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Yoshida, Kazuhiro*; Sakata, Hideyuki*; Sago, Hiromi*; Shiraishi, Tadashi*; Oyama, Kazuhiro*; Hagiwara, Hiroyuki*; Yamano, Hidemasa; Yamamoto, Tomohiko
Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 9 Pages, 2012/12
To prevent the vortex cavitations, asymmetric flow in the upper plenum due to the radial slit with upper internal structure (UIS) has been mitigated by installing a cylindrical structure named as dummy plug instead of the fuel handling machine only used for refueling period. In this study, the extended brim and the division plate at the slit of UIS have been proposed in order to improve flow pattern in upper plenum for the purpose of the vortex cavitation prevention.
Sago, Hiromi*; Shiraishi, Tadashi*; Watakabe, Hisato*; Xu, Y.*; Aizawa, Kosuke; Yamano, Hidemasa
Nihon Kikai Gakkai Rombunshu, B, 78(792), p.1378 - 1382, 2012/08
A conceptual design study of the Japan Sodium-cooled Fast Reactor (JSFR) is in progress in "the Fast Reactor Cycle Technology Development (FaCT) project", and a two-loop primary system is adopted in order to economize the plant construction cost. In the JSFR the pipe thickness is designed to be considerably thinner and the mean sodium velocity increases. To understand the behavior of flow-induced vibration that is derived from the hydraulic characteristics under high Reynolds number conditions experiments were performed to evaluate and confirm the integrity.
Sago, Hiromi*; Shiraishi, Tadashi*; Watakabe, Hisato*; Xu, Y.*; Aizawa, Kosuke; Yamano, Hidemasa
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 8 Pages, 2011/10
Chikazawa, Yoshitaka; Aizawa, Kosuke; Shiraishi, Tadashi*; Sakata, Hideyuki*
Journal of Nuclear Science and Technology, 46(4), p.321 - 330, 2009/04
Times Cited Count：6 Percentile：41.05(Nuclear Science & Technology)Shiraishi, Tadashi*; Watakabe, Hisato*; Sago, Hiromi*; Yamano, Hidemasa
Journal of Fluid Science and Technology (Internet), 4(2), p.430 - 441, 2009/00
For the Japan Sodium-cooled Fast Reactor, an experimental study on the fluctuating pressure of the hot legs was carried out with tests using a 1/3-scale model. The total resistance coefficient is consistent with the published data, and our research has given some additional data up to the Reynolds number of 8.0
10
. The flow pattern in the postcritical regime is independent of a Reynolds number. The statistical examination revealed that fluctuating pressures on the pipe wall depend on the mean velocity but not on the viscosity of the fluid. Negative spikes of pressure appeared for high velocity. Based on these experimental data it is concluded that, there are similarity laws for the scale of a model and the property of fluid, but not for the velocity in the pipe. Theoretical considerations also gave a discussion how to extrapolate the fluctuating pressure to the actual hot-leg conditions.
Shiraishi, Tadashi*; Watakabe, Hisato*; Sago, Hiromi*; Kotake, Shoji; Yamano, Hidemasa
Proceedings of 2nd International Conference on Jets, Wakes and Separated Flows (ICJWSF 2008) (CD-ROM), 11 Pages, 2008/09
For the JAEA sodium-cooled fast reactor, an experimental study on the fluctuating pressure of the hot legs was carried out with tests using a 1/3-scale model. The total resistance coefficient is consistent with the published data, and our research has given some additional data up to the Reynolds number of 8.010
. The flow pattern in the postcritical regime is independent of a Reynolds number. The statistical examination revealed that fluctuating pressures on the pipe wall depend on the mean velocity but not on the viscosity of the fluid. Negative spikes of pressure appeared for high velocity. Based on these experimental data it is revealed that, there are similarity laws for the scale of a model and the property of fluid, but not for the velocity in the pipe. We also discussed how to extrapolate the fluctuating pressure to the actual hot-leg conditions.
Hirota, Kazuo*; Ishitani, Yoshihide*; Nakamura, Tomomichi*; Shiraishi, Tadashi*; Sago, Hiromi*; Yamano, Hidemasa; Kotake, Shoji
Proceedings of 9th International Conference on Flow-induced Vibrations (FIV 2008), 6 Pages, 2008/00
The present study is intended to grasp flow-induced vibration characteristics in the piping by newly taken experimental data as well as to verify a vibration analysis tool with its data. It was found that a flow velocity-dependent periodic phenomenon with maximum random vibration force appears in the downstream region of the elbow. The Strouhal number of dominant pressure fluctuations in the downstream of elbow is estimated to be around 0.45. In addition, the validity of the analytical tool was confirmed by comparing between analysis and experiment.
