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Fujishima, Tadatsune; Sakamoto, Naoki; Mizukoshi, Yasutaka; Amagai, Tomio; Omori, Tsuyoshi
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.388 - 392, 2008/07
no abstracts in English
Sakamoto, Naoki; Yoshikawa, Katsunori; Kushida, Naoya; Nakamura, Yasuo; Sukegawa, Kiyoshi*
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.226 - 230, 2008/07
no abstracts in English
Terunuma, Tomohiro; Ozeki, Tatsuya; Fukuari, Yoshihiro
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.129 - 132, 2008/07
The two dissolvers installed in the Tokai reprocessing plant had failed occurred successively in 1982 and 1983. Then, remote-controlled equipment for repair and inspection has been developed because the dissolvers were installed under the high dose of radiation and cannot access easily. After repair of the dissolvers, the periodic inspection by remoteness is periodically carried out once per year for soundness confirmation of the vessels. Moreover, the remote inspection equipment for periodic inspection was developed, which time required for inspection is too short compared with former equipment.
Nio, Daisuke; Ota, Kazunori; Ishizaki, Katsuhiko
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.393 - 395, 2008/07
The research reactor JRR-3 was constructed for the purpose of development of nuclear technology and a large scale modification was done. It is necessary to investigate a maintenance methods considering high aging, because more than 15 years has passed from a large modification. In such situation, we should continue condition monitoring method which does not spoil safety and reliability and apply other instruments. So far, monitoring of vibration and lubricating oil has been done, and we might think it appropriate. From now on, we continue investigating that condition monitoring could be applied for other instruments.
Yasuo, Kiyoshi; Seto, Nobuhiko; Watahiki, Seiichi; Fukuari, Yoshihiro
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.385 - 387, 2008/07
The nitric acid solution including nuclear fuel material is transferred by the three way valve called VCV (VCV: vide-casse-vide in Fr.) using vacuum in the Tokai Reprocessing Plant. The reliability of initial three way valve was not obtained because failure occurred by use for one or two years. The cause of failure was damage of the plastic diaphragms in the moving parts. Then, the new three way valve with stainless-steel bellows was developed. there is no failure in moving parts, reliability improved significantly.
Tagawa, Akihiro; Ueda, Masashi; Miyahara, Shinya; Yamashita, Takuya
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.470 - 472, 2008/07
This paper describes the development of a new sensor for the pipe health monitoring. The Hybrid measuring using EMAT was made as a trial. It examined and checked that it could measure. The result confirmed that the high accuracy of 200 
C at high temperature was acquired in pipe surface temperature, pipe wall thinning, and water temperature.
Takamine, Jun; Haruyama, Mitsuo; Takase, Misao
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.481 - 484, 2008/07
We have not yet known the nondestructive detection method to determine each quantity of the object which Uranium and Plutonium is mixed in, such a waste generated from nuclear fuel cycle facility, and so radioactive intensity of Pu-239 is 10,000 times as much as U-235. Therefore, on radioactive assessment, it is important to precisely quantify each mass. Then we paid attention to the component of delayed and prompt neutron obtained by 14 MeV neutron direct interrogation method and so developed the new method to determine mass ratio between Uranium and Plutonium from those correlations.
Kobayashi, Tetsuya; Ichimura, Toshiyuki; Sato, Masayuki
Nihon Hozen Gakkai Dai-5-Kai Gakujutsu Koenkai Yoshishu, p.340 - 343, 2008/07
The maintenance evaluation for research reactors has been obligated in Japan from 2004 as for power reactors. JAEA (Japan Atomic Energy Agency) has started to evaluate the maintenance for own research reactors on 2004. In this paper, we report the present status of the maintenance for JRR-3 (Japanese Research Reactor No.3), as well as the linear evaluation methods used. It is found that a series of preventing maintenance task on equipment and building of the reactor is properly performed.