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Suzuki, Kazuyuki; Hatanaka, Akira; Samoto, Hirotaka; Suwa, Toshio; Tanaka, Kosuke; Tanaka, Yukiyoshi
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 6 Pages, 2011/12
The properties of the sludge in dissolver vessels from the reprocessing of ATR-MOX and ATR-UO
fuels were investigated on the pilot-plant scale at the Tokai Reprocessing Plant (TRP). This sludge is mainly composed of platinum-group elements, zircaloy fragments, and post-precipitates from the dissolver solution. The sludge deposited on the dissolver causes difficulties such as pipe clogging. The characteristics of the sludge collected from the dissolver vessels, which affect the reprocessing operation, were revealed through chemical composition analysis using ICP-AES, and XRD. It was confirmed that the major component of the sludge was zirconium molybdate, and no significant differences between ATR-MOX and ATR-UO fuels were observed in terms of the sludge compositions. In order to gain further understanding of the properties of the sludge, the distributions of Pu and other trace elements were EPMA.
Otani, Takehisa; Suzuki, Kazuyuki; Hata, Katsuro; Kikuchi, Hideki; Nakamura, Daishi; Samoto, Hirotaka; Tanaka, Yukiyoshi
no journal, ,
The investigation of the behavior of krypton gas arising due to reprocessing of spent fuels has been performed at TRP. The whole amount of Kr gas transfers to the off-gas system through shearing and dissolution process, so it is applicable as an indicator to determine the progress of fuel dissolution. It is thought that the behavior of gaseous fission product, including Kr, in the spent fuels depends on burn-up and the type of spent fuels. In the reprocessing process, these deference are reflected to the migration rate of krypton gas between shearing off-gas system (SOG) and dissolver off-gas system (DOG). At TRP, four types of spent fuels (LWR; PWR, BWR and ATR; UO, MOX) were treated and examined about their release characteristics of krypton gas in order to understand the effect on burn-up and type of spent fuels. In this report, the results concerning the ATR-UO fuel and ATR-MOX fuel are discussed compared with the results of LWR fuel.
Otani, Takehisa; Takahashi, Makoto; Akutsu, Tomoyuki*; Kimura, Norimichi; Tanaka, Yukiyoshi
no journal, ,
Optimum geometry of electrodes, which were equipped at the top and bottom of the krypton gas immobilizing chamber, was investigated for improvement of the immobilizing capability with enlarged krypton gas immobilizing chamber.
Nakamura, Daishi; Kikuchi, Hideki; Terunuma, Hirotaka; Uchida, Naoki; Tanaka, Yukiyoshi
no journal, ,
Sludge generated in the dissolution vessel deposit on storage vessel and caused translation pipe to be choked. It is difficult to remove sludge from vessel and translation piping for few of accessible point in this line and high radioactive environment. In this report, we report on the blockage removal device and method in translation piping adapted on existing machine in order to establish sludge removal technique.
Kikuchi, Hideki; Numata, Shinji; Suzuki, Kazuyuki; Wakimoto, Fumitsugu; Tanaka, Yukiyoshi
no journal, ,
Tokai Reprocess Plant (TRP) has reprocessed about 1140 tU spent nuclear fuel for 35 years. In clarification process, there are 2 kinds of valves that used under spent fuel dissolving solution environment. These valves operation data are very valuable in process handling dissolving solution because the valves are rarely used in this process. In this report, we summarize malfunctions of the valves that we have experienced until now, and explain the method of maintenance and operation management.
Namatame, Toshihiro; Masui, Kenji; Takahashi, Masatomi; Sato, Takehiko; Fujimoto, Ikuo; Tanaka, Yukiyoshi
no journal, ,
no abstracts in English