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Shibata, Taiju; Kunimoto, Eiji*; Eto, Motokuni*; Shiozawa, Shusaku; Sawa, Kazuhiro; Oku, Tatsuo*; Maruyama, Tadashi*
Journal of Nuclear Science and Technology, 47(7), p.591 - 598, 2010/07
Times Cited Count：10 Percentile：56.2(Nuclear Science & Technology)no abstracts in English
Shibata, Taiju; Eto, Motokuni*; Kunimoto, Eiji*; Shiozawa, Shusaku; Sawa, Kazuhiro; Oku, Tatsuo*; Maruyama, Tadashi*
JAEA-Research 2009-042, 119 Pages, 2010/01
JAEA-Research-2009-042.pdf:26.28MB
For the design of the graphite components in the High Temperature Engineering Test Reactor (HTTR), the graphite structural design code for the HTTR etc. were applied. However, general standard systems for the High Temperature Gas-cooled Reactor (HTGR) have not been established yet. The authors had studied on the technical issues which is necessary for the establishment of a general standard system for the graphite components in the HTGR. The results of the study were documented and discussed at a "Special committee on research on preparation for codes for graphite components in HTGR" at Atomic Energy Society of Japan (AESJ). As a result, "Draft of Standard for Graphite Core Components in High Temperature Gas-cooled Reactor" was established. In this draft standard, the graphite components are classified three categories (A, B and C) in the standpoints of safety functions and possibility of replacement. For the components in the each class, design standard, material and product standards, and in-service inspection and maintenance standard are determined. This draft standard is the first standard in the world which shows the concept of standard for the graphite core components in HTGR.
Kunimoto, Eiji; Shibata, Taiju; Shimazaki, Yosuke; Eto, Motokuni*; Shiozawa, Shusaku; Sawa, Kazuhiro; Maruyama, Tadashi*; Oku, Tatsuo*
JAEA-Research 2009-008, 28 Pages, 2009/06
JAEA-Research-2009-008.pdf:4.6MB
The VHTR is being focused and developed internationally. In Japan, the HTTR of the JAEA is in operation, and research and development for the development of commercial HTGRs are carried out. Nuclear graphites are used for core components of the HTGRs and expansion of irradiation data is necessary when enough irradiation data are not established, because the graphite components in the HTGRs are used at severer condition than that in the HTTR. The necessary database can be established by expansion of existing irradiation data with appropriate interpolation and extrapolation methods. This paper shows the reasonable interpolation and extrapolation method for IG-110 graphite which is used for the HTTR and a major candidate for the VHTR. The interpolation and extrapolation method was developed so as to be general by using the irradiation data of the other graphites. As a result, irradiation properties of the IG-110 graphite were successfully expanded to the VHTR condition for the first time and the irradiation properties being necessary for the design could be developed.
Oku, Tatsuo*; Kurumada, Akira*; Imamura, Yoshio*; Ishihara, Masahiro
Journal of Nuclear Materials, 381(1-2), p.92 - 97, 2008/10
Times Cited Count：11 Percentile：59.06(Materials Science, Multidisciplinary)Four grades of graphites and two grades of C/C composites were irradiated by argon ions with 175 MeV. The load-depth curves were obtained from the micro indentation tests before and after ion irradiation, and the apparent hardness and the hardness property parameters B and D (close rerating to the strength and Young's modulus, respectively) were investigated. As a result, it is found that the apparent hardness and the parameters B and D increase due to argon ion irradiation, and that these micro hardness properties of the carbon materials are able to be expressed as a function of dpa values, including neutron irradiation data.
Ishihara, Masahiro; Sumita, Junya; Shibata, Taiju; Iyoku, Tatsuo; Oku, Tatsuo*
Nuclear Engineering and Design, 233(1-3), p.251 - 260, 2004/10
Times Cited Count：35 Percentile：88.7(Nuclear Science & Technology)The High Temperature Engineering Test Reactor (HTTR) constructed by Japan Atomic Energy Research Institute (JAERI) is a graphite-moderated and helium-gas-cooled reactor with prismatic fuel elements of hexagonal blocks. The reactor internal structures of the HTTR are mainly made up of graphite components. As well known, the graphite is a brittle material and there were no available design criteria for brittle materials. Therefore, JAERI had to develop the design criteria taking account of the brittle fracture behavior. In this paper, concept and key specification of the developed graphite design criteria is described, and also an outline of the quality control specified in the design criteria is mentioned.
