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Hayashi, Takao; Sakurai, Shinji; Sakasai, Akira; Shibanuma, Kiyoshi; Kono, Wataru*; Onawa, Toshio*; Matsukage, Takeshi*
Fusion Engineering and Design, 101, p.180 - 185, 2015/12
Times Cited Count：4 Percentile：33.25(Nuclear Science & Technology)Remote pipe welding tool accessing from inside pipe has been newly developed for JT-60SA. Remote handling (RH) system is necessary for the maintenance and repair of in-vessel components such as lower divertor cassettes in JT-60SA. Cooling pipes, which connects between the divertor cassette and the vacuum vessel with bellows are required to be cut and welded in the vacuum vessel by RH system. The available space for RH system is very limited inside the vacuum vessel, especially around the divertor cassettes. Thus, the cooling pipes are required to be cut and weld from the inside in the vacuum vessel. The inner diameter, thickness and material of the cooling pipe are 54.2 mm, 2.8 mm and SUS316L, respectively. An upper pipe connected to the divertor cassette has a jut on the edge to fill the gap between pipes. Owing to the jut and two-times welding, the welding tool achieved the maximum allowable gap of 0.7 mm.
Koide, Yoshihiko; Yoshida, Kiyoshi; Wanner, M.*; Barabaschi, P.*; Cucchiaro, A.*; Davis, S.*; Decool, P.*; Di Pietro, E.*; Disset, G.*; Genini, L.*; et al.
Nuclear Fusion, 55(8), p.086001_1 - 086001_7, 2015/08
Times Cited Count：31 Percentile：83.35(Physics, Fluids & Plasmas)The most distinctive feature of the superconducting magnet system for JT-60SA is the optimized coil structure in terms of the space utilization as well as the highly accurate coil manufacturing, thus meeting the requirements for the steady-state tokamak research: A conceptually new outer inter-coil structure separated from the casing is introduced to the toroidal field coils to realize their slender shape, allowing large-bore diagnostic ports for detailed plasma measurements. A method to minimize the manufacturing error of the equilibrium-field coils has been established, aiming at the precise plasma shape/position control. A compact butt-joint has been successfully developed for the Central Solenoid, which allows an optimized utilization of the limited space for the Central Solenoid to extend the duration of the plasma pulse.
Hayashi, Takao; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Fusion Engineering and Design, 89(9-10), p.2299 - 2303, 2014/10
Times Cited Count：13 Percentile：67.4(Nuclear Science & Technology)Remote handling (RH) system is necessary for the maintenance and repair of in-vessel components of JT-60SA. Design study of RH system, focusing on the deployment of remote pipe cutting tool for JT-60SA divertor cassette is reported in this conference. Some cooling pipes on the outboard side in the divertor cassette should be cut and welded in the vacuum vessel. The outer diameter, thickness and material of the cooling pipe is 59.7 mm, 2.7 mm and SUS316L, respectively. Cutting tool head equips a disk cutter blade and rollers which are subjected to the reaction force. The cooling pipe is cut by rotating the cutting tool head with pushing out the disk cutter blade. Newly developed cutting tool indicates that the cooling pipe is cut by pushing out the disk cutter blade up to 30.5 mm in radius, i.e. 61 mm in diameter.
Suzuki, Sadaaki; Yagyu, Junichi; Masaki, Kei; Nishiyama, Tomokazu; Nakamura, Shigetoshi; Saeki, Hisashi; Hoshi, Ryo; Sawai, Hiroaki; Hasegawa, Koichi; Arai, Takashi; et al.
NIFS-MEMO-67, p.266 - 271, 2014/02
no abstracts in English
Okano, Fuminori; Masaki, Kei; Yagyu, Junichi; Shibama, Yusuke; Sakasai, Akira; Miyo, Yasuhiko; Kaminaga, Atsushi; Nishiyama, Tomokazu; Suzuki, Sadaaki; Nakamura, Shigetoshi; et al.
