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Taniguchi, Naoki; Suzuki, Hiroyuki*; Nakanishi, Tomoaki*; Nakayama, Takenori*; Masugata, Tsuyoshi*; Tateishi, Tsuyoshi*
Zairyo To Kankyo, 56(12), p.576 - 584, 2007/12
The long term hydrogen absorption behavior and the possibility of hydrogen embrittlement were studied for titanium overpack for high level radioactive waste disposal. The results of galvanostatic cathodic polarization tests showed that as the cathodic current density is lowered, the amount of absorbed hydrogen for a constant cathodic charge was increased as well as hydrogen permeated into inside of titanium. The hydrogen absorption ratio for a cathodic current density equivalent to the corrosion rate under anaerobic condition was estimated to nearly 100 percent, and the amount of absorbed hydrogen for 1000 years was evaluated to be 400 ppm. The mechanical property of titanium containing hydrogen depended on not only hydrogen concentration but also hydrogen distribution type. The more hydrogen distribution is uniform, the degree of embrittlement was larger. It was expected that the rupture of titanium overpack with 6 mm thickness would be initiated if the crack size in titanium is over about 2-3 mm under the stress corresponds to yield strength.
Wada, Ryutaro*; Nishimura, Tsutomu*; Nakanishi, Tomoaki*; Nakayama, Takenori*; Sakashita, Shinji*; Fujiwara, Kazuo*; Tateishi, Tsuyoshi*
JNC TJ8400 2005-001, 224 Pages, 2004/02
JNC-TJ8400-2005-001.pdf:16.23MB
For repository container material of high-level radioactive waste, titanium and nickel-base alloys have been investigated as high corrosion resistance metal. In this study, the effects of environmental and material factors on hydrogen absorption of titanium were investigated experimentally. As for nickel-base allys, previous studies on corrosion behavior were serched.
Tsuneoka, Masaki; Imai, Tsuyoshi; Nakayama, Nobuyoshi*; Iiyama, Toshimitsu*
Denki Gakkai Rombunshi, D, 123-D(2), p.170 - 171, 2003/02
no abstracts in English
Sugimoto, Masayoshi; Imai, Tsuyoshi; Okumura, Yoshikazu; Nakayama, Koichi*; Suzuki, Shohei*; Saigusa, Mikio*
Journal of Nuclear Materials, 307-311(Part2), p.1691 - 1695, 2002/12
Times Cited Count：2 Percentile：17.03(Materials Science, Multidisciplinary)International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based intense neutron source for fusion reactor materials development. Each one of the two accelerator modules needs to have a capability to provide the 40MeV/125mA deuteron beam continuously. Although the technology to produce the 7MeV/100mA proton beam is already verified using 350 MHz linac in the past, an engineering study using a prototype is necessary to verify the performance of IFMIF 175 MHz deuteron linac, and Engineering Validation Phase (EVP) is planned for this purpose. Some critical design parameters, like final and transition energies of linacs or RF source characteristics, are needed to be optimised for the prototype. As it is also important to verify the essential component technology, e.g. ion source, RFQ beam matching, rf system components, etc., the present status and expected results of such undergoing verification tests are described. An integrated concept of prototype accelerator is shown as a Japanese proposal for EVP to provide for the international discussion.
Sugiyama, Akira; *; Kato, Masaaki; Maruyama, Yoichiro
Applied Optics, 36(24), p.5849 - 5854, 1997/08
Times Cited Count：3 Percentile：23.13(Optics)no abstracts in English
Sugiyama, Akira; ; Kato, Masaaki; Maruyama, Yoichiro; Arisawa, Takashi
Opt. Eng., 35(4), p.1093 - 1097, 1996/04
Times Cited Count：17 Percentile：66.59(Optics)no abstracts in English
Taniguchi, Naoki; Suzuki, Hiroyuki*; Yui, Mikazu; Nakanishi, Tomoaki*; Nakayama, Takenori*; Masugata, Tsuyoshi*; Tateishi, Tsuyoshi*
no journal, ,
Titanium (including titanium alloy) is one of the candidate materials of overpacks for geological disposal of high-level radioactive waste, and required long term integrity against the groundwater for more than 1000 years. As the corrosion of titanium occurs, hydrogen is generated since the deep underground environment is originally low oxygen concentration condition. There is a possibility that the titanium overpack will be attackd by the hydrogen embrittlement due to long term hydrogen absorption. In this study, the amount of hydrogen and the possibility of embrittlement were investigated based on the experimental data on the corrosion rate, hydrogen absorption behavior, mechanical proparty of titanium containing hydrogen.
Otsuka, Ichiro; Taki, Hiroshi*; Yamaguchi, Tetsuji; Iida, Yoshihisa; Yamada, Fumika; Tanaka, Tadao; Nakayama, Shinichi; Kato, Osamu*; Tateishi, Tsuyoshi*
no journal, ,
no abstracts in English
Abe, Hiroaki*; Kano, Sho*; Yang, H.*; Takanabe, Kazuhiro*; Nakayama, Akira*; Chen, Y.*; Yamaguchi, Masatake; Shinohara, Yasunari*; Ogata, Koichi*
no journal, ,
no abstracts in English
Kano, Sho*; Murakami, Kenta*; Yang, H.*; Takanabe, Kazuhiro*; Nakayama, Akira*; Chen, Y.*; Yamaguchi, Masatake; Shinohara, Yasunari*; Ogata, Koichi*; Abe, Hiroaki*
no journal, ,
no abstracts in English
Abe, Hiroaki*; Takanabe, Kazuhiro*; Nakayama, Akira*; Yamaguchi, Masatake; Yang, H.*; Kano, Sho*
no journal, ,
no abstracts in English
