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Seki, Misaki; Fujita, Yoshitaka; Fujihara, Yasuyuki*; Zhang, J.*; Yoshinaga, Hisao*; Sano, Tadafumi*; Hori, Junichi*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; et al.
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 29(1), p.2 - 9, 2022/06
no abstracts in English
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.
Aizawa, Kosuke; Fujita, Kaoru; Kamide, Hideki; Kasahara, Naoto*
Nuclear Technology, 189(2), p.111 - 121, 2015/02
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Selector-valve mechanism is adopted in the design of JSFR for its failed-fuel detection and location (FFDL) system. JSFR has only two FFDL units for 562 core fuel subassemblies to reduce construction cost by decreasing the reactor vessel diameter. Consequently, one SV-FFDL unit must handle about 300 subassemblies. In addition, JSFR adopts an upper internal structure (UIS) with a slit above the core. Sampling performance for the subassemblies under the UIS slit has been evaluated to be lower than those under the normal UIS position in the previous water experiments and numerical simulation. In this paper, the outline of FFDL system is shown, which can be applied to so large number of fuel subassemblies in a compact reactor vessel. Detection capability of the FFDL system was studied to achieve the design conditions. Operation modes and procedure of the FFDL system also investigated.
Aizawa, Kosuke; Fujita, Kaoru; Hirata, Shingo*; Kasahara, Naoto*
Nuclear Technology, 183(1), p.1 - 12, 2013/07
In the design of Japan Sodium-cooled Fast Reactor (JSFR), a selector-valve mechanism is adopted for its failed-fuel detection and location (FFDL) system. Since JSFR has only two FFDL units for about 600 fuel subassemblies, one FFDL unit must handle much larger number of subassemblies than in previous designs. In addition, during long plant life of 60 years, the wear length of the selector-valve will become longer than those of past reactors. Therefore, the endurance of the selector-valve becomes important. To demonstrate the manufacturability and endurance of the selector-valve, a full size mock-up was manufactured, and an endurance experiment of the mock-up model under high-temperature sodium were conducted. The cross-section observation, hardness measurement, and chemical assay results after the endurance experiment showed that the coating layer on the sliding surface still remains. Thus, the endurance of the JSFR selector-valve was demonstrated.
Fujita, Kaoru; Yamano, Hidemasa; Kubo, Shigenobu*; Eto, Masao*; Yamada, Yumi*; Toyoshi, Akira*
Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 6 Pages, 2012/12
no abstracts in English
Ishikawa, Nobuyuki; Chikazawa, Yoshitaka; Fujita, Kaoru; Yamada, Yumi*; Okazaki, Hitoshi*; Suzuki, Shinichi*
Proceedings of 2012 International Congress on Advances in Nuclear Power Plants (ICAPP '12) (CD-ROM), p.483 - 489, 2012/06
The development of safety protection system for JSFR is progressed in terms of logic circuits, selection of trip signals and its setting values for reactor trip. In addition, it is necessitated to evaluate the satisfaction for requirements of the safety protection system by safety analyses considering comprehensive parameter ranges. For this purpose, we will report the current status of the development focusing on the evaluation results for satisfaction of safety protection system based on safety standard.
Yamano, Hidemasa; Kubo, Shigenobu; Shimakawa, Yoshio*; Fujita, Kaoru; Suzuki, Toru; Kurisaka, Kenichi
Science and Technology of Nuclear Installations, 2012, p.614973_1 - 614973_14, 2012/00
Times Cited Count:14 Percentile:71.22(Nuclear Science & Technology)This paper describes safety requirements for JSFR conformed to the defense-in-depth principle in IAEA. The safety design accommodation in JSFR was validated by safety analyses for representative DBEs: primary pump seizure and long-term loss-of-offsite power accidents. The safety analysis also showed the effectiveness of the passive shutdown system and mitigation measures against a typical ATWS.
Aizawa, Kosuke; Fujita, Kaoru; Kamide, Hideki; Kasahara, Naoto
Proceedings of 2011 International Congress on Advances in Nuclear Power Plants (ICAPP '11) (CD-ROM), p.605 - 613, 2011/05
A conceptual design study of an advanced large-sized (1,500 MWe class) sodium-cooled fast reactor, JSFR, is in progress in the FaCT project in Japan. JSFR has adopted a selector-valve mechanism for a failed-fuel detection and location (FFDL) system. The selector-valve FFDL system identifies a failed fuel subassembly by sampling sodium from each fuel subassembly outlet and detecting fission product gas or delayed neutron precursors of fission products. One of the technologies which JSFR has adopted is an upper internal structure (UIS) with a radial slit. Because sampling nozzles cannot be set in the UIS slit, several sampling nozzles are installed around the slit so as to sample sodium from the failed fuel subassemblies under the UIS slit. In this study, a signal and noise detected by the delayed neutron detector have been calculated. On the basis of these results, appropriate operation patterns of the selector-valve FFDL system for JSFR have been constructed.
