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Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Sunagawa, Hikaru*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Fujihara, Masayoshi; Tampo, Motonobu*; Kawamura, Naritoshi*; et al.
Interactions (Internet), 245(1), p.31_1 - 31_6, 2024/12
Kadono, Ryosuke*; Hiraishi, Masatoshi*; Okabe, Hirotaka*; Koda, Akihiro*; Ito, Takashi
Journal of Physics; Condensed Matter, 35(28), p.285503_1 - 285503_13, 2023/07
Times Cited Count:0 Percentile:0(Physics, Condensed Matter)Ono, Masahiro*; Uchibori, Akihiro; Okano, Yasushi; Takata, Takashi*
JAEA-Testing 2022-004, 193 Pages, 2023/03
A computer code TRACER (Transport phenomena of Radionuclides for Accident Consequence Evaluation of Reactor) version 2.4.1 has been developed to evaluate species and quantities of fission products (FPs) released into cover gas due to a fuel pin failure in an LMFBR. The TRACER version 2.4.1 includes the models related to NUREG-0772 and also new or modified computational program codes in order to possess a new function shown below, and partial modify of coefficient of FP transition model between coolant and cover gas. This manual includes manual conventions for TRACER Version 2.3, addition of reference such as formula, improvement of explanation of input file creation method, addition of improvement of NUREG-0772 model added to TRACER code, modification of figure of sample analysis performed in appendix. It includes modifications and additions of sample analysis.
Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Natori, Hiroaki*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Tampo, Motonobu*; Kawamura, Naritoshi*; Teshima, Natsuki*; et al.
Journal of Physics; Conference Series, 2462, p.012033_1 - 012033_5, 2023/03
Times Cited Count:0 Percentile:0.21(Physics, Applied)Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Sakoda, Akihiro; Nomura, Naoki*; Kuroda, Yujiro*; Kono, Takahiko; Naito, Wataru*; Yoshida, Hiroko*
Journal of Radiological Protection, 41(4), p.1258 - 1287, 2021/12
Times Cited Count:1 Percentile:11.13(Environmental Sciences)Following the Fukushima Daiichi Nuclear Power Plant accident, many radiation experts directly experienced a vast gap between ideal and real public understanding (PU) of radiation in risk communication. Therefore, this study collated and reviewed information about PU activities for radiation and its risk that six Japanese academic societies - which seemed to be socially neutral expert communities - related to radiation and radiation risk conducted before and after the accident. Activities these radiation-related societies provided to general public were discussed from the following perspectives: (1) difficulties in two-way communication due to resources, motivation, public interest and concerns; (2) balance between academic research and PU activities; (3) academic societies' building trust with the public whilst ensuring member experts' neutrality and independence; (4) discussions among academic societies to prepare for public engagement. We hope that this paper encourages experts and academic societies in radiation protection to hold more national and international discussions about their roles in public communication and outreach.
Yoshida, Hiroko*; Kuroda, Yujiro*; Kono, Takahiko; Naito, Wataru*; Sakoda, Akihiro
Journal of Radiation Protection and Research, 46(3), p.134 - 142, 2021/09
The Japan Health Physics Society established a task group on "Public Understanding after the Fukushima Daiichi Nuclear Power Plant Accident" in the 2018-2019 fiscal year. This task group collected and analyzed various activities that had been made for promotion of public understanding since the Fukushima accident, and then discussed some issues such as expert's roles. This paper outlines a panel session for this task group held at the 53rd Annual Meeting of the Japanese Health Physics Society (Online). This session consisted of (1) reporting what the task group achieved, (2) having comments by two designated experts in the fields of sociology and ethics, (3) making a panel discussion with three representatives from the task group and the two designated speakers, and (4) summarizing this session by a rapporteur.
Andresz, S.*; Sakoda, Akihiro; Ha, W.-H.*; Kabrt, F.*; Kono, Takahiko; Sez Muoz, M.*; Nusrat, O.*; Papp, C.*; Qiu, R.*; Bryant, P.*
Journal of Radiation Protection and Research, 46(3), p.143 - 150, 2021/09
The Young Generation Network (YGN) was officially established as part of the International Radiation Protection Association (IRPA) in the spring of 2018. Since then, it has been dedicated to a variety of activities to promote communication, collaboration and professional development of students and young professionals in the area of radiation protection and its allied fields. This article reports our recent activities from the middle of 2018 to the beginning of 2021, with highlights on some important events: (1) Joint JHPS-SRP-KARP Workshop of Young Generation Network (December 2019 in Japan); (2) Contribution to Nuclear Energy Agency Workshop on Optimization - Rethinking the Art of Reasonable (January 2020 in Portugal); (3) Survey on the impact of COVID-19 on radiation protection among IRPA YGN members (March 2020); (4) Contribution to IRPA15 (January-February 2021; online). The discussion and insight obtained from each activity are also summarized. The IRPA YGN will aim to achieve its on-going activities and continue to follow the ways paved in the Strategic Agenda and despite the challenges raised by the COVID-19 pandemic. Namely, running an international survey (for example, on the usage of social media in radiation protection, and on the long-term consequences of the COVID-19 pandemic), engaging national YGNs, extending the network, finding new relationships with networks with an interest in the young generation and participation in (remote) events will be aspired for.
