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Kugo, Teruhiko; Ishikawa, Makoto; Nagaya, Yasunobu; Yokoyama, Kenji; Fukaya, Yuji; Maruyama, Hiromi*; Ishii, Yoshihiko*; Fujimura, Koji*; Kondo, Takao*; Minato, Hirokazu*; et al.
JAEA-Research 2013-046, 53 Pages, 2014/03
JAEA-Research-2013-046.pdf:4.42MB
The present report summarizes the results of a 2-year cooperative study between JAEA and Hitachi-GE in order to contribute to the settlement of the Fukushima-Daiichi Nuclear Power Plants which suffered from the severe accident on March 2011. In the present study, the possible scenarios to reach the recriticality events in Fukushima-Daiichi were investigated first. Then, the analytical methodology to evaluate the time-dependent recriticality events has been developed by modelling the reactivity insertion rate and the possible feedback according to the recriticality scenarios identified in the first step. The methodology developed here has been equipped as a transient simulation tool, PORCAS, which is operated on a multi-purpose platform for reactor analysis, MARBLE. Finally, the radiation exposure rates by the postulated recriticality events in Fukushima-Daiichi were approximately evaluated to estimate the impact to the public environment.
Cu
Al
bulk glassy alloyOnodera, Naoto*; Ishii, Akito*; Ishii, Koji*; Iwase, Akihiro*; Yokoyama, Yoshihiko*; Saito, Yuichi; Ishikawa, Norito; Yabuuchi, Atsushi*; Hori, Fuminobu*
Nuclear Instruments and Methods in Physics Research B, 314, p.122 - 124, 2013/11
Times Cited Count：3 Percentile：26.71(Instruments & Instrumentation)It has been reported that heavy ion irradiation causes softening in some cases of Zr-based bulk metallic glass alloys. However, the fundamental mechanisms of such softening have not been clarified yet. In this study, ZrCuAl bulk glassy alloys were irradiated with heavy ions of 10 MeV I at room temperature. Positron annihilation measurements have performed before and after irradiation to investigate changes in free volume. We discuss the relationship between the energy loss and local open volume change after 10 MeV I irradiation compared with those obtained for 200 MeV Xe and 5 MeV Al. The energy loss analysis in ion irradiation for the positron lifetime has revealed that the decreasing trend of positron lifetime is well expressed as a function of total electronic energy deposition rather than total elastic energy deposition. It means that the positron lifetime change by the irradiation has a relationship with the inelastic collisions with electrons during heavy ion irradiation.
Hori, Fuminobu*; Onodera, Naoto*; Fukumoto, Yuka*; Ishii, Akito*; Iwase, Akihiro*; Kawasuso, Atsuo; Yabuuchi, Atsushi; Maekawa, Masaki; Yokoyama, Yoshihiko*
Journal of Physics; Conference Series, 262, p.012025_1 - 012025_4, 2011/01
Times Cited Count：5 Percentile：84.8(Physics, Applied)Free volume changes in ZrCuAl bulk glassy alloys irradiated by 200 and 2.5 MeV Xe ions, 180 keV He ions, and 2 MeV electrons were investigated at room temperature using positron annihilation techniques. X-ray diffraction revealed that no crystallization took place in any of the irradiated sample. The positron lifetime increased only after electron and 180 keV He irradiation. This indicates that the radiation has increased the open volume size (free volume). On the other hand, the positron lifetime was decreased by irradiation with heavy Xe-ions at either energy of 2.5 or 200 MeV. It is conceivable that the difference in behavior can be attributed to the difference in displacements per radiation particle (dpp), because the dpp estimated for 2 MeV electrons and 180 keV He ions is three or more orders of magnitude less than that for heavy Xe ions. We found that the radiation effect in ZrCuAl bulk glassy alloy is dependent on the displacement per radiation particle.
Ishii, Akito*; Iwase, Akihiro*; Yokoyama, Yoshihiko*; Konno, Toyohiko*; Kawasuso, Atsuo; Yabuuchi, Atsushi; Maekawa, Masaki; Hori, Fuminobu*
Journal of Physics; Conference Series, 225, p.012020_1 - 012020_6, 2010/06
Times Cited Count：5 Percentile：85.19(Physics, Applied)To reveal the relationship between mechanical properties and microscopic structure of Zr-based amorphous metals, we performed positron annihilation measurements on specimens with different Zr contents. Although the positron lifetimes were nearly the same for all the specimens, the Doppler broadening of annihilation radiation spectra were significantly different for the specimens at and above the eutectic point. This indicates that both the structure and composition of free volumes depend on the Zr-content.
Iwamura, Takamichi; Okubo, Tsutomu; Akie, Hiroshi; Kugo, Teruhiko; Yonomoto, Taisuke; Kureta, Masatoshi; Ishikawa, Nobuyuki; Nagaya, Yasunobu; Araya, Fumimasa; Okajima, Shigeaki; et al.
