Lubricant management is very important to maintain the integrity of rotating equipment. Lubricant is periodically replaced and monitored on its aging degr adation between replacement times. On the other hand, only the confirmation of specification document has been performed as acceptance inspection in case of new lubricant. However, a comparatively large amount of impurity substances has been found in new lubricant by sample analysis. Therefore, the introduc tion of contamination control of new lubricant ...
英字タイトル:
Application of Contamination Control of Lubricant to Proactive Maintenance

In nuclear power plants, surface treatment including the shot peening is carried out after welding for the prevention of stress corrosion cracking. In this research, the authors developed evaluation systems of the persistence of compressive residual stresses due to shot peening based on the Idealized Explicit FEM which can conduct large-scale non-linear structure analyses in realistic computing time. The developed evaluation system was applied to the analysis of the compressive residual stress due to sho...
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Study of behaver to relieve residual stress at the time of the shot peening

An in-vessel repairing machine for Fast Breeder Reactor (FBR) needs to work under liquid sodium environment. W e have been worked the development of a repairing machine based on Friction Stir Welding (FSW) method. The expe riment of repairing artificial crack in liquid sodium was successful by prototype FSW-repairing machine. In th is report, we also introduce our studies on the particular problems of FSW-repairing such as burr and end hole....
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Development of a repairing machine based on Friction Stir Welding (FSW) for the sodium coolant Fast Breeder Reactor

A concept of a plutonium burner HTGR (High Temperature Gas-cooled Reactor) with a high nuclear proliferation resistance has been proposed by Japan Atomic Energy Agency. In addition to the high nuclear proliferation resistance, in order to attain the high burn-up, we propose to introduce a PuO2-YSZ (Yttria Stabilized Zirconia) fuel kernel with ZrC coating to the plutonium burner HTGR. In this study, we conduct design of the coated fuel particle and of the reactor core to confirm the feasibility of the plut...
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Design Study on Fuel and Reactor Core for Plutonium Burner High Temperature Gas-cooled Reactor

This paper describes the result of demonstration test using WesDyne International's inspection system in terms of its sizing capability of crack from the inner diameter (ID) of PWR RV head penetrations, detectability of the crack e mbedded under repair welding, which was applied for isolation from the primary water environment, and the propagation of ultrasonic wave from the ID penetration to the inside of J-weld. The result of the laboratory tests have demon strated the sizing capabilities of both ultraso...
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Sizing Capabilities of Crack for the Inspection of PWR RV Head Penetrations

The aim of this study is to research and evaluate new technologies i n the world from the point of view to improve the safety and securi ty of pipeline for gas distribution toward the next generation which can practice the productive maintenance and preventive maintenance....
英字タイトル:
Research and Evaluation of New Technologies to Improve the Maintenance of Pipeline for GasDistribution toward the Next Generation

The aim of this study is to research and evaluate new technologies in the world from the point of view to improve the safety and security of pipeline for gas distribution toward the next generation which can practice the productive maintenance and prevent ive maintenance. ...
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Research and Evaluation of New Technologies to Improve the Maintenance of Pipeline for GasDistribution toward the Next Generation

To validate the FEM simulation technique presented in the previous report, we made pipe butt welded joints between base metals of the same material SUS316L and between base metals of the dissimilar materials SUS316L and STPT370. Shot peening (SP) on the outer surface or the inner surface of these welded joints induces high compressive residual stresses on the surface. After heat treatment with the peak temperature of 623 K was applied to the welded joints, they retained high compressive residual stresses ...
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Evaluation of the sustainability of compressive residual stress by introduced a stress improvement method (the second report) ?Residual stress change of welded joint with shot peening by thermal cycle and stress loading.

When the steel structure is built such as nuclear power plant, residual stress occurs in or near the welding joint and it may cause the stress collision cracking(SCC). Therefore, as prediction of SCC, surface treatment such as the shot peening(following SP) is carried out in the weld, but the case analyzed about residual stress reforming by the SP does not exist. So, we developed the analysis method that can predict compressive residual stress relaxation behavior during shot peening by modelling dynami...
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Evaluation of the sustainability of compressive residual stress by introduced a stress improvement method (the first report) -Development of analysis method of the shot peening using idealized explicit FEM

Abstract: Laser peening (LP) is a process to introduce residual compressive stress on metal surface by irradiating laser pulses underwater without any surface preparations. Toshiba has developed and applied LP system to preventive maintenance against stress corrosion cracking (SCC) in nuclear power reactors since 1999. The system is composed of laser oscillators, a beam delivery system, a laser irradiation head, remote handling equipment and a monitor/control system. In the early applications, a rigidly l...
英字タイトル:
Next Generation LP System for Maintenance in Nuclear Power Reactors