Okuma, Ryutaro*; Kofu, Maiko; Asai, Shinichiro*; Avdeev, M.*; Koda, Akihiro*; Okabe, Hirotaka*; Hiraishi, Masatoshi*; Takeshita, Soshi*; Kojima, Kenji*; Kadono, Ryosuke*; et al.
Nature Communications (Internet), 12, p.4382_1 - 4382_7, 2021/07
Times Cited Count:7 Percentile:60.19(Multidisciplinary Sciences)Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.
Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03
Times Cited Count:2 Percentile:17.05(Materials Science, Multidisciplinary)The layered perovskite PrBaCoO demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCoO is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.
Yoshida, Hiroko*; Kuroda, Yujiro*; Kono, Takahiko; Naito, Wataru*; Sakoda, Akihiro
Hoken Butsuri (Internet), 55(4), p.257 - 263, 2020/12
no abstracts in English
Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.
JAEA-Research 2020-007, 249 Pages, 2020/10
The accident of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, Japan Atomic Energy Agency (JAEA) has been conducting "Long-term Assessment of Transport of Radioactive Contaminants in the Environment of Fukushima" concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.
Naito, Wataru*; Uesaka, Motoki*; Kuroda, Yujiro*; Kono, Takahiko; Sakoda, Akihiro; Yoshida, Hiroko*
Radioprotection, 55(4), p.297 - 307, 2020/10
Times Cited Count:7 Percentile:75.99(Environmental Sciences)After the Fukushima nuclear accident in Japan, a number of practical activities related to public understanding (PU) of radiation risks were implemented inside and outside Fukushima Prefecture. The various noteworthy approaches and strategies behind those practical activities have not been organized and made explicit thus far. In this study, we have organized the noteworthy practical activities related to PU of radiation risks following the Fukushima nuclear accident, and discussed them mainly from the standpoints of communication strategies and approaches. As several examples demonstrate, efforts to contextualize and localize radiation risk in various forms were observed during post-accident recovery in Fukushima, and these efforts were confirmed, through actual experiences, to be an important component of effective PU activities of radiation risks. Community-based or citizen science approaches, such as having affected residents or citizens to measure radioactivity, have contributed to the PU of radiological situations, but some challenges, such as ethical aspects and the handling of uncertainty, have also been revealed. In the era of information and communications technology, a number of citizens, experts, and agencies have made social media a popular platform for disseminating radiation risk messages to the public and have demonstrated that social media can play an important role in providing radiological risk information. The knowledge and lessons learned from the practical activities discussed in this study can be useful in enhancing PU of risks not only radiation but also other stressors such as toxic chemicals, preparing future disasters and supporting risk communication plans during recovery periods after disasters.
Hagiwara, Hiroki; Nakanishi, Takahiro; Konishi, Hiromi*; Tsuruta, Tadahiko; Misono, Toshiharu; Fujiwara, Kenso; Kitamura, Akihiro
Journal of Environmental Radioactivity, 220-221, p.106294_1 - 106294_9, 2020/09
Times Cited Count:0 Percentile:0(Environmental Sciences)Kuwata, Haruka*; Misono, Toshiharu; Fujiwara, Kenso; Takeishi, Minoru; Manabe, Sachi*; Kitamura, Akihiro
Radiation Environment and Medicine, 9(1), p.28 - 34, 2020/02
The analysis of tritium in aquatic biota is one of the most important research areas in Fukushima. The conventional method for measuring the concentration of tritium consists of complicated pretreatment procedures and requires skillful techniques as well as a significant amount of time. Consequently, there are only a few reports on tritium monitoring data in marine products from the coast of Fukushima. In this study, we measured the Tissue Free Water Tritium (TFWT) and Organically Bound Tritium (OBT) in flounders collected from the coast of Fukushima to examine the impacts of the nuclear accident on aquatic biota. The study was done for a period of 4 years; from 2015 to 2018. The conventional method of analysis was firstly used, after which the method was modified by improving the freeze-drying and combustion water recovery processes. Results from both methods show that the most of the concentrations of the TFWT and OBT in the flounder were below the detection or quantitative limit. The effect of the nuclear accident on humans, through internal exposure, was also examined and found to be negligible. Although some uncertainties exist due to the short cut of the processes, the modified version could be considered an effective and practical approximate method.
Sakoda, Akihiro; Kono, Takahiko; Kataoka, Noriaki*; Andresz, S.*
Hoken Butsuri (Internet), 54(3), p.181 - 187, 2019/10
no abstracts in English
Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.
JAEA-Research 2019-002, 235 Pages, 2019/08
The accident of the Fukushima Daiichi Nuclear Power Station (hereinafter referred to 1F), Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, JAEA has been conducting Long-term Environmental Dynamics Research concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count:8 Percentile:55.71(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Iida, Kazuki*; Yoshida, Hiroyuki*; Okabe, Hirotaka*; Katayama, Naoyuki*; Ishii, Yuto*; Koda, Akihiro*; Inamura, Yasuhiro; Murai, Naoki; Ishikado, Motoyuki*; Kadono, Ryosuke*; et al.
Scientific Reports (Internet), 9(1), p.1826_1 - 1826_9, 2019/02
Times Cited Count:10 Percentile:58.97(Multidisciplinary Sciences)Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count:13 Percentile:98.93(Quantum Science & Technology)