Oto, Tsutomu; Asano, Norikazu; Kawamata, Takanori; Yanai, Tomohiro; Nishimura, Arashi; Araki, Daisuke; Otsuka, Kaoru; Takabe, Yugo; Otsuka, Noriaki; Kojima, Keidai; et al.
JAEA-Review 2020-018, 66 Pages, 2020/11
A collapse event of the cooling tower of secondary cooling system in the JMTR (Japan Materials Testing Reactor) was caused by the strong wind of Typhoon No.15 on September 9, 2019. The cause of the collapse of the cooling tower was investigated and analyzed. As the result, it was identified that four causes occurred in combination. Thus, the soundness of the cooling tower of Utility Cooling Loop (UCL cooling tower), which is a wooden cooling tower installed at the same period as the cooling tower of secondary cooling system, was investigated. The items of soundness survey are to grasp the operation conditions of the UCL cooling tower, to confirm the degradation of structural materials, the inspection items and inspection status of the UCL cooling tower, and to investigate the past meteorological data. As the results of soundness survey of the UCL cooling tower, the improvement of inspection items of the UCL cooling tower was carried out and the replacement and repair of the structural materials of the UCL cooling tower were planned for safe maintenance and management of this facility. And the renewal plan of new cooling tower was created to replace the existing UCL cooling tower. This report is summarized the soundness survey of the UCL cooling tower.
Hanakawa, Hiroki; Kawamata, Takanori; Ogasawara, Yasushi; Otsuka, Kaoru; Omori, Takazumi; Ide, Hiroshi; Tsuchiya, Kunihiko
UTNL-R-0499, p.11_1 - 11_7, 2019/03
no abstracts in English
Kawamata, Takanori; Oto, Tsutomu; Ogasawara, Yasushi; Watahiki, Shunsuke; Araki, Daisuke
UTNL-R-0486, p.8_1 - 8_10, 2014/03
no abstracts in English
Nemoto, Hiroyoshi; Ebisawa, Hiroyuki; Ogasawara, Yasushi; Echigoya, Shinichi
JAEA-Review 2010-018, 32 Pages, 2010/07
An integrity investigation was carried out for the JMTR reactor installations, which were the primary cooling system tanks (the surge tank, the degas tank and the purify water tank) and they would be used for the long term after JMTR restart, before the renewal work for the JMTR on FY2007. The visual inspection and the liquid penetrate test (PT) were carried out as the integrity investigation to confirm the integrity of primary cooling system tanks. In order to use the surge tank, the degas tank and the purify water tank continuously for long term, it is important for maintaining the integrity of the surge tank, the degas tank and the purify water tank by the periodical maintenance and the repairing work.
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
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.
Nemoto, Hiroyoshi; Ebisawa, Hiroyuki; Takahashi, Masayoshi*; Ihara, Yoshihisa*; Ogasawara, Yasushi; Echigoya, Shinichi
no journal, ,
JMTR (Japan Materials Testing Reactor) has started refurbishment of reactor facilities from FY2007, and the renewed and upgraded JMTR will start from FY2011. Control system of the JMTR has been used for 42 years since first criticality in 1968. Distributed control system (DCS) introduced in this project will enable the operators to monitor and control the entire plant information on a unified platform and realize digitalization / integration of various data. In addition, adoption of large screens will make it possible to show versatile information collectively, and it will lead to increase operability, visibility and assistance for plant operators. For the reactor control room, new layout design is introduced based on desired ergonomics. This report summarizes the outline of refurbishment project on plant control upgrading from analog control panels to the latest distributed control system (DCS).
Yanai, Tomohiro; Ogasawara, Yasushi; Hanakawa, Hiroki; Oto, Tsutomu; Kawamata, Takanori; Kameyama, Yasuhiko
no journal, ,
JMTR refurbishment had started since 2007. Refurbishment of instrumentation system has completed on March 2011. Official inspections before operation was carried out 4 times between March 2010 and April 2011. Refurbishment work was carried out in schedule except delay of the last inspection official inspection before operation due to Great East Japan Earthquake. Instrumentation system had used for 42 years since first criticality. Nuclear instrumentation was partly refurbished in 1981 but other instrumentation devices were in service till August 2006. The refurbishment plan was made not only by using original design concept also by considering aging, important degree of safety, availability of change parts, and raising operation rate. Almost all devices were renewal in this refurbishment work in order to be able to use the instrumentation system for 20 year for which JMTR will operate. This report summarized the refurbishment work and future task of JMTR instrumentation system.