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Nakahira, Masataka; Shibanuma, Kiyoshi; Kajiura, Soji*; Shibui, Masanao*; Koizumi, Koichi; Takeda, Nobukazu; Kakudate, Satoshi; Taguchi, Ko*; Oka, Kiyoshi; Obara, Kenjiro; et al.
JAERI-Tech 2002-029, 27 Pages, 2002/03
JAERI-Tech-2002-029.pdf:2.04MB
The ITER vacuum vessel (VV) R&D has progressed with the international collaborative efforts by the Japan, Russia and US Parties during the Engineering Design Activities (EDA). Fabrication and testing of a full-scale VV sector model and a port extension have yielded critical information on the fabrication and assembly technologies of the vacuum vessel, magnitude of welding distortions, dimensional accuracy and achievable tolerances during sector fabrication and field assembly. In particular, the dimensional tolerances of 
3 mm for VV sector fabrication and 10 mm for VV sector field assembly have been achieved and satisfied the requirements of 5 mm and 20 mm, respectively. Also, the basic feasibility of the remote welding robot has been demonstrated. This report presents detailed fabrication and assembly technologies such as welding technology applicable to the thick wall without large distortion, field joint welding technology between sectors and remote welding technology through the VV R&D project.
Ikeda, Yoshitaka; Okano, Fuminori; Hanada, Masaya; Sakasai, Akira; Miya, Naoyuki; Watanabe, Takashi*; Daigo, Yasuhiko*; Hosogane, Nobuyuki*; Aoto, Mitsuo*
no journal, ,
JT-60, to which the Radiation Hazard Prevention Act is applied, stopped its operation in October 2008 after 18 years deuterium operation since 1991. JT-60 will be upgraded to JT-60SA with superconducting magnet coils, which is the Satellite Tokamak Program under the EU-Japan collaboration, so as to demonstrate the high-beta long-pulse plasma operation. To establish this new device, the existing JT-60 facilities such as magnetic coils, vacuum vessel, basement, diagnostics and heating system. The disassembly of JT-60 is featured by the radiactivation of all components due to neutron from the D-D reaction, and thus, one of the main issues is to manage the physical control of the radiated material for the application of clearance regulation. The disassembly has started since 2009 and will complete by the autumn of 2012. Then a new JT-60SA basement, which will be shipped from EU, will be installed within March 2013.
Okano, Fuminori; Ikeda, Yoshitaka; Sakasai, Akira; Hanada, Masaya; Watanabe, Takashi*; Daigo, Yasuhiko*; Hosogane, Nobuyuki*; Aoto, Mitsuo*
no journal, ,
no abstracts in English
Ikeda, Yoshitaka; Okano, Fuminori; Hanada, Masaya; Sakasai, Akira; JT-60 Team; Watanabe, Takashi*; Daigo, Yasuhiko*; Hosogane, Nobuyuki*; Aoto, Mitsuo*
no journal, ,
Break-even Plasma Test Facilities (JT-60) is the only tokamak device applied by the Radiation Hazard Prevention Act, and is under upgrading towards the super-conducting magnetic device "JT-60SA" aiming long pulse and high beta plasmas. The JT-60SA project is in progress as the satellite Tokamak project under the Japan-EU international program "ITER Broader Approach". At the first step towards JT-60SA, the disassembly of JT-60 tokamak and its affiliated facilities was done for three years and completed in October 2012. All disassembly and cutting works were in control of radiation management. Total number and weight of disassembly components were about 13000 and about 5400 tons, respectively. The JT-60 was composed of a lot of high mechanical strength materials such as high manganese steel which is difficult-to-machine material. New technologies such as a diamond wire-saw which cut the complicated structure simultaneously enabled the effective disassembly.