JAERI-Research 2004-008, 383 Pages, 2004/06
JAERI-Research-2004-008.pdf:21.49MB
The present report contains the achievement of "Research and Development on Reduced-Moderation Light Water Reactor with Passive Safety Features", which was performed by Japan Atomic Energy Research Institute (JAERI), Hitachi Ltd., Japan Atomic Power Company and Tokyo Institute of Technology in FY2000-2002 as the innovative and viable nuclear energy technology (IVNET) development project operated by the Institute of Applied Energy (IAE). In the present project, the reduced-moderation water reactor (RMWR) has been developed to ensure sustainable energy supply and to solve the recent problems of nuclear power and nuclear fuel cycle, such as economical competitiveness, effective use of plutonium and reduction of spent fuel storage. The RMWR can attain the favorable characteristics such as high burnup, long operation cycle, multiple recycling of plutonium (Pu) and effective utilization of uranium resources based on accumulated LWR technologies.
Takeji, Satoru; Tokuda, Shinji; Fujita, Takaaki; Suzuki, Takahiro; Isayama, Akihiko; Ide, Shunsuke; Ishii, Yasutomo; Kamada, Yutaka; Koide, Yoshihiko; Matsumoto, Taro; et al.
Nuclear Fusion, 42(1), p.5 - 13, 2002/01
Times Cited Count：75 Percentile：89.25(Physics, Fluids & Plasmas)no abstracts in English
Kato, Takashi; Tsuji, Hiroshi; Ando, Toshinari; Takahashi, Yoshikazu; Nakajima, Hideo; Sugimoto, Makoto; Isono, Takaaki; Koizumi, Norikiyo; Kawano, Katsumi; Oshikiri, Masayuki*; et al.
Fusion Engineering and Design, 56-57, p.59 - 70, 2001/10
Times Cited Count：17 Percentile：74.85(Nuclear Science & Technology)no abstracts in English
Matsui, Kunihiro; Nunoya, Yoshihiko; Kawano, Katsumi; Takahashi, Yoshikazu; Nishii, Kenji*; CS Model Coil Test Group
Teion Kogaku, 36(6), p.361 - 367, 2001/06
no abstracts in English
Tsuji, Hiroshi; Okuno, Kiyoshi*; Thome, R.*; Salpietro, E.*; Egorov, S. A.*; Martovetsky, N.*; Ricci, M.*; Zanino, R.*; Zahn, G.*; Martinez, A.*; et al.
Nuclear Fusion, 41(5), p.645 - 651, 2001/05
Times Cited Count：57 Percentile：83.02(Physics, Fluids & Plasmas)no abstracts in English
Sn conductor for ITERTakahashi, Yoshikazu; Matsui, Kunihiro; Nishii, Kenji; Koizumi, Norikiyo; Nunoya, Yoshihiko; Isono, Takaaki; Ando, Toshinari; Tsuji, Hiroshi; Murase, Satoru*; Shimamoto, Susumu*
IEEE Transactions on Applied Superconductivity, 11(1), p.1546 - 1549, 2001/03
Times Cited Count：29 Percentile：77.42(Engineering, Electrical & Electronic)no abstracts in English
Kamada, Yutaka; Isayama, Akihiko; Oikawa, Toshihiro; Sakamoto, Yoshiteru; Hosogane, Nobuyuki; Takenaga, Hidenobu; Kusama, Yoshinori; Fujita, Takaaki; Takeji, Satoru; Ozeki, Takahisa; et al.
Nuclear Fusion, 39(11Y), p.1845 - 1853, 1999/11
no abstracts in English
Fujita, Takaaki; Kamada, Yutaka; Ishida, Shinichi; Neyatani, Yuzuru; Oikawa, Toshihiro; Ide, Shunsuke; Takeji, Satoru; Koide, Yoshihiko; Isayama, Akihiko; Fukuda, Takeshi; et al.
Nuclear Fusion, 39(11Y), p.1627 - 1636, 1999/11
Times Cited Count：93 Percentile：91.91(Physics, Fluids & Plasmas)no abstracts in English
Kamada, Yutaka; Isayama, Akihiko; Oikawa, Toshihiro; Sakamoto, Yoshiteru; Hosogane, Nobuyuki; Takenaga, Hidenobu; Kusama, Yoshinori; Fujita, Takaaki; Takeji, Satoru; Ozeki, Takahisa; et al.
Nuclear Fusion, 39(11Y), p.1845 - 1853, 1999/11
Times Cited Count：69 Percentile：87.48(Physics, Fluids & Plasmas)no abstracts in English
Fujita, Takaaki; Kamada, Yutaka; Ishida, Shinichi; Neyatani, Yuzuru; Oikawa, Toshihiro; Ide, Shunsuke; Takeji, Satoru; Koide, Yoshihiko; Isayama, Akihiko; Fukuda, Takeshi; et al.
IAEA-CN-69/EX1/2 (CD-ROM), 8 Pages, 1999/00
no abstracts in English
Fujita, Takaaki; Hatae, Takaki; Oikawa, Toshihiro; Takeji, Satoru; Shirai, Hiroshi; Koide, Yoshihiko; Ishida, Shinichi; Ide, Shunsuke; Ishii, Yasutomo; Ozeki, Takahisa; et al.
Nuclear Fusion, 38(2), p.207 - 221, 1998/02
Times Cited Count：64 Percentile：86.63(Physics, Fluids & Plasmas)no abstracts in English
