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Idehara, Toshitaka*; Mitsudo, Seitaro*; Hoshizuki, Hisanori*; Ogawa, Isamu*; Shibahara, Itaru; Nishi, Hiroshi; Kitano, Akihiro; Ishibashi, Junichi
JNC TY4400 2003-005, 106 Pages, 2003/03
JNC-TY4400-2003-005.pdf:9.48MB
Boron Carbide B4C pellet is an important part of control rod used to control the reactivity of nuclear reactors. B4C pellet put in a nuclear reactor suffers heavy radiation damage and deformation, which result in a partial destruction and shorten the lifetime of B4C. It is important to improve the characteristics of the B4C pellets for extension of its lifetime. As the results, if the control rod without the shroud will be available, we can realize much simpler structure. In order to improve, the B4C pellet, which was sintered by the hot-press methods, we have re-sintered it by high power millimeter wave ceramics nano-indentation test. The increase of the plasticity is observed. The same improvement of plasticity was observed in alumina pellets that were sintered by millimeter wave sintering methods. Such results imply that the further improvement is expected, if the B4C pellet is sintered from powder specimen by the high power millimeter-wave sintering method. To simulate a partial destruction of B4C pellet under the thermal stress, preliminary internal heating experiments of B4C pellet are performed by using high power millimeter-wave. At the difference between internal and surface temperatures of 1000C, the partial destructions and small cracks are observed in B4C pellet. Thes may be a kind of model experiment for destruction of B4C pellet irradiated by neutrons.
Yoshida, Eiichi; Sakurai, Tadashi*; Shibahara, Itaru
JNC TN9400 2003-050, 77 Pages, 2003/03
JNC-TN9400-2003-050.pdf:5.93MB
Sodium-bond double porous-plug is one of the candidates in development of the long-life life control rod for prototype reactor MONJU. Gas hold pressure and sodium penetration pressure of the porous-plug in liquid sodium are an important factor which determines the filling up of sodium into porous-plug and the gas plenum length in control rod pin. In this study, the fundamental characteristic of porous-plug was clarified by experiment in high temperature sodium. Moreover, the characteristic equation of design for a porous-plug was evaluated based on the obtained data.
C ceramics sintering using 24 GHz gyrotron radiationHoshizuki, Hisanori*; Kuroda, Tsutomu*; Mitsudo, Seitaro*; Idehara, Toshitaka*; Glyavin, M.*; Kitano, Akihiro; Ishibashi, Junichi; Nishi, Hiroshi; Shibahara, Itaru
En Sekigai Ryoiki Kaihatsu Kenkyu, 4, p.179 - 185, 2003/00
None
C by using a compact gyrotron systemHoshizuki, Hisanori*; Mitsudo, Seitaro*; Glyavin, M.*; Eremeev, A.*; ; Iwai, Yoshiro*; Kitano, Akihiro; Ishibashi, Junichi; Nishi, Hiroshi; Shibahara, Itaru; et al.
Proceedings of 28th International Conference on Infrared and Millimeter Waves (IRMMW 2003), P. 1005, 2003/00
None
Shibahara, I.; Shibahara, Itaru
Proceedings of 4th International Conference on Nuclear Engineering (ICONE-4), P. 219, 1996/00
-
hot cell in the materials monitoring facility; ; ; ; Shibahara, Itaru
3rd Int.Conf.on Nuclear Engineering, 0 Pages, 1995/00
None
Aoto, Kazumi; Abe, Yasuhiro; Shibahara, Itaru; Wada, Yusaku
IAEA-TECDOC-817, p.27 - 37, 1995/00
None
Ishino, Shiori*; Sekimura, Naoto*; Suzuki, Masahide; ; ; Shibahara, Itaru*
Nihon Genshiryoku Gakkai-Shi, 36(5), p.396 - 404, 1994/00
Times Cited Count：1 Percentile：17.75(Nuclear Science & Technology)no abstracts in English
Shikakura, Sakae; Ukai, Shigeharu; Sato, Yoshinori; Harada, Makoto; Koyama, Shinichi; ; Nomura, Shigeo; Shibahara, Itaru
Nihon Genshiryoku Gakkai-Shi, 36(5), p.441 - 455, 1994/00
None
Shibahara, Itaru; Onose, Shoji; Akasaka, Naoaki
6th Int.Conf.Fusion Reactor Materials (ICFRN-6), 1 Pages, 1993/09
None
