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Ariyoshi, Gen; Saruta, Koichi; Kogawa, Hiroyuki; Futakawa, Masatoshi; Maeno, Koki*; Li, Y.*; Tsutsui, Kihei*
Proceedings of 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) (Internet), p.1407 - 1420, 2023/08
Cavitation damage on a target vessel due to proton beam-induced pressure waves is one of the crucial issues for the pulsed neutron source using a mercury spallation target. As a mitigation technique for the damage, the helium microbubble injection into the mercury has been carried out by using a swirl bubbler in order to utilize compressibility of bubbles. Moreover, double-walled structure, which consists of an outer wall and an inner wall, has been applied as the target head structure. In this study, we aim to develop an abnormality diagnostic technology to detect the inner wall cracking, which is caused by such cavitation damage, from the outside of the target vessel. The mercury flow fields in the case with the cracking are evaluated by computational fluid dynamics analysis based on finite element method. And then, effect of the cracking on the flow field is discussed from the point of view of the flow-induced vibration and the acoustic vibration.
Ito, Kei; Tanaka, Masaaki; Ohno, Shuji; Ohshima, Hiroyuki
JAEA-Research 2014-023, 34 Pages, 2014/11
JAEA-Research-2014-023.pdf:4.48MB
In a sodium-cooled fast reactor, inert gas (bubbles or dissolved gas) exists in the primary coolant system. Such inert gas may cause disturbance in reactivity and/or degradation of IHX performance, and therefore, the inert gas behaviors have to be investigated to ensure the stable operation of a fast reactor. The authors have developed a plant dynamics code SYRENA to simulate the concentration distributions of the dissolved gas and the bubbles in a fast reactor. In this study, the models in SYRENA code are improved to achieve accurate simulations. Moreover, new models are introduced to simulate the various bubble behaviors in liquid metal flows. To validate the improved models and the newly developed models, the inert gas behaviors in the large-scale sodium-cooled reactor are simulated. As a result, it is confirmed that the complicated bubble dynamics in each component can be simulated appropriately by SYRENA code.
Saito, Yasushi*; Hibiki, Takashi*; Mishima, Kaichiro*; Tobita, Y.*; Suzuki, Toru*; Matsubayashi, Masahito
Proceedings of 9th International Symposium on Flow Visualization, p.391_1 - 391_10, 2000/00
no abstracts in English
Nakamura, Hideo; Shibamoto, Yasuteru; Anoda, Yoshinari; Kukita, Yutaka*; Mishima, Kaichiro*; Hibiki, Takashi*
Nuclear Technology, 125(2), p.213 - 224, 1999/02
Times Cited Count：8 Percentile：53.55(Nuclear Science & Technology)no abstracts in English
Mishima, Kaichiro*; Hibiki, Takashi*; Saito, Y.*; Nishihara, Hideaki*; Tobita, Y.*; *; Matsubayashi, Masahito
Nuclear Instruments and Methods in Physics Research A, 424(1), p.229 - 234, 1999/00
Times Cited Count：31 Percentile：88.42(Instruments & Instrumentation)no abstracts in English
*; *; Fujii, Terushige*; *; *; Matsubayashi, Masahito; Tsuruno, Akira
Nuclear Instruments and Methods in Physics Research A, 377, p.156 - 160, 1996/00
Times Cited Count：7 Percentile：55.21(Instruments & Instrumentation)no abstracts in English
Matsubayashi, Masahito; Tsuruno, Akira; Ichikawa, Hiroki; Kodaira, Tsuneo; Shirai, Eiji
Proceedings of 4th Asian Symposium on Research Reactors (ASRR-4), p.192 - 197, 1993/00
no abstracts in English
Kunugi, Tomoaki; M.S.Tillack*; M.A.Abdou*
Fusion Technology, 19, p.1000 - 1005, 1991/05
no abstracts in English
Ariyoshi, Gen; Ito, Kei*; Kogawa, Hiroyuki; Futakawa, Masatoshi
no journal, ,
Cavitation damage caused by pressure waves is one of the important issues which threaten the integrity of the mercury spallation target vessel in J-PARC. To mitigate the damage, technology using mercury-helium two-phase flow has been developed. Although effective bubble radius for absorption/attenuation of the waves is evaluated as less than 0.1 mm, actual bubble radius might be different from the evaluated one due to microbubble coalescence phenomena. Therefore, the purpose of present study is to clarify and predict the bubble radius distribution in the target. To achieve that, visualization of microbubble coalescence phenomena was performed by using air-water two-phase flow as a model flow. Obtained experimental results and numerical prediction code presently developed will be explained.
