Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nakamura, Hironori*; Hayakawa, Satoshi*; Shibata, Akihiro*; Sasa, Kyohei*; Yamano, Hidemasa; Kubo, Shigenobu
Proceedings of 12th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS12) (Internet), 7 Pages, 2022/10
In order to evaluate long-term coolablity of the debris-bed with decay heat, a three-dimensional calculation method coupled with the debris bed module was developed in this study. The coupled code calculation results show that natural circulation of the coolant between the hot pool and the cold pool is established through the four intermediate heat exchangers after the activation of the dipped direct heat exchangers. The cold pool with the debris-bed is continually cooled not only by the natural circulation flow, but also by heat transfer to the hot pool through the plenum separation plate between the hot pool and the cold pool. The effect of the three-dimensional flow field around the core catcher on the temperature in the debris-bed is about 20K under the current calculation condition.
Yamano, Hidemasa; Kubo, Shigenobu; Sasa, Kyohei*; Shibata, Akihiro*; Hourcade, E.*; Dirat, J. F.*
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 9 Pages, 2022/08
This paper describes coolability evaluations of a debris bed with a variety of decay heat removal system (DHRS) operating conditions with a whole vessel model assuming fuel accumulation on the core catcher in a short term. The evaluation tool is a one-dimensional plant dynamics code, Super-COPD, with a debris bed module. The coolability evaluations have indicated that the current core catcher design secures sufficient natural circulation flows around the core catcher to ensure the debris bed cooling when at least one circuit of DHRS was activated. Sensitivity analyses under a pessimistic condition have shown that the debris bed is coolable with at least one circuit of improved DHRS even if most of fuel accumulates on the core catcher in a short term.
Sonoda, Tetsu*; Katayama, Ichiro*; Wada, Michiharu*; Iimura, Hideki; Sonnenschein, V.*; Iimura, Shun*; Takamine, Aiko*; Rosenbusch, M.*; Kojima, Takao*; Ahn, D. S.*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11
Times Cited Count：1 Percentile：11.61(Physics, Multidisciplinary)An in-flight separator, BigRIPS, at RIBF in RIKEN provides each experiment with specific nuclides separated from many nuclides produced by projectile fragmentation or in-flight fission. In this process, nuclides other than separated ones are discarded on the slits in BigRIPS, although they include many nuclides interested from the view point of nuclear structure. In order to extract these nuclides for parasitic experiments, we are developing a method using laser ion-source (PALIS). A test experiment with 
Se beam from RIBF has been performed by using a gas cell set in BigRIPS. Unstable nuclides around 
Se were stopped in the gas cell in accordance with a calculation using LISE code. The stopping efficiency has been estimated to be about 30%. As a next step, we will establish the technique for extracting reaction products from the gas cell.
Matsuo, Eiji*; Sasa, Kyohei*; Koyama, Kazuya*; Yamano, Hidemasa; Kubo, Shigenobu; Hourcade, E.*; Bertrand, F.*; Marie, N.*; Bachrata, A.*; Dirat, J. F.*
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 5 Pages, 2019/05
Discharged molten-fuel from the core during Core Disruptive Accident (CDA) could become solidified particle debris by fuel-coolant interaction in the lower sodium plenum, and then the debris could form a bed on a core catcher located at the bottom of the reactor vessel. Coolability evaluations for the debris bed are necessary for the design of the core catcher. The purpose of this study is to evaluate the coolability of the debris bed on the core catcher for the ASTRID design. For this purpose, as a first step, the coolability calculations of the debris beds formed both in short term and later phase have been performed by modeling only the debris bed itself. Thus, details of core catcher design and decay heat removal system are not described in this paper. In all the calculations, coolant temperature around the debris bed is a parameter. The calculation tool is the debris bed module implemented into a one-dimensional plant dynamics code, Super-COPD. The evaluations have shown that the debris beds formed both in short term and later phase are coolable by the design which secures sufficient coolant flow around the core catcher located in the cold pool.
Zn
Cr
Se
Iikubo, Satoshi*; Yasui, Yukio*; Oda, Keisuke*; Ono, Yohei*; Kobayashi, Yoshiaki*; Sato, Masatoshi*; Kakurai, Kazuhisa
Journal of the Physical Society of Japan, 71(11), p.2792 - 2799, 2002/11
Times Cited Count：11 Percentile：56.91(Physics, Multidisciplinary)no abstracts in English
Ogawa, Tsuyoshi; Takahatake, Yoko; Koma, Yoshikazu; Nakajima, Yasuo; Sano, Kyohei*; Arai, Tsuyoshi*; Hashimoto, Jun*; Kubo, Kaname*; Kaneko, Masashi*
no journal, ,
no abstracts in English
Nakaya, Atsushi*; Tada, Hiroyuki*; Okuyama, Yasuji*; Iwasaki, Masahiro*; Kusano, Takashi*; Kubo, Yohei*; Yamawaki, Hiroyuki; Sato, Toshinori
no journal, ,
no abstracts in English
Takahatake, Yoko; Shibata, Atsuhiro; Koma, Yoshikazu; Nakajima, Yasuo; Sano, Kyohei*; Arai, Tsuyoshi*; Hashimoto, Jun*; Kubo, Kaname*; Kaneko, Masashi*
no journal, ,
no abstracts in English
Nakai, Kei*; Yamamoto, Yohei*; Yamamoto, Tetsuya*; Yoshida, Fumiyo*; Matsumura, Akira*; Koka, Masashi; Yamada, Naoto; Kitamura, Akane; Sato, Takahiro; Yokoyama, Akihito; et al.
no journal, ,
no abstracts in English
Kiyohara, Keita*; Murakawa, Hideki*; Sugimoto, Katsumi*; Kubo, Yohei*; Kurita, Keisuke; Iikura, Hiroshi; Asano, Hitoshi*
no journal, ,
Boiling two-phase flows in mini-channel cross-flow vaporizer had been visualized by two methods, neutron radiography and the method by replacing the outer wall with a transparent wall.
