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Ouchi, Satoshi; Kurumada, Osamu; Kamiishi, Eigo; Sato, Masayuki; Ikekame, Yoshinori; Wada, Shigeru
JAEA-Technology 2016-015, 42 Pages, 2016/06
The purpose of the control rod drive mechanism seating position detector for JRR-3 is one of a method for confirming the shutdown condition of the reactor. The detector has been utilizing more than 25 years with maintenance regularly. However, it is occurred some trouble recently. Moreover, the detector has already been end of manufacture, and even in the successor detector, it unsuitable for the control rod drive mechanism of JRR-3 was confirmed. Therefore, it was necessary to select the adequate detector to the control rod drive mechanism of JRR-3. Accordingly, we built a test device with the aim of verify several detectors for integrity and function. At the time of the test for performance confirmation, it was occurred unexpected problems. Nevertheless, we devise improvement of the problems and took measures. Thus we were able to collect adequate detector for JRR-3 and replace to enhanced detector. This paper reports the Enhanced of Control rod drive mechanism seat position detector.
Kurumada, Osamu; Ikekame, Yoshinori; Ouchi, Satoshi; Sato, Masayuki; Kamiishi, Eigo; Wada, Shigeru
JAEA-Technology 2015-056, 35 Pages, 2016/03
The power supply for reactor control rod magnet of JRR-3 has been utilized for generating electromagnetic power of control rod coil and that was using more than 25 years. The power supply was required for provide to stabilize DC current. Therefore, we adopted series regulator method. Although, the power supply generate a high heat. Then, we decided to create switching regulator method in order to improve the aging and heat generation of the series regulator method. This paper reports the replacement of switching regulator method.
Kurumada, Osamu; Ouchi, Satoshi; Sato, Masayuki; Kamiishi, Eigo; Ikekame, Yoshinori
UTNL-R-0489, p.8_1 - 8_8, 2015/03
no abstracts in English
Jiang, M. Y.*; Onuki, Toshihiko; Tanaka, Kazuya*; Kozai, Naofumi; Kamiishi, Eigo; Utsunomiya, Satoshi*
Geochimica et Cosmochimica Acta, 93, p.30 - 46, 2012/09
Times Cited Count:33 Percentile:64.77(Geochemistry & Geophysics)We have investigated the post-adsorption process of ytterbium (Yb) phosphate nano-particle formation by . We have elucidated the nano particle formation by TEM and EXAFS analyses, that adsorbed Yb reacts on the cell surface with the released pohosphate from inside the cell.
Jiang, M.; Onuki, Toshihiko; Kozai, Naofumi; Tanaka, Kazuya; Suzuki, Yoshinori*; Sakamoto, Fuminori; Kamiishi, Eigo*; Utsunomiya, Satoshi*
Chemical Geology, 277(1-2), p.61 - 69, 2010/10
Times Cited Count:40 Percentile:68.27(Geochemistry & Geophysics)We have investigated the mechanism underlying Ce sequestration by yeast after exposure to Ce(III) solution at pH 3, 4, or 5. We found that needle-shaped Ce(III) phosphate nanocrystallites with a monazite structure formed on the yeast cells by exposure to Ce(III) for 42 h, even though the initial solutions did not contain any P species. These results suggest that the sorbed Ce on the cell surfaces reacted with P released from inside the yeast cell, resulting in the formation of Ce(III) phosphate nanocrystallites.
Kamiishi, Eigo; Wada, Shigeru; Murayama, Yoji
no journal, ,
Jiang, M.; Onuki, Toshihiko; Tanaka, Kazuya*; Kamiishi, Eigo; Utsunomiya, Satoshi*
no journal, ,
Formation process of samarium phosphate mineralization on the cell surface of microorganisms has been studied. The rate of nano-particles formation on the cells of yeast was lower than that of soil bacteria, suggesting that thicker cell wall of yeast than soil bacteria gave lower release rate of phosphate ions from inside of cells.
Suzuki, Yoshinori*; Tanaka, Kazuya; Kogawa, Masashi*; Kamiishi, Eigo*; Utsunomiya, Satoshi*; Onuki, Toshihiko
no journal, ,
We have formed nano-particles of CuPd in ferritin protein. The size and structure of the CuPd formed were analyzed by TEM and EXAFS. TEM-EDS analysis showed the formation of CuPd in ferritin. EXAFS analysis suggests that CuPd is alloy compounds.
Ouchi, Yasuhiro; Kawamata, Satoshi; Taguchi, Yuji; Kamiishi, Eigo; Koda, Nobuyuki
no journal, ,
no abstracts in English
Onuki, Toshihiko; Jiang, M.; Kamiishi, Eigo*; Utsunomiya, Satoshi*; Tanaka, Kazuya; Kozai, Naofumi; Suzuki, Yoshinori*
no journal, ,
We have investigated the association of heavy REE of Yb with yeast after exposure at pH of 3, 4 or 5. A variety of analytical techniques including FESEM-EDS, TEM, ICP-AES, XAFS have been employed to investigate the sequestration mechanism of Yb by yeast as a function of exposure time. Ytterbium concentrations in solutions decrease as the exposure time increases. FESEM, TEM, and XAFS analyses revealed that nano-sized blocky Yb phosphate with amorphous phase formed on the yeast cells surface after 24 h. These results suggest that the sorbed Yb on the cell surfaces reacted with P released from inside of the yeast cell, resulting in the formation of amorphous Yb phosphate.
Jiang, M.; Onuki, Toshihiko; Tanaka, Kazuya*; Kozai, Naofumi; Kamiishi, Eigo; Utsunomiya, Satoshi*
no journal, ,
The objective of the present study is to further understand the post-adsorption process of middle REE (Sm) and heavy REE (Yb) biomineralization by several representative microbes for the long-term exposure. Based on the FESEM and TEM analyses, nano-sized Sm phosphate crystallites with monazite structure formed on these three kinds of microbial cells surfaces and nano-sized Yb phosphate with amorphous phase formed on yeast cells surfaces. The EXAFS data indicated that the chemical states of accumulated Sm and Yb on cells surfaces changed from the mixture of both phosphate and carboxyl sites at 30 min to phosphate precipitates phase at 5 days, suggesting the REE-phosphate mineralization as a major post-adsorption process.