JAEA-Technology 2013-032, 32 Pages, 2013/11
JAEA-Technology-2013-032.pdf:8.86MB
Japan Atomic Energy Agency started to construct a fully superconducting tokamak experiment device, JT-60SA, to support the ITER since January, 2013 at the Fusion Research and Development Directorate in Naka, Japan. The JT-60SA will be constructed with enhancing the previous JT-60 infrastructures, in the JT-60 torus hall, where the ex-JT-60 machine was disassembled. The JT-60SA Cryostat Base, for base of the entire tokamak structure, were assembly as first step of this construction. The Cryostat Base (CB, 250 tons) is consists of 7 main made of stainless steel, 12m diameter and 3m height. It was built in the Spain and transported to the Naka site with the seven major parts split, via Hitachi port. The assembly work of these steps, preliminary measurements, sole plate adjustments of its height and flatness, and assembly of the CB. Introduces the concrete result of assembly work and transport of JT-60SA cryostat base.
Takato, Kiyoto; Murakami, Tatsutoshi; Suzuki, Kiichi; Shibanuma, Kimikazu; Hatanaka, Nobuhiro; Yamaguchi, Bungo; Tobita, Yoshimasa; Shinozaki, Masaru; Iimura, Naoto; Okita, Takatoshi; et al.
JAEA-Technology 2013-026, 42 Pages, 2013/10
JAEA-Technology-2013-026.pdf:3.17MB
In order to cope with making a commercial fast reactor fuel burn-up higher, oxygen-to-metal (O/M) ratio in the fuel specification is designed to 1.95. As the test for the fabrication of such low O/M ratio pellets, two kinds of O/M ratio preparation tests of different reduction mechanism were done. In the first test, we evaluated the technology to prepare the O/M ratio low by annealing the sintered pellets in production scale. In addition, we know from past experience that O/M ratio of the sintered pellets can be reduced by residual carbon when the de-waxed pellets with high carbon content are sintered. Thus, in another test, the green pellets containing a large amount of organic additives were sintered and we evaluated the technology to produce the low O/M ratio sintered pellets by the reduction due to residual carbon. From the first test results, we found a tendency that the higher annealing temperature or the longer annealing time resulted in the lower O/M ratio. However, the amount of O/M ratio reduction was small and it is estimated that a substantial annealing time is necessary to prepare the O/M ratio to 1.95. It is considered that reducing O/M ratio by annealing was difficult because atmosphere gas containing oxygen released from pellets remained and the O/M ratio was changed to the value equilibrated with the gas having high oxygen potential. From another test results, it was confirmed that O/M ratio was reduced by the reduction due to residual carbon. We found that it was important to manage an oxygen potential of atmosphere gas in a sintering furnace low to reduce the O/M ratio effectively.
Shibanuma, Kiyoshi; Arai, Takashi; Hasegawa, Koichi; Hoshi, Ryo; Kamiya, Koji; Kawashima, Hisato; Kubo, Hirotaka; Masaki, Kei; Saeki, Hisashi; Sakurai, Shinji; et al.
Fusion Engineering and Design, 88(6-8), p.705 - 710, 2013/10
Times Cited Count：10 Percentile：61.16(Nuclear Science & Technology)Shibama, Yusuke; Masaki, Kei; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira; Onawa, Toshio*; Araki, Takao*; Asano, Shiro*
Fusion Engineering and Design, 88(9-10), p.1916 - 1919, 2013/10
Times Cited Count：2 Percentile：18.63(Nuclear Science & Technology)This presentation focuses on the welding technology R&D between the JT-60SA vacuum vessel and the ports. The vacuum vessel is designed to allow port bore penetration to access the vessel inside for plasma diagnostics, and so on. There are various types of 73 ports and these are categorized by their locations; the upper/lower vertical, the upper/lower oblique, and the horizontal. Ports are onsite-welded onto the VV port stub after the assembly of the VV. This assembly sequence involves the out-vessel components such as VV thermal shield and toroidal field magnets, so that these ports welding are accessed from the inside of the vessel and limited by the internal port wall. The one of the most difficult ports are the upper vertical port with corner radius of 50 mm under narrow space, and it is necessary to clarify mobility of the weld torch head. The port weldability is discussed with the mock-up trial, which consists of the partial test pieces of the product size. The TIG welding manipulator, optimized for this R&D, is prepared by its operational simulation and examined not to interfere with the internal port wall.
