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Arai, Yoichi; Watanabe, So; Nakahara, Masaumi; Funakoshi, Tomomasa; Hoshino, Takanori; Takahatake, Yoko; Sakamoto, Atsushi; Aihara, Haruka; Hasegawa, Kenta; Yoshida, Toshiki; et al.
Progress in Nuclear Science and Technology (Internet), 7, p.168 - 174, 2025/05
The Japan Atomic Energy Agency (JAEA) has been conducting a project named "Systematic Treatment of RAdioactive liquid waste for Decommissioning (STRAD)" project since 2018 for fundamental and practical studies for treating radioactive liquid wastes with complicated compositions. Fundamental studies have been conducted using genuine liquid wastes accumulated in a hot laboratory of the JAEA called the Chemical Processing Facility (CPF), and treatment procedures for all liquid wastes in CPF were successfully designed on the results obtained. As the next phase of the project, new fundamental and practical studies on primarily organic liquid wastes accumulated in different facilities of JAEA are in progress. This paper reviews the representative achievements of the STRAD project and introduces an overview of ongoing studies.
Arai, Yoichi; Hasegawa, Kenta; Watanabe, So; Watanabe, Masayuki; Minowa, Kazuki*; Matsuura, Haruaki*; Hagura, Naoto*; Katsuki, Kenta*; Arai, Tsuyoshi*; Konishi, Yasuhiro*
Journal of Radioanalytical and Nuclear Chemistry, 333(7), p.3585 - 3593, 2024/07
Times Cited Count：1 Percentile：23.64(Chemistry, Analytical)Watanabe, So; Ogi, Hiromichi*; Shibata, Atsuhiro; Nomura, Kazunori
International Journal of Nuclear and Quantum Engineering (Internet), 13(4), p.169 - 174, 2019/04
As a part of STRAD project conducted by JAEA, condensation of radioactive liquid waste containing various chemical compounds using reverse osmosis (RO) membrane filter was examined for efficient and safety treatment of the liquid wastes accumulated inside hot laboratories. NH
ion in the feed solution was successfully concentrated, and NH ion involved in the effluents became lower than target value; 100 ppm. Solidification of simulated aqueous and organic liquid wastes was also tested. Those liquids were successfully solidified by adding cement or coagulants. Nevertheless, optimization in materials for confinement of chemicals is required for long time storage of the final solidified wastes.
Nomura, Kazunori; Ogi, Hiromichi*; Nakahara, Masaumi; Watanabe, So; Shibata, Atsuhiro
International Journal of Nuclear and Quantum Engineering (Internet), 13(5), p.209 - 212, 2019/00
-estradiol in waterKimura, Atsushi; Taguchi, Mitsumasa; Arai, Hidehiko*; Hiratsuka, Hiroshi*; Namba, Hideki; Kojima, Takuji
Radiation Physics and Chemistry, 69(4), p.295 - 301, 2004/03
Times Cited Count：27 Percentile：82.67(Chemistry, Physical)no abstracts in English
Taguchi, Mitsumasa
JAERI-Conf 2003-016, p.111 - 116, 2003/08
None
Watanabe, So; Arai, Yoichi; Ogi, Hiromichi*; Nakamura, Masahiro; Shibata, Atsuhiro; Osugi, Takeshi; Taniguchi, Takumi; Sone, Tomoyuki; Nomura, Kazunori
no journal, ,
Suzuki, Seiya; Watanabe, So; Arai, Yoichi; Nakamura, Masahiro; Kajinami, Akihiko*
no journal, ,
Vitrification technology has been adopted as a treatment technology for high-level radioactive liquid waste (HLLW). In this vitrification process, HLLW is mixed with borosilicate glass that has been heated to over 1000 degree Celsius and melted, and then rapidly cooled to form a chemically stable solidified product. In this way, vitrification technology has already been established. On the other hand, there are some drawbacks of this technology due to the high temperature. Our group is focusing on a procedure to immobilize radioactive species into a chemically stable material at lower temperatures using freeze-drying (FD) technology. In the experiment on simulating HLLW, it was confirmed that major elements such as Ru, Pd and Nd were retained in the solidified material. The retention mechanism of cation groups in the solidified material is presumed to be electrostatic interaction with negatively charged sites in the matrix. However, Mo and Zr were eluted as anionic species. Tc, which is included as an anion species in HLLW, was not targeted in the simulated experiment, but immobilization of volatile Tc is challenging and important. In this study, to establish an immobilization technology of Tc, FD solidification tests on a nitric acid solution of 99Tc were carried out, and the immobilization mechanism of anion species is discussed.
Hoshino, Takanori; Arai, Yoichi; Watanabe, So; Nakamura, Masahiro; Suzuki, Hideya*; Ban, Yasutoshi
no journal, ,
Arai, Yoichi; Watanabe, So; Kubota, Toshio*; Arai, Tsuyoshi*; Seko, Noriaki*; Nomura, Kazunori
no journal, ,
no abstracts in English
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Kubota, Toshio*
no journal, ,
no abstracts in English
