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-ray analysisKinoshita, Norikazu*; Noto, Takuma*; Nakajima, Hitoshi*; Kosako, Kazuaki*; Kato, Takahiro*; Kuroiwa, Yoichi*; Kurabe, Misako*; Sasaki, Yuki*; Torii, Kazuyuki*; Maeda, Makoto; et al.
Journal of Radioanalytical and Nuclear Chemistry, 332(2), p.479 - 486, 2023/02
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
Times Cited Count：8 Percentile：57.39(Geosciences, Multidisciplinary)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.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：51.19(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Nakashima, Hiroshi; Nakamura, Takemi; Kobayashi, Hitoshi*; Tanaka, Susumu*; Kumada, Hiroaki*
NEA/NSC/R(2021)2 (Internet), p.142 - 151, 2021/12
Aiming of development of facilities for boron neutron capture therapy (BNCT) that can be installed in hospitals, an accelerator-based BNCT facility is being developed at the Ibaraki Neutron Medical Research Center under a collaboration among the Japan Atomic Energy Agency, the High Energy Accelerator Research Organization, the University of Tsukuba, and other institutions. It consists of a proton accelerator, having a maximum beam power of 80 kW, and a target, moderator, collimator and shield (TMCS) system. For the design concept, to satisfy the BNCT beam conditions and achieve a low activation, the radiation behavior in the TMCS system was simulated by the Monte Carlo method and this system configuration was optimized accordingly. In addition, the radiation estimation of the TMCS system was verified via several experiments and its applicability for BNCT was proved. This report reviews the estimation and validation studies for the development of the accelerator-based BNCT facility.
Furuya, Osamu*; Fujita, Satoshi*; Muta, Hitoshi*; Otori, Yasuki*; Itoi, Tatsuya*; Okamura, Shigeki*; Minagawa, Keisuke*; Nakamura, Izumi*; Fujimoto, Shigeru*; Otani, Akihito*; et al.
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 6 Pages, 2021/07
Since the Fukushima accident, with the higher safety requirements of nuclear facilities in Japan, suppliers, manufacturers and academic societies have been actively considering the reconstruction of the safety of nuclear facilities from various perspectives. The Nuclear Regulation Authority has formulated new regulatory standards and is in operation. The new regulatory standards are based on defense in depth, and have significantly raised the levels of natural hazards and have requested to strengthen the countermeasures from the perspective of preventing the simultaneous loss of safety functions due to common factors. Facilities for dealing with specific serious accidents are required to have robustness to ensure functions against earthquakes that exceed the design standards to a certain extent. In addition, since the probabilistic risk assessment (PRA) and the safety margin evaluation are performed to include the range beyond the design assumption in the safety improvement evaluation, it is very important to extent the special knowledge in the strength of important equipment for seismic safety. This paper summarizes the research and examination results of specialized knowledge on the concept of maintaining the functions of important seismic facilities and the damage index to be considered by severe earthquakes. In the other paper, the study on reliability of seismic capacity analysis for important equipment in nuclear facilities will be reported.
Negishi, Hitoshi; Kamide, Hideki; Maeda, Seiichiro; Nakamura, Hirofumi; Abe, Tomoyuki
Nihon Genshiryoku Gakkai-Shi ATOMO
, 62(8), p.438 - 441, 2020/08
Prototype Fast Breeder Reactor, Monju, was under decommission since April, 2018. It is the first time for Japan to make a sodium cooled reactor into decommission. It is significant work and will take 30 years. The Monju has provided wide spectrum and huge amount of findings and knowledge, e.g., design, R&D, manufacturing, construction, and operation up to 40% of full power over 50 years of development history. It is significant to utilize such findings and knowledge for the development and commercialization of a fast rector in Japan.
Si
without local inversion symmetryNakamura, Shota*; Hyodo, Kazushi*; Matsumoto, Yuji*; Haga, Yoshinori; Sato, Hitoshi*; Ueda, Shigenori*; Mimura, Kojiro*; Saiki, Katsuyoshi*; Iso, Kosei*; Yamashita, Minoru*; et al.
