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.
Kameyama, Yasuhiko; Yanai, Tomohiro; Sugaya, Naoto; Kusunoki, Hidehiko; Sato, Shinichi; Fukasaku, Akitomi
JAEA-Review 2012-011, 35 Pages, 2012/03
The Japan materials testing reactor (here-in-after "JMTR") was used for irradiation experimental facility such as fuels and materials for commercial reactor. And the JMTR renewal work was started in 2006 and was completed in 2011. In this report, a part of renewal work for (1) freezer and its accompanying pipe and electricity facilities which the purpose of humidification and air-conditioning in the reactor and hot laboratory building, (2) boiler and its accompanying facilities which the purpose of humidification and heating in the reactor, hot laboratory and Alpha Gamma Facility (AGF) is summarized.
Kameyama, Yasuhiko; Yanai, Tomohiro; Kurosawa, Akihiko; Asano, Norikazu; Hiyama, Kazuhisa; Kusunoki, Hidehiko; Fukasaku, Akitomi
JAEA-Review 2011-017, 19 Pages, 2011/06
The Japan Materials Testing Reactor (JMTR) is a testing reactor dedicated to the irradiation tests of materials and fuels. The JMTR has been in a shutdown period since 2006 for its refurbishment, and will restart in 2011. Water analysis and so on are carried out in the hot experimental room, and sample preparation and measurement for the radiation management are carried out in the radiation control room. The waste fluid such as hand-wash water, sample water, washing water generated in these rooms is transferred to the waste tank in the hot machine room through the buried pipe. The crack was found at the flange of the buried pipe when sewerage works were carried out. The flange is located in a non-controlled area. A small amount of radionuclide (cesium 137 and cobalt 60) was detected as a result of radioactivity measurement from the surrounding soil. In this report, the cause of the leakage from the buried pipe, the countermeasure and the prevention measure are summarized.
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.
Tomimoto, Hiroshi; Kato, Yasushi; Owada, Hiroyuki; Sato, Nao; Shimazaki, Yosuke; Kozawa, Takayuki; Shinohara, Masanori; Hamamoto, Shimpei; Tochio, Daisuke; Nojiri, Naoki; et al.
JAEA-Technology 2009-025, 29 Pages, 2009/06
The first driver fuel of the HTTR (High Temperature Engineering test Reactor) was loaded in 1998 and the HTTR reached first criticality state in the same year. The HTTR has been operated using the first driver fuel for a decade. In Fuel elements assembling, 4770 of fuel rods which consist of 12 kinds of enrichment uranium are loaded into 150 fuel graphite blocks for HTTR second driver fuel elements. Measures of prevention of fuel rod miss loading, are employed in fuel design. Additionally, precaution of fuel handling on assembling are considered. Reception of fuel rods, assembling of fuel elements and storage of second driver fuels in the fresh fuel storage rack in the HTTR were started since June, 2008. Assembling, storage and pre-service inspection were divided into three parts. The second driver fuel assembling was completed in September, 2008. This report describes concerns of fuel handling on assembling and storage work for the HTTR fuel elements.
Kaminaga, Katsuo; Tsuboi, Kazuaki; Kusunoki, Hidehiko; Asano, Norikazu; Yanai, Tomohiro
JAERI-Tech 2003-051, 26 Pages, 2003/05
The sixth replacement of beryllium frame has been accomplished for the west and north frame, while the old east frame of fifth generation is preserved for use. JMTR achieved its first criticality in 1968 and has been in operation until today, with an integrated thermal output of 141.454.5 MWd. During that period replacement was carried out 4 times for all the frames, east, west and north. This time, differently from the previous replacement, west and north frames only were manufactured and installed, when the old east frame was left for continuous use, based on the past experience. Such a strategy contributed to reduction of budget and the waste associated.
Asano, Norikazu; Kurosawa, Akihiko; Yanai, Tomohiro; Watahiki, Shunsuke; Kameyama, Yasuhiko; Onoue, Ryuji; Tobita, Kenji; Fukasaku, Akitomi
no journal, ,
no abstracts in English
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.