Yamano, Hidemasa; Kubo, Shigenobu*; Shimakawa, Yoshio*; Fujita, Kaoru; Suzuki, Toru; Kurisaka, Kenichi
Proceedings of 2011 International Congress on Advances in Nuclear Power Plants (ICAPP '11) (CD-ROM), p.728 - 740, 2011/05
Aizawa, Kosuke; Fujita, Kaoru; Kamide, Hideki; Kasahara, Naoto
Nihon Kikai Gakkai Rombunshu, B, 77(776), p.982 - 986, 2011/04
A conceptual design study of Japan Sodium-cooled Fast Reactor (JSFR) is in progress as an issue of the "Fast Reactor Cycle Technology Development (FaCT)" project in Japan. JSFR adopts a Selector-Valve mechanism for a failed fuel detection and location (FFDL) system. The Selector-Valve FFDL system identifies failed fuel subassemblies by sampling sodium from each fuel subassembly outlet and detecting fission product. One of the JSFR design features is employing an upper internal structure (UIS) with a radial slit, in which an arm of fuel handling machine can move and access the fuel assemblies under the UIS. Thus, JSFR cannot place sampling nozzles right above the fuel subassemblies located under the slit. In this study, appropriate sampling method for indentifying under-slit failed fuel subassemblies has been developed by water experiments.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Kawamura, Seiko; Yokoo, Tetsuya*; Nakatani, Takeshi; Maruyama, Ryuji; Soyama, Kazuhiko; et al.
Journal of the Physical Society of Japan, 80(Suppl.B), p.SB025_1 - SB025_6, 2011/01
Times Cited Count:102 Percentile:94.01(Physics, Multidisciplinary)Aizawa, Kosuke; Fujita, Kaoru; Kamide, Hideki; Kasahara, Naoto
Dai-15-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.229 - 230, 2010/06
A conceptual design study of Japan Sodium-cooled Fast Reactor (JSFR) is in progress as an issue of the "Fast Reactor Cycle Technology Development (FaCT)" project in Japan. JSFR adopts a selector-valve mechanism for the Failed Fuel Detection and Location (FFDL) system. The selector-valve FFDL system identifies failed fuel subassemblies by sampling sodium from each fuel subassembly outlet and detecting fission product. One of the JSFR design features is employing an Upper Internal Structure (UIS) with a radial slit, in which an arm of fuel handling machine can move and access the fuel assemblies under the UIS. Thus, JSFR cannot place sampling nozzles right above the fuel subassemblies located under the slit. In this study, the sampling method for identifying under-slit failed fuel subassemblies has been demonstrated by water experiments.
Aizawa, Kosuke; Fujita, Kaoru; Hirata, Shingo; Kasahara, Naoto
Proceedings of 2010 International Congress on Advances in Nuclear Power Plants (ICAPP '10) (CD-ROM), p.645 - 652, 2010/06
A conceptual design study of an advanced large-sized (1500MWe class) sodium-cooled fast reactor (named JSFR) has progressed in the FaCT project in Japan. JSFR adopts a selector-valve mechanism for the failed fuel detection and location (FFDL) system. The drive shaft rotates and moves vertically in order to select the channel. And, the drive shaft is in contact with the selector-valve drum by spring load. Thus, a mechanical wear could occur between the drive shaft and the drum of the selector-valve FFDL system. There is concern about manufacturing capability and endurance of the JSFR selector-valve. To demonstrate manufacturing capability and endurance of the JSFR selector-valve, a mock-up was manufactured and an endurance experiment under high temperature sodium has been conducted.
Kai, Tetsuya; Kobayashi, Katsuhei*; Yamamoto, Shuji*; Cho, H.*; Fujita, Yoshiaki*; Kimura, Itsuro*; Okawachi, Yasushi*; Wakabayashi, Toshio*
Annals of Nuclear Energy, 28(8), p.723 - 739, 2001/05
Times Cited Count:7 Percentile:48.68(Nuclear Science & Technology)no abstracts in English
Nishimori, Nobuyuki; Sagara, K.*; Fujita, T.*; Wakamatsu, Fumihiko*; Bussaki, Toru*; Maeda, Kazuhide*; Akiyoshi, H.*; Tsuruta, Kaoru*; Nakamura, Hiroyuki*; Nakashima, Takao*
Nuclear Fusion, 631, p.697C - 700C, 1998/03
no abstracts in English
Oigawa, Hiroyuki; Fujita, Yoshiaki*; *; Yamamoto, Shuji*; Kimura, Itsuro*
Journal of Nuclear Science and Technology, 28(10), p.879 - 893, 1991/10
no abstracts in English
Kaneko, Yoshihika; Iijima, Tsutomu; Mizuho, Mitsuru; Fuse, Takayoshi*; Fujita, Yoshiaki*; Nakazawa, Masaharu*; Sekiguchi, Akira*; Kimura, Itsuro*
Nihon Genshiryoku Gakkai-Shi, 18(2), p.77 - 88, 1976/02
no abstracts in English
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Nakamura, Mitsutaka; Nakajima, Kenji; Inamura, Yasuhiro; Takahashi, Nobuaki; Maruyama, Ryuji; Soyama, Kazuhiko; Mizuno, Fumio; Shibata, Kaoru; et al.
no journal, ,
no abstracts in English
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Nakamura, Mitsutaka; Nakajima, Kenji; Inamura, Yasuhiro; Takahashi, Nobuaki; Maruyama, Ryuji; Soyama, Kazuhiko; Mizuno, Fumio; Shibata, Kaoru; et al.
no journal, ,
no abstracts in English
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Takahashi, Nobuaki; Kawamura, Seiko; Maruyama, Ryuji; Soyama, Kazuhiko; et al.
no journal, ,
no abstracts in English