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Ebisawa, Hiroyuki; Hanakawa, Hiroki; Asano, Norikazu; Kusunoki, Hidehiko; Yanai, Tomohiro; Sato, Shinichi; Miyauchi, Masaru; Oto, Tsutomu; Kimura, Tadashi; Kawamata, Takanori; et al.
JAEA-Technology 2009-030, 165 Pages, 2009/07
JAEA-Technology-2009-030.pdf:69.18MB
The condition of facilities and machinery used continuously were investigated before the renewal work of JMTR on FY 2007. The subjects of investigation were reactor building, primary cooling system tanks, secondary cooling system piping and tower, emergency generator and so on. As the result, it was confirmed that some facilities and machinery were necessary to repair and others were used continuously for long term by maintaining on the long-term maintenance plan. JMTR is planed to renew by the result of this investigation.
Asano, Norikazu; Kurosawa, Akihiko; Yanai, Tomohiro; Watahiki, Shunsuke; Kameyama, Yasuhiko; Onoue, Ryuji; Tobita, Kenji; Fukasaku, Akitomi
no journal, ,
no abstracts in English
Yasuo, Kiyoshi; Morimoto, Kenji; Seto, Nobuhiko; Watahiki, Seiichi
no journal, ,
JP, 2009-105389 Patent publication (In Japanese)
Cells and vessels as well as buildings have maintained as a negative pressure to keep nuclear materials inside. Differential pressure switches, detecting change of liquid level and pressure at reprocessing plant, have been required airtightness for the nuclear materials containment under negative pressure. Problem of using the conventional airtight switch is, however, that could not meet the acceptable range with deep negative pressure. We have designed and made a prototype airtight switch applying a new type of pressure detection component. The prototype switch has been reliable on the actual usage, which has been evaluated by an operation, a vibration and an endurance test. We are improving its quality for adapting to the reprocessing process.
Watahiki, Kenji; Ishii, Takahiro; Sukigara, Koji; Sanyoshi, Hirotaka; Inami, Shinichi
no journal, ,
Treated water of The Tokai Reprocessing Plant used for cooling water and fire fighting water, is supplied by the steel pipes. These pipes are laid down under the ground or in the trench. Treated water had leaked, because the part of the underground pipe flange corrosion. The cause of this breakage was presumed that the pipe flange has been loaded the stress continuously. The stress generated depend of that the underground pipes sank with the ground subsidence by influence of the 2011 earthquake of the Pacific coast of Tohoku. The repair of the breakage flange and the pipes was adopted to use clamp (flexibility joint) for pipe connection as one of the countermeasures for tremble of the earthquake. This report shows the technical evaluation for the clamp performance on the practical use.
Masui, Kenji; Kitao, Takahiko; Inada, Satoshi; Yamada, Keiji; Watahiki, Masaru
no journal, ,
no abstracts in English
Watahiki, Kenji; Kawasumi, Hiroyuki; Yatogi, Hideo; Inami, Shinichi
no journal, ,
Off-gas of Tokai Reprocessing Plant, including gaseous radio-active element, has been emitted from main stack after through exhaust duct. There corrosion and crack at the part of the iron exhaust duct near the main stack. Repairing method was planned to be used iron plate covering the corroded and cracked area, which would be attached welded. To take into considering of reducing the weight of the attachment, much lighter materials namely carbon fiber reinforce polymer, CFRP, was applied except for the iron plate. Necessary numbers of layers of CFRP to be enough strength and inner pressure was calculated for designing. In order to achieve satisfying essential specification with workmanship, training for the workers was carried out using mock-up before the actual one. In this paper, we report the CFRP method is the efficient and effective method repairing corrosion and crack at the iron duct, in Tokai Reprocessing Plant.
Masui, Kenji; Suzuki, Yasaka*; Kitao, Takahiko; Inada, Satoshi; Yamada, Keiji; Watahiki, Masaru
no journal, ,
no abstracts in English
Kuno, Takehiko; Okano, Masanori; Masui, Kenji; Suzuki, Yutaka; Yamada, Keiji; Watahiki, Masaru; Hiyama, Toshiaki
no journal, ,
no abstracts in English