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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
Ota, Kazunori; Kurumada, Osamu; Nio, Daisuke; Uno, Yuki; Murayama, Yoji
JAEA-Testing 2011-004, 47 Pages, 2011/08
The JRR-3 start-up channels, used for monitoring neutron flux during the start-up procedure, are exchanged periodically. The exchange procedure was reviewed and improved to the JRR-3 start-up channels exchanging manual. Following the manual, exchanging work would be carried out adequately.
Nio, Daisuke; Ikekame, Yoshinori; Kurumada, Osamu
UTNL-R-0471, p.12_2_1 - 12_2_8, 2009/03
no abstracts in English
Kurumada, Osamu
no journal, ,
JRR-3 at Tokai site of JAEA was in its regular maintenance period, when the Great East Japan Earthquake took place on 11th March 2011. The reactor building with the solid foundations and the equipment important to safety survived the earthquake without serious damage, and no radioactive leakage has been occurred. Recovery work, check and test of the integrity for all components have been carried out. In response to the accident at Fukushima Daiichi NPS, the Reactor Regulation Act was revised in June 2012, for the purpose of introducing new regulations based on the latest technical analysis. The revision introduces the "backfit system" under which the existing nuclear facilities are also required to conform to new regulatory requirements. Now, we confirmed that JRR-3 conforms to new regulations on research and test reactor facilities which came into force on 18th December 2013. Therefore, we have applied for permission for changes in reactor installment license on 26th September 2014. We will present the current state of JRR-3 and future plan.