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Isaka, Koji; Suwa, Masayuki; Kimura, Kazuya; Suzuki, Makoto; Ikekame, Yoshinori; Nagadomi, Hideki
JAEA-Technology 2021-039, 48 Pages, 2023/02
JRR-3 Process control system is used from the initial criticality (1990) after remodeling JRR- 3 as equipment used for monitoring and control of flow rate, temperature, pressure, water level, etc. of coolant and operation of nuclear reactor equipment, and it became necessary to renew as the aging progressed and spare parts could not be obtained sufficiently. Upon renewal, from the viewpoint of ensuring conservation of the core such as decay heat removal and minimizing the impact on reactor users and minimizing costs, it is important not to stop long-term reactor shutdown we planned to divide it into three stages and make it on a continuous basis. This report summarizes the renewal plan and renewal work divided into three stages.
Ouchi, Satoshi; Kurumada, Osamu; Kamiishi, Eigo; Sato, Masayuki; Ikekame, Yoshinori; Wada, Shigeru
JAEA-Technology 2016-015, 42 Pages, 2016/06
The purpose of the control rod drive mechanism seating position detector for JRR-3 is one of a method for confirming the shutdown condition of the reactor. The detector has been utilizing more than 25 years with maintenance regularly. However, it is occurred some trouble recently. Moreover, the detector has already been end of manufacture, and even in the successor detector, it unsuitable for the control rod drive mechanism of JRR-3 was confirmed. Therefore, it was necessary to select the adequate detector to the control rod drive mechanism of JRR-3. Accordingly, we built a test device with the aim of verify several detectors for integrity and function. At the time of the test for performance confirmation, it was occurred unexpected problems. Nevertheless, we devise improvement of the problems and took measures. Thus we were able to collect adequate detector for JRR-3 and replace to enhanced detector. This paper reports the Enhanced of Control rod drive mechanism seat position detector.
Kurumada, Osamu; Ikekame, Yoshinori; Ouchi, Satoshi; Sato, Masayuki; Kamiishi, Eigo; Wada, Shigeru
JAEA-Technology 2015-056, 35 Pages, 2016/03
The power supply for reactor control rod magnet of JRR-3 has been utilized for generating electromagnetic power of control rod coil and that was using more than 25 years. The power supply was required for provide to stabilize DC current. Therefore, we adopted series regulator method. Although, the power supply generate a high heat. Then, we decided to create switching regulator method in order to improve the aging and heat generation of the series regulator method. This paper reports the replacement of switching regulator method.
Kurumada, Osamu; Ouchi, Satoshi; Sato, Masayuki; Kamiishi, Eigo; Ikekame, Yoshinori
UTNL-R-0489, p.8_1 - 8_8, 2015/03
no abstracts in English
Suwa, Masayuki; Isaka, Koji; Ouchi, Satoshi; Goto, Shingo; Ikekame, Yoshinori; Terakado, Yoshibumi
JAEA-Technology 2011-041, 35 Pages, 2012/03
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
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.
Nio, Daisuke; Ikekame, Yoshinori; Kurumada, Osamu
UTNL-R-0471, p.12_2_1 - 12_2_8, 2009/03
no abstracts in English
Ota, Kazunori; Ikekame, Yoshinori; Owada, Minoru; Fukushima, Manabu; Oba, Toshinobu; Takeuchi, Masaki; Imahashi, Masaki; Murayama, Yoji
JAEA-Technology 2008-023, 31 Pages, 2008/03
JRR-3 uses shell and tube heat exchangers. The secondary coolant flushes into the tubes and the primary coolant flows outside of the tubes. The heat exchangers are cleaned with the ball-cleaning method, which is a method to clean inside of the tubes by passing the sponge balls with secondary coolant. Decline in the performance of heat exchanger could rise temperature of the primary coolant and then influence the safe and stable reactor operation. The effective way of ball-cleaning for JRR-3 heat exchangers is examined based on past cleaning data. The results show the optimal ball size and the way to determine the cleaning time.
Ota, Kazunori; Ikekame, Yoshinori; Owada, Minoru; Murayama, Yoji
UTNL-R-0466, p.7_1 - 7_10, 2008/03
JRR-3 uses shell and tube heat exchangers. The secondary coolant flushes into the tubes and the primary coolant flows outside of the tubes. The heat exchangers are cleaned with the ball-cleaning method, which is a method to clean inside of the tubes by passing the sponge balls with secondary coolant. Decline in the performance of heat exchanger could rise temperature of the primary coolant and then influence the safe and stable reactor operation. The effective way of ball-cleaning for JRR-3 heat exchangers is examined based on past cleaning data. The results show the optimal ball size and the way to determine the cleaning time.
Ikekame, Yoshinori; Ouchi, Satoshi; Suwa, Masayuki; Isaka, Koji; Goto, Shingo; Murayama, Yoji
JAEA-Technology 2007-052, 47 Pages, 2007/08
In order to sustain safe and stable operation of JRR-3, it is necessary to measure and indicate appropriately the process values such as flow rate of coolant with the process instrumentation facilities of JRR-3. Whenever reactor facilities such as cooling pump or measuring device are maintained or refurbished, the process instrumentation facilities are calibrated with the appropriate criteria established by considering overall accuracy of the facilities. In this report, for all of the safety protection system, a part of the process instrumentation facilities, accuracy of each component and overall accuracy of the system are compiled. Using these date, the process instrumentation facilities would be maintained more effectively and objectively.
Kabumoto, Hiroshi; Asozu, Takuhiro; Matsui, Yutaka; Nakagawa, Sohei; Ikekame, Takuma; Kato, Yuta; Ishizaki, Nobuhiro; Kutsukake, Kenichi; Otokawa, Yoshinori; Nakamura, Masahiko; et al.
no journal, ,
no abstracts in English
Nio, Daisuke; Ikekame, Yoshinori; Suwa, Masayuki; Isaka, Koji; Ouchi, Satoshi; Mineshima, Hiromi; Motohashi, Jun; Torii, Yoshiya; Kinase, Masami; Murayama, Yoji
no journal, ,
no abstracts in English
Suwa, Masayuki; Terunuma, Noriaki; Isaka, Koji; Ouchi, Satoshi; Ikekame, Yoshinori
no journal, ,
no abstracts in English
Nakagawa, Sohei; Matsuda, Makoto; Nakamura, Masahiko; Ishizaki, Nobuhiro; Kutsukake, Kenichi; Asozu, Takuhiro; Ikekame, Takuma; Kabumoto, Hiroshi; Otokawa, Yoshinori; Matsui, Yutaka; et al.
no journal, ,
no abstracts in English
Matsui, Yutaka; Nakamura, Masahiko; Kutsukake, Kenichi; Kabumoto, Hiroshi; Asozu, Takuhiro; Otokawa, Yoshinori; Ikekame, Takuma; Nakagawa, Sohei; Kato, Yuta; Ishizaki, Nobuhiro; et al.
no journal, ,
no abstracts in English
Nakamura, Masahiko; Otokawa, Yoshinori; Kato, Yuta; Kabumoto, Hiroshi; Kutsukake, Kenichi; Matsui, Yutaka; Matsuda, Makoto; Ishizaki, Nobuhiro; Ikekame, Takuma; Nakagawa, Sohei; et al.
no journal, ,
no abstracts in English