Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
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.
Noguchi, Akira; Kishi, Hirokazu; Hatanaka, Koichiro; Naito, Morimasa
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 6 Pages, 2011/10
A standardized method for choosing a mix design of low pH shotcrete is proposed for their intended use in the construction of a High Level Radioactive Waste (HLW) repository in order to be applied to the various geological environment of the location of the HLW repositories. There are two improvement in this method. One is estimating binder composition to satisfy low pH. The other is estimating water bender ratio to satisfy the strength of sprayed concrete. The method uses a sequential development process with consideration given to a number of physicochemical requirements, incorporates current shotcrete technology. The method is demonstrated in its entirety through a series of experiments and tests using a low pH cement binder comprised of a mixture of ordinary Portland cement, fly ash (FA) and silica fume (SF), referred to here as high-volume FA SF cement (HFSC). Moreover, the method is referred from the demonstration of HFSC shotcrete in Horonobe underground research laboratory.
Doughty, C.*; Tsang, C.-F.*; Hatanaka, Koichiro; Yabuuchi, Satoshi; Kurikami, Hiroshi
Water Resources Research, 44(8), p.W08403_1 - W08403_11, 2008/08
Times Cited Count：17 Percentile：44.06(Environmental Sciences)The flowing fluid electric conductivity (FFEC) logging method is an efficient way to provide information on the depths, salinities, and inflow strengths of individual conductive features intercepted by a borehole, without the use of specialized probes. The present paper presents the application of the method to two zones within a 1000-m borehole in sedimentary rock, which produced, for each zone, three sets of logs at different pumping rates, each set measured over a period of about one day.
Sugai, Eiji; Terunuma, Hirotaka; Otani, Takehisa; Hikita, Keiichi; Hatanaka, Akira; Samoto, Hirotaka; Okano, Masanori; Hayashi, Shinichiro
no journal, ,
A dissolution test of the sludge gathered from the dissolver of Tokai Reprocessing Plant (TRP) was performed for the purpose of eliminating of the sludge, which deposited in the dissolver and clogged pipes equipped in the dissolver. In the result, the sludge consisted primarily of ZrMoO
(OH)(HO) and was possible to eliminate at the rate of about 80% by using NaOH and HNO
reagent which was commonly-used in the PUREX process. From this experimental result, it is thought that the method of using NaOH and HNO reagent is effective method for the elimination of the sludge which deposited in the dissolver.
Sugai, Eiji; Kikuchi, Hideki; Hatanaka, Akira; Otani, Takehisa; Suzuki, Kazuyuki; Taguchi, Katsuya
no journal, ,
no abstracts in English
Yokota, Satoru; Hatanaka, Akira; Fujimori, Masahito; Shimoyamada, Tetsuya; Nakamura, Yoshinobu
no journal, ,
Three batch-type dissolvers in the Tokai Reprocessing Plant are a device for dissolving spent fuel. The dissolver is composed of one slab and two barrels (stainless steel 310s). Install a fuel basket (stainless steel 304L) in the barrel and accept the sheared spent fuel to dissolve it. The insoluble fuel cladding is taken out of the barrels with the basket. The dissolution time of operation for one batch is approximately 10 hours. During dissolution operation, nitric acid was added to the dissolver into the spent fuel in the basket with water. The solution was heated with steam. Corrosion failure has occurred in the past because the dissolver is exposed to a high corrosive environment (high temperature, high acid concentration). Therefore, we carry out the periodical wall thickness measurement of the barrel by the remote control. On the other hand, the wall thickness measurement of the fuel basket was carried out only once by destructive measurement at the time of renewal in 1999. The details of the corrosion tendency of the fuel basket are unknown, and it is urgent to establish a non-destructive measurement method by remote handling. Therefore, we examined the method of wall thickness measurement of the fuel basket and established the measuring technique.