Kudo, Kenji; Kawatsuma, Shinji; Rindo, Hiroshi; Watabe, Kozo; Tomii, Hiroyuki; Shiraishi, Kunio; Yagi, Naoto; Fukushima, Tadashi; Zaitsu, Tomohisa
Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 8 Pages, 2006/07
Japan Atomic Energy Research Institute (JAERI) played a leading role in basic research in the field of atomic energy research and development, while Japan Nuclear Cycle Development Institute (JNC) did a major role in FBR cycle development and high level waste disposal. Following the Government's decision in December 2001, JAERI and JNC was merged as of October 1st, 2005. The new organization, Japan Atomic Energy Agency (JAEA), is an institute for comprehensive R&D for atomic energy, and is the largest research and development institute among Governmental R&D organizations. Its missions are basic research on atomic energy, R&D for nuclear fuel cycle, decommissioning of own facilities and disposal of waste, contribution to safety and non-proliferation, etc. The JAEA owns a number of nuclear facilities: research reactors such as JRR-2 and Joyo, prototype reactors such as ATR "Fugen" and FBR "Monju", fuel cycle plants such as Uranium Enrichment Demonstration Plant at Ningyo-Toge, MOX fuel plants at Tokai, Reprocessing Plant at Tokai, and Hot Laboratories such as JRTF and FMF. As a part of preparation of the mergence, JNC and JAERI have jointly developed a comprehensive cost estimation method for decommissioning, based on decommissioning and refurbishing experiences of JAERI and JNC. This method involves more estimation parameters from typical decommissioning activities than before, so as to make it more reliable. JAERI and JNC have estimated the total cost for decommissioning by using this method, and concluded that the cost would be 600 billion yen (approx. 5 billion USD).
Harada, Akio; Sato, Tadashi*; Nakajima, Kunihisa; Komuro, Yuichi; Shiraishi, Hirotsugu*; Hattori, Takamitsu; Ikuta, Yuko; Yachi, Shigeyasu; Kushita, Kohei
JAERI-Review 2005-026, 55 Pages, 2005/09
JAERI-Review-2005-026.pdf:1.95MB
This report provides an example of answers to the problems of the 37th Examination for the Chief Engineer of Nuclear Fuel. This examination was done as a national qualification in March 2005. Brief explanations or references are added to some answers.
Aizawa, Kosuke; Chikazawa, Yoshitaka; Shiraishi, Tadashi*; Sakata, Hideyuki*; Okubo, Yoshiyuki*
no journal, ,
no abstracts in English
Tachibana, Mitsuo; Shiraishi, Kunio; Fukushima, Tadashi; Naito, Akira; Ishigami, Tsutomu
no journal, ,
no abstracts in English
Shiraishi, Tadashi*; Sago, Hiromi*; Watakabe, Hisato*; Yamano, Hidemasa; Kotake, Shoji
no journal, ,
This paper reports test results with room-temperature and hot (60 
C) water in order to investigate the effect of coolant viscosity on flow dynamics and pressure fluctuations of a hot-leg piping in the post critical Reynolds number regime.
Shiraishi, Tadashi*; Sago, Hiromi*; Watakabe, Hisato*; Xu, Y.*; Aizawa, Kosuke; Yamano, Hidemasa
no journal, ,
Flow characteristics in an elbow with swirl flow were experimentally obtained under a high Reynolds number regime. In the range of 0
15% of swirl flow fraction, no significant effect of the swirl flow on the magnitude of pressure fluctuation was not seen although the flow separation region at the elbow was twisted by the swirl flow.
Sago, Hiromi*; Shiraishi, Tadashi*; Watakabe, Hisato*; Xu, Y.*; Aizawa, Kosuke; Yamano, Hidemasa
no journal, ,
no abstracts in English
Sago, Hiromi*; Shiraishi, Tadashi*; Watakabe, Hisato*; Xu, Y.*; Aizawa, Kosuke; Yamano, Hidemasa
no journal, ,
no abstracts in English
Yoshida, Kazuhiro*; Sakata, Hideyuki*; Sago, Hiromi*; Shiraishi, Tadashi*; Oyama, Kazuhiro*; Hagiwara, Hiroyuki*; Yamano, Hidemasa; Yamamoto, Tomohiko
no journal, ,
no abstracts in English