Sakasai, Akira; Masaki, Kei; Shibama, Yusuke; Sakurai, Shinji; Hayashi, Takao; Nakamura, Shigetoshi; Ozaki, Hidetsugu; Yokoyama, Kenji; Seki, Yohji; Shibanuma, Kiyoshi; et al.
Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03
The JT-60SA vacuum vessel (VV) and divertor are key components for the performance requirements. Therefore the manufacturing and development of VV and divertor are in progress, inclusive of the superconducting magnets. The vacuum vessel has a double wall structure in high rigidity to withstand electromagnetic force at disruption and to keep high toroidal one-turn resistance. In addition, the double wall structure fulfills originally two functions. (1) The remarkable reduction of the nuclear heating in the superconducting magnets is made by boric-acid water circulated in the double wall. (2) The effective baking is enabled by nitrogen gas flow of 200
C in the double wall after draining of water. Three welding types were chosen for the manufacturing of the double wall structure VV to minimize deformation by welding. Divertor cassettes with fully water cooled plasma facing components were designed to realize the JT-60SA lower single null closed divertor. The divertor cassettes in the radio-active VV have been developed to ensure compatibility with remote handling (RH) maintenance in order to allow long pulse high performance discharges with high neutron yield. The manufacturing of divertor cassettes with typical accuracy of *1 mm has been successfully completed. Brazed CFC (carbon fiber composite) monoblock targets for a divertor target have been manufactured by precise control of tolerances inside CFC blocks. The infrared thermography test of monoblock targets has been developed as new acceptance inspection.
Masaki, Kei; Shibama, Yusuke; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Fusion Engineering and Design, 87(5-6), p.742 - 746, 2012/08
Times Cited Count：21 Percentile：81.88(Nuclear Science & Technology)The JT-60SA vacuum vessel (VV) has a D-shaped poloidal cross section and a toroidal configuration with 10 segmented facets. A double wall structure is adopted to ensure high rigidity at operational load and high toroidal one-turn resistance. The material is 316L stainless steel with low cobalt content (
0.05wt%). In the double wall, boric-acid water (max. 50C) is circulated at plasma operation to reduce the nuclear heating of the superconducting magnets. For baking, nitrogen gas (200C) is circulated in the double wall after draining of the boric-acid water. The manufacturing of the VV started in November 2009 after a fundamental welding R&D and a trial manufacturing of 20 upper half mock-up. A basic VV assembly scenario and procedure were studied to complete the 360 VV including positioning method and joint welding between sectors considering misalignment.
Hayashi, Takao; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Fusion Science and Technology, 60(2), p.549 - 553, 2011/08
Times Cited Count：6 Percentile：44.28(Nuclear Science & Technology)Design study of RH system, especially the expansion of the RH rail and replacement of the lower divertor cassettes, was described in this paper. The dimensions and weight of the divertor cassette, which is 10 degrees wide in toroidal direction, are 1.62
0.57
1.25
m and 800 kg, respectively. The RH system can use four horizontal ports whose inside dimensions are 0.66 1.83 m. The space for RH system is very limited. The RH rail is installed before transporting divertor cassettes. The RH rail can cover 180 degrees in toroidal direction. A divertor cassette can be replaced by heavy weight manipulator (HWM) consists of an end effector, a telescopic arm and a vehicle. The HWM brings the divertor cassette to the front of another horizontal port, which is used for supporting the rail and/or carrying in and out equipments. Then another RH device, which is installed from outside the vacuum vessel, receives and brings out the divertor cassette.
