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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.
Song, F.*; Chen, H.*; Hayashida, Hirotoshi*; Kai, Tetsuya; Shinohara, Takenao; Yabutsuka, Takeshi*; Yao, Takeshi*; Takai, Shigeomi*
Solid State Ionics, 377, p.115873_1 - 115873_6, 2022/04
Times Cited Count:2 Percentile:31.08(Chemistry, Physical)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.
Taguchi, Shigeo; Taguchi, Katsuya; Makino, Risa; Yamanaka, Atsushi; Suzuki, Kazuyuki; Takano, Masato; Koshino, Katsuhiko; Ishida, Michihiko; Nakano, Takafumi; Yamaguchi, Toshiya
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.499 - 502, 2021/07
In 2018, Tokai Reprocessing Plan (TRP) shifted to the decommissioning stage. In order to proceed with steady decommissioning work, TRP effort to enhance project management function. This paper describes the establishment and role of the Decommissioning Project Management Office, effectiveness of applying the project management tool and its utilization concept, and the method of materialize the equipment dismantling plan.
Horigome, Kazushi; Taguchi, Shigeo; Nishida, Naoki; Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko
Nihon Hozen Gakkai Dai-14-Kai Gakujutsu Koenkai Yoshishu, p.381 - 384, 2017/08
no abstracts in English
Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.
JAEA-Review 2014-048, 69 Pages, 2015/02
JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations
Miyamura, Hiroko; Hu, H.-Y.*; Yoshida, Masahiro*; Ozahata, Satoshi*; Nakao, Akihiro*; Takahashi, Shigeo*
Shingaku Giho, 112(463), p.577 - 582, 2013/03
This report presents a method for visualizing scale-free networks including Overlay networks as an typical example. Visualizing large-scale and complicated networks such as social networks has recently been very popular while conventional network visualization techniques cannot allow us to understand the topological structure of the scale-free networks. This is because the vertex degrees vary at an exponential rate in the scale-free network and thus special attention should be given when visualizing the network connectivity and analyzing the network traffic there. In this report, we employ the hierarchical representation of the scale-free network by referring to their vertex degrees and autonomous system relationships, so that we can clearly visualize the topological structure of the network in 3D space and retrieve the traffic paths over the network.
Murata, Isao*; Ota, Masayuki*; Miyamaru, Hiroyuki*; Kondo, Keitaro; Yoshida, Shigeo*; Iida, Toshiyuki*; Ochiai, Kentaro; Konno, Chikara
Journal of Nuclear Materials, 417(1-3), p.1127 - 1130, 2011/10
Times Cited Count:2 Percentile:18.29(Materials Science, Multidisciplinary)Nuclear data are indispensable for development of fusion reactor candidate materials. However, benchmarking of the nuclear data in MeV energy region is not sufficient even now. In the present study, benchmark performance in the MeV energy region was investigated theoretically in case of experiments by using a 14MeV neutron source. We carried out a systematical analysis for light to heavy materials. As a result, the benchmark performance for neutron spectrum was confirmed to be acceptable, while for -ray it was not sufficient. This indicates it was effective to use a spectrum shifter. As a shifter beryllium had the best performance. Moreover, it was preliminarily examined whether it is really acceptable that only the spectrum before last collision is considered in the benchmark performance analysis. It was pointed out that not only the last collision but also more previous collisions should be taken into account equally in the benchmark performance analysis.
Shimizu, Hiroyuki*; Koyama, Tomofumi*; Murata, Sumihiko*; Ishida, Tsuyoshi*; Chijimatsu, Masakazu*; Fujita, Tomoo; Nakama, Shigeo
International Journal of the JCRM (Internet), 7(1), p.33 - 36, 2011/09
In this research, newly developed numerical approaches using the Distinct Element Method (DEM) were presented, and a series of DEM simulations were performed for better understanding the physical phenomena and mechanism for the following two fundamental issues in rock engineering field. The first issue is the Class II behavior of the brittle rocks under uniaxial compression. The radial strain control method for uniaxial compression tests was introduced in the DEM codes and the Class II behavior of rocks was simulated. The simulation results suggest that the DEM can reproduce the Class II behavior of the rock successfully and revealed that the loading condition of rocks will play an important role for the Class II behavior. The second issue is the hydraulic fracturing behavior in rocks. A series of simulations for hydraulic fracturing in rock was performed by using the flow-coupled DEM code. Simulation results clearly show that the fluid infiltration behavior depends on the fluid viscosity. The fluid infiltrates into the fracture immediately, when a low viscosity fluid is used and the fluid infiltrates slowly into the cracks after the fracture generation and propagation, when a high viscosity fluid is used. Moreover, the tensile cracks are dominantly generated in the DEM simulations as expected in the conventional theory. However, the energy released from tensile cracks becomes smaller due to the fact that the tensile strength of rock is usually smaller than the compressive one. Such a small AE events is not distinguishable from noise and hard to recognize during laboratory experiments. Therefore, in AE measurements, shear type AE events with large energy are dominantly observed.
Shimizu, Hiroyuki*; Koyama, Tomofumi*; Ishida, Tsuyoshi*; Chijimatsu, Masakazu*; Fujita, Tomoo; Nakama, Shigeo
International Journal of Rock Mechanics and Mining Sciences, 47(2), p.323 - 333, 2010/02
Times Cited Count:39 Percentile:88.5(Engineering, Geological)Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.
JAEA-Review 2009-001, 110 Pages, 2009/03
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2006 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.
