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Terunuma, Tomohiro; Ozeki, Tatsuya; Iwasaki, Shogo
Proceedings of 7th International Conference on NDE in relation to Structural Integrity for Nuclear and Pressurized Components (CD-ROM), p.424 - 429, 2010/00
After spent fuel is chopped mechanically, the pieces of spent fuel are dissolved with high temperature nitric acid in a dissolver. Uranium, plutonium and fission products dissolved in this solution are separated through extraction process, respectively. Although the dissolver is made of stainless steel, corrosion might occur because the dissolver is always exposed to high temperature nitric acid and the nitric acid hume, etc. The dissolver is installed in a hot cell where is under high radiation environment, and it is difficult for operators it to approach. Therefore, the remote-controlled equipment has been developed to repair and inspect the dissolver.
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.
Wakimoto, Fumitsugu; Morimoto, Kenji; Terunuma, Tomohiro; Ozeki, Tatsuya; Iwasaki, Shogo; Inami, Shinichi
no journal, ,
To investigate the cause of the leak phenomenon from the sea release facilities of the Tokai reprocessing plant, the part of the pipe having the leak point was collected, and the investigations such as surface observation, chemical analysis etc. were performed. As a result, following things were shown as estimated causes; the leak point of the release pipe was mechanically damaged during the construction, breaking occurred on the damaged part by a successive change; and the leak occurred. This paper reports the details of the identified cause that the initial damage by external force would affect the leak phenomenon of the sea release piping.