Refine your search:     
Report No.
 - 
Search Results: Records 1-14 displayed on this page of 14
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Analysis on ex-vessel loss of coolant accident for a water-cooled fusion DEMO reactor

Watanabe, Kazuhito; Nakamura, Makoto; Tobita, Kenji; Someya, Yoji; Tanigawa, Hisashi; Uto, Hiroyasu; Sakamoto, Yoshiteru; Araki, Takao*; Asano, Shiro*; Asano, Kazuhito*

Proceedings of 26th IEEE Symposium on Fusion Engineering (SOFE 2015), 6 Pages, 2016/06

Safety studies of a water-cooled fusion DEMO reactor have been performed. In the event of the blanket cooling pipe break outside the vacuum vessel, i.e. ex-vacuum vessel loss of coolant accident (ex-VV LOCA), the pressurized steam and air may lead to damage reactor building walls which have confinement function, and to release the radioactive materials to the environment. In response to this accident, we proposed three cases of confinement strategies. In each case, the pressure and thermal loads to the confinement boundaries and total mass of tritium released to outside the boundaries were analyzed by accident analysis code MELCOR modified for fusion reactor. These analyses developed design parameters to maintain the integrity of the confinement boundaries.

Journal Articles

Welding technology on sector assembly of the JT-60SA vacuum vessel

Shibama, Yusuke; Okano, Fuminori; Yagyu, Junichi; Kaminaga, Atsushi; Miyo, Yasuhiko; Hayakawa, Atsuro*; Sagawa, Keiich*; Mochida, Tsutomu*; Morimoto, Tamotsu*; Hamada, Takashi*; et al.

Fusion Engineering and Design, 98-99, p.1614 - 1619, 2015/10

 Times Cited Count:4 Percentile:33.51(Nuclear Science & Technology)

The JT-60SA vacuum vessel (150 tons) is a double wall torus structure and the maximum major radius of 5.0 m and height of 6.6 m. The manufacturing design concept is that the vessel is split in the 10 toroidal sectors manufactured at factory, and assembled on-site; seven of the 40-degree sectors, two of the 30-degree beside final one, and the final of the 20-degree. The final sector is assembled with the VV thermal shield and toroidal field magnets into the 340-degree as prepared in one sector. Sectors are temporally fitted on-site and adjusted one over the other before the assembly. After measurement of the dimensions and the reference, these sectors are transferred onto the cryostat base. First, three 80-degree sectors are manufactured with mating each 40-degree sector by direct joint welding. The rest sectors including the final sector are jointed with splice plates. Welding manipulator and its guide rails are used for these welding. In this paper, the detail of the VV sectors assembly including the final sector is explained. Welding technologies to joint the two of 40-degree sectors are reported with the present manufacturing status and the welding trial on the vertical stub with the partial mock-up of the final sector are discussed with the assembly process.

Journal Articles

Welding technology R&D on port joint of JT-60SA vacuum vessel

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:18.71(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.

Journal Articles

Fundamental welding R&D results for manufacturing vacuum vessel of JT-60SA

Asano, Shiro*; Okuyama, Toshihisa*; Onawa, Toshio*; Yanagi, Yutaka*; Ejiri, Mitsuru*; Kanahara, Toshio*; Ichihashi, Koji*; Kikuchi, Atsushi*; Mizumaki, Shoichi*; Masaki, Kei; et al.

Fusion Engineering and Design, 86(9-11), p.1816 - 1820, 2011/10

 Times Cited Count:12 Percentile:66.95(Nuclear Science & Technology)

The real vacuum vessel (VV) manufacturing of JT-60SA has started since Nov. 2009 at Toshiba. Prior to starting manufacturing, fundamental welding R&Ds had been performed by three stages. In the first stage, primary tests for screening welding method were performed. In the second stage, the trial welding for 1m-long straight and curved double shell samples were conducted. The dependences of welding quality and distortion on the welding conditions, such as arc voltage and current, setting accuracy, welding sequence, the shape of grooves, etc. were measured. In addition, welding condition with low heat input was explored. In the last stage, fabrication sequence was confirmed and established by the trial manufacturing of the 20$$^{circ}$$ upper half mock-up. This poster presents the R&D results obtained in the first and second stages.

Journal Articles

Development of insulation technology with cyanate ester resins for ITER TF coils

Hemmi, Tsutomu; Koizumi, Norikiyo; Matsui, Kunihiro; Okuno, Kiyoshi; Nishimura, Arata*; Sakai, Masahiro*; Asano, Shiro*

Fusion Engineering and Design, 84(2-6), p.923 - 927, 2009/06

 Times Cited Count:14 Percentile:67(Nuclear Science & Technology)

The insulation for ITER-TF coils is required to withstand a total radiation dose of 10$$^{22}$$ fast n/m$$^{2}$$. For this purpose, cyanate ester resins with high radiation-resistant have been considered instead of epoxy resins. In order to evaluate an applicability of cyanate ester resins for ITER-TF coils, the developments of the vacuum pressure impregnation technology and evaluation of the high radiation-resistant properties have been carried out. This paper presents results of these developments with the cyanater ester resin.

Oral presentation

R&D study for ITER-TF coils fabrication technique

Hemmi, Tsutomu; Koizumi, Norikiyo; Matsui, Kunihiro; Hamada, Kazuya; Takahashi, Yoshikazu; Nakajima, Hideo; Okuno, Kiyoshi; Kuno, Kazuo*; Nomoto, Kazuhiro*; Sakai, Masahiro*; et al.

no journal, , 

Japan Atomic Energy Agency starts the procurement of ITER-TF coils from this year. ITER-TF coils are three times larger than TF model coil (TFMC), which is developed in ITER-EDA. From result of development of TFMC, the basic fabrication technique has been demonstrated. However, new technical issue has generated due to the scale-up from TFMC. In order to solve the issue, high accurate D-shaped winding technique, impregnation test using high radiation-resistant resin and cover-plate welding and deformation evaluation have been performed. In this presentation, these results of the fabrications and the tests are reported.