Journal of the Physical Society of Japan, 89(2), p.024705_1 - 024705_5, 2020/02
Times Cited Count：2 Percentile：22.16(Physics, Multidisciplinary)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
Times Cited Count：15 Percentile：61.19(Physics, Condensed Matter)Suekuni, Koichiro*; Lee, C. H.*; Tanaka, Hiromi*; Nishibori, Eiji*; Nakamura, Atsushi*; Kasai, Hidetaka*; Mori, Hitoshi*; Usui, Hidetomo*; Ochi, Masayuki*; Hasegawa, Takumi*; et al.
Advanced Materials, 30(13), p.1706230_1 - 1706230_6, 2018/03
Times Cited Count：51 Percentile：89.35(Chemistry, Multidisciplinary)Thermoelectric materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. In this paper, we studied the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)
(Sb,As)
S
. The results revealed that the Cu atoms in a planar coordination are rattling, which effectively scatter phonons. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination.
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
Times Cited Count：32 Percentile：80.67(Biochemistry & Molecular Biology)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.
Watanabe, Norio; Yonomoto, Taisuke; Tamaki, Hitoshi; Nakamura, Takehiko; Maruyama, Yu
Journal of Nuclear Science and Technology, 52(1), p.41 - 56, 2015/01
Times Cited Count：11 Percentile：67.3(Nuclear Science & Technology)On March 11, 2011, the Tohoku District-off the Pacific Ocean Earthquake and the subsequent tsunami resulted in the severe core damage at TEPCO's Fukushima Dai-ichi Nuclear Power Plant Units 1-3, involving hydrogen explosions at Units 1, 3, and 4 and the large release of radioactive materials to the environment. Four independent committees were established by the Japanese government, the Diet of Japan, the Rebuild Japan Initiative Foundation, and TEPCO to investigate the accident and published their respective reports. Also, the Nuclear and Industrial Safety Agency carried out an analysis of accident causes to obtain the lessons learned from the accident and made its report public. This article reviews the reports and clarifies the differences in their positions, from the technological point of view, focusing on the accident progression and causes. Moreover, the undiscussed issues are identified to provide insights useful for the near-term regulatory activities including accident investigation by the Nuclear Regulation Authority.
Harigae, Hitoshi; Takagi, Tsuyohiko; Hamano, Tomoharu; Nakamura, Shoichi; Oba, Toshio; Ebashi, Masaaki; Okuda, Eiichi; Kinoshita, Tomonobu
JAEA-Technology 2013-014, 150 Pages, 2013/07
JAEA-Technology-2013-014.pdf:24.38MB
In-Vessel Transfer Machine (IVTM) came off from the gripper claw in the Auxiliary Handling Machine (AHM) and fell at a height of approximately two meters during a withdrawal work of the IVTM in the Fast Breeder Reactor (FBR) Monju. The withdrawal work of IVTM from the reactor vessel by AHM was performed. The work, however, was suspended due to the excessive load alarm. To grasp the situation of the IVTM fall, observation of the machine was necessary. An interior observation and an exterior observation of the dropped IVTM were performed. As a result of these observations, the radially deformed lower end of the upper guide tube was observed at the connection part, and it was jammed in the fuel throat sleeve when the dropped IVTM was withdrawn. Based on this information, the IVTM could be safely withdrawn from the reactor vessel with the fuel throat sleeve.
Watanabe, Norio; Yonomoto, Taisuke; Tamaki, Hitoshi; Nakamura, Takehiko; Maruyama, Yu
Nihon Genshiryoku Gakkai Wabun Rombunshi, 12(2), p.113 - 127, 2013/06
On March 11, 2011, the Tohoku District - off the Pacific Ocean Earthquake and the subsequent tsunami resulted in the severe core damage at the TEPCO's Fukushima Dai-ichi Nuclear Power Station Units 1-3, involving hydrogen explosions at Units 1, 3, and 4 and the large release of radioactive materials to the environment. The four independent committees were established by the Government, the Diet of Japan and the Rebuild Japan Initiative Foundation as well as TEPCO to investigate the accident and published their respective reports. Also, the Nuclear and Industrial Safety Agency carried out the analysis of accident causes to obtain the lessons learned from the accident and made its report public. This article reviews the reports and clarifies the differences in their positions, from the technological point of view, focusing on the accident progression and causes. As well, the undiscussed issues are identified to provide insights useful for the near-term regulatory activities including accident investigation by the Nuclear Regulation Authority.
