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Nishimura, Akihiko; Takenaka, Yusuke*; Furuyama, Takehiro*; Shimomura, Takuya; Terada, Takaya; Daido, Hiroyuki
Journal of Laser Micro/Nanoengineering, 9(3), p.221 - 224, 2014/11
Times Cited Count：0 Percentile：0(Nanoscience & Nanotechnology)Heat resistant FBG sensors were developed by femtosecond laser processing to apply them to high temperature operated piping system of nuclear power plants. The FBG sensor was installed on the surface of a steel blade and a vibration test was conducted to detect the resonant vibration frequency of the vibrating blade. The FBG sensor had the heatproof performance at 600
C. A frequency stabilized sensing system using a tunable laser was tested for structural health monitoring in daily operation of nuclear power plants. The FBG sensor was installed on the surface of a steel blade for vibration induced strain measurements. Welding, brazing, soldering and noble metal powder adhesive were discussed for molding the FBG sensors.
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
Progress in Nuclear Science and Technology (Internet), 4, p.623 - 626, 2014/04
In the previous study, we developed a multi-layered concrete structure to reduce induced activity in concrete applied for neutron generation facilities such as a fusion reactor. This structure is composed of low activation concrete as the first layer, boron doped low activation concrete as the second layer and ordinary concrete as the third layer from the side of the neutron source. In this study, as an alternative of the boron doped low activation concrete we have developed the boron doped resin sheet with boron carbonate and resin to reduce the construction cost. The weight ratio of the boron carbonate to the resin is 0.75. The developed boron sheet has good flexibility and sufficient strength for repeated bending. DT neutron irradiation experiments for four multi-layered concrete structures with the boron sheet have been performed at the FNS (Fusion Neutronics Source) facility in JAEA in order to study shielding performance of the structures with the boron sheet. Structure-1 of about 30 cm in width, 30 cm in height and 50 cm in thickness is composed of low activation concrete of 20 cm in thickness as the first layer and ordinary concrete of 30 cm in thickness as the second layer. The boron sheet is inserted between the first and second layers. In Structure-2 one more boron sheet is inserted at the 10 cm depth from the surface of Structure-1. Structure-3 added one more boron sheet at 30 cm depth from the surface of Strucure-2. For comparison, Structure-4 has no boron sheet. The reaction rates were measured every 5 cm in depth with activation foils of gold and niobium. By inserting the boron sheet, the reaction rate of the gold generated by low energy neutrons decreases by a factor of about four. It is demonstrated that the multi-layered concrete structure with the boron sheet effectively reduces low energy neutrons.
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
Journal of Nuclear Materials, 417(1-3), p.1131 - 1134, 2011/10
Times Cited Count：11 Percentile：60.88(Materials Science, Multidisciplinary)The multi-layered concrete structure has been developed to reduce induced activity in the concrete applied for neutron generation facilities such as a fusion reactor. The multi-layered concrete structure is composed of the low activation concrete as the first layer, the boron-doped low activation concrete as the second layer and the ordinary concrete as the third layer from the side of the neutron source. By applying the multi-layered concrete structure, the volume of the boron can drastically decrease compared with the monolithic boron-doped concrete. A 14 MeV neutron irradiation experiment with the multi-layered concrete structure mockups was performed at FNS and several reaction rates and induced activities in the mockups were measured. This experiment demonstrated that the multi-layered concrete effectively reduced low energy neutrons and induced activities.
Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Satoshi
Genshiryoku eye, 54(11), p.54 - 57, 2008/11
no abstracts in English
Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Satoshi
Denryoku Doboku, (334), p.86 - 89, 2008/03
no abstracts in English
Division of Fusion Energy Technology
JAEA-Review 2007-036, 98 Pages, 2007/11
JAEA-Review-2007-036.pdf:32.22MB
The Division of Fusion Energy Technology of the Fusion Research and Development Directorate is carrying out cooperating researches with universities, research institutes and industries using five fusion engineering facilities; Caisson Assembly for Tritium Safety Study (CATS), Fusion Neutronics Source (FNS), MeV Test Facility (MTF), JAEA Electron Beam Irradiation System (JEBIS), RF Test Stand (RFTS). In the fiscal year 2006 (from April 1, 2006 to March 31, 2007), 23 activities were carried out as the cooperating researches. This report reviews the results of 7 activities which were completed in the fiscal year 2006.
Maegawa, Toshio*; Umetsu, Tomotake*; Nonaka, Akira*; Yoshimatsu, Kenji*; Sato, Koichi*; Sato, Satoshi; Nishitani, Takeo
Semento, Konkurito, (719), p.26 - 31, 2007/01
no abstracts in English
Nonaka, Akira*; Yoshimatsu, Kenji*; Sato, Koichi*; Maegawa, Toshio*; Sasaki, Shizuo*; Umetsu, Tomotake*; Sato, Satoshi
no journal, ,
no abstracts in English
Umetsu, Tomotake*; Yoshimatsu, Kenji*; Sato, Koichi*; Maegawa, Toshio*; Sasaki, Shizuo*; Nonaka, Akira*; Sato, Satoshi
no journal, ,
no abstracts in English
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
no journal, ,
no abstracts in English
Maegawa, Toshio*; Sato, Satoshi; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
no journal, ,
no abstracts in English
Shimada, Yukihiro; Nishimura, Akihiko; Suzuki, Hirokazu*; Ishibashi, Hisayoshi*; Ito, Keisuke; Ito, Chikara; Yoshida, Akihiro
no journal, ,
A Fiber Bragg Grating (FBG) sensor with heat resistance was produced via a point microfabrication technique using a femtosecond pulse laser. It can be used as temperature or a strain sensor by measuring change of the reflective wavelength of FBG. Heating test under operational temperature of Fast Reactors is now planed. This time, we did the withstand type test on the sensor by using the piping material in the environment of 400 degrees. As a result, it succeeded in a small oscillation and measuring a strain. The heat-resistant FBG sensor developed using ultra-short pulse laser processing will contribute to the surveillance of power plants for seismic safety.
Shimada, Yukihiro*; Nishimura, Akihiko; Suzuki, Hirokazu*
no journal, ,
no abstracts in English
Nishimura, Akihiko; Shimada, Yukihiro*; Suzuki, Hirokazu*
no journal, ,
Fiber Bragg grating was made by ultrashort laser processing. Carbon silicate fabric was used to reinforce the FBG sensor. Ceramic adhesive was applied to bond it on the piping material. Loading test was done ranging from 400 to 600 degree. The FBG sensors were prepared for the structural health monitoring of high temperature complex piping system.
