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Ito, Fuyumi; Nishimura, Akihiko
Transactions of the Materials Research Society of Japan, 38(4), p.667 - 672, 2013/12
We are proposing Magnetic particle Testing (MT) using fabricated micro capsules by the hand-shake method. Here a test piece magnetized beforehand is immersed in liquid dispersed with magnetic particles. Fluorescent pigment adheres to the magnetic particles. So, MT is able to facilitate the crack visually as long as a certain amount of magnetic particles are holding the fluorescent pigment. However, separation between particle and pigment degrades transparency in liquid. Finally the hazy liquid makes difficult to find any crack. To solve this problem, we propose to use the Magnetic Particle Micro Capsule (MPMC). In addition, to applying this MPMC, the surround of the nuclear power plant should be confirmed. To confirm inside wall, the Laser Induced Breakdown Spectroscopy (LIBS) was applied.
Ito, Fuyumi; Nishimura, Akihiko
E-Journal of Advanced Maintenance (Internet), 4(2), p.57 - 63, 2012/08
Stress corrosion cracking sometimes occurs in the heat exchanger tubes of aging nuclear power plants. At the present time, Eddy Current Testing (ECT) is used to inspect these heat exchanger tubes. When symptoms of corrosion or cracks are found on the inside wall of the tubes, they are usually repaired. As repaired tubes increase in number, the cost of repair work rises considerably. Therefore, discovering tiny cracks has the purpose of ensuring not only progress on safety but also economical benefit. Cracks are observed not only by ECT but also by Magnetic particle Testing (MT), which facilitates visual observation. In the case of MT, a dispersed liquid with magnetic particles is applied to a magnetized sample. However, this dispersed liquid could potentially enter inside the crack. To solve this problem, this paper proposes that magnetic particles be contained inside a micro capsule, this capsule calls Magnetic Particle Micro Capsule (MPMC).
Ito, Fuyumi; Nishimura, Akihiko
Nihon Hozen Gakkai Dai-6-Kai Gakujutsu Koenkai Yoshishu, p.551 - 553, 2009/08
Fine magnetic particles having UV fluorescence are commonly used in magnetic crack detection technique. Stress corrosion cracking sometimes happens in nuclear power plants. To apply this technique to maintain the heat exchanger tubes, it is desired that these particles has performance to be collected with ease. To collect these fine magnetic particles from millimeter size crack depth, a chemosynthesis technique to produce the micro capsules successfully produced hundreds micron sized capsules containing the fine magnetic particles. The synthesized micro capsules indicated the collective sensitivity for lines of magnetic force.
Ito, Fuyumi; Nishimura, Akihiko
no journal, ,
Fine magnetic particles having UV fluorescence are commonly used in magnetic crack detection technique. Stress corrosion cracking sometimes happens in nuclear power plants. To apply this technique to maintain the heat exchanger tubes, it is desired that these particles has performance to be collected with ease. To collect these fine magnetic particles from millimeter size crack depth, a chemosynthesis technique to produce the micro capsules successfully produced hundreds micron sized capsules containing the fine magnetic particles. The synthesized micro capsules indicated the collective sensitivity for lines of magnetic force.
Ito, Fuyumi; Nishimura, Akihiko; Shimada, Yukihiro; Ishikawa, Noriko
no journal, ,
no abstracts in English
Ito, Fuyumi; Nishimura, Akihiko; Norimatsu, Takayoshi*; Nagai, Keiji*
no journal, ,
The purpose of the research is to apply the micro capsule technology to the facility maintenance. The micro capsule technology for laser fusion target was developed at the institute of laser engineering Osaka University. We have a plan to apply the fabrication technology of polystyrene micro capsules to the facility maintenance where the magnetic particle testing for complex piping system is investigated.