JAEA-Review 2008-073, 99 Pages, 2009/03
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2005 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Suzuki, Toshiyuki; Muramatsu, Yasuyuki; Kamoshida, Shigeo
JAEA-Testing 2007-001, 58 Pages, 2007/03
As a part of safety research of light water reactors (LWR), fuel behavior during a reactivity-initiated accident (RIA) has being studied in the Nuclear Safety Research Reactor (NSRR) using irradiated fuels in commercial reactors. During a past decade, RIA-simulating experiments in the NSRR showed that cladding failures at higher burnup occurred at lower enthalpy values than those would be expected. It was supposed that this type of the fuel failure may be influenced by an initial temperature of cladding since the failure occurs before the temperature escalation of the cladding due to the power burst. In order to verify the influence of the cladding temperature before the onset of power escalation during an RIA, we developed B-I type (the 1st type to simulate BWR operation condition) high pressure water capsule. This manual describes a series of working procedures from receiving the capsule to transporting it after experiment and a procedure in case of an emergency in order to perform the RIA-simulating experiments using the B-I type capsule safely and smoothly.
Hase, Yoshihiro; Fujioka, Shozo*; Yoshida, Shigeo*; Sun, G.; Umeda, Masaaki*; Tanaka, Atsushi
Journal of Experimental Botany, 56(414), p.1263 - 1268, 2005/04
Times Cited Count:40 Percentile:65.3(Plant Sciences)The () mutant, that has serrated petals and sepals but no other large changes in plant morphology, was studied. The had a mutation in and an altered sterol composition. It was found that the mutation causes ectopic endoreduplication in petal tips that do not normally endoreduplicate. The rosette leaves of also showed an enhanced level of endoreduplication, but their morphology was hardly affected. These facts suggest that the suppression of endoreduplication is important for petal morphogenesis and the normal sterol composition is required for this suppression.
Nishitani, Takeo; Ochiai, Kentaro; Yoshida, Shigeo*; Tanaka, Ryohei*; Wakisaka, Masashi*; Nakao, Makoto*; Sato, Satoshi; Yamauchi, Michinori*; Hori, Junichi; Wada, Masayuki*; et al.
Journal of Nuclear Science and Technology, 41(Suppl.4), p.58 - 61, 2004/03
no abstracts in English
Yoshida, Shigeo*; Nishitani, Takeo; Ochiai, Kentaro; Kaneko, Junichi*; Hori, Junichi; Sato, Satoshi; Yamauchi, Michinori*; Tanaka, Ryohei*; Nakao, Makoto*; Wada, Masayuki*; et al.
Fusion Engineering and Design, 69(1-4), p.637 - 641, 2003/09
Times Cited Count:9 Percentile:53.35(Nuclear Science & Technology)no abstracts in English
Nishitani, Takeo; Ochiai, Kentaro; Yoshida, Shigeo*; Tanaka, Ryohei*; Wakisaka, Masashi*; Nakao, Makoto*; Sato, Satoshi; Yamauchi, Michinori*; Hori, Junichi; Takahashi, Akito*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 79(3), p.282 - 289, 2003/03
no abstracts in English
Kisohara, Naoyuki; Uchita, Masato; Konomura, Mamoru; Kasai, Shigeo; Soman, Yoshindo; Shimakawa, Yoshio; Hori, Toru; Chikazawa, Yoshitaka; Miyahara, Shinya; Hamada, Hirotsugu; et al.
JNC TN9400 2003-002, 109 Pages, 2002/12
Sodium is the most promising candidate of an FBR coolant because of its excellent properties such as high thermal conductivity. Whereas, sodium reacts with water/air and its opaqueness makes it difficult to inspect sodium components. These weaknesses of sodium affect not only plant safety but also plant availability (economy). To overcome these sodium weak points, the appropriate countermeasure must be adopted to commercialized FBR plants. This report describes the working group activities for sodium/water reaction of steam generators (SG), in-service inspection for sodium components and sodium leak due to sodium components boundary failure. The prospect of each countermeasure is discussed in the viewpoint of the commercialized FBR plants. (1)Sodium/water reaction. The principle of the countermeasure for sodium/water reaction accidents was organized in the viewpoint of economy (the investment of SG and the plant availability). The countermeasures to restrain failure propagation were investigated for a large-sized SG. Preliminary analysis revealed the possibility of minimizing tubes failure propagation by improving the leak detection system and the blow down system. Detailed failure propagation analysis will be required and the early water leak detection system and rapid blow down system must be evaluated to realize its performance. (2)In-service inspection (ISI&R). The viewpoint of the commercialized plant's ISI&R was organized by comparing with the prototype reactor's ISI&R method. We also investigated short-term ISI&R methods without sodium draining to prevent the degrading of the plant availability, however, it is difficult to realize them with the present technology. Hereafter, the ISI&R of the commercialized plants must be defined by considering its characteristics. (3)Sodium leak from the components. This report organized the basic countermeasure policy for primary and secondary sodium leak accidents. Double-wall structure of sodium piping was ...
Choe, S.*; Dilkes, B. P.*; Gregory, B. D.*; Ross, A. S.*; Yuan, H.*; Noguchi, Takahiro*; Fujioka, Shozo*; Takatsuto, Suguru*; Tanaka, Atsushi; Yoshida, Shigeo*; et al.
Plant Physiology, 119(3), p.897 - 907, 1999/03
Times Cited Count:189 Percentile:97.23(Plant Sciences)no abstracts in English
Choe, S.*; Noguchi, Takahiro*; Fujioka, Shozo*; Takatsuto, Suguru*; Tissier, C. P.*; Gregory, B. D.*; Ross, A. S.*; Tanaka, Atsushi; Yoshida, Shigeo*; Tax. F. E.*; et al.
Plant Cell, 11, p.207 - 221, 1999/02
Times Cited Count:201 Percentile:97.59(Biochemistry & Molecular Biology)no abstracts in English