Shibahara, Itaru; Ukai, Shigeharu; Onose, Shoji; Shikakura, Sakae
Journal of Nuclear Materials, 204(2), p.131 - 140, 1993/09
Times Cited Count：43 Percentile：94.98(Materials Science, Multidisciplinary)None
Koike, Mitsutaka; ; Nagamatsu, Kenji; Shibahara, Itaru
10th International Symposium on Zirconium in the Nuclear Industry, 0 Pages, 1993/00
None
Asaka, Takeo; ; ; ; Shibahara, Itaru; Shikakura, Sakae
Journal of Nuclear Materials, 204, p.102 - 108, 1993/00
Times Cited Count：4 Percentile：44.66(Materials Science, Multidisciplinary)None
Tsukada, Takashi; Jitsukawa, Shiro; Shiba, Kiyoyuki; Sato, Yoshinori*; Shibahara, Itaru*; Nakajima, Hajime
Journal of Nuclear Materials, 207, p.159 - 168, 1993/00
Times Cited Count：7 Percentile：60.12(Materials Science, Multidisciplinary)no abstracts in English
Shiba, Kiyoyuki; Tsukada, Takashi; Nakajima, Hajime; ; Kitagawa, Isamu; ; Sekino, Hajime; ; ; Itonaga, Fumio; et al.
JAERI-M 92-166, 27 Pages, 1992/11
no abstracts in English
Tsukada, Takashi; Shiba, Kiyoyuki; Nakajima, Hajime; Usui, Takeshi; Omi, Masao; Goto, Ichiro; ; Nakagawa, Tetsuya; Kawamata, Kazuo; ; et al.
JAERI-M 92-165, 41 Pages, 1992/11
no abstracts in English
; ; ; ; ; Shibahara, Itaru
PNC TN9410 92-321, 30 Pages, 1992/10
Integrity evaluations have been performed for the 2nd Fugen pressure tube test (8 years irradiation, 5.6 
10
n/cm
(E
1Mev)). Test items mainly consist of tensile test, bending test, corrosion test and hydrogen analysis. It has become clear using these data that the pressure tube material has maintained its integrity during the irradiation by the integrity assessment on both tensile and fracture toughness properties. Besides, both thickness loss by corrosion and absorbed hydrogen content were lower than those of design values.
Sato, Yoshinori; Shibahara, Itaru; ;
Journal of Nuclear Materials, 0 Pages, 1992/00
None
Tsukada, Takashi; Shiba, Kiyoyuki; Nakajima, Hajime; Sato, Yoshinori*; Shibahara, Itaru*
PNC-TN9410 92-295, 67 Pages, 1992/00
no abstracts in English
C neutron absorber materials; Results of the JOYO AMIR irradiation experimentsKimura, Yoshio; Kaito, Takeji; Onose, Shoji; Sato, Yoshinori; Shibahara, Itaru
PNC TN9410 91-171, 17 Pages, 1991/04
The BC neutron absorber material has great advantage of high neutron absorbing capability, although the He release and the swelling limit the life time of control rod. So it is important for the life time extension and reliability improvement to investigate the irradiation behavior of the BC. This report discuss the important parameters which may control the absorber pin behavior based on the irradiation test results obtained recently by the JOYO AMIR experiments, and re-evaluate the current technical issues and the way of improvements. The He release from BC pellet increase rapidly after a burnup of 10010
cap/cm
and exceed the value predicted by the equation which has been applied to the MONJU design. The data is still required when we adopt the seal type absorber pin to use at high burnup. The He release found to depend on the 
B enrichment as well as the grain size. The He release could be reduced by the optimization of these parameters although the swelling behavior should also be considered since the swelling generally increases with decreasing the He release. The absorber cladding mechanical interaction (ACMI) is accelerated due to pellet cracking and relocation and essentially limits the life time of control rod. The relocation becomes generally extensive as the pellet-to-cladding gap is increased, but this behavior consider to be stochastic and difficult to make quantitative prediction. Improvement could be attained by using a shroud type absorber pin. Reduction of thermal conductivity during irradiation is considered to be caused by micro-defects including the micro-cracking. The degradation may be improved by introducing BC cermet.
