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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.
Iyoku, Tatsuo; Nojiri, Naoki; Tochio, Daisuke; Mizushima, Toshihiko; Tachibana, Yukio; Fujimoto, Nozomu
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
A HTGR is particularly attractive because of its capability of producing high temperature helium gas and its inherent safety characteristics. Hence, the HTTR wasconstructed at the Oarai Research Establishment of the Japan Atomic Energy Agency. The HTTR achieved the full power of 30MW and reactor outlet coolant temperature of about 850
C on December 7, 2001. After several operation cycles, 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. Extensive tests are planned in the HTTR and a process heat application system will be coupled to the HTTR, where hydrogen will be produced directly from the nuclear energy.
Motegi, Toshihiro; Iigaki, Kazuhiko; Saito, Kenji; Sawahata, Hiroaki; Hirato, Yoji; Kondo, Makoto; Shibutani, Hideki; Ogawa, Satoru; Shinozaki, Masayuki; Mizushima, Toshihiko; et al.
JAEA-Technology 2006-029, 67 Pages, 2006/06
JAEA-Technology-2006-029.pdf:3.07MB
The plant control performance of the IHX helium flow rate control system, the PPWC helium flow rate control system, the secondary helium flow rate control system, the inlet temperature control system, the reactor power control system and the outlet temperature control system of the HTTR are obtained through function tests and power-up tests. As the test results, the control systems show stable control response under transient condition. Both of inlet temperature control system and reactor power control system shows stable operation from 30% to 100%, respectively. This report describes the outline of control systems and test results.
Hamamoto, Shimpei; Iigaki, Kazuhiko; Shimizu, Atsushi; Sawahata, Hiroaki; Kondo, Makoto; Oyama, Sunao; Kawano, Shuichi; Kobayashi, Shoichi; Kawamoto, Taiki; Suzuki, Hisashi; et al.
JAEA-Technology 2006-030, 58 Pages, 2006/03
JAEA-Technology-2006-030.pdf:10.69MB
During normal operation of High Temperature engineering Test Reactor (HTTR) in Japan Atomic Energy Agency (JAEA), the reactivity is controlled by the Control Rods (CRs) system which consists of 32 CRs (16 pairs) and 16 Control Rod Drive Mechanisms (CRDMs). The CR system is located in stand-pipes accompanied by the Reserved Shutdown System (RSS). In the unlikely event that the CRs fail to be inserted, the RSS is provided to insert B
C/C pellets into the core. The RSS shall be designed so that the reactor should be held subcriticality from any operation condition by dropping in the pellets. The RSS consists of BC/C pellets, hoppers which contain the pellets, electric plug, driving mechanisms, guide tubes and so on. In accidents when the CRs cannot be inserted, an electric plug is pulled out by a motor and the absorber pellets fall into the core by gravity. A trouble, malfunction of one RSS out of sixteen, occurred during a series of the pre-start up checks of HTTR on February 21, 2005. We investigated the cause of the RSS trouble and took countermeasures to prevent the issue. As the result of investigation, the cause of the trouble was attributed to the following reason: In the motor inside, The Oil of grease of the multiplying gear flowed down from a gap of the oil seal which has been deformed and was mixed with abrasion powder of brake disk. Therefore the adhesive mixture prevented a motor from rotating.
Saito, Kenji; Nakagawa, Shigeaki; Hirato, Yoji; Kondo, Makoto; Sawahata, Hiroaki; Tsuchiyama, Masaru*; Ando, Toshio*; Motegi, Toshihiro; Mizushima, Toshihiko; Nakazawa, Toshio
JAERI-Tech 2004-042, 26 Pages, 2004/04
JAERI-Tech-2004-042.pdf:1.16MB
The reactor control system of HTTR is composed of the reactor power control system, the reactor inlet coolant temperature control system, the primary coolant flow rate control system and so on. The reactor control system of HTTR achieves reactor power 30MW, reactor outlet coolant temperature 850C, reactor inlet coolant temperature 395C under the condition that primary coolant flow rate is fixed. In the Rise-to-Power Test, the performance test of the reactor inlet coolant temperature control system was carried out in order to confirm the control capability of this control system. This report shows the test results of performance test. As a result, the control parameters, which can control the reactor inlet coolant temperature stably during the reactor operation, were successfully selected. And it was confirmed that the reactor inlet coolant temperature control system has the capability of controlling the reactor inlet coolant temperature stably against any disturbances on the basis of operational condition of HTTR.
