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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.
Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Takahashi, Yoshikazu; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Ebisawa, Noboru; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4804804_1 - 4804804_4, 2012/06
Times Cited Count:18 Percentile:64.78(Engineering, Electrical & Electronic)no abstracts in English
Hemmi, Tsutomu; Nunoya, Yoshihiko; Nabara, Yoshihiro; Yoshikawa, Masatoshi*; Matsui, Kunihiro; Kajitani, Hideki; Hamada, Kazuya; Isono, Takaaki; Takahashi, Yoshikazu; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4803305_1 - 4803305_5, 2012/06
Times Cited Count:47 Percentile:86.03(Engineering, Electrical & Electronic)To characterize the performance of the CS conductor, a CS conductor sample was tested in the SULTAN facility at CRPP. As a result of the cyclic test up to 1000 cycles, measured Tcs was in good agreement with the expected Tcs, which is calculated by the characteristics of the NbSn strands and the designed strain. However, continuous degradation of Tcs was observed after 1000 cycles. The degradation of Tcs was around 0.6 K from 1000 cycles to 6000 cycles. On the other hand, the degradation of Tcs by cyclic operation is nearly 0.1 K from 1000 cycles to 10,000 cycles in the CS Insert test at JAEA in 2000. To investigate the causes for the degradation of Tcs, the following items are performed; (1) strain measurement by neutron diffraction, (2) strain measurement by sample cuttings, (3) strand position observation, (4) visual inspection on strands, (5) filament breakage observation, (6) modeling and calculation of the degradation. Detailed results will be presented and discussed.
Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4801904_1 - 4801904_4, 2012/06
Times Cited Count:7 Percentile:40.83(Engineering, Electrical & Electronic)Japan Atomic Energy Agency is the first to start the mass production of the TF conductors in Phase IV in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The conductor is cable-in-conduit conductor with a central spiral. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and then wrapped with stainless steel tape whose thickness is 0.1 mm. Approximately 60 tons of NbSn strands were manufactured by the two suppliers in December 2010. This amount corresponds to approximately 55% of the total contribution from Japan. Approximately 30% of the total contribution from Japan was completed as of February 2011. JAEA is manufacturing one conductor per month under a contract with two Japanese companies for strands, one company for cabling and one company for jacketing. This paper summarizes the technical developments including a high-level quality assurance. This progress is a significant step in the construction of the ITER machine.
Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Uno, Yasuhiro; Takahashi, Yoshikazu; Nakajima, Hideo; Tsuzuku, Seiji*; Tagawa, Kohei*; Miyashita, Katsumi*; et al.
Teion Kogaku, 47(3), p.140 - 146, 2012/03
no abstracts in English
Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
Nuclear Fusion, 51(11), p.113015_1 - 113015_11, 2011/11
Times Cited Count:13 Percentile:48.50(Physics, Fluids & Plasmas)Japan Atomic Energy Agency is procuring the NbSn superconductors for Toroidal Field (TF) Coils under the ITER project. Because manufacturing amount of NbSn strands is quite large compared with the past experience and required superconducting performance is higher than that of the model coils which have been fabricated and tested in the ITER-EDA, quality control technique is very important for the manufacture of the strands. Sophisticated control technique is also required for the jacketing, in order to fabricate the conductors with the precise outer diameter and without leakage at welding part. This paper summarizes the technical developments leading to the first successful mass production of ITER TF conductors.
Seki, Yohji; Onishi, Yoichi*; Yoshikawa, Akira; Tanigawa, Hisashi; Hirose, Takanori; Ozu, Akira; Ezato, Koichiro; Tsuru, Daigo; Suzuki, Satoshi; Yokoyama, Kenji; et al.
Progress in Nuclear Science and Technology (Internet), 2, p.139 - 142, 2011/10
R&D of a test blanket module (TBM) with a water-cooled solid breeder has been performed for ITER. For our design, the temperature of a coolant pressurized up to 15 MPa is designed as 598 K in an outlet of the TBM, respectively. Establishment of estimation methods of the flow phenomena is important for designs of the channel network and predictions of the material corrosion and erosion. A purpose of our research is to establish and verify the method for the prediction of the flow phenomena. The Large-eddy simulation and Reynolds averaged Navier-Stokes simulation have been performed to predict the pressure drop and flow rates in the channels of the side wall. It results the inhomogeneous flow rates in each channel. At viewpoint of the heat removal capability, however, the smallest flow-rates near the first wall are evaluated with satisfying acceptance criteria. Moreover, the results of the numerical simulation correspond with those of experiment performed for the real size mock-up.
Nunoya, Yoshihiko; Nabara, Yoshihiro; Yoshikawa, Masatoshi*; Matsui, Kunihiro; Hemmi, Tsutomu; Takahashi, Yoshikazu; Isono, Takaaki; Koizumi, Norikiyo; Nakajima, Hideo; Stephanov, B.*; et al.
IEEE Transactions on Applied Superconductivity, 21(3), p.1982 - 1986, 2011/06
Times Cited Count:23 Percentile:70.71(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) has developed ITER TF NbSn conductors that fulfill ITER requirements and then commenced fabricating conductors to be used for ITER TF coils. As a qualification of conductor fabrication, two full-size conductor samples named as JATF4 were prepared and tested by the SULTAN facility at CRPP in Switzerland. The length of the samples was about 3 m, and temperature sensors and voltage taps were attached on conductors to measure the current sharing temperature (Tcs). The measurement was performed at the beginning of the test campaign, during cyclic test, and at the end of the campaign that corresponded to after once warm up and cool down. The Tcs values electrically assessed by the agreed procedure at outer magnetic fields of 10.78 T were 6.5 K and 6.2 K at the beginning and 6.1 K and 6.0 K at the end of the campaign for each conductor, respectively. These values concluded that the conductors have enough Tcs margin to satisfy the criterion of 5.7 K as ITER TF conductor, and conductor fabrication is qualified. Detail of the test results will be presented and discussed.
Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Japan Atomic Energy Agency is procuring the NbSn superconductors for Toroidal Field (TF) coils under the ITER project. Because manufacturing amount of NbSn strands is quite large compared with the past experience and required superconducting performance is higher than that of the model coils which have been fabricated and tested in the ITER-EDA, quality control technique is very important for the manufacture of the strands. Sophisticated control technique is also required for the jacketing, in order to fabricate the conductors with the precise outer diameter and without leakage at welding part. Cu dummy conductor with full length (760 m) has been fabricated successfully and all jacketing technology was confirmed through this fabrication. The fabrication of the NbSn conductor for TF coils will start in March 2010.
Seki, Yohji; Onishi, Yoichi*; Yoshikawa, Akira; Tanigawa, Hisashi; Hirose, Takanori; Ozu, Akira; Ezato, Koichiro; Tsuru, Daigo; Suzuki, Satoshi; Yokoyama, Kenji; et al.
Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 4 Pages, 2010/10
R&D of a test blanket module (TBM) with a water-cooled solid breeder has been performed for ITER. For our design, the temperature of a coolant pressurized up to 15 MPa is designed as 598 K in an outlet of the TBM, respectively. Establishment of estimation methods of the flow phenomena is important for designs of the channel network and predictions of the material corrosion and erosion. A purpose of our research is to establish and verify the method for the prediction of the flow phenomena. The Large-eddy simulation and Reynolds averaged Navier-Stokes simulation have been performed to predict the pressure drop and flow rates in the channels of the side wall. It results the inhomogeneous flow rates in each channel. At viewpoint of the heat removal capability, however, the smallest flow-rates near the first wall are evaluated with satisfying acceptance criteria. Moreover, the results of the numerical simulation correspond with those of experiment performed for the real size mockup.
Nabara, Yoshihiro; Isono, Takaaki; Nunoya, Yoshihiko; Koizumi, Norikiyo; Hamada, Kazuya; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Uno, Yasuhiro*; Seki, Shuichi*; et al.
Journal of Plasma and Fusion Research SERIES, Vol.9, p.270 - 275, 2010/08
Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.
Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10
J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.
Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Koizumi, Norikiyo; Hamada, Kazuya; Matsui, Kunihiro; Hemmi, Tsutomu; Yoshikawa, Masatoshi*; Uno, Yasuhiro; Oshikiri, Masayuki; et al.
no journal, ,
no abstracts in English
Hamada, Kazuya; Takahashi, Yoshikazu; Isono, Takaaki; Nunoya, Yoshihiko; Matsui, Kunihiro; Nabara, Yoshihiro; Hemmi, Tsutomu; Kawano, Katsumi; Yoshikawa, Masatoshi*; Oshikiri, Masayuki; et al.
no journal, ,
Japan Atomic Energy Agency is in charge of procurement of Toroidal Field (TF) coil and conductors for International Thermonuclear Experimental Reactor(ITER) as a domestic agency of ITER in Japan. The TF conductor is composed of cable using 900 superconducting strands and 522 copper strands with a diameter of 0.8mm sheathed in the jacket with a thickness of 2mm and outer diameter of 43.7mm and the maximum length is 760m. The procurement of conductor was started from 2008 and preparations of strands, cabling, jacket and jacketing facility have progressed under the cooperation from industries. As a result, preparation to manufacture conductor is completed. First of all, to demonstrate the manufacturing procedure, 760m long dummy conductor has been manufactured and successfully completed. Based on the achievement, Japan started to make superconducting conductor. In the conference, status of procurement of TF conductor and conductor manufacturing technologies are introduced.
Nabara, Yoshihiro; Isono, Takaaki; Nunoya, Yoshihiko; Koizumi, Norikiyo; Hamada, Kazuya; Matsui, Kunihiro; Hemmi, Tsutomu; Oshikiri, Masayuki; Uno, Yasuhiro*; Seki, Shuichi*; et al.
no journal, ,
no abstracts in English
Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Koizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Yoshikawa, Masatoshi*; Uno, Yasuhiro; et al.
no journal, ,
no abstracts in English
Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Koizumi, Norikiyo; Kawano, Katsumi; Oshikiri, Masayuki; et al.
no journal, ,
The toroidal field (TF) coil system of the International Thermonuclear Experimental Reactor (ITER) consists of 18 D-shape coils. The operating current, the maximum field and the stored magnetic energy are 68 kA, 11.8 T and about 41 GJ, respectively. NbSn cable-in-conduit conductor (CICC) with a central channel is used. The superconducting cable consists of 900 NbSn strands and 522 copper strands, and they are cabled to a 5th stage cable with a central cooling spiral. The conductor manufacture started in 4 companies (strands in 2 companies, cabling, jacketing) in Japan, from March 2008. The 14.4 tonnes of strands were completed and satisfy their specifications in 2 companies. The copper dummy cable with a length of 760 m was successfully fabricated. The jacketing line was also completed. These details are reported.