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Suwa, Masayuki; Isaka, Koji; Ouchi, Satoshi; Goto, Shingo; Ikekame, Yoshinori; Terakado, Yoshibumi
JAEA-Technology 2011-041, 35 Pages, 2012/03
JAEA-Technology-2011-041.pdf:7.11MB
JRR-3 process control computer system is used to monitor and control various process parameters such as flow rates, temperatures, pressures and so on, and operate many reactor components such as cooling pumps and valves. The system has been under aging degradation at this time and the renewal of the system has become indispensable. The renewal work has planned, paying a due consideration to minimizing renewal costs and duration, to be separated in three stages. This paper describes the renewal plan and renewal works of main part of the system.
Ouchi, Satoshi; Suwa, Masayuki; Isaka, Koji; Ikekame, Yoshinori; Terakado, Yoshibumi
JAEA-Testing 2011-006, 43 Pages, 2012/02
JAEA-Testing-2011-006.pdf:2.9MB
JRR-3 has been utilized for various researches such as neutron irradiation experiment, neutron beam experiment and so on as a high performance research reactor with thermal power of 20 MW since the first criticality in March, 1990. Process data needed for JRR-3 operation such as temperatures, pressures, and flow rates, etc. had been processed by JRR-3 process computer system which consisted of several computer systems and several application softwares. The system needed complicated data administration and conservation. Also there was a problem in the administration of recording data. Data discrepancy among computers used in the system was taken place since the system was not so designed as to synchronize the process timing among the computers. Therefore, we developed a program to synchronize among all of the computers. This paper reports the development of data processing computer system.
Fukushima, Manabu; Owada, Minoru; Ota, Kazunori; Takeuchi, Masaki; Goto, Shingo; Imahashi, Masaki; Terakado, Yoshibumi
JAEA-Technology 2010-028, 24 Pages, 2010/09
JAEA-Technology-2010-028.pdf:1.01MB
The cooling tower of the JRR-3's secondary cooling system is used to emit the heat from the core into the atmosphere. The appropriate maintenance of the cooling tower has helped the safe and stable reactor operation. Temperature of the secondary coolant had controlled constantly by changing the number of cooling fans. But, just after the number of fans changed, the temperature changed transiently and consequently the reactor thermal power changed. In order to amend this some weakness, the control system has improved to change the speed of fans constantly. The maintenance and improvement activities with the records of inspection are compiled to be utilized for future work.
Oba, Toshinobu; Fukushima, Manabu; Takeuchi, Masaki; Uno, Yuki; Owada, Minoru; Terakado, Yoshibumi
JAEA-Technology 2010-020, 31 Pages, 2010/07
JAEA-Technology-2010-020.pdf:1.33MB
Japan research reactor No.3 (JRR-3) has a heavy water tank. The heavy water tank surrounds the reactor core to use thermalize neutrons for experiments. The heavy water cooling system removes the heat generated by 
ray in the heavy water reflector. The heavy water cooling system is composed of the cooling system and the helium gas system. The helium gas system has an important role of helium gas circulation. The helium gas system also has a role to recombine deuterium gas and oxygen gas. We had overhauled the helium compressor regularly and replaced consumable parts. However, in recent year, the helium compressor had sometimes stopped by the leakage of seal oil. In 2007, we refurbished the helium compressor with new one. This report describes refurbishment of helium compressor.
Ichimura, Toshiyuki; Suwa, Masayuki; Fukushima, Manabu; Oba, Toshinobu; Nemoto, Yoshinori; Terakado, Yoshibumi
Proceedings of 12th International Group on Research Reactors (12th IGORR) (USB Flash Drive), 8 Pages, 2009/10
Murao, Hiroyuki; Yachi, Shigeyasu; Ota, Kazunori; Muramatsu, Yasuyuki; Nakamura, Takehiko; Terakado, Yoshibumi
UTNL-R-0435, p.15_1 - 15_9, 2004/03
no abstracts in English
Murao, Hiroyuki; Yachi, Shigeyasu; Ota, Kazunori; Muramatsu, Yasuyuki; Nakamura, Takehiko; Terakado, Yoshibumi
JAERI-Tech 2003-094, 41 Pages, 2004/01
JAERI-Tech-2003-094.pdf:2.26MB
Prior to actual runs in the shaped pulse and in the combined pulse operations, the online simulation and the offline simulation must be performed to examine safety and appropriation. Actual reactor power of the NSRR can be simulated practically, but a slight difference canbe observed between the present simulation results and the actual operation during the NSRR start-up phase and power controled operation. Regulating rod worth and fuel temperature feedback reactivity were re-evaluated and installed into the simulators. As a result, the accuracy of the simulator was remarkably improved. So that the application and safety of the shaped pulse and combined pulse operation were improved.
Nakamura, Takehiko; Katanishi, Shoji; Kashima, Yoichi; Yachi, Shigeyasu; Yoshinaga, Makio; Terakado, Yoshibumi
Journal of Nuclear Science and Technology, 39(3), p.264 - 272, 2002/03
Times Cited Count：8 Percentile：47.9(Nuclear Science & Technology)In order to study fuel behavior under abnormal transients and accidents, the control system of the Nuclear Safety Research Reactor (NSRR) of the Japan Atomic Energy Research Institute (JAERI) was modified to achieve high power transients. With this new operational mode, called Shaped Pulse (SP), transients at the maximum power of 10 MW can be conducted for a few seconds. This new operational mode supplements the previous Natural Pulse (NP) operation at the maximum power of 23 GW for milliseconds. For high power transient operation, a simulator using a point kinetic model was developed, and characteristics of the NSRR in the new operational mode were examined through tests and calculations. With the new operational mode, new types of fuel irradiation tests simulating power oscillations of boiling water reactors (BWRs) can to be conducted in the NSRR. Reactor characteristics and capability, such as control rod worth, feedback reactivity, and operational limits of the NSRR for SP operations are discussed.
Inabe, Teruo; Terakado, Yoshibumi; Tanzawa, Sadamitsu; ; Kobayashi, Hideo
JAERI-M 88-218, 124 Pages, 1988/11
no abstracts in English
Uezu, Yasuhiro; Ouchi, Takeshi; Shirai, Kenji; Terakado, Yoshibumi
no journal, ,
no abstracts in English
Hosoya, Toshiaki; Yamaguchi, Atsushi; Kato, Tomoaki; Terakado, Yoshibumi
no journal, ,
no abstracts in English
Nio, Daisuke; Yagi, Masahiro; Hirane, Nobuhiko; Horiguchi, Hironori; Terakado, Yoshibumi
no journal, ,
no abstracts in English
