Low activation materials applicable to the IFMIF accelerator

Sugimoto, Masayoshi; Takeuchi, Hiroshi

Journal of Nuclear Materials, 329-333(Part1), p.198 - 201, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.328

IFMIF is an accelerator-based intense neutron source for developing fusion reactor materials, and a stable and continuous operation is a primary importance. The radioactivity produced by the beam loss prolongs the cooling time before maintenance and results in a potential limit to the availability. The materials selection is important for minimizing the total radioactivity produced by ion beam and neutrons, after about one day cooling time in advance of hands-on maintenance. For the major parts, Cu for cavity and Al for beam duct, the beam loss needs to be reduced below 5nA/m. Such a low loss can be realized by suppressing the beam halo and by using the scrapers made from high-Z material, Ta, to cut the tail of beam. The insertion points of the scrapers are determined from the beam size evolution along the accelerator and the available room for radiation shielding around them. The reduction of the radioactivity after the whole lifetime of facility is another issue and the possibility to use low activation materials coating for cavity and beam duct is presented.

Highly thermal conductive sintered SiC fiber-reinforced 3D SiC/SiC composites; Experiments and finite-element analysis of the thermal diffusivity/conductivity

Yamada, Reiji; Igawa, Naoki; Taguchi, Tomitsugu; Jitsukawa, Shiro

Journal of Nuclear Materials, 307-311(Part2), p.1215 - 1220, 2002/12

https://doi.org/10.1016/S0022-3115(02)00957-1

SiC fiber-reinforced SiC composites (SiC/SiC) are considered an advanced structural material for blanket modules of a fusion reactor, which requires high thermal conductivity in order to keep thermal stresses in the material lower than the allowable design stress. The sintered SiC fiber recently developed has obtained high thermal conductivity, so it is highly expected that sintered SiC fiber-reinforced SiC/SiC composites would also show high thermal conductivity. In this study several types of 3D SiC/SiC composites were fabricated by either CVI or PIP method. The results of the thermal conductivity measurements show that the maximum thermal conductivity at room temperature was about 60 W/mK for CVI composites or 25W/mK for PIP ones. These values are considerably higher than those of non-sintered SiC fiber reinforced SiC/SiC composites, which indicates a possibility that the developed materials would be promising. The FEM thremal analysis shows the good agreement between the caluculated and experimental results.

Engineering design study of JT-60 superconducting modification

Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Kurita, Genichi; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ichige, Hisashi; Kaminaga, Atsushi; Kato, Takashi; et al.

Proceedings of 19th IEEE/NPSS Symposium on Fusion Engineering (SOFE), p.221 - 225, 2002/00

no abstracts in English

Experiments on induced radioactivity characteristics of vanadium alloy

Ikeda, Yujiro; Kasugai, Yoshimi; Maekawa, Fujio; Uno, Yoshitomo; R.Johnson*; E.T.Cheng*

Fusion Technology, 34(3), p.714 - 718, 1998/11

no abstracts in English

Design study of nuclear shielding and fuel cycle for steady-state tokamak device JT-60SU

Miya, Naoyuki; Hayashi, Takumi; *; Nagashima, Keisuke; Neyatani, Yuzuru; ; *; Kikuchi, Mitsuru; *;

Fusion Engineering and Design, 36(2-3), p.309 - 324, 1997/00

https://doi.org/10.1016/S0920-3796(96)00696-5

no abstracts in English

Preliminary design study of a steady state tokamak device

Miya, Naoyuki; *; Ushigusa, Kenkichi; Oikawa, Akira; Imai, Tsuyoshi; ; Nishitani, Takeo; Matsuzaki, Yoshimi; Kuriyama, Masaaki;

JAERI-M 92-140, 156 Pages, 1992/09

JAERI-M-92-140.pdf:4.19MB

no abstracts in English