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Inoi, Hiroyuki; Shimizu, Atsushi; Kameyama, Yasuhiko; Kobayashi, Shoichi; Shinozaki, Masayuki; Ota, Yukimaru; Kubo, Tsukasa*; Emori, Koichi
JAEA-Technology 2009-048, 48 Pages, 2009/10
JAEA-Technology-2009-048.pdf:5.0MB
The emergency power feeders of the High Temperature Engineering Test Reactor (HTTR) have gas turbine generators which are composed of gas turbin engines, generators and current breakers. The gas turbine generators have been overhauled and maintained to keep the performance. The maintenance technology was upgraded by improving their parts and surveillance method on the basis of the operational and maintenance experience. It can be clarified that the deterioration levels and the sudden deterioration timing are judged at an early stage by measuring the max exhaust temperature at the time of start in addition to check the starting time of the Gas Turbine Engines.
Iyoku, Tatsuo; Nojiri, Naoki; Fujimoto, Nozomu; Shinohara, Masanori; Ota, Yukimaru; Tachibana, Yukio
Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10
The High Temperature Gas-cooled Reactor (HTGR) is expected to be one of the most promising energy sources not only for electricity generation and but also for process heat applications such as hydrogen production, desalination, etc. In Japan, since 1960s Japan Atomic Energy Agency (JAEA) has been developing HTGR technologies such fuel, high temperature metal, graphite, core physics, thermal hydraulics control and so forth. These technologies were well developed and used to design and construct the Japan's first HTGR, High Temperature Engineering Test Reactor (HTTR). It is a graphite-moderated and helium-cooled HTGR with the rated thermal power of 30 MW and the maximum outlet coolant temperature of 950
C. The HTTR achieved the reactor outlet coolant temperature of 950C on April 19, 2004. It is the highest coolant temperature outside reactor pressure vessel in the world. So far, basic performance data of the HTTR during the power-up and long-term high temperature operation tests are accumulated. Except that, various unique tests concerning the HTGR safety are conducted to confirm inherent safety characteristics of the HTGR.
Yamazaki, Kazunori; Kameyama, Yasuhiko; Inoi, Hiroyuki; Arakaki, Etsushi; Shinozaki, Masayuki; Ota, Yukimaru
JAEA-Testing 2008-002, 52 Pages, 2008/03
JAEA-Testing-2008-002.pdf:15.54MB
The High Temperature Engineering Test Reactor (HTTR) has the Gaseous Radwaste Treatment System (GRTS). This system appropriately collects all potentially radioactive gases discharged from the plant. After the gases are decayed with the Decay tank and decreased with the Filtering system, the gases are discharged into the atmosphere under monitoring. This system is maintained every year for keeping the performance. The maintenance is very important. Furthermore, the maintenance is profitable for designing a new High Temperature Gas cooled Reactor. This report describes the newly developed, maintenance items and improvements of the GRTS.
Kameyama, Yasuhiko; Watanabe, Shuji; Inoi, Hiroyuki; Shimizu, Yasunori; Aragaki, Etsushi; Shinozaki, Masayuki; Ota, Yukimaru
JAEA-Testing 2008-001, 63 Pages, 2008/03
JAEA-Testing-2008-001.pdf:20.97MB
The High Temperature Engineering Test Reactor (HTTR) has the Auxiliary Component Cooling Water System (ACCWS) and the General Cooling Water System (GCWS). ACCWS supplies the cooling water to the many facilities those are necessary to operate and cool the reactor. GCWS supplies the cooling water to the many facilities those are necessary to operate and cool the reactor in normal circumstances. Two kinds of the cooling water are cooled with the Cooling Tower. Each facility has the circulation pump, the cooling tower, the piping, the valve, the strainer and the injection system of the chemical solution. And these two facilities are operating all the year. This report describes maintenance items, improvements and management of the ACCWS and the GCWS.
Oyama, Sunao*; Hamamoto, Shimpei; Kaneshiro, Noriyuki*; Nemoto, Takahiro; Sekita, Kenji; Isozaki, Minoru; Emori, Koichi; Ito, Yoshiteru*; Yamamoto, Hideo*; Ota, Yukimaru; et al.
JAEA-Technology 2007-047, 40 Pages, 2007/08
JAEA-Technology-2007-047.pdf:18.83MB
High-Temperature engineering Test Reactor (HTTR) built by Japan Atomic Energy Agency (JAEA) has commonly used reciprocating compressor to extract helium gas and discharge helium gas into primary/secondary coolant helium loop from helium purification system. Rod-seal structure of the compressor is complicated from a prevention coolant leak standpoint. Because of frequently leakage of seal oil in operation, Rod seal structure isn't as reliable as it should be sustainable in the stable condition during long term operation. As a result of investigations, leakage's root is found in that seal were used in a range beyond limit sliding properties of seal material. Therefore a lip of the seal was worn and transformed itself and was not able to sustain a seal function. Endurance test using materials testing facility and verification test using a actual equipment on candidate materials suggest that a seal of fluorine contained resin mixed graphite is potentially feasible material of seal.
