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Wakui, Takashi; Ishii, Hideaki*; Naoe, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Wakai, Eiichi; Takada, Hiroshi; Futakawa, Masatoshi
Materials Transactions, 60(6), p.1026 - 1033, 2019/06
Times Cited Count：3 Percentile：17.96(Materials Science, Multidisciplinary)The mercury target has large size as 1.3
1.32.5 m
. In view of reducing the amount of wastes, we studied the structure so that the fore part could be separated. The flange is required to have high seal performance less than 110
Pa m/s. Invar with low thermal expansion is a candidate. Due to its low stiffness, however, the flange may deform when it is fastened by bolts. Practically invar is reinforced with stainless steel where all interface between them has to be bonded completely with the HIP bonding. In this study, we made specimens at four temperatures and conducted tensile tests. The specimen bonded at 973 K had little diffusion layer, and so fractured at the interface. The tensile strength reduced with increasing the temperature, and the reduced amount was about 10% at 1473 K. The analyzed residual stresses near the interface increased by 50% at maximum. Then, we concluded that the optimum temperature was 1173 K.
Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Naoe, Takashi; Takada, Hiroshi
Journal of Nuclear Science and Technology, 55(2), p.160 - 168, 2018/02
Times Cited Count：5 Percentile：46.12(Nuclear Science & Technology)The mercury target vessel used for the spallation neutron source in J-PARC has multi-walled structure made of stainless steel type 316L, which comprises a mercury vessel and a water shroud. In 2015, water leak incidents from the water shroud occurred while the mercury target was operated with a proton beam power of 500 kW. Several investigations were conducted to identify the cause of failure. The results of the visual inspections, mockup tests, and analytical evaluations suggested that the water leak was caused by the combination of two factors. One was the diffusion bonding failure due to the large thermal stress induced by welding of the bolt head, which fixes the mercury vessel and the water shroud, during the fabrication process. The other was the thermal fatigue failure of the seal weld due to the repetitive beam trip during the operating period. These target failures point to the importance of eliminating initial defects from welding lines and to secure the rigidity and reliability of welded structures. The next mercury target was fabricated with an improved design which adopted parts of monolithic structure machined by wire EDM to reduce welding lines, and intensified inspections to eliminate the initial defects. The operation with the improved target is planned to be started in October 2017.
Hamada, Kazuya; Nakajima, Hideo; Okuno, Kiyoshi; Endo, Sakaru*; Kikuchi, Kenichi*; Kubo, Yoshio*; Aoki, Nobuo*; Yamada, Yuichi*; Osaki, Osamu*; Sasaki, Takashi*; et al.
JAERI-Tech 2002-027, 23 Pages, 2002/03
JAERI-Tech-2002-027.pdf:2.94MB
The Engineering Design Activities (EDA) for the International Thermonuclear Experimental Reactor (ITER) was performed under the collaboration of Japan, EU, Russia and the US. The EDA was successfully completed in July 2001, in which the development of fabrication technology for advanced components, such as superconducting coils, was conducted. The ITER magnet system consists of Toroidal Field coils, a Central Solenoid (CS), Poloidal Field coils and Correction coils. The construction of these coils requires advanced technologies that fairly exceeded those available at the start of the EDA. Therefore, CS Model Coil and TF Model Coil projects were implemented. To fabricate the CS Model Coil, the fabrication technologies for high performance strand, large cable, winding, heat treatment, joint and insulation are indispensable. This report describes the above detailed fabrication technologies successfully developed in the CS Model Coil Project.
Sn conductor joint for ITER model coilsTakahashi, Yoshikazu; Nunoya, Yoshihiko; Nishijima, Gen; Koizumi, Norikiyo; Matsui, Kunihiro; Ando, Toshinari; Hiyama, Tadao; Nakajima, Hideo; Kato, Takashi; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 10(1), p.580 - 583, 2000/03
Times Cited Count：20 Percentile：68.9(Engineering, Electrical & Electronic)no abstracts in English
-ZrO(Y){or ThO}-AlO-MgO at burn-up of 20 MWd/kgYanagisawa, Kazuaki; Omichi, Toshihiko; Kanazawa, Hiroyuki; Amano, Hidetoshi; Yamahara, Takeshi
JAERI-Research 97-085, 31 Pages, 1997/11
JAERI-Research-97-085.pdf:2.38MB
no abstracts in English
Sato, Satoshi; Takatsu, Hideyuki; Hashimoto, T.*; Kurasawa, Toshimasa; Furuya, Kazuyuki; *; Osaki, Toshio*; Kuroda, Toshimasa*
Journal of Nuclear Materials, 233-237(PT.B), p.940 - 944, 1996/00
Times Cited Count：34 Percentile：92(Materials Science, Multidisciplinary)no abstracts in English
Ishii, Hideaki*; Wakui, Takashi; Naoe, Takashi; Wan, T.; Xiong, Z.*; Haga, Katsuhiro; Takada, Hiroshi; Futakawa, Masatoshi
no journal, ,
no abstracts in English
Wakui, Takashi; Naoe, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Wakai, Eiichi; Takada, Hiroshi; Futakawa, Masatoshi
no journal, ,
The mercury target vessel has large size as 1.31.32.5 m. In view of reducing the amount of wastes, we have studied the structure so that the fore part could be separated. The flange is required to have high seal performance less than 110 Pam/s. Invar with low thermal expansion is a candidate. Due to its low stiffness, however, the flange may deform when it is fastened by bolts. Practically invar is reinforced with stainless steel where all interface between them has to be bonded completely with the HIP bonding. In this study, we made specimens at four temperatures of 973, 1173, 1373 and 1473 K and conducted tensile tests. The specimen bonded at 973 K had little diffusion layer, and so fractured at the interface. The tensile strength reduced with increasing the temperature, and the reduced amount was about 10 % at 1473 K. The analyzed residual stresses near the interface increased by 50 % at maximum. Then, we concluded that the optimum temperature was 1173 K.