Nishimura, Akihiko; Ito, Fuyumi; Terada, Takaya; Shimada, Yukihiro
no journal, ,
no abstracts in English
Nishimura, Akihiko; Akatsu, Tomohiro*; Takenaka, Yusuke*; Yamaguchi, Toshihiko; Ito, Fuyumi; Oka, Kiyoshi; Yamashita, Takuya
no journal, ,
no abstracts in English
Nishimura, Akihiko; Akatsu, Tomohiro*; Seki, Takeshi*; Oka, Kiyoshi; Ito, Fuyumi; Shimada, Yukihiro
no journal, ,
no abstracts in English
Nishimura, Akihiko; Yamaguchi, Toshihiko; Akatsu, Tomohiro*; Ito, Fuyumi; Oka, Kiyoshi
no journal, ,
no abstracts in English
Ito, Fuyumi; Nishimura, Akihiko; Yonemoto, Yukihiro*; Terada, Takaya; Shimada, Yukihiro
no journal, ,
Development of inspection repair technology for tube inner wall of aging nuclear power plants was described. Three functions of the pulse laser, observation by the composite-type optical fiber scope, and laser-induced breakdown spectroscopy (LIBS) are built into a coupling device. In addition, to facilitate the observation of the cracks, we adopted the magnetic particle testing (MT). And to remove the dispersed magnetic particle liquid from cracks after MT, we manufactured a microcapsule containing the magnetic particle liquid. Furthermore, pulse laser ablation with LIBS can clean up the oxide layer of the inner wall of heat exchanger tubes. Applying LIBS on tube inner wall before MT can give us the information about cracks and defects.
Tomiyoshi, Kentaro; Ito, Fuyumi; Nishimura, Akihiko
no journal, ,
Careful inspection should be paid on aging nuclear power plants. Due to the Fukushima BWR accident, more advanced inspection techniques are now requested in Japan. To find SCC along welded sections by Ultrasonic Testing or Eddy Current Testing is difficult due to the low S/N. Here we propose to apply Magnetic particle Testing (MT) on the inspection. MT uses magnetic particles uniting fluorescent pigment. It is a weak point of MT that uniting particles and pigment is breakable. To extend the lifetime. We developed unique capsule for the magnetic particle to coexist with fluorescent pigment. In addition, MT using the micro capsules and related devices are presented.
Nishimura, Akihiko; Ito, Fuyumi; Terada, Takaya; Tomiyoshi, Kentaro; Oka, Kiyoshi
no journal, ,
no abstracts in English
Nishimura, Akihiko; Yamaguchi, Toshihiko; Oka, Kiyoshi; Akatsu, Tomohiro*; Ito, Fuyumi; Yamashita, Takuya
no journal, ,
no abstracts in English
Tomiyoshi, Kentaro; Ito, Fuyumi; Terada, Takaya; Oka, Kiyoshi; Nishimura, Akihiko
no journal, ,
no abstracts in English
Terada, Takaya; Ito, Fuyumi; Nishimura, Akihiko
no journal, ,
no abstracts in English
Terada, Takaya; Ito, Fuyumi; Nishimura, Akihiko
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Ito, Fuyumi; Nishimura, Akihiko; Terada, Takaya; Shimada, Yukihiro
no journal, ,
An optical fiber coupling device for maintenance is developed. A function such as observation of target object by wide-angle image, and the technique such as the elemental analysis by spectroscope and laser are built in the very compact device. Therefore, this device would permit wide-angle image and laser processing at oppressive conditions. The target object was measured and observed by these functions. Finally, industry application of this device was discussed.
Ito, Fuyumi; Nishimura, Akihiko; Tomiyoshi, Kentaro; Ito, Chikara; Sugiyama, Akira
no journal, ,
An innovative probing system should be required for the case of reactor core melt down accidents. In the Fukushima Daiichi BWRs, molten debris might drop in the pedestal under the reactor pressure vessel. Due to the high radioactive situation, the probing system is going to be inserted into the pedestal by a remote controlled robotic arm. We are planning the probing system which consists of optics of Laser Induced Breakdown Spectroscopy (LIBS), a waterproof view scope, radiation resistant optical fibers, radiation dose monitor, and so on. The purpose of LIBS is to analyze the composition of the molten debris. That of the waterproof view scope is to know its position in the pedestal. The following paragraph mentions each outline which we did until now.
Terada, Takaya; Kitsunai, Daisuke; Nishimura, Akihiko; Ito, Fuyumi*
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