Ito, Ayumi*; Yamashita, Susumu; Tasaki, Yudai; Kakiuchi, Kazuo; Kobayashi, Yoshinao*
Journal of Nuclear Science and Technology, 60(4), p.450 - 459, 2023/04
Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki
Teion Kogaku, 50(8), p.400 - 408, 2015/08
Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.
Ishihara, Yoshinao*; Ito, Takashi*; Kobayashi, Shigeki*; Neyama, Atsushi*
JNC TJ8440 2004-005, 137 Pages, 2004/02
On this work, system manufacture about disposal technology and safety assessment field was performed towards construction of the JNC Geological Disposal Technical Information Integration System which systematized three fields of technical information acquired in investigation (site characteristic investigation) of geology environmental conditions, disposal technology (design of deep repository), and performance/safety assessment.The technical information database managed focusing on the technical information concerning individual research of an examination, analysis, etc. and the parameter set database managed focusing on the set up data set used in case of comprehensive evaluation are examined.In order to support and promote share and use of the technical information registered and managed by the database, utility functions, such as a technical information registration function, technical information search / browse function, analysis support function, and visualization function, are considered, and the system realized in these functions is built.The built system is installed in the server of JNC, and the functional check examination is carried out.
Ishihara, Yoshinao*; Neyama, Atsushi*; Kobayashi, Shigeki*; Iwamoto, Hiroshi*
JNC TJ8440 2003-006, 250 Pages, 2003/02
In order to develop "Geological Disposal Technology Integration System" that is intended to systematize as knowledge base for fundamental study of geologixal environment, repository design and safety assessment, the computational design of an indispensable database and main function of "Geolodical Disposal Technology Integrated System" was done. The prototype was made in order to verify the system function.
Tsunematsu, Toshihide; Namba, Haruyuki*; Akutsu, Yoichi; Okawa, Yoshinao; Yagenji, Akira; Takeda, Masatoshi*; Yajima, Kensaku*; Nitta, Yoshio*; Kobayashi, Kenichi*; Maeda, Ikuo*; et al.
Fusion Engineering and Design, 41(1-4), p.415 - 420, 1998/09
no abstracts in English
Sumita, Takehiro*; Yonekawa, Kazuo*; Sekio, Yoshihiro; Sato, Isamu*; Kobayashi, Yoshinao*; Osaka, Masahiko; Maeda, Koji; Akasaka, Naoaki
no journal, ,
During Fukushima Daiichi Nuclear Power Plant (1F) accident, high radionuclides such as Cs and I were mainly released as fission products (FPs) due to fuel melting in units 1 to 3, and it increased radiation dose in reactor buildings. With the aim of 1F decommissioning, it is necessary to establish methods to retrieve fuel and an adequate access route, which requires knowledge of Cs adsorption behavior on the surface of structural materials during Severe Accidents (SA). However, there are no Cs adsorption behavior evaluations under the simulated SA condition with high pressure in the previous studies. In this study, CsI adsorption behavior on SUS304L under the condition was evaluated using newly designed apparatus which can control temperature, pressure, moisture and gas atmosphere. The findings from microstructural observation and elemental analysis after the adsorption test suggested that the adsorption of CsI was influenced by especially pressure.
Zheng, L.*; Hosoi, Kazuya*; Ueda, Shigeru*; Gao, X.*; Kitamura, Shinya*; Kobayashi, Yoshinao*; Osaka, Masahiko
no journal, ,
Si source for Cs-bearing particle formed by Fukushima-Daiichi NPS accident has yet to be revealed. Stainless steel is possible Si source since it is used as structure material in the reactor and includes Si. In this study, Si vaporization behavior was evaluated by investigation of Si behavior in oxide layer formed in steam atmosphere at 1473 K.
Kobayashi, Yoshinao*; Ueda, Shigeru*; Sato, Isamu*; Osaka, Masahiko
no journal, ,
SiO and Si(OH) can be Si source for Cs-bearing particle and other in-reactor compounds during Fukushima-Daiichi NPS accident. Dependencies of vapor pressure of those species on oxygen partial pressure and tenperature were evaluated thermodunamically. And experimental condition by chemical equilibrium method was determined in focusing CsO-SiO system.