Kizu, Kaname; Kashiwa, Yoshitoshi; Murakami, Haruyuki; Obana, Tetsuhiro*; Takahata, Kazuya*; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Hamaguchi, Shinji*; Matsui, Kunihiro; Nakamura, Kazuya*; et al.
Fusion Engineering and Design, 86(6-8), p.1432 - 1435, 2011/10
Times Cited Count：8 Percentile：53.37(Nuclear Science & Technology)In JT-60SA, central solenoid (CS) and plasma equilibrium field (EF) coils are procured by Japan. EF coil conductors are NbTi cable-in-conduit (CIC) conductor. Delivered superconducting cables and jackets are fabricated into CIC conductors at the jacketing facility with the length of 680 m constructed in the Naka site of JAEA. The production of superconductors with 444 m in length for actual EF coils was started from March 2010. The measurements of superconducting performance like current sharing temperature (Tcs) were conducted prior to the mass production. The measured Tcs was agreed with the expectation values from strand values indicating that no degradation was happened by production process.
Hoshino, Tsuyoshi; Tsuchiya, Kunihiko; Hayashi, Kimio; Nakamura, Mutsumi*; Terunuma, Hitoshi*; Tatenuma, Katsuyoshi*
Journal of Nuclear Materials, 386-388, p.1107 - 1110, 2009/04
Times Cited Count：9 Percentile：53.3(Materials Science, Multidisciplinary)no abstracts in English
Fujita, Reiko*; Nakamura, Hitoshi*; Mizuguchi, Koji*; Utsunomiya, Kazuhiro*; Amamoto, Ippei
Proceedings of 2008 Joint Symposium on Molten Salts (USB Flash Drive), p.886 - 891, 2008/10
Pyrochemical treatment in molten salts is a promising process for decontamination of radioactive wastes without producing large amounts of secondary waste. In this report, the fundamental experiment was carried out to treat the wastes which had complicated shapes such as Magnoxend corps, metallic waste contaminated by uranium, spent chemical trap fillers and spent Zircaloy channel boxs from BWR and acquired good results.
Nakamura, Tatsufumi*; Sakagami, Hitoshi*; Jozaki, Tomoyuki*; Nagatomo, Hideo*; Mima, Kunioki*; Koga, J. K.
Physics of Plasmas, 14(10), p.103105_1 - 103105_7, 2007/10
Times Cited Count：72 Percentile：91.03(Physics, Fluids & Plasmas)Nakamura, Tatsufumi*; Sakagami, Hitoshi*; Jozaki, Tomoyuki*; Nagatomo, Hideo*; Mima, Kunioki*; Koga, J. K.
Plasma and Fusion Research (Internet), 2, p.018_1 - 018_6, 2007/05
Electron acceleration processes taking place in the interaction of ultra-intense laser pulses with cone targets are studied by using two-dimensional Particle-in-Cell (PIC) simulations to understand the characteristics of electrons generated from cone targets. It is explained that there are two dominant acceleration processes which are distinctive in the laser-cone interaction. One is the acceleration and transport along the side wall of the cone target, where electrons are guided along the side wall surface towards the cone tip by surface magnetic and electric fields. The second is the ponderomotive acceleration at the cone tip by the laser field which is intensified by cone focusing. The understanding of these acceleration processes helps to design cone targets to control the electron energy characteristics.
Harada, Hideo; Sakane, Hitoshi; Nakamura, Shoji; Furutaka, Kazuyoshi; Hori, Junichi*; Fujii, Toshiyuki*; Yamana, Hajimu*
Nuclear Data Needs for Generation IV Nuclear Energy Systems, p.216 - 221, 2006/05
Recent activities on the measurement of neutron capture cross sections by a Japan Nuclear Cycle Development Institute (JNC) and Kyoto university group is reviewed focusing on 
Np and 
Np. Firstly, an experimental issue on the measurement of thermal-neutron capture cross section and resonance integral of Np is discussed. In second, the effectiveness of utilizing a double-neutron capture reaction for the measurement of the neutron capture cross section for short-lived nuclei Np is discussed. In third, the measurements of the energy dependence of the neutron capture cross section of Np are reviewed focusing on the experimental progress, including a total-energy detector and a flash-ADC based data-taking system. The experimental results were compared each other and also with some nuclear data libraries to make the problems clear.
