Watanabe, Kazuyoshi; Ida, Mizuho; Kondo, Hiroo; Miyashita, Makoto; Nakamura, Hiroo
Journal of Nuclear Materials, 417(1-3), p.1299 - 1302, 2011/10
The Engineering Validation and Engineering Design Activity (EVEDA) of the International Fusion Materials Irradiation Facility (IFMIF) has been started under the Broader Approach Agreement. For the target assembly in the EVEDA Li test loop, two kinds of the back plates, "Integrated type" of SUS316L and "Bayonet type" of F82H, are going to be manufactured and tested. For thermo-structural design of the target assembly, we carried out thermo-structural analysis for these two types of the back plates by using the ABAQUS computer code. In the case of assuming thermal insulation for outer surface of the target assembly, the maximum stress of integrated type was 39.2 MPa, and that of Bayonet type was 340 MPa. These were lower than the permissible stress of their materials, therefore it was evaluated that insulation was effective against decreasing thermal stress.
Ida, Mizuho; Fukada, Satoshi*; Furukawa, Tomohiro; Hirakawa, Yasushi; Horiike, Hiroshi*; Kanemura, Takuji*; Kondo, Hiroo; Miyashita, Makoto; Nakamura, Hiroo; Sugiura, Hirokazu*; et al.
Journal of Nuclear Materials, 417(1-3), p.1294 - 1298, 2011/10
Engineering Validation and Engineering Design Activities (EVEDA) of the International Fusion Materials Irradiation Facility (IFMIF) was started. As a Japanese activity for the target system, EVEDA Lithium Test Loop simulating hydraulic and impurity conditions of IFMIF is under design and preparation for fabrication. Feasibility of thermo-mechanical structure of the target assembly and the replaceable back-plate made of F82H (a RAFM) and 316L (a stainless steel) is a key issue. Toward final validation on the EVEDA loop, diagnostics applicable to a high-speed free-surface Li flow and hot traps to control nitrogen and hydrogen in Li are under tests. For remote handling of target assemblies and the replaceable back-plates activated up to 50 dpa/y, lip weld on 316L-316L by laser and dissimilar weld on F82H-316L are under investigation. As engineering design of the IFMIF target system, water experiments and hydraulic/thermo-mechanical analyses of the back-plate are going.
Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi; Nakamura, Hiroo*; Ida, Mizuho; Watanabe, Kazuyoshi; Miyashita, Makoto*; Horiike, Hiroshi*; Yamaoka, Nobuo*; Kanemura, Takuji; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2010/10
The Engineering Validation and Engineering Design Activity (EVEDA) for the International Fusion Materials Irradiation Facility (IFMIF) is proceeded as one of the ITER Broader Approach (BA) activities. The EVEDA Li test loop (ELTL) is aimed at validating stability of the Li target and feasibility of a Li purification system as the key issues. In this paper, the design of the ELTL especially of a target assembly in which the Li target is produced by the contraction nozzle is presented.
Miyashita, Makoto; Furuya, Kazuyuki*; Ida, Mizuho; Nakamura, Hiroo
Fusion Engineering and Design, 84(7-11), p.1333 - 1338, 2009/06
The IFMIF is an accelerator-based intense neutron source for testing candidate fusion materials. Intense neutrons equivalent to neutron irradiation damage of about 50 dpa/y are emitted inside the Li flow through a back-plate. Around the back plate, a lip seal made of 316L is welded by laser welding system for replacement by remote handling. The back plate will be designed for replacement at least every year. According to material tests of the lip seal weld joint, significant deterioration was not observed. Remote handling procedure of the back plate are examined. At first, rip seal joints of connection piping will be cut by the laser welding device and then the target assembly with the back plate will be moved to a hot cell. The back plate lip seal will be cut by the laser arm in the hot cell. And a new back plate will be welded and moved to test cell/target room. In the presentation, conceptual design of the laser cutting/welding device and remote handling procedure will be shown.
Nakamura, Hiroo; Agostini, P.*; Ara, Kuniaki; Fukada, Satoshi*; Furuya, Kazuyuki*; Garin, P.*; Gessii, A.*; Giusti, D.*; Groeschel, F.*; Horiike, Hiroshi*; et al.
Fusion Engineering and Design, 84(2-6), p.252 - 258, 2009/06
Furuya, Kazuyuki*; Ida, Mizuho; Miyashita, Makoto; Nakamura, Hiroo
Journal of Nuclear Materials, 386-388, p.963 - 966, 2009/04
The current material design of the IFMIF back wall in Japan consists of a stainless steel type-316L and F82H steel. The 316L and F82H are welded each other. The 316L region of the back wall is also welded with the target assembly made of 316L. Since the back-wall is operating under severe neutron irradiation condition (50 dpa/year), it is therefore important to perform metallurgical and mechanical tests for these welds. In result of the tests, significant issues were not found in the F82H/316L TIG-weld. On the other hand, although the 316L/316L YAG-weld offered the weld without any harmful weld defect, the hardness decreased somewhat in the fusion metal. The rupture occurred in the fusion metal, and the strength and elongation decreased somewhat. Furthermore, small dimples include several number of large voids were also seen in the fracture surface.
Nakamura, Hiroo; Agostini, P.*; Ara, Kuniaki; Cevolani, S.*; Chida, Teruo*; Ciotti, M.*; Fukada, Satoshi*; Furuya, Kazuyuki*; Garin, P.*; Gessii, A.*; et al.
