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Hotta, Akitoshi*; Akiba, Miyuki*; Morita, Akinobu*; Konovalenko, A.*; Vilanueva, W.*; Bechta, S.*; Komlev, A.*; Thakre, S.*; Hoseyni, S. M.*; Skld, P.*; et al.
Journal of Nuclear Science and Technology, 57(4), p.353 - 369, 2020/04
Times Cited Count:14 Percentile:71.46(Nuclear Science & Technology)Akiba, Miyuki*; Hotta, Akitoshi*; Abe, Yutaka*; Sun, Haomin
Nihon Genshiryoku Gakkai Wabun Rombunshi, 19(1), p.1 - 15, 2020/02
Tests at three different scales were conducted in order to understand the mechanisms of pool scrubbing. In the small-scale separate effect test, high resolution two-phase flow measurement techniques such as a high-speed camera, wire mesh sensor and PIV were applied to capture the behaviors of a single bubble and two-phase flow structures. In the large-scale integral effect test, the dependence of the aerosol removal efficiency on submergence and pool temperature was measured under constant pressure and depressurized conditions. To clarify relationships between individual phenomena and combined phenomena observed in two tests, the mid-scale integral effect test was undertaken.
Hotta, Akitoshi*; Morita, Akinobu*; Kajimoto, Mitsuhiro*; Maruyama, Yu
Nihon Genshiryoku Gakkai Wabun Rombunshi, 16(3), p.139 - 152, 2017/09
Shibamoto, Yasuteru; Yonomoto, Taisuke; Hotta, Akitoshi*
Nihon Genshiryoku Gakkai-Shi ATOMO, 58(9), p.553 - 557, 2016/09
no abstracts in English
Zhang, W.; Yoshida, Hiroyuki; Ose, Yasuo*; Onuki, Akira; Akimoto, Hajime; Hotta, Akitoshi*; Fujimura, Ken*
Journal of Power and Energy Systems (Internet), 2(2), p.456 - 466, 2008/00
Zhang, W.; Yoshida, Hiroyuki; Ose, Yasuo*; Onuki, Akira; Akimoto, Hajime; Hotta, Akitoshi*; Fujimura, Ken*
Dai-12-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.85 - 88, 2007/06
As a candidate for next generation reactor, the innovative FLexible-fuel-cycle Water Reactor (FLWR) adopts a remarkably tight triangular lattice arrangement with about 1 mm gap spacing between adjacent fuel rods. In relation to its design, this study presents a statistical evaluation of numerical simulation results of a detailed two-phase flow simulation code (named TPFIT). In order to make clear mechanisms of cross flow in such tight lattice rod bundles, the TPFIT is used to simulate cross flow between two modeled subchannels. Attention was focused on instantaneous fluctuation characteristics of differential pressure between two subchannels and gas/liquid mixing coefficients. With the calculation of correlation coefficients between the differential pressure and gas/liquid mixing coefficients, the time scales of cross flow, e.g. lag times were evaluated, and the effects of mixing section length, flow pattern and gap spacing on correlation coefficients were extensively investigated. The difference in mechanism between gas and liquid cross flows was pointed out.
Zhang, W.; Yoshida, Hiroyuki; Ose, Yasuo*; Onuki, Akira; Akimoto, Hajime; Hotta, Akitoshi*; Fujimura, Ken*
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
The innovative Water Reactor for FLexible fuel cycle (FLWR) adopts a tight triangular lattice arrangement with about 1 mm gap between adjacent fuel rods. In view of the importance of accurate prediction of cross flow between subchannels in the evaluation of the boiling transition (BT) in the FLWR core, this study numerically simulated steam-water two-phase cross flow between two modeled subchannels of tight-lattice rod bundle for the FLWR by using a detailed two-phase flow simulation code with an advanced interface tracking method (named TPFIT), statistically evaluated the simulation results, and clarified mechanisms of cross flow for developing a model. The effects of flow pattern, inlet and outlet of mixing section, and gap spacing on cross flow, and the local and general characters of cross flow were extensively investigated.
Chitose, Hiromasa*; Hotta, Akitoshi*; Onuki, Akira; Fujimura, Ken*
Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 6 Pages, 2006/07
no abstracts in English
Onuki, Akira; Tamai, Hidesada; Yoshida, Hiroyuki; Shibata, Mitsuhiko; Akimoto, Hajime; Chitose, Hiromasa*; Hotta, Akitoshi*; Fujimura, Ken*
no journal, ,
no abstracts in English
Chitose, Hiromasa*; Hotta, Akitoshi*; Onuki, Akira; Tamai, Hidesada; Yoshida, Hiroyuki; Shibata, Mitsuhiko; Akimoto, Hajime; Fujimura, Ken*
no journal, ,
no abstracts in English
Tamai, Hidesada; Onuki, Akira; Shibata, Mitsuhiko; Akimoto, Hajime; Chitose, Hiromasa*; Hotta, Akitoshi*; Fujimura, Ken*
no journal, ,
no abstracts in English
Yoshida, Hiroyuki; Ose, Yasuo*; Onuki, Akira; Akimoto, Hajime; Hotta, Akitoshi*; Fujimura, Ken*
no journal, ,
no abstracts in English
Kataoka, Isao*; Narabayashi, Tadashi*; Sakaba, Hiroshi*; Yoshida, Hiroyuki; Nishida, Koji*; Hotta, Akitoshi*
no journal, ,
no abstracts in English
Nakamura, Hideo; Hotta, Akitoshi*; Okamoto, Koji*; Ui, Jun*; Koshizuka, Seiichi*
no journal, ,
no abstracts in English
Kikuchi, Wataru*; Akiba, Miyuki*; Hotta, Akitoshi*; Alexander, K.*; Walter, V.*; Sevostian, B.*; Matsumoto, Toshinori
no journal, ,
To develop the analytical models for jet breakup and debris bed formation, we are conducting experiments that simulate these behaviors. Various uncertainty items associate to the experiment were clarified, and the reflection in the analysis model was examined.