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Yamamoto, Masato*; Kimura, Akihiko*; Onizawa, Kunio; Yoshimoto, Kentaro*; Ogawa, Takuya*; Chiba, Atsushi*; Hirano, Takashi*; Sugihara, Takuji*; Sugiyama, Masanari*; Miura, Naoki*; et al.
Proceedings of 2012 ASME Pressure Vessels and Piping Conference (PVP 2012) (DVD-ROM), 7 Pages, 2012/07
Master curve (MC) approach for the fracture toughness evaluation is expected to be a powerful tool to assess the structural integrity of reactor pressure vessels (RPVs). In order to get sufficient number of reliable data for the MC approach from broken halves of surveillance test specimens for RPVs, the use of miniature specimens is necessary. For this purpose, a round robin test program on the miniature compact tension specimens (Mini-CT) of 4 mm thick for the MC approach of a Japanese RPV steel has been launched with the participation of academia, industries and a research institute in Japan. The program aims to verify the reliability of experimental data from Mini-CT, and to pick out further investigation items to be solved. As the first step of this program, four institutes carried out MC testing and evaluation using common test procedure and specimens. Valid reference temperature T
was successfully obtained in each institute. However, the T values showed large differences with maximum of 34
C. It was indicated on the reason of difference that there is a strong correlation between the T values and loading rate, which was selected by each institute per test standard.
Ara, Kuniaki; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Nagai, Masahiko*; Yoshioka, Naoki*
Journal of Nuclear Science and Technology, 47(12), p.1165 - 1170, 2010/12
Times Cited Count：11 Percentile：59.76(Nuclear Science & Technology)A study on the chemical reactivity control of sodium utilizing the atomic interaction of sodium with suspended nanoparticles was carried out. The atomic interaction between nanoparticles and sodium atoms were estimated by theoretical calculations and verified by fundamental physical properties measurements. Results showed the atomic bond of the sodium atom and the nanoparticle atom was significantly larger than that of the sodium atoms, when the transition metals that have the property of large electronegativity are applied as nanoparticles. From the theoretical calculation results, it was suggested that charge transfer occurs from the sodium atom to the nanoparticle atom. The fundamental physical properties of sodium with suspended nanoparticles were examined in comparison with that of sodium to verify the change of the atomic interaction. From the experimental results, it became clear that the surface tension becomes larger and the evaporation rate becomes smaller. These changes in fundamental physical properties were measured to verify the stability of the atomic interaction under the conditions of wide temperature range and the phase transformation from solid phase to liquid phase.
Ara, Kuniaki; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Nagai, Masahiko*; Yoshioka, Naoki*
Journal of Nuclear Science and Technology, 47(12), p.1171 - 1181, 2010/12
Times Cited Count：10 Percentile：56.7(Nuclear Science & Technology)A study was conducted on the control of the chemical reactivity of sodium utilizing the atomic interaction between sodium and nanoparticles. The authors reported in a previous paper that the atomic interaction between sodium and nanoparticles increases and has the potential to suppress chemical reactivity. In this paper, the authors examined the released reaction heat and the reaction behavior. As a result, it was confirmed that the released reaction heat and the reaction rate decreased. From the results of experimental studies, it is clear that the suppressions of chemical reactivity are caused by a change in the sodium evaporation rate and fundamental physical properties such as surface tension which originate in the change in the atomic interaction between sodium and nanoparticle atoms. The suppression of chemical reactivity applying to FBR coolant was estimated for the case of sodium combustion and sodium-water reaction. It was confirmed that the concept of suspending nanoparticles into sodium has high potential for the suppression of chemical reactivity. Applicability as coolant to the FBR was investigated, including not only the chemical reaction properties but also the aspects of heat transfer and operation.
Saito, Junichi; Ara, Kuniaki; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Nakano, Haruyuki*; Ogata, Kan*; Yoshioka, Naoki*
Proceedings of 16th International Conference on Nuclear Engineering (ICONE-16) (CD-ROM), 4 Pages, 2008/05
no abstracts in English
Saito, Junichi; Ara, Kuniaki; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Oka, Nobuki*; Yoshioka, Naoki*
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 5 Pages, 2007/04
Liquid sodium is used as the coolant of the fast breeder reactor (FBR), because of its high thermal conductivity and wide temperature range of liquid. However the chemical reactivity with water and oxygen of sodium is very high. So an innovative technology to control the reactivity is desired. The purpose of this study is to reduce the chemical reactivity of liquid sodium by dispersing the nanometer-size metallic particles into liquid sodium. Sub-themes of this study are nanoparticles production, evaluation of reaction control of liquid sodium, and feasibility study to FBR. In this paper, we describe the research program of them.
Kawai, Jun*; Yabuta, Naohiro*; Furuya, Shunsuke*; Sugiyama, Naoki*
JNC TJ1400 2005-021, 350 Pages, 1998/02
Saito, Junichi; Ara, Kuniaki; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Yamauchi, Miho*; Yamashita, Akihiro*; Oka, Nobuki*; Yoshioka, Naoki*
no journal, ,
no abstracts in English
Ara, Kuniaki; Saito, Junichi; Sugiyama, Kenichiro*; Kitagawa, Hiroshi*; Ogata, Hiroshi*; Toda, Mikio*; Yoshioka, Naoki*
no journal, ,
no abstracts in English
Makino, Hitoshi; Hioki, Kazumasa; Umeki, Hiroyuki; Sugiyama, Naoki; Ochi, Yasuhiro; Okazaki, Wataru; Naito, Morimasa; Miyahara, Kaname; Okubo, Hiroo*; Ishihara, Yoshinao*
no journal, ,
This presentation will introduce developmenmt of methodology for optimisation of waste disposal considering variation of waste charcteristics from LWR cycle and also advanced cycle.
Makino, Hitoshi; Umeki, Hiroyuki; Hioki, Kazumasa; Sugiyama, Naoki*; Okubo, Hiroo*
no journal, ,
This project aims to develop the technology basis for holistic waste management taking into consideration whole fuel cycle system. This presentation provides overview of the whole project and introduces an approach for integration of outcomes centering on optimization.
Oda, Takashi; Inoue, Rintaro*; Morishima, Ken*; Aizawa, Naoki*; Oi, Rika*; Ishino, Yoshizumi*; Oku, Takayuki; Sato, Mamoru*; Sugiyama, Masaaki*
no journal, ,
no abstracts in English