Tochio, Daisuke; Kameyama, Yasuhiko; Shimizu, Atsushi; Inoi, Hiroyuki; Yamazaki, Kazunori; Shimizu, Yasunori; Aragaki, Etsushi; Ota, Yukimaru; Fujimoto, Nozomu
JAEA-Technology 2006-045, 43 Pages, 2006/09
JAEA-Technology-2006-045.pdf:5.97MB
The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR) The ACCWS has the features not only many facilities cooling but also heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design.
Hamamoto, Shimpei; Watanabe, Shuji; Oyama, Sunao*; Ota, Yukimaru; Tochio, Daisuke; Fujimoto, Nozomu
JAERI-Tech 2005-035, 35 Pages, 2005/07
JAERI-Tech-2005-035.pdf:2.54MB
The Vessel Cooling System (VCS) is one of the safety engineered features of the HTTR. The VCS removes the decay heat of the reactor core when the forced circulation can not be maintained due to pipe rupture accidents, etc. VCS cools the core by water cooling panels surrounding the reactor pressure vessel. The VCS also keeps the temperature of the concrete of the primary shielding under the design limit during the operation. The temperature of cooling water of the VCS has recently tended to rise gradually, though the amount of heat removal of VCS has been constant. Accompanying with the increase of the cooling water temperature, the temperature of the shielding concrete is also possible to rise and exceed the limit. The heat exchange performance of the VCS cooler was evaluated and the deterioration of the cooler was verified. Therefore, the cleaning of heat transfer tubes was carried out to recover the heat exchange performance. The cleaning recovered the performance of the VCS cooler drastically and the cooling water temperature of the VCS could be reduced sufficiently.
Sakaba, Nariaki; Furusawa, Takayuki; Kawamoto, Taiki; Ishii, Yoshiki; Ota, Yukimaru
Nuclear Engineering and Design, 233(1-3), p.147 - 154, 2004/10
Times Cited Count：10 Percentile：56.13(Nuclear Science & Technology)The HTTR mainly consists of the core components, reactor pressure vessel, cooling systems, instrumentation and control systems, and containment structures. The design of remaining utility systems is described in this paper. They are: auxiliary helium systems which include the helium purification system, the helium sampling system, and the helium storage and supply system; fuel handling and storage system. The helium purification systems are installed in the primary and secondary helium cooling systems in order to reduce the quantity of chemical impurities. The helium sampling systems monitor the concentration of impurities. The helium storage and supply systems keep the steady pressure of the helium system during the normal operation. The fuel handling and storage system is utilised to handle the new and spent fuels safely and reliably.
Takamatsu, Kuniyoshi; Nakazawa, Toshio; Furusawa, Takayuki; Homma, Fumitaka; Saito, Kenji; Kokusen, Shigeru; Kamata, Takashi; Ota, Yukimaru; Ishii, Yoshiki; Emori, Koichi
JAERI-Tech 2003-062, 94 Pages, 2003/06
JAERI-Tech-2003-062.pdf:26.47MB
no abstracts in English
Hino, Ryutaro; Fujisaki, Katsuo; ; ; Ota, Yukimaru; ; ; Haga, Katsuhiro; ; Mogi, Haruyoshi; et al.
JAERI-Tech 96-037, 45 Pages, 1996/09
no abstracts in English
; Fujisaki, Katsuo; ; ; Ota, Yukimaru; Watanabe, Shuji; Kobayashi, Hideki*; Mogi, Haruyoshi
JAERI-Tech 96-030, 244 Pages, 1996/07
no abstracts in English
Takada, Shoji; Shibata, Mitsuhiko; ; Fujisaki, Katsuo; Ota, Yukimaru; ;
JAERI-M 94-013, 89 Pages, 1994/02
no abstracts in English
Inagaki, Yoshiyuki; Takada, Shoji; ; ; Ota, Yukimaru; Shimomura, Hiroaki;
Nucl. Eng. Des., 146, p.301 - 309, 1994/00
Times Cited Count：6 Percentile：52.36(Nuclear Science & Technology)no abstracts in English
Shimomura, Hiroaki; Kawaji, Satoshi; Ota, Yukimaru
Proc. of the 2nd Int. Symp. on Magnetic Bearings, p.93 - 99, 1990/00
no abstracts in English
Inoi, Hiroyuki; Isozaki, Minoru; Shinozaki, Masayuki; Tachibana, Yukio; Ota, Yukimaru; Fujimoto, Nozomu; Iyoku, Tatsuo
no journal, ,
no abstracts in English
Nojiri, Naoki; Ota, Yukimaru; Fujimoto, Nozomu
no journal, ,
no abstracts in English
Furusawa, Takayuki; Homma, Fumitaka; Inoi, Hiroyuki; Sawahata, Hiroaki; Nemoto, Takahiro; Watanabe, Shuji; Ota, Yukimaru
no journal, ,
Japan Atomic Energy Agency has constructed the HTTR (High Temperature engineering Test Reactor), which is the Japan's first High Temperature Gas-cooled Reactor (HTGR). The HTTR achieved the full power of 30MW and reactor outlet coolant temperature of 950C on April 19, 2004. Based on the HTTR maintenance experiences, the preservation technology for HTGR are developed. This paper describes its preservation philosophy and typical developed technologies.
