel through the interaction such as dissolution, diffusion and recombination, and is released on the atmosphere. Therefore, it is important to clarify permeation behavior of tritium in stainless steel from the viewpoint for improvement of the social acceptability o...
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Study on permeation behavior of hydrogen isotope in stainless steel

Tritium from the nuclear power plants should be monitored at real-time. The development of real-time atmospheric tritium monitor is an important issue, since it was reported that tritium from the nuclear power plants was released as the form of HT and HTO, and released tritium was adsorbed plants and transported to numan through photosynthesis and food chain processes. This study was carried out to develop the separation-condensation technique for tritium using polyimide hollow fiber module. At first, ion ...
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Research and development of real-time atmospheric tritium monitor by polyimide hollow fiber

In the remote field eddy current testing, we proposed the method of enhancing the magnetic flux density in the vicinity of an exciter coil by controlling the ma gnetic flux direction for increasing the sensitivity of detecting outer defects on a tube and used the flux guide made of a magnetic material for the method. T he optimum structural shape of the flux guide was designed by the magnetic field analysis. On the experiment with the application of the flux guide, the magneti c flux density increased by 5...
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Sensitive Technique for Detecting Outer Defect on Tube with Remote Field Eddy Current Testing

We confirmed the defect detection performance of the eddy current testing (ECT) system in order to inspect the bottom-mounted instrumentation (BMI) nozzle in reactor pressure vessel. We developed the small size cross coil type ECT sensor that has the magnetic cores near the coils and the sensor scanning equipment based on the portable laser peening system. According to the experimental results that measured the sensitivity for the defects on the concave specimen and the relationship between the senso...
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Development of Eddy Current Testing System for Bottom-Mounted Instrumentation Nozzle in Reactor Pressure Vessel

We confirmed the defect detection performance of the eddy current testing (ECT) system in order to inspect the bottom-Mounted instrumentation (BMI) nozzle in reactor pressure vessel. We developed the small size cross coil type ECT sensor that has the magnetic cores near the coils and the sensor driving unit based on the portable laser peening system. According to the experimental result that measured the relationship between the sensor inclined angle and defect detecting sensitivity on the convex surfa...
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Development of Eddy Current Testing System for Bottom-Mounted Instrumentation Nozzle in Reactor Pressure Vessel

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