Oral presentation

Trial manufacturing of vacuum vessel for JT-60SA

Asano, Shiro*; Ejiri, Mitsuru*; Yanagi, Yutaka*; Ichihashi, Koji*; Kikuchi, Atsushi*; Mizumaki, Shoichi*; Okuyama, Toshihisa*; Masaki, Kei; Shibama, Yusuke; Katayama, Masahiro*; et al.

no journal, , 

no abstracts in English

Oral presentation

Real product manufacturing of vacuum vessel for JT-60SA

Asano, Shiro*; Ejiri, Mitsuru*; Okuyama, Toshihisa*; Yanagi, Yutaka*; Kikuchi, Atsushi*; Mizumaki, Shoichi*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira

no journal, , 

Based on the R&Ds including trial manufacturing of 20 deg. upper half mock-up, the real product manufacturing of vacuum vessel for JT-60SA has started since November 2009 at TOSHIBA Keihin Product Operations. The cross section of the VV is D-shaped and made of low cobalt content SUS316L. The height and outer diameter of the torus are 6.6m and 9.95m respectively. The weight is about 150 ton. The present status of the manufacturing is introduced in this poster presentation. 2009 for the inboard (IB) and since August, 2010 for the outboard (OB). Completed IB and OB 20-degree upper or lower segments for VV-D02 and VV-D03 will be connected into full 40-degree IB and OB segments from December, 2010. The welding between 40-degree IB and OB segments of the first 40-degree sector (VV-D02) is to be started at JAEA Naka Fusion Institute in 2011.

Oral presentation

Buckling analysis of gravity support legs for JT-60SA vacuum vessel

Ejiri, Mitsuru*; Kitamura, Kazunori*; Araki, Takao*; Omori, Junji*; Asano, Shiro*; Hayakawa, Atsuro*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira

no journal, , 

In the operation of tokamak, such loads as electromagnetic and seismic are assumed to be imposed on the vacuum vessel (VV), and not a little thermal expansion takes place when VV is baked. The gravity support leg (GS) has to support the loads described above in addition to the dead weight of VV including in-vessel components and compensate deformation. The GS is equipped with plate spring (PS) to have both stiffness and flexibility. In this study, the buckling strength of the PSs was evaluated. The effect of the initial imperfection of the PSs which is assumed to result from machining or welding process on the buckling strength was also studied. It is concluded that GS has sufficient buckling strength against assumed initial imperfections.

Oral presentation

Fatigue behavior on welded joint for JT-60SA vacuum vessel

Yanagi, Yutaka*; Shibui, Masanao*; Kanahara, Toshio*; Mochida, Tsutomu*; Ejiri, Mitsuru*; Asano, Shiro*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira

no journal, , 

JT-60SA Vacuum Vessel (VV) has D-shaped cross section and double-walled structure. It consists of the inner and outer wall reinforced by poloidal ribs and is made of SUS316L (Co$$<$$0.05wt%). The welding outer wall on rib (so called continuous plug) is performed from the outside of double-wall. Since it is difficult to confirm the penetration bead from the inside of double-wall, an incomplete penetration is assumed to be included in this welded joint. In this study, the fatigue test of continuous plug welded joint with an artificial incomplete penetration was performed to investigate the effect of the incomplete penetration on fatigue behavior and fatigue strength.

Oral presentation

Manufacturing of vacuum vessel for JT-60SA

Asano, Shiro*; Okuyama, Toshihisa*; Mochida, Tsutomu*; Kikuchi, Atsushi*; Odashima, Wataru*; Ejiri, Mitsuru*; Mizumaki, Shoichi*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira

no journal, , 

no abstracts in English

Oral presentation

Completion of vacuum vessel sector manufacturing and subsequent torus assembly for the JT-60SA

Asano, Shiro*; Okuyama, Toshihisa*; Ejiri, Mitsuru*; Mizumaki, Shoichi*; Mochida, Tsutomu*; Hamada, Takashi*; Araki, Takao*; Hayakawa, Atsuro*; Sagawa, Keiich*; Kai, Toshiya*; et al.

no journal, , 

no abstracts in English

Oral presentation

Sector manufacturing and assembly of the JT-60SA vacuum vessel

Shibama, Yusuke; Okano, Fuminori; Yagyu, Junichi; Kaminaga, Atsushi; Miyo, Yasuhiko; Hayakawa, Atsuro*; Sagawa, Keiich*; Mochida, Tsutomu*; Morimoto, Tamotsu*; Hamada, Takashi*; et al.

no journal, , 

no abstracts in English

Oral presentation

Gravity support design and manufacturing of the JT-60SA vacuum vessel

Ejiri, Mitsuru*; Asano, Shiro*; Omori, Junji*; Okuyama, Toshihisa*; Takahashi, Nobuji*; Yamada, Masahiro*; Araki, Takao*; Kai, Toshiya*; Shibama, Yusuke; Masaki, Kei; et al.

no journal, , 

In the operation of Tokamak device, such loads as electromagnetic and seismic are assumed to be imposed on the vacuum vessel (VV), and not a little thermal expansion takes place when VV is baked. The gravity support (GS) has to support the loads described above in addition to the dead weight of VV including in-vessel components and compensate deformation. The GS is equipped with leaf spring that has both stiffness and flexibility. In this study, the FEM analysis-based design and assembly procedure of the GS is reported. The manufacturing process of GS components is also reported with trial manufacturing results.

14 (Records 1-14 displayed on this page)
  • 1