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; Aita, Tsuyoshi; Murakami, Takanori; Ito, Hideaki; Aoki, Hiroshi; Odo, Toshihiro
JNC TN9410 2004-006, 36 Pages, 2004/03
Joyo Plant Operation Management Expert Tool system named JOYPET has developed with the aim of confirming the stable and safety operation of JOYO and improving operational reliability in future FBR plants.New JOYPET system was designed and manufactured in 2002, and began or operation in 2003, because the former system, which was designed in 1988 and operated from 1991 to 2002, was superannuated, and it was difficult to obtain alternative hardwares and replace parts.The difference between the former one and the later new one was adopted the web-online system to use lan(Lacal area network) instead of the host and the terminal computer processing system.Then the new system enabled to take unitary document management for reactor operation, and each person in one's rost was able to search, refer and wake document on line directly.This document reported new JOYPET system design, manufacturing, system constitution and operation actual result.
Ito, Hideaki; Noritsugi, Hiroaki; Suzuki, Toshiaki; Yamazaki, Manabu; Okawa, Toshikatsu
Saikuru Kiko Giho, (21), p.77 - 97, 2004/00
Focusing on the cover layer materials (as the Radon Barrier Materials), which could have the effect to restrain the radon from scattering into the air and the effect of the radiation shielding, we produced the radon barrier materials with crude bentonite on an experimental basis, using the rotary type comprehensive unit for grinding and mixing, through which we carried out the evaluation of the characteristics thereof.
Yoshihara, Shizuya; Okawa, Toshikatsu; Inoue, Setsunari
no journal, ,
no abstracts in English
Karube, Koji; Aita, Tsuyoshi; Okawa, Toshikatsu
no journal, ,
no abstracts in English
Suzuki, Nobuhiro; Ito, Hiromichi; Sasaki, Jun; Okawa, Toshikatsu; Kawahara, Hirotaka; Kobayashi, Tetsuhiko; Sakao, Ryuta*; Murata, Chotaro*; Tanaka, Junya*; Matsusaka, Yasunori*; et al.
no journal, ,
no abstracts in English
Ushiki, Hiroshi; Ito, Hiromichi; Okuda, Eiji; Suzuki, Nobuhiro; Sasaki, Jun; Ota, Katsu; Kawahara, Hirotaka; Takamatsu, Misao; Nagai, Akinori; Okawa, Toshikatsu
no journal, ,
In the experimental fast reactor Joyo, it was confirmed that the top of the irradiation test sub-assembly of MARICO-2 (material testing rig with temperature control) had bent onto the in-vessel storage rack as an obstacle and had damaged the upper core structure (UCS) in 2007. As a part of the restoration work, UCS replacement was begun at March 24, 2014 and was completed at December 17. In-vessel repair (including observation) for sodium-cooled fast reactors (SFRs) is distinct from that for light water reactors and necessitates independent development. Application of developed in-vessel repair techniques to operation and maintenance of SFRs enhanced their safety and integrity. There is little UCS replacement experience in the world and this experience and insights, which were accumulated in the replacement work of in-vessel large sturucture (UCS) used for more than 30 years, are expected to improve the in-vessel repair techniques in SFRs.
Ashida, Takashi; Takamatsu, Misao; Ito, Hideaki; Okawa, Toshikatsu; Yoshihara, Shizuya
no journal, ,
In the experimental fast reactor Joyo, it was confirmed that the top of the irradiation test sub-assembly (S/A) of MARICO-2 (material testing rig with temperature control) had been broken and bent onto the in-vessel storage rack as an obstacle and had damaged the upper core structure (UCS). This incident necessitated the replacement of the UCS and the retrieval of the MARICO-2 sub-assembly for Joyo restoration. This paper describes the summary of Joyo restoration works. In-vessel repair techniques for sodium cooled fast reactors (SFRs) are important in confirming safety and integrity of SFRs. However, the demonstrated techniques under the actual reactor environment with high temperature, high radiation dose and remaining sodium are not enough to secure the reliability of these techniques. The experience and knowledge accumulated in the UCS replacement provides valuable insights into further improvements for in-vessel repair techniques in SFRs.
Aizawa, Kenji; Iseki, Atsushi; Okawa, Toshikatsu; Aita, Tsuyoshi; Kamata, Hidehisa
no journal, ,
no abstracts in English
