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Arai, Yoichi; Watanabe, So; Hasegawa, Kenta; Okamura, Nobuo; Watanabe, Masayuki; Takeda, Keisuke*; Fukumoto, Hiroki*; Ago, Tomohiro*; Hagura, Naoto*; Tsukahara, Takehiko*
Nuclear Instruments and Methods in Physics Research B, 542, p.206 - 213, 2023/09
Times Cited Count:1 Percentile:0.02(Instruments & Instrumentation)Suzuki, Seiya; Arai, Yoichi; Okamura, Nobuo; Watanabe, Masayuki
Journal of Nuclear Science and Technology, 60(7), p.839 - 848, 2023/07
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The fuel debris, consisting of nuclear fuel materials and reactor structural materials, generated in the accident of Fukushima Daiichi Nuclear Power Plant can become deteriorated like rocks under the changes of environmental temperature. Although the fuel debris have been cooled by water for 10 years, they are affected by seasonal and/or day-and-night temperature changes. Therefore, in evaluating the aging behavior of the fuel debris, it is essential to consider the changes in environmental temperature. Assuming that the fuel debris are deteriorated, radioactive substances that have recently undergone micronization could be eluted into the cooling water, and such condition may affect defueling methods. We focused on the effect of repeated changes in environmental temperature on the occurrence of cracks, and an accelerated test using simulated fuel debris was carried out. The length of the crack increases with increasing number of heat cycle; therefore, the fuel debris become brittle by stress caused by thermal expansion and contraction. In conclusion, it was confirmed that the mechanical deterioration of the fuel debris is similar to that of rocks or minerals, and it became possible to predict changes in the length of the crack in the simulated fuel debris and environmental model.
Iwamoto, Toshihiro; Saito, Madoka*; Takahatake, Yoko; Watanabe, So; Watanabe, Masayuki; Naruse, Atsuki*; Tsukahara, Takehiko*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 4 Pages, 2023/05
Applicability of temperature swing extraction technology employing monoamides was examined for uranium contaminated waste treatment procedure. Separation experiments on simulated target solution with three kinds of monoamides with different structure showed that Ce(IV) in the solution was selectively recovered by the temperature swing extraction operation. Based on the experiments, an appropriate monoamide for the procedure was selected.
Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Ambai, Hiromu; Watanabe, So; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 5 Pages, 2023/05
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, 9 Pages, 2023/00
Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)Takahatake, Yoko; Watanabe, So; Irisawa, Keita; Shiwaku, Hideaki; Watanabe, Masayuki
Journal of Nuclear Materials, 556, p.153170_1 - 153170_7, 2021/12
Times Cited Count:1 Percentile:15.7(Materials Science, Multidisciplinary)Miyazaki, Yasunori; Sano, Yuichi; Okamura, Nobuo; Watanabe, Masayuki; Koka, Masashi*
QST-M-29; QST Takasaki Annual Report 2019, P. 72, 2021/03
no abstracts in English
Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*
Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11
The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above 0.2-0.3 MeV/nucleon for A=2030 amu; the PKA mass identification thresholds decrease to 0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.
Nakayoshi, Akira; Suzuki, Seiya; Okamura, Nobuo; Watanabe, Masayuki; Koizumi, Kenji
Journal of Nuclear Science and Technology, 55(10), p.1119 - 1129, 2018/10
Times Cited Count:2 Percentile:20.74(Nuclear Science & Technology)Takaki, Naoyuki; ;
Proceedings of 7th Infornation Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, 0 Pages, 2002/00
None
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Solvent Extraction and Ion Exchange, 16(6), p.1357 - 1367, 2002/00
Times Cited Count:52 Percentile:84.26(Chemistry, Multidisciplinary)None
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JNC TN9400 2001-034, 157 Pages, 2001/01
In Japan Nuclear Cycle Development Institute, the feasibility study has been carried out in order to evaluate various methods of FBR cycle technology and to propose candidate concepts as practical technology. As a part of this, we investigated a process flow diagram and material balance of various recovery systems for Am and Cm from high level radioactive liquid waste, and we preliminarily evaluated the equipment scale, the cost and waste generation rate of these systems. As a result, it was obtained that these values are about 1.1-1.4, 0.9-1.4 and 1.2-1.5 times, respectively, of the SETFICS process. From these results, the systems we evaluated are considered to be same for the equipment scale at conceptual design stage, and each system is applicable as the recovery system of Am and Cm. But these results suggest that the facility may be much larger than the PUREX plant, in spite of small contents of the materials (Am and Cm) that is to be recovered. Therefore, whichever method is applied to the recovery system of Am and Cm, we need to develop the process in order to make the system more compact and economical. And then, we need to continue to collect information of these systems and new systems and to comparatively evaluate each system. And we should select finally a practical system of recovery for Am and Cm. *1 : various recovery systems to : (1)DIAMEX process + SANEX process (France - CEA) (2)TRPO process + Cyanex process (China) (3)DIDPA process (Japan-JAERI) (4)TALSPEAK process (U.S.A.-ORNL etc.)
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JNC TN9400 2000-084, 115 Pages, 2000/07
ln JAPAN NUCLEAR CYCLE DEVELOPMENT INSTITUTE, the feasiblity study has been carried out in order to evaluate various methods of FBR cycle technology and to propose candidate concepts of practical technology. As a part of this, we investigated material balance and a process flow diagram of SETFICS process for the recovery system of Am and Cm from high level radioactive liquid waste, and we preliminarily evaluated the equipment scale, the cost and waste generation rate of this system. As a result, it was obtained that these values are about 17, 15 and 10%, respectively, of the recycle plant based on the simplified PUREX process. ln addition, we investigated preliminary flowsheets of 4 recovery systems for Am and Cm, and compared each to each of them. lt was evaluated that the equipment scale of any process was also equivalent. From these results, each system is applicable as the recovery system of Am and Cm. But these results suggest that the facility may be much larger than the PUREX plant, in spite of small contents of the recovery materials in each system. Therefore, whichever method is applied to the recovery system of Am and Cm, we need to develop the process in order to make the system more compact and economical.
Kase, Takeshi; ; Fujita, Yuji; Ueda, Yoshinori
Saikuru Kiko Giho, (4), 27-35 Pages, 1999/00
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Journal of Nuclear Science and Technology, 35(2), p.130 - 136, 1998/02
None
; Sugiyama, Kenji; ; ; ; Ojima, Hisao;
PNC TN1430 97-005, 229 Pages, 1997/11
no abstracts in English