Fusion Engineering and Design, 83(7-9), p.1007 - 1014, 2008/12
This paper describes the latest design of liquid lithium target system in IFMIF. Design requirement of the Li target is to provide a stable Li jet with a speed of 20 m/s to handle an averaged heat flux of 1 GW/m. A double reducer nozzle and a concaved flow are applied to the target design. On Li purification, a cold trap and two kinds of hot trap are applied to control impurities below permissible levels. Nitrogen concentration shall be controlled below 10 wppm by one of the hot trap. Tritium concentration shall be controlled below 1 wppm by an yttrium hot trap. To maintain reliable continuous operation, various diagnostics are attached to the target assembly. Among the target assembly, a back-plate made of RAFM is located in the most severe region of neutron irradiation (50 dpa/y). Therefore, two design options of replaceable back wall and their remote handling systems are under investigation.
Ida, Mizuho; Nakamura, Hiroo; Chida, Teruo*; Miyashita, Makoto; Furuya, Kazuyuki*; Yoshida, Eiichi; Hirakawa, Yasushi; Miyake, Osamu; Hirabayashi, Masaru; Ara, Kuniaki; et al.
JAEA-Review 2008-008, 38 Pages, 2008/03
Engineering Validation Design and Engineering Design Activity (EVEDA) of the International Fusion Materials Irradiation Facility (IFMIF) is under going. IFMIF is an accelerator-based Deuterium-Lithium (D-Li) neutron source to produce intense high energy neutrons and a sufficient irradiation volume for testing candidate materials for fusion reactors. To realize such a condition, 40 MeV deuteron beam with a current of 250 mA is injected into high speed liquid Li flow with a speed of 20 m/s. In target system, nuclear heating due to neutron causes thermal stress especially on a back-wall of the target assembly. In addition, radioactive species such as beryllium-7, tritium and activated corrosion products are generated. In this report, thermal stress analyses of the back-wall, mechanical tests on weld specimen made of the back-wall material, estimations of beryllium-7 behavior and worker dose at the IFMIF Li loop and consideration on major EVEDA tasks are summarized.
Miyashita, Makoto; Yutani, Toshiaki*; Sugimoto, Masayoshi
JAEA-Technology 2007-016, 62 Pages, 2007/03
This report describes investigation on structure of a high neutron flux test module (HFTM) for the International Fusion Materials Irradiation Facilities (IFMIF). The HFTM is aimed for neutron irradiation of a specimen in a high neutron flux domain of the test cell for irradiation ground of IFMIF. We investigated the overall structure of the HFTM that was able to include specimens in a rig and thermocouple arrangement, an interface of control signal and support structure. Moreover, pressure and the amount of the bend in the module vessel (a rectangular section pressure vessel) were calculated. The module vessel did a rectangular section from limitation of a high neutron flux domain. Also, we investigated damage of thermocouples under neutron irradiation, which was a temperature sensor of irradiation materials temperature control demanded high precision. Based on these results, drawings on the HTFM structure.
Kubo, Shinji; Yoshida, Mitsunori; Sakurai, Makoto*; Tanaka, Kotaro*; Miyashita, Reiko*
Bunri Gijutsu, 35(3), p.148 - 152, 2005/05
no abstracts in English
Miyashita, Makoto; Ida, Mizuho; Wakai, Eiichi; Nakamura, Hiroo; Furuya, Kazuyuki*
no journal, ,
no abstracts in English
Nakamura, Hiroo; Ida, Mizuho; Miyashita, Makoto; Yoshida, Eiichi; Ara, Kuniaki; Nishitani, Takeo; Okumura, Yoshikazu; Horiike, Hiroshi*; Kondo, Hiroo*; Terai, Takayuki*; et al.
no journal, ,
no abstracts in English
Furuya, Kazuyuki*; Miyashita, Makoto; Ida, Mizuho; Wakai, Eiichi; Nakamura, Hiroo
no journal, ,
The IFMIF is an accelerator-based intense neutron source for testing candidate materials for fusion reactors. Intense neutrons are emitted inside the Li flow through a backplate. Since the backplate will be operated under a severe neutron irradiation of 50 dpa / year, application of RAF/Ms such as F82H steel is selected. In Japanese design option, F82H is welded with a lip seal made of an austenitic stainless steel type-316L, by TIG-welding. Purpose of this study is to investigate metallurgical and mechanical property of dissimilar welding joint applied for different type of welding rod (SMW82), and to select the optimum welding rod material.
Miyashita, Makoto; Ida, Mizuho; Kondo, Hiroo; Watanabe, Kazuyoshi; Nakamura, Hiroo; Uenaka, Tsukasa*
no journal, ,
International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based intense neutron source for testing candidate fusion materials. Development of the IFMIF is executed under IFMIF- Engineering Validation and Engineering design Activities (EVEDA) of Broader Approach (BA) agreement. Intense neutrons equivalent to neutron irradiation damage of about 50dpa/y are emitted inside the Li flow through a target assembly made of RAFM such as F82H. The activated target assembly should be remotely replaced at least every year. The target assembly has three flange connections. The lip seal joint structure is employed for the connection at the Li inlet pipe interface. Lip seal joint will be cut by fiber laser cutting/welding device (Laser Subsystem) in target/test cell (TTC) vessel containing the target assembly, and then the target assembly will be moved to access cell over the TTC vessel. A new target assembly will be installed in the TTC vessel.