Ishii, Mamoru*; Shiota, Daiko*; Tao, Chihiro*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Ishii, Takako*; Ichimoto, Kiyoshi*; Kataoka, Ryuho*; Koga, Kiyokazu*; Kubo, Yuki*; et al.
Earth, Planets and Space (Internet), 73(1), p.108_1 - 108_20, 2021/12
We surveyed the relationship between the scale of space weather events and their occurrence rate in Japan and we discussed the social impact of these phenomena during the Project for Solar-Terrestrial Environment Prediction (PSTEP). The information was compiled for domestic users of space weather forecasts for appropriate preparedness against space weather disasters. This paper gives a comprehensive summary of the survey, focusing on the fields of electricity, satellite operations, communication and broadcasting, satellite positioning usage, aviation, human space activity, and daily life on the Earth's surface, using the cutting-edge knowledge of space weather. Quantitative estimations of the economic impact of space weather events on electricity and aviation are also given.
Saito, Yuji; Fujiwara, Hidenori*; Yasui, Akira*; Kadono, Toshiharu*; Sugawara, Hitoshi*; Kikuchi, Daisuke*; Sato, Hideyuki*; Suga, Shigemasa*; Yamasaki, Atsushi*; Sekiyama, Akira*; et al.
Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Maehara, Yushi; Narita, Ryosuke; et al.
JAEA-Review 2019-048, 165 Pages, 2020/03
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2018 to March 2019. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Tsuji, Masakuni*; Nakashima, Hitoshi*; Saito, Akira*; Okihara, Mitsunobu*; Sato, Toshinori
45th Annual Waste Management Conference (WM 2019); Encouraging Young Men & Women to Achieve Their Goals in Radwaste Management, Vol.7, p.4749 - 4763, 2020/01
A rock excavation grouting technology has been recently studied as significant technology for reducing the ingress of water into the deep repository. However, it has not been studied for applying to the coastal region, where it is discussed to be a more suitable region for the geological disposal in Japan. The latest material called colloidal silica grout (CSG) is good for sealing narrow fractures but is known to be sensitive to the salinity of groundwater because of its gelling property with salt accelerator. Although the gelling of CSG can be controlled by adding an acidic pH adjuster, the methodology for delivering the appropriate grout is not well established for such conditions of saline groundwater. Therefore, this research project was established to enhance the existing rock grouting technology for deep repositories.
Tsuji, Masakuni*; Okihara, Mitsunobu*; Nakashima, Hitoshi*; Saito, Akira*; Aoyagi, Kazuhei; Sato, Toshinori
Dai-47-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (Internet), p.266 - 271, 2020/01
As engineering technique for geological disposal, a lot of advancement development of the grout technology has been performed. But the design, construction method in consideration of the properties of matter acquisition and mechanism of the hardening that assumed a seawater condition bottom is non-establishment. As we carried out the knowledge under saline water, the basic properties acquisition, the penetration properties acquisition, a study revue based on such situation.
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Nakamura, Mitsutaka; Kawakita, Yukinobu; Matsuura, Masato*; Endo, Hitoshi*; Seto, Hideki*; Ito, Shinichi*; Nakajima, Kenji; Kawamura, Seiko
Physica B; Condensed Matter, 562, p.148 - 154, 2019/06
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Hokama, Tomonori; Nishimura, Tomohiro; Matsubara, Natsumi; et al.
JAEA-Review 2018-025, 171 Pages, 2019/02
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Haraga, Tomoko; Ouchi, Kazuki; Sato, Yoshiyuki; Hoshino, Hitoshi*; Tanana, Rei*; Fujihara, Takashi*; Kurokawa, Hideki*; Shibukawa, Masami*; Ishimori, Kenichiro; Kameo, Yutaka; et al.
Analytica Chimica Acta, 1032, p.188 - 196, 2018/11
The development of safe, rapid and highly sensitive analytical methods for radioactive samples, especially actinide (An) ions, represents an important challenge. Here we propose a methodology for selecting appropriate emissive probes for An ions with very low consumption and emission of radioactivity by capillary electrophoresis-laser-induced fluorescence detection (CE-LIF), using a small chemical library of probes with eight different chelating moieties. It was found that the emissive probe, which possesses the tetradentate chelating moiety, was suitable for detecting uranyl ions. The detection limit for the uranyl-probe complex using CE-LIF combined with dynamic ternary complexation and on-capillary concentration techniques was determined to be 0.7 ppt. This method was successfully applied to real radioactive liquid samples collected from nuclear facilities.