Shibama, Yusuke; Masaki, Kei; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Proceedings of 2011 ASME Pressure Vessels and Piping Conference (PVP 2011) (CD-ROM), 10 Pages, 2011/07
This paper focuses on the JT-60SA vacuum vessel (VV, 150 tons) and presents manufacturing status of the VV with the design concept and the related technology of welding. The VV is a torus type vessel to ensure the sufficient ultrahigh vacuum space for core plasma and consists of 18 sectors with 73 port penetrations. The dimensions are the maximum major radius of 5.0 m and height of 6.6 m with a double wall structure to secure the stiffness against operational loads. The type 316L stainless steel is selected as a structural material and various welding technologies are developed. The weldment is mostly manipulated to achieve uniform welding quality and the welding conditions are evaluated to explore the distortion reduction, and to increase deposition rate. These resultants are applied to the 20 degree upper half mock-up and the manufacturing procedures, the correction of the welding distortion, and the optimization of constraint jigs are obtained.
Yagyu, Junichi; Miyo, Yasuhiko; Sasajima, Tadayuki; Sakasai, Akira; Shibanuma, Kiyoshi
Heisei-22-Nendo Kumamoto Daigaku Sogo Gijutsu Kenkyukai Hokokushu (CD-ROM), 4 Pages, 2011/03
no abstracts in English
Masaki, Kei; Shibama, Yusuke; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(1), p.55 - 62, 2011/01
JT-60 is planned to be upgraded to JT-60SA superconducting tokamak machine. This project is the JA-EU satellite tokamak program under both Broader Approach program and Japanese domestic program. The JT-60SA tokamak is composed of the following main components; vacuum vessel (VV), thermal shield, superconducting coils (toroidal field coil, equilibrium field coil, center solenoid), cryostat, heating facilities. The VV has a D-shape poloidal cross section and a double wall structure to ensure high rigidity and high toroidal one-turn resistance simultaneously. The material of the VV is 316L stainless steel with low cobalt content of 0.05wt%. Before start of the VV manufacturing, fundamental welding R&D was performed to study the manufacturing procedures. The manufacturing procedures were successfully established with a trial manufacturing of 20 upper half of the VV. Based on the results, the actual VV manufacturing has started in November 2009.
Shibama, Yusuke; Masaki, Kei; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Nihon Kikai Gakkai M&M 2010 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM), p.239 - 241, 2010/10
Present JT-60U is upgraded to be a fully superconducting coil tokamak, and one of the main components dedicated by Japan is a vacuum vessel. This paper presents a design status of the vacuum vessel; the design concept and trial manufacture. The design concept is developed from the ASME Boiler and Pressure Vessel Code Section VIII Division 2, and the damage tolerant concept is adopted into the welding part hardly inspected. The typical size of the vessel segment is manufactured to validate the welding technologies, and to select the technical elements. Feasibility to manufacture the real structure is discussed with present perspectives.
Sakurai, Shinji; Higashijima, Satoru; Hayashi, Takao; Shibama, Yusuke; Masuo, Hiroshige*; Ozaki, Hidetsugu; Sakasai, Akira; Shibanuma, Kiyoshi
Fusion Engineering and Design, 85(10-12), p.2187 - 2191, 2010/08
Times Cited Count：10 Percentile：56.32(Nuclear Science & Technology)JT-60SA tokamak project has just started construction phase under both the Japanese domestic program and the Japan-EU international program "ITER Broader Approach". All of plasma facing components (PFC) shall be actively cooled due to high power long pulse plasma heating. Lower single null closed divertor with vertical target (VT) will be installed at the start of experiment phase. Each divertor module covers a 10-degree sector in toroidal direction. PFCs such as VTs, baffles and dome shall be assembled on a divertor cassette, which provides integrated coolant pipe connection to coolant headers in the VV. Static structural analysis for dead weight, coolant pressure and EM loads shows that displacement and stress of the divertor module are generally small but a part of support structure of PFC requires improvement.
