Abstract. A NDT method using electromagnetic waves has strong possibility for crack dete ction in large structure such as large pipes. In this study, electromagnetic wave with a TM0,-mode is used for detecting a circumferential crack and also time of flight (TOF) of the electromagnetic wave in several pipes is evaluated to determine the crack location....
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Evaluation of Crack Location in Straight Pipe by Using Microwave

Authors previously reported that magnetic data obtained by using Eddy current method and AC magnetization method showed correlation with the increase of susceptibility of the irradiation assisted stress corrosion cracking (IASCC) on neutron irradiated austenitic stainless alloy specimens. To discuss the mechanism of the correlation, microstructure observation was conducted on the irradiated specimen, and this result, magnetic the permalloy radiation induced phase (FeNimagnetic 3) formation phase form...
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Study on Magnetic Property Change on Neutron Irradiated Austenitic Stainless Steel

For the commercialization of fast breeder reactors (FBR), it is essential to enhance the economic competitiveness by reduction of total cost by elongation of plant service period. In this point of view, it is important to establish the assessment method of integrity of aged weld joint and repair welding for the components of future long life FBR. In the present study, evolution of microstructure is evaluated for the 304SS-304SS weld joint which was used for 88,000h at 526-545°C in the French proto-typ...
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Influence of FBR plant service and repair welding on microstructure and residual stress of austenitic stainless steel weld joint

The reasons of accidents are reported frequently that “I was too busy to avoid an error“ or “I had no time to make a check“. Though there is a view on that personnel reduction and increase in quantity of occupations heighten the feeling of busyness of workers, there are few previous studies on the factors that affect the feeling of busyness. Then, the questionnaire about the feeling of busyness is developed. In this study, in order to make clear the background factors influencing the feeling of busyness, ...
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A Study of the Background Factors Influencing the Feeling of Busyness of Plant Workers

For the commercialization of fast breeder reactors (FBR), it is essential to enhance the economic competitiveness by reduction of total cost by elongation of plant service period. For this reason, it is needed to establish the aged weld joint integrity assessment method for future FBR compon ents. Additionally, since it is expected to employ the repair weld for aged structural components, it is essential to investigate the effect of repair weld. To investigate the influence of high temperature-long service...
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Basic investigation of aging weld joint and repair weld joint integrity assessmentusing neutron residual stress measurement method

We proposed a novel sodium leak detection technique based on laser spectroscopy to improve the reliability of sodium le ak monitoring. In this technique, sodium atoms are excited into a first excitation level by atmospheric plasma before l aser spectroscopy. The detection limit concentration was preliminarily evaluated to be comparative to the sodium aeros ol detector. We confirmed that the maximum of 3p level population can be achieved at a proper plasma burning condition....
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Development of a Sodium Leak Detector based on Atomic Spectroscopy using a Laser Diode

In this study, a new simulation method is developed for optimization of maintenance strategy in NPP as a multiple-objective optimization problem (MOP). The result of operation is evaluated as the average of the following three measures in 3 000trials: Cost of Electricity (COE) as economic risk, Frequency of unplanned shutdown as plant reliability, and Unavailability of Regular Service System (RSS) and Engineering Safety Features (ESF) as safety measures. The following maintena nce parameters are considered...
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Development of an evaluation method for optimization of maintenance strategy in commercial plant

1．はじめに近年、沸騰水型原子力発電所（以下BWRという） の原子炉再循環系（以下PLRという）配管溶接部で応力腐食割れ（Stress Corrosion Cracking、以下SCCという）が多数確認された。これらの配管の材質は、低炭素ステンレス鋼（SUS316（LC）材）であり、材料を低炭素化することにより、鋭敏化による応力腐食割れは生じないと考えられていたが、その後の実機材料調査結果や実験等により、表面が硬化すると粒内型応力腐食割れ感受性が上昇し、BWR 炉水模擬環境中にてき裂進展試験を行うと、粒界......

An evaluation method of the occurrence probability of a through-wall crack in a reactor vessel of a fast breeder reactor due to fatigue-creep interaction has been proposed. Input data were p repared for a trial evaluation and the proposed evaluation method was applied. The result was c ompared with the allowable occurrence probability derived from the safety requirements for FBR....
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Development of a Reliability Evaluation Method for Fatigue-Creep Interaction Failure of an FBR Reactor Vessel 髙屋 茂 Shigeru TAKAYA

A circular electromagnetic TE11-mode is used for detection of longitudinal crack in a stainless steel pipe. To show the capability of microwave nondestructive t esting for detection of crack in large and complex piping systems such as steam generator (SG) tube, inspected pipe including U-bend are examined in this study....
英字タイトル:
Microwave Nondestructive Detection of Longitudinal Crack in Pipe with U-bend