Oku, Tatsuo*; Ishihara, Masahiro
Nuclear Engineering and Design, 227(2), p.209 - 217, 2004/01
Times Cited Count：32 Percentile：87.09(Nuclear Science & Technology)The lifetime of graphite material and/or components has been discussed individually from different concepts, and sometimes gives confusion to material researchers as well as designers. The lifetime of graphite materials is determined based on the dimensional changes due to neutron irradiation, at which they return to their original dimensions after initially contracting. On the other hand, the lifetime of graphite components for HTGRs is defined based on a margin of the specified minimum ultimate strengths of the graphite to the stresses induced in the graphite components. As an example, the stresses induced in the graphite block for the HTTR were, then, compared with the limited stress value determined from the specified minimum ultimate strength, and the lifetime of the graphite component was evaluated and compared with that defined as dimensional changes. As a result, it was found that the lifetime of graphite components for HTGRs should be determined as the shorter one in the two lifetimes defined by the stress-strength relationship and by the dimensional changes.
Oku, Tatsuo*; Baba, Shinichi
Tanso, 2002(202), p.90 - 95, 2002/05
no abstracts in English
Sudo, Yukio; Hoshiya, Taiji; Ishihara, Masahiro; Shibata, Taiju; Ishino, Shiori*; Terai, Takayuki*; Oku, Tatsuo*; Motohashi, Yoshinobu*; Tagawa, Seiichi*; Katsumura, Yosuke*; et al.
Proceedings of OECD/NEA 2nd Information Exchange Meeting on Basic Studies in the Field of High-temperature Engineering, p.39 - 50, 2001/00
no abstracts in English
Ishino, Shiori*; Terai, Takayuki*; Oku, Tatsuo*; Arai, Taketoshi; Hayashi, Kimio; Ito, Hisayoshi; Yano, Toyohiko*; Motohashi, Yoshinobu*; *; *; et al.
JAERI-Review 99-019, 238 Pages, 1999/08
JAERI-Review-99-019.pdf:14.88MB
no abstracts in English
Oku, Tatsuo*; Kurumada, Akira*; McEnaney, B.*; Burchell, T. D.*; Ishihara, Masahiro; Hayashi, Kimio; Baba, Shinichi; Aihara, Jun
Proceedings of 1st World Conference of Carbon (EUROCARBON 2000), 1, p.947 - 947, 1999/07
no abstracts in English
Oku, Tatsuo*; Kurumada, A.*; Nakata, M.*; Takeda, K.*; Kawamata, K.*; Arai, Taketoshi; Ishihara, Masahiro
Proceedings of 24th Biennial Conference on Carbon (CARBON '99), p.574 - 575, 1999/07
no abstracts in English
*; Futakawa, Masatoshi; Ioka, Ikuo; Onuki, Kaoru; Shimizu, Saburo; Eto, Motokuni; Oku, Tatsuo*; *
Zairyo, 48(7), p.746 - 752, 1999/07
no abstracts in English
Ishihara, Masahiro; Aihara, Jun; Oku, Tatsuo*
Proc. of 14th Int. Conf. on Structural Mechanics in Reactor Technology, 2, p.455 - 462, 1997/00
no abstracts in English
Ishihara, Masahiro; Futakawa, Masatoshi; Iyoku, Tatsuo; Oku, Tatsuo*
Nihon Genshiryoku Gakkai-Shi, 38(12), p.1005 - 1012, 1996/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
; Oku, Tatsuo*; Ishiyama, Shintaro; Eto, Motokuni
Nihon Kikai Gakkai Rombunshu, A, 62(593), p.10 - 17, 1996/00
no abstracts in English
Ishihara, Masahiro; Oku, Tatsuo*
Nihon Kikai Gakkai Rombunshu, A, 62(602), p.2305 - 2309, 1996/00
no abstracts in English
; Minato, Kazuo; Eto, Motokuni; Oku, Tatsuo*; *
JAERI-M 92-085, 28 Pages, 1992/06
no abstracts in English
Nishiyama, Yutaka; Fukaya, Kiyoshi; Suzuki, Masahide; Kodaira, Tsuneo; Oku, Tatsuo*
Effects of Radiation on Materials; 15th International Symposium (ASTM STP 1125), p.1287 - 1303, 1992/00
no abstracts in English
Ishiyama, Shintaro; Eto, Motokuni; Oku, Tatsuo*
Tanso, 0(153), p.155 - 162, 1992/00
no abstracts in English
Ishiyama, Shintaro; Eto, Motokuni; Oku, Tatsuo*
Tanso, (152), p.67 - 73, 1992/00
no abstracts in English
