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Senzaki, Tatsuya; Arai, Yoichi; Yano, Kimihiko; Sato, Daisuke; Tada, Kohei; Ogi, Hiromichi*; Kawanobe, Takayuki*; Ono, Shimpei; Nakamura, Masahiro; Kitawaki, Shinichi; et al.
JAEA-Testing 2022-001, 28 Pages, 2022/05
In preparation for the decommissioning of Laboratory B of the Nuclear Fuel Cycle Engineering Laboratory, the nuclear fuel material that had been stored in the glove box for a long time was moved to the Chemical Processing Facility (CPF). This nuclear fuel material was stored with sealed by a polyvinyl chloride (PVC) bag in the storage. Since it was confirmed that the PVC bag swelled during storage, it seems that any gas was generated by radiolysis of the some components contained in the nuclear fuel material. In order to avoid breakage of the PVC bag and keep it safety for long time, we began the study on the stabilization treatment of the nuclear fuel material. First, in order to clarify the properties of nuclear fuel material, radioactivity analysis, component analysis, and thermal analysis were carried out. From the results of thermal analysis, the existence of organic matter was clarified. Then, ion exchange resin with similar thermal characteristics was selected and the thermal decomposition conditions were investigated. From the results of these analyzes and examinations, the conditions for thermal decomposition of the nuclear fuel material contained with organic matter was established. Performing a heat treatment of a small amount of nuclear fuel material in order to confirm the safety, after which the treatment amount was scaled up. It was confirmed by the weight change after the heat treatment that the nuclear fuel material contained with organic matter was completely decomposed.
Tada, Kohei; Kitawaki, Shinichi; Watanabe, So; Aihara, Haruka; Shibata, Atsuhiro; Nomura, Kazunori
Proceedings of International Nuclear Fuel Cycle Conference (GLOBAL 2017) (USB Flash Drive), 3 Pages, 2017/09
Radioactive liquid waste containing chloride ion (Cl) is generated by chemical analysis for process control of pyroprocessing. To realize discharging this liquid waste to the sea, it's necessary to carry out the process in order to separate Cl and recover U, Pu. This study carried out a combination of the AgCl precipitation method and extraction chromatography method to separate Cl and recover U, Pu. The result of precipitation test showed that U and Pu didn't occur the co-precipitation after the test. The result of solid phase extraction test showed that 95% of Pu was successfully recovered from the liquid waste. It was difficult to analyze radioactivity about U because the concentration of U is not enough. These results showed that these process has the feasibility of the discharging the liquid waste to the sea.
Yamada, Hidenori*; Tamada, Taro; Kosaka, Megumi*; Miyata, Kohei*; Fujiki, Shinya*; Tano, Masaru*; Moriya, Masayuki*; Yamanishi, Mamoru*; Honjo, Eijiro; Tada, Horiko*; et al.
Protein Science, 16(7), p.1389 - 1397, 2007/07
Times Cited Count:39 Percentile:59.43(Biochemistry & Molecular Biology)In an attempt to control protein incorporation in a crystal lattice, a leucine zipper-like hydrophobic interface (comprising four leucine residues) was introduced into a helical region (helix 2) of the human pancreatic ribonuclease 1 (RNase 1) that was predicted to form a suitable crystallization interface. Although crystallization of wild type RNase 1 has not yet been reported, the RNase 1 mutant having four leucines (4L-RNase 1) was successfully crystallized under several different conditions. The crystal structures were subsequently determined by X-ray crystallography by molecular replacement using the structure of bovine RNase A. The overall structure of 4L-RNase 1 is quite similar to that of the bovine RNase A, and the introduced leucine residues formed the designed crystal interface. To further characterize the role of the introduced leucine residues in crystallization of RNase 1, the number of leucines was reduced to three or two (3L- and 2L-RNase 1, respectively). Both mutants crystallized and a similar hydrophobic interface as in 4L-RNase 1 was observed. A related approach to engineer crystal contacts at helix 3 of RNase 1 (N4L-RNase 1) was also evaluated. N4L-RNase 1 also successfully crystallized, and formed the expected hydrophobic packing interface. These results suggest that appropriate introduction of a leucine zipper-like hydrophobic interface can promote intra molecular symmetry for more efficient protein crystallization in crystal lattice engineering efforts.
Tada, Kenichi; Hagura, Naoto*; Kitada, Takanori*; Yamagata, Hiroshi*; Iwanaga, Kohei*
no journal, ,
For the future human resources development in reactor physics, the present status and tasks are shared with the member of reactor physics division. To overcome tasks of the human resources development, we will debate to the member of reactor physics division in this session.
Iizuka, Masatoshi*; Nohira, Toshiyuki*; Tada, Kohei; Murakami, Tsuyoshi*; Kofuji, Hirohide
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Tada, Kohei; Kitawaki, Shinichi; Sakamura, Yoshiharu*; Murakami, Tsuyoshi*
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no abstracts in English
Tada, Kohei; Kitawaki, Shinichi; Kofuji, Hirohide; Murakami, Tsuyoshi*; Sakamura, Yoshiharu*
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no abstracts in English
Kofuji, Hirohide; Tada, Kohei; Kitawaki, Shinichi; Hayashi, Hirokazu; Murakami, Tsuyoshi*; Sakamura, Yoshiharu*
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Metal electrorefining technology which is the most promising method of pyro-reprocessing has been developed in JAEA under the collaboration with CRIEPI. Through the research and development, feasibility of the process had been confirmed and design of process equipment and facility has been progressed. Technology would be expected suitable for the future nuclear fuel cycle concept which will be focused on reduction of environmental burden of the radioactive waste.
Tada, Kohei; Kofuji, Hirohide; Murakami, Tsuyoshi*
no journal, ,
no abstracts in English
Tada, Kohei; Kitawaki, Shinichi; Watanabe, So; Hinai, Hiroshi; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
no abstracts in English
Tada, Kohei; Kitawaki, Shinichi; Watanabe, So; Hinai, Hiroshi; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
no abstracts in English
Tada, Kohei; Arai, Yoichi; Watanabe, So; Ogi, Hiromichi*; Nakamura, Masahiro; Shibata, Atsuhiro
no journal, ,
no abstracts in English
Tada, Kohei; Kofuji, Hirohide; Murakami, Tsuyoshi*
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no abstracts in English
Tada, Kohei; Kofuji, Hirohide; Murakami, Tsuyoshi*
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