Shibata, Takanori*; Takagi, Akira*; Ikegami, Kiyoshi*; Sugimura, Takashi*; Nammo, Kesao*; Naito, Fujio*; Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Honda, Yosuke*; Sato, Masaharu*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.385 - 387, 2018/10
Toguri, Satohito*; Okihara, Mitsunobu*; Tsuji, Masakuni*; Nakashima, Hitoshi*; Sugiyama, Hirokazu*; Saito, Akira*; Sato, Toshinori; Aoyagi, Kazuhei; Masunaga, Kosuke
JAEA-Research 2017-013, 131 Pages, 2018/02
The discussions on scientifically promising site for the geological disposal has been made at the council of studying group on techniques for geological disposal of radioactive wastes, which is held by Resources and Energy Agency. From the aspect of ensuring safety during the transportation of disposal waste, the coastal area is discussed to be a more suitable area. This report shows the result of the first year of this project as following items; Study on the state-of-art technology and remain tasks; laboratory tests on characterization of colloidal silica grout under sea water; Study on the development of grouting technology (design and the evaluation method of influence on the rock mass).
Nagai, Kodai*; Fujiwara, Hidenori*; Aratani, Hidekazu*; Fujioka, Shuhei*; Yomosa, Hiroshi*; Nakatani, Yasuhiro*; Kiss, Takayuki*; Sekiyama, Akira*; Kuroda, Fumiaki*; Fujii, Hitoshi*; et al.
Physical Review B, 97(3), p.035143_1 - 035143_8, 2018/01
We have studied the electronic structure of ferrimagnetic MnVAl single crystals by means of soft X-ray absorption spectroscopy (XAS), X-ray absorption magnetic circular dichroism (XMCD), and resonant soft X-ray inelastic scattering (RIXS). We have successfully observed the XMCD signals for all the constituent elements. The Mn L XAS and XMCD spectra are reproduced by spectral simulations based on density-functional theory, indicating the itinerant character of the Mn 3 states. On the other hand, the V 3 electrons are rather localized since the ionic model can qualitatively explain the V L XAS and XMCD spectra. This picture is consistent with local excitations revealed by the V L RIXS.
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Seto, Hideki; Ito, Shinichi; Yokoo, Tetsuya*; Endo, Hitoshi*; Nakajima, Kenji; Shibata, Kaoru; Kajimoto, Ryoichi; Kawamura, Seiko; Nakamura, Mitsutaka; Kawakita, Yukinobu; et al.
Biochimica et Biophysica Acta; General Subjects, 1861(1), p.3651 - 3660, 2017/01
J-PARC, Japan Proton Accelerator Research Complex provides short pulse proton beam at a repetition rate 25 Hz and the maximum power is expected to be 1 MW. Materials and Life Science Experimental Facility (MLF) has 23 neutron beam ports and 21 instruments have already been operated or under construction / commissioning. There are 6 inelastic / quasi-elastic neutron scattering spectrometers and the complementary use of these spectrometers will open new insight for life science.
Sako, Hiroyuki; Harada, Hiroyuki; Sakaguchi, Takao*; Chujo, Tatsuya*; Esumi, Shinichi*; Gunji, Taku*; Hasegawa, Shoichi; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; et al.
Nuclear Physics A, 956, p.850 - 853, 2016/12
Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11
The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.
Zheng, X.; Ito, Hiroto; Tamaki, Hitoshi; Maruyama, Yu
Journal of Nuclear Science and Technology, 53(3), p.333 - 344, 2016/03
Zheng, X.; Ito, Hiroto; Tamaki, Hitoshi; Maruyama, Yu
Mechanical Engineering Journal (Internet), 2(5), p.15-00032_1 - 15-00032_14, 2015/10
Mizumaki, Masaichiro*; Fujii, Hitoshi*; Yoshii, Kenji; Hayashi, Naoaki*; Saito, Takashi*; Shimakawa, Yuichi*; Uozumi, Takayuki*; Takano, Mikio*
Physica Status Solidi (C), 12(6), p.818 - 821, 2015/06
We investigated the electronic structure of BaFeO by using HAXPES and XAS measurements and first principle studies. The experimental and theoretical results indicated that BaFeO is a negative charge transfer compound. We concluded that the on-site Coulomb energy and the strong hybridization between Fe-3d and O-2p orbitals play a very important role of emergence of negative charge transfer. And we found the new structure in the Fe-2p XPS spectrum and concluded this structure is originated from non-local screening.
Zheng, X.; Ito, Hiroto; Kawaguchi, Kenji; Tamaki, Hitoshi; Maruyama, Yu
Reliability Engineering & System Safety, 138, p.253 - 262, 2015/06
Haraga, Tomoko; Saito, Shingo*; Sato, Yoshiyuki; Asai, Shiho; Hanzawa, Yukiko; Hoshino, Hitoshi*; Shibukawa, Masami*; Ishimori, Kenichiro; Takahashi, Kuniaki
Analytical Sciences, 30(7), p.773 - 776, 2014/07
A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by CE with LIF detection using a fluorescent ligand having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 3% recovery. This is due to method's high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role.