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Okitsu, Takayuki*; Hojo, Tomohiko*; Morooka, Satoshi; Miyamoto, Goro*
Tetsu To Hagane, 110(3), p.260 - 267, 2024/02
Takada, Hiroshi; Haga, Katsuhiro
JPS Conference Proceedings (Internet), 28, p.081003_1 - 081003_7, 2020/02
At the Japan Proton Accelerator Research Complex (J-PARC), the pulsed spallation neutron source has been in operation with a redesigned mercury target vessel from October 2017 to July 2018, during which the operational beam power was restored to 500 kW and the operation with a 1-MW equivalent beam was demonstrated for one hour. The target vessel includes a gas-micro-bubbles injector and a 2-mm-wide narrow mercury flow channel at the front end as measures to suppress the cavitation damage. After the operating period, it was observed that the cavitation damage at the 3-mm-thick front end of the target vessel could be suppressed less than 17.5 
m.
Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2019-025, 36 Pages, 2020/01
JAEA-Review-2019-025.pdf:2.57MB
CLADS, JAEA, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of Technology to Simultaneously Measure Viscosity and Surface Tension of Molten Materials in Reactor Core". Since (U,Zr)O
and boride, molten materials in reactor core, exist at extremely high temperature, chemical reactions between the vessel and these molten materials are unavoidable. Therefore, it is difficult to measure the thermophysical property of these materials. In the present study, droplets are produced by heating and melting the samples levitated by a gas levitation method, then the droplets are collided with a substrate. From the instant behavior of the collision, a new technology to simultaneously derive the viscosity and surface tension will be developed.
Kawamura, Shunsuke; Naoe, Takashi; Ikeda, Tsubasa*; Tanaka, Nobuatsu*; Futakawa, Masatoshi
Advanced Experimental Mechanics, 4, p.33 - 37, 2019/08
A mercury enclosure vessel made of stainless steel is used as a spallation target in the pulsed spallation neutron source at J-PARC. It is severely damaged by the cavitation induced with pressure waves in association with the pulsed proton beam injection. A double-walled structure with a narrow mercury channel was adopted in the front end of the target vessel to reduce the cavitation damage. It has been experimentally demonstrated that the cavitation damage could be mitigated in the narrow channel but its mechanism has been unclarified yet. In this study, we investigated the cavitation from growing to collapsing through visualizing the spark-induced cavitation bubbles under flow field using a high-speed video camera. Furthermore, we measured the wall vibration due to the cavitation bubble collapse with changing flow velocity parametrically. It was found that the microjet collided perpendicular to the wall in the stagnant flow condition while it collided with an inclined angle from the perpendicular direction, suggesting that the collision pressure on the wall was reduced by flowing.
Doi, Daisuke; Seino, Hiroshi; Miyahara, Shinya*; Uno, Masayoshi*
Journal of Nuclear Science and Technology, 56(6), p.521 - 532, 2019/06
Times Cited Count：1 Percentile：11.15(Nuclear Science & Technology)Date, Hidefumi*; Futakawa, Masatoshi; Ishikura, Shuichi*
Jikken Rikigaku, 2(2), p.103 - 108, 2002/06
In order to examine the impact behavior of mercury, which is one of important key-issues in a facility for high intensity neutron sources, the falling and colliding profiles of mercury droplets were recorded by high-speed video recorder. The impact force was also measured using the strain gage glued on an elastic bar. The falling mercury droplet oscillated between a prolate spheroid and an oblate one, repeatedly. The regathering and jumping of mercury at the collision point on the impact face of the target were observed after impact because of the strong surface tension of mercury. The impact force of mercury droplet was in proportion to the impact velocities and the square root of the potential energy. Scince the non-dimensional duration time K that obtained experimentally is independent of the impact velocity and the size of the droplet, the mean applied stress due to the mercury droplet against the target is easily predictable by the equatiion using K value and the impact velocity is known.
Abe, Yutaka*
JAERI-Tech 2002-011, 70 Pages, 2002/03
JAERI-Tech-2002-011.pdf:5.62MB
no abstracts in English
Ito, Kazuhiro*; Tsuji, Yoshiyuki*; Nakamura, Hideo; Kukita, Yutaka*
Fusion Technology, 37(1), p.74 - 88, 2000/01
no abstracts in English
Ito, Kazuhiro*; Tsuji, Yoshiyuki*; Nakamura, Hideo; Kukita, Yutaka*
9th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-9)(CD-ROM), 16 Pages, 1999/00
no abstracts in English
*; *; *; Tabata, Yoneho*; Seguchi, Tadao; *
Radiation Physics and Chemistry, 54(2), p.165 - 171, 1999/00
Times Cited Count：78 Percentile：97.56(Chemistry, Physical)no abstracts in English
Araki, Masanori; *
Review of Scientific Instruments, 67(1), p.178 - 184, 1996/01
Times Cited Count：4 Percentile：43.42(Instruments & Instrumentation)no abstracts in English
Nakamura, Hideo; Shibamoto, Yasuteru; Anoda, Yoshinari; Kukita, Yutaka; Mishima, Kaichiro*; Hibiki, Takashi*
Fifth World Conf. on Neutron Radiography, 0, p.665 - 672, 1996/00
no abstracts in English
Kaneko, Yoshihiko*; Yamane, Tsuyoshi; Shimakawa, Satoshi; Yamashita, Kiyonobu
Nihon Genshiryoku Gakkai-Shi, 38(11), p.907 - 911, 1996/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
4, 1994, Tokai, JapanJAERI-Conf 95-006, 207 Pages, 1995/03
no abstracts in English
Mishima, Kaichiro*; Hibiki, Takashi*; Fujine, Shigenori*; Yoneda, Kenji*; Kanda, Keiji*; Nishihara, Hideaki*; Tsuruno, Akira; Matsubayashi, Masahito; Sobajima, Makoto
Proc. of 2nd Int. Topical Meeting on Neutron Radiography System Design and Characterization, 0, p.309 - 315, 1995/00
no abstracts in English
Abe, Tetsuya; Murakami, Yoshio; *; *; *; *; Hata, Satoshi*
JAERI-M 92-092, 54 Pages, 1992/06
no abstracts in English
Chino, Masamichi; Hayashi, Takashi
Nihon Genshiryoku Gakkai-Shi, 32(8), p.799 - 802, 1990/08
Times Cited Count：1 Percentile：40.82(Nuclear Science & Technology)no abstracts in English
Yanagihara, Satoshi; ; Nakamura, Hisashi
Nuclear Technology, 86, p.159 - 167, 1989/08
Times Cited Count：3 Percentile：41.87(Nuclear Science & Technology)no abstracts in English
Nihon Genshiryoku Gakkai-Shi, 16(5), p.282 - 288, 1974/05
no abstracts in English
Japanese Journal of Applied Physics, 9(9), p.1163 - 1166, 1970/09
Times Cited Count：0no abstracts in English