Shibama, Yusuke; Masaki, Kei; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira
Journal of Plasma and Fusion Research SERIES, Vol.9, p.180 - 185, 2010/08
JT-60SA is a combined JA-EU satellite tokamak program, aiming at the ITER program supports as well as the supplements toward the DEMO, under both broader approach agreement and the JA domestic program. The VV is a vessel to ensure sufficient ultrahigh vacuum space and one turn toroidal resistance for plasma breakdown. A double wall structure is selected to secure the higher rigidity against operational mechanical loads. The space between walls is utilized for the neutron shielding by 323 K boron water circulation, as well as for baking at 473 K by nitrogen gas flow to achieve the vacuum less than 10
Pa. Present design status of the structural integrity is discussed with numerical analyses, which are issues of a seismic event and plasma disruptions. The feasibility of the VV manufacture is studied and latest status is presented.
Oshima, Takayuki; Fujita, Takaaki; Seki, Masami; Kawashima, Hisato; Hoshino, Katsumichi; Shibanuma, Kiyoshi; Verrecchia, M.*; Teuchner, B.*
Journal of Plasma and Fusion Research SERIES, Vol.9, p.620 - 624, 2010/08
For interface control and assembly, the CAD data will be exchanged and integrated in a new Data Base server installed at Naka for JT-60SA, where a common computer network efficiently connected between the Naka site for JAEA and the Garching site for F4E is needed to be established. To ensure the design environments, a VPN (Virtual Private Network) was introduced with CAD LAN on computer network physically-separated from JAEA intranet area and firewall. In July 2009, a new VPN connection between the Naka and Garching sites has been successfully demonstrated using IPSec-VPN technology with a commercial and cost-effective firewall/router for security. The VPN technology would provide a common platform for the development of remote experimentation techniques on JT-60SA between Rokkasho and Naka in collaboration with activities of the ITER Remote Experimentation Centre for the IFERC Project at Rokkasho.
Shibanuma, Kiyoshi; Arai, Takashi; Kawashima, Hisato; Hoshino, Katsumichi; Hoshi, Ryo; Kobayashi, Kaoru; Sawai, Hiroaki; Masaki, Kei; Sakurai, Shinji; Shibama, Yusuke; et al.
Journal of Plasma and Fusion Research SERIES, Vol.9, p.276 - 281, 2010/08
The JT-60 SA project is a combined project of JA-EU satellite tokamak program under the Broader Approach (BA) agreement and JA domestic program. Major components of JT-60SA for assembly are vacuum vessel (VV), superconducting coils (TF coils, EF coils and CS coil), in-vessel components such as divertor, thermal shield and cryostat. An assembly frame (with the dedicated cranes), which is located around the tokamak, is adopted to carry out effectively the assembly of tokamak components in the tokamak hall, independently of the facility cranes in the building. The assembly frame also provides assembly tools and jigs with jacks to support temporarily the components as well as to adjust the components at right positions. In this paper, the assembly scenario and scequence of the major components such as VV and TFC and the concept of the assembly frame including special jigs and fixtures are discussed.
Nakahira, Masataka; Matsumoto, Yasuhiro; Kakudate, Satoshi; Takeda, Nobukazu; Shibanuma, Kiyoshi; Tesini, A.*
Fusion Engineering and Design, 84(7-11), p.1394 - 1398, 2009/06
Times Cited Count：20 Percentile：77.78(Nuclear Science & Technology)Invessel components of ITER have to be maintained by remote handling (RH) equipment due to high radiation level in the vacuum vessel (VV) after D-D operation. Blanket module (BM) is maintained by a manipulator mounted on a vehicle traveled through an articulated rail deployed inside the VV. Towards the construction, the BLRH equipment design has been improved and developed in more detail. The overview of design results are introduced in this paper. The design of rail deployment system of the BLRH has been updated to enable the rail connection in the transfer cask in order to minimize occupation space. For this purpose, design works have been performed for concept, sequence and typical simulation of BL replacement in the VV and rail deployment of the RH equipment in the cask, including cask docking. The technical issues of the rail connection in the cask are (1) tight tolerance of a pin at a hinge, (2) limited space of the connection inside a cask and (3) tight positioning accuracy. This paper summarizes the idea to solve these issues and a result of the design work. The paper also introduces a new cable handling equipment, rail support equipment and BL receiver/transporter.
