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Ichimura, Toshiyuki; Suwa, Masayuki; Fukushima, Manabu; Oba, Toshinobu; Nemoto, Yoshinori; Terakado, Yoshibumi
Proceedings of 12th International Group on Research Reactors (12th IGORR) (USB Flash Drive), 8 Pages, 2009/10
Kobayashi, Tetsuya; Ichimura, Toshiyuki; Sato, Masayuki
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.340 - 343, 2008/07
The maintenance evaluation for research reactors has been obligated in Japan from 2004 as for power reactors. JAEA (Japan Atomic Energy Agency) has started to evaluate the maintenance for own research reactors on 2004. In this paper, we report the present status of the maintenance for JRR-3 (Japanese Research Reactor No.3), as well as the linear evaluation methods used. It is found that a series of preventing maintenance task on equipment and building of the reactor is properly performed.
Matsuda, Norihiro; Nakashima, Hiroshi; Kasugai, Yoshimi; Sasamoto, Nobuo*; Kinno, Masaharu*; Kitami, Takayuki; Ichimura, Takahito; Hori, Junichi*; Ochiai, Kentaro; Nishitani, Takeo
Journal of Nuclear Science and Technology, 41(Suppl.4), p.74 - 77, 2004/03
In high power proton accelerator facilities, concrete shield can be highly activated, which makes maintenance work quite difficult. So, a low-activationized concrete (limestone concrete) is to be partially adopted as a concrete shield for Japan Proton Accelerator Research Complex (J-PARC) aiming at reducing 
-ray exposure dose during maintenance period. A new quantity, 
Na-equivalent, was introduced as a criterion to assure effectiveness of the low-activationized concrete. In order of its verification, powdered low-activationized concrete and ordinary one were irradiated using FNS at JAERI. The measurements were analyzed by a shielding design code system being used for J-PARC, showing that the calculations reproduce the measured induced activity within a factor of 2. Furthermore, by using the same code system, -ray exposure dose was calculated for the configuration of J-PARC to find out that -ray exposure dose by the low-activationized concrete was about 10 times lower than that by the ordinary concrete in a period of less than a few days after operation.
Yamanaka, Haruhiko; Hayashi, Kazuhiko; Motohashi, Jun; Kawashima, Kazuhito; Ichimura, Toshiyuki; Tamai, Kazuo; Takeuchi, Mitsuo
JAERI-Tech 2001-084, 110 Pages, 2002/01
JAERI-Tech-2001-084.pdf:10.15MB
no abstracts in English
Kubo, Takashi; Kitami, Takayuki; Itabashi, Hideharu; Horiguchi, Takashi; Ichimura, Takahito
no journal, ,
no abstracts in English
Horiguchi, Takashi; Kitami, Takayuki; Itabashi, Hideharu; Ichimura, Takahito; Kubo, Takashi
no journal, ,
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Ichimura, Takahito; Kitami, Takayuki; Horiguchi, Takashi; Kawama, Itsuo*
no journal, ,
no abstracts in English
Kawama, Itsuo*; Ichimura, Takahito; Kitami, Takayuki; Horiguchi, Takashi; Aoki, Yusuke*
no journal, ,
no abstracts in English
Kobayashi, Kenichi; Ichimura, Toshiyuki; Sato, Masayuki; Nemoto, Yoshinori; Nemoto, Takumi
no journal, ,
no abstracts in English
Yoshimura, Aya*; Ichimura, Takahito; Kitami, Takayuki; Horiguchi, Takashi; Kawama, Itsuo*; Ouchi, Hajime*; Tsunokake, Hisao*
no journal, ,
no abstracts in English
