Matsuda, Kosuke*; Muramatsu, Ken*; Muta, Hitoshi*; Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; et al.
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04
This paper proposes a set of procedures for accident sequence analysis in seismic PRAs of HTGRs that can consider the unique accident progression characteristics of HTGRs. Main features of our proposed procedure are as follows: (1) Systematic analysis techniques including Master Logic Diagrams are used to ensure reasonable completeness in identification of initiating events and classification of accident sequences, (2) Information on factors that govern the accident progression and source terms are effectively reflected to the construction of event trees for delineation of accident sequences, and (3) Frequency quantification of seismically-initiated accident sequence frequencies that involve multiplepipe ruptures are made with the use of the Direct Quantification of Fault Trees by Monte Carlo (DQFM) method by a computer code SECOM-DQFM.
Nabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06
Hamada, Kazuya; Kawano, Katsumi; Saito, Toru; Iguchi, Masahide; Nakajima, Hideo; Teshima, Osamu*; Matsuda, Hidemitsu*
AIP Conference Proceedings 1435, p.55 - 62, 2012/06
The TF coil conductor was composed of 900 NbSn superconducting strands and 522 Cu strands protected by circular sheath tube (jacket) with the outer diameter of 43.7 mm. The jacket section is a seamless tube made of modified 316LN. JAEA tested different types of tensile specimen (Japanese Industrial Standards (JIS) type and ASTM type) cut from jacket. ASTM type specimen has longer and wider reduced section than those of JIS type specimen. Elongation of as received condition is not dependent on specimen shape. But after cold work and aging, the elongation is deteriorated due to a sensitization and scattering of elongation is larger than that of as received condition. Fracture mode of aged jacket is "cup and cone fracture", which have a mixture of inter granular at center area and trans-granular factures in circumference area. It is considered that initiation of fracture is more sensitive on test specimen shape with low ductility.
Hamada, Kazuya; Nunoya, Yoshihiko; Isono, Takaaki; Takahashi, Yoshikazu; Kawano, Katsumi; Saito, Toru; Oshikiri, Masayuki; Uno, Yasuhiro; Koizumi, Norikiyo; Nakajima, Hideo; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4203404_1 - 4203404_4, 2012/06
Japan Atomic Energy Agency (JAEA) has the responsibility for procurement of all of the ITER central solenoid (CS) conductor lengths. The CS conductor is composed of 576 Nb Sn superconducting strands and 288 Cu strands assembled together into a multistage cable and protected by a circle-in-square sheath tube (jacket) with the outer dimension of 49 mm. In preparation for CS conductor production, the following R&D activities have been performed; (1) Mechanical tests at 4 K have been performed for jacket candidate materials such as 316LN and JK2LB, (2) Welding test for filler selection, (3) Measurement of coefficient of sliding friction using a 100-m long dummy cable, (4) Deformation characteristics of the conductor cross section after compaction and spooling. As a result of these R&D, the CS conductor jacket manufacturing technologies have been confirmed to start the procurement of the CS conductor.
Hamada, Kazuya; Takahashi, Yoshikazu; Nabara, Yoshihiro; Kawano, Katsumi; Ebisawa, Noboru; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Saito, Toru*; Nakajima, Hideo; Matsuda, Hidemitsu*; et al.
Teion Kogaku, 47(3), p.153 - 159, 2012/03
The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA has constructed newly conductor manufacturing facility. Prior to starting conductor, JAEA manufactured a 760-m long Cu dummy conductor as process qualification of dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.
Hamada, Kazuya; Takahashi, Yoshikazu; Isono, Takaaki; Nunoya, Yoshihiko; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Koizumi, Norikiyo; Nakajima, Hideo; et al.
Fusion Engineering and Design, 86(6-8), p.1506 - 1510, 2011/10
Japan Atomic Energy Agency has a responsibility for procurement of the ITER toroidal field coil conductors as Japanese Domestic Agency (JADA) of the ITER project. The TF conductor is a circular shaped cable-in-conduit conductor, which is composed of cable and stainless steel conduit (jacket). The outer diameter and wall thickness of jacket are 43.7mm and 2mm, respectively. The cable consists of 900 NbSn superconducting strands and 522 Cu strands. The length of TF conductor is 780m in maximum. Preparation of conductor fabrication was completed in December 2009. And then, to demonstrate a conductor manufacturing procedure, JADA fabricated 780m-long Cu dummy conductor as a process qualification. Finally, the 780m-long Cu dummy conductor has been successfully completed, ahead of other domestic agencies that are in charge of TF conductor procurement. Since all of manufacturing processes have been qualified, JADA started to fabricate superconducting conductors for TF coils.
Nunoya, Yoshihiko; Takahashi, Yoshikazu; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Nabara, Yoshihiro; Takamura, Jun; Chuheishi, Shinji; Shibutani, Kazuyuki*; Suwa, Tomone; Matsuda, Hidemitsu*
no journal, ,
no abstracts in English
Suwa, Tomone; Nabara, Yoshihiro; Takahashi, Yoshikazu; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Shibutani, Kazuyuki*; Sekiguchi, Nobuo*; Matsuda, Hidemitsu*
no journal, ,
no abstracts in English