Hirato, Yoji; Saito, Kenji; Kondo, Makoto; Sawahata, Hiroaki; Motegi, Toshihiro; Tsuchiyama, Masaru*; Ando, Toshio*; Mizushima, Toshihiko; Nakazawa, Toshio
JAERI-Tech 2004-037, 33 Pages, 2004/04
JAERI-Tech-2004-037.pdf:4.08MB
HTTR (High Temperature Engineering Test Reactor) was operated from May 6th, 2003 to June 18th, 2003 to obtain operation data in parallel loaded operation mode and in safety demonstration tests. Operated with the reactor power at 60% of the rated power on May 21st, HTTR was automatically scrammed by a signalof "Primary coolant flow rate of the Primary Pressurized Water Cooler (PPWC): Low". The cause of the shutdown was the primary gas circulator (A) automatically stopped. The primary coolant flow rate of the PPWC decresed and reached the scram set value due to the gas circulator stop. As a result of investigation, it became clear that the cause of the gas circulator stop was malfunction of an auxiliary relay which monitored electric power of a circuit breaker in power line of the gas circulator. The cause of malfunction was deterioration of the relay under high temperature condition because the relay was installed beside an electric part which was heated up by electricity.
Aramaki, Takafumi; Mizushima, Toshihiko; Kuji, Tomoyuki*; Povinec, P. P.*; Togawa, Orihiko
Radiocarbon, 43(2B), p.857 - 867, 2001/03
no abstracts in English
Kitamura, Toshikatsu; Aramaki, Takafumi; Mizutani, Yoshihiko*; Togawa, Orihiko; Mizushima, Toshihiko; Kabuto, Shoji*; Sudo, Kazuhiko*
JAERI-Conf 2000-019, p.26 - 29, 2001/02
no abstracts in English
C in the north pacific and the pursuit of the anthropogenic carbonAramaki, Takafumi; Watanabe, Shuichi*; Tsunogai, Shizuo*; Kuji, Tomoyuki*; Mizushima, Toshihiko; Togawa, Orihiko
JAERI-Conf 2000-019, p.73 - 75, 2001/02
no abstracts in English
Aramaki, Takafumi; Mizushima, Toshihiko; Mizutani, Yoshihiko*; Yamamoto, Tadatoshi; Togawa, Orihiko; Kabuto, Shoji*; Kuji, Tomoyuki*; Gottdang, A.*; Klein, M.*; Mous, D. J. W.*
Nuclear Instruments and Methods in Physics Research B, 172(1-4), p.18 - 23, 2000/10
Times Cited Count：26 Percentile：82.67(Instruments & Instrumentation)no abstracts in English
Mizushima, Toshihiko; Togawa, Orihiko; Mizutani, Yoshihiko*; Kabuto, Shoji*; Yamamoto, Tadatoshi
JAERI-Tech 2000-004, p.68 - 0, 2000/02
JAERI-Tech-2000-004.pdf:7.24MB
no abstracts in English
Togawa, Orihiko; *; Mizushima, Toshihiko; Yabuuchi, Noriaki; Kobayashi, Takuya
JAERI-Research 98-062, 50 Pages, 1998/10
JAERI-Research-98-062.pdf:3.49MB
no abstracts in English
Yamaki, Jikei; Fujikawa, Seigo; ; Ishida, Toshihisa; Mizushima, Toshihiko; *; Sakamoto, Yukio;
Genshiryoku Kogyo, 38(4), p.13 - 28, 1992/04
no abstracts in English
Kakuta, Tsunemi; Kitamura, Toshikatsu; Mizushima, Toshihiko; ; *; *; *; *; *
JAERI-M 92-034, 82 Pages, 1992/03
no abstracts in English
; Kitamura, Toshikatsu; Mizushima, Toshihiko; Kakuta, Tsunemi; *; *; *; *; *; *
JAERI-M 91-212, 107 Pages, 1992/01
no abstracts in English
*; Mizushima, Toshihiko; Kakuta, Tsunemi; Nakazawa, Toshio
DEI-91-136, p.59 - 68, 1991/12
no abstracts in English
*; Kakuta, Tsunemi; Mizushima, Toshihiko; Nakazawa, Toshio; *
EIM-89-124, p.27 - 36, 1989/12
no abstracts in English
Shimizu, Atsushi; Hamamoto, Shimpei; Kobayashi, Shoichi; Ishii, Yoshiki; Iigaki, Kazuhiko; Inoi, Hiroyuki; Kawamoto, Taiki; Mizushima, Toshihiko; Nakazawa, Toshio
no journal, ,
no abstracts in English
Fujimoto, Nozomu; Nojiri, Naoki; Tachibana, Yukio; Mizushima, Toshihiko
no journal, ,
A High Temperature Gas-cooled Reactor (HTGR) is particularly attractive because of its capability of producing high temperature helium gas and its inherent safety characteristics. Hence, the High Temperature Engineering Test Reactor (HTTR) was successfully constructed at the Oarai Research Establishment of the Japan Atomic Energy Agency. 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. This is one of the major milestones in HTGR development of high temperature nuclear process heat application. Extensive tests are planned in the HTTR and a process heat application system will be coupled to the HTTR, where hydrogen will be produced directly from the nuclear energy. This paper gives an overview of the HTTR Project focusing on the latest results from the HTTR test and the future test plan using the HTTR.
