Seal welding is a repair method when crack by Stress Corrosion Cracking (SCC) is found in weld rtion of core internals including pressure b oundary component in nuclear power plant. Seal lding is welded directly on surface of existing SCC crack and prevents SCC propagation by la ting SCC crack from reactor water environment. In this study, development of seal welding hnology using automatic TIG Welding was executed, and the applicability of seal welding method CRD stub-tube weld portion was confirmed by ex...
英字タイトル:
Development of Seal Welding Repair Technology for CRD Stub-tube

Combination of Microwave Hyperthermia and Radiation Therapy is effective for treatment of tumor. After increasing the temperature the tumor becomes more sensitive to radiation dose. In this paper, the Invasive and Non-invasive microwave antennas were designed and applied on different tissues including malignant tumor, and respective Specific Absorption rate (SAR) patterns and temperature rises were investigated. For invasive antenna, coaxial-slot antennas was investigated and for non-invasive antenna, ...
英字タイトル:
SAR Patterns of Invasive and Non-invasive Antenna Array in Combination of Hyperthermia and Radiation Brachytherapy

Abstract In the nuclear power plants, the reservation of safety and before-it-happens prevention of a trouble are important themes. Moreover, in connection with the life extension of a plant, life-expectancy diagnosis has also been an important subject. Although it is technology required in order that a non-destructive test may secure the safety of a power generation plant, Ultrasonic Testing (UT) is applied. However, generally the welding of stainl ess steel piping used widely in the PWR type nuclear powe...
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Ultrasonic Testing Technique for Stainless Steel Pipe

Weld pass sequence generally affects residual stress profiles. In this study, the profiles of a multi pass bead on plate specimen were experimentally and analytically examined. Material used in this study was the low alloy steel SQV2A (JIS G 3120). Phase transformation usually occurs around welded area in SQV2A and also affects the profiles. Five pass bead on plate specimen was fabricated. Residual stress profiles of the specimen were measured by using the strain relief method. Longitudinal residual st...
英字タイトル:
Residual Stress Analysis of Multi Pass Bead on Plate Specimen of Low Alloy Steel SQV2A by Considering Phase Transformation in Welding Process

High active liquid waste is stored in the facility equipped with cooling system and hydrogen scavenging system because of hydrogen generation due to radiolysis, and heat generation due to decay heat. The facilities related to these systems maintenance have been designed to be fed by emergency power generators in the conventional design. In addition to that, in light of the lessons learned from accident at the Fukushima daiichi nuclear power plant, we took safety measures for emergencies such as securem...
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Emergency safety measures at the Tokai reprocessing plant（Part 1）

Nonlinear ultrasonic imaging technique is applied for detection and sizing of tight cracks. Tight crack su rfaces are clapped and rubbed repeatedly by high-powered burst waves, thus higher and sub-harmonics are ge nerated. By using a band-pass or high-pass filter, the second and higher harmonic components are extracted from the received signals and the amplitude map is constructed. We can make the ultrasonic images of the cracked surface itself, by focusing the ultrasonic beams on peaks of rugged cracked s...
英字タイトル:
Imaging of Small Defects and Tight Cracks with Nonlinear Ultrasonics