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Kondo, Hiroo; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Wakai, Eiichi
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05
A liquid-Li free-surface stream is to serve as a beam target (Li target) for the IFMIF. As a major activity for the Li target in the IFMIF/EVEDA, the EVEDA Li test loop (ELTL) was constructed. This study focuses on cavitation-like acoustic noise in a conduit downstream of the Li target. This noise was detected by using acoustic-emission sensors. The intensity of the noise was examined versus cavitation number of the Li target. In addition, a time-frequency analysis for the acoustic signal was performed to characterize the noise. The results are as follows: (1) the intensity of the noise was increased as decreasing the cavitation number; (2) the noise was at first intermittent in a larger cavitation number, subsequently the noise became continuous as decreasing the cavitation number; (3) the noise consisted of a number of a high frequency acoustic emission which occurred in a short duration. For these results, we conclude that cavitation occurred in the downstream conduit.
Wakai, Eiichi; Ando, Masami; Okubo, Nariaki
Journal of Plasma and Fusion Research SERIES, Vol.11, p.104 - 112, 2015/03
The reduced-activation ferritic/martensitic (RAFM) steels for the fusion DEMO reactor have been developing from around the 1980s. RAFM steels are the first candidate materials for the first wall and blanket structure of fusion DEMO reactors, the target back-plate and the target assembly of IFMIF. In this study, two subjects had been examined and are summarized as below: (1) Effect of initial heat treatment on the microstructures and mechanical properties of RAFM steels, including irradiation damage, is very important to design the fusion DEMO reactors and also control the changes of mechanical properties after the irradiation. (2) Effects of He and H production on the microstructures and mechanical properties of RAFM steels, including irradiation damage, are essential in the evaluation of design of fusion DEMO reactor, and we have to check and evaluate them in Fusion irradiation environment like IFMIF.
Nakamura, Hiroo; Ida, Mizuho*; Matsuhiro, Kenjiro; Fischer, U.*; Hayashi, Takumi; Mori, Seiji*; Nakamura, Hirofumi; Nishitani, Takeo; Shimizu, Katsusuke*; Simakov, S.*; et al.
JAERI-Review 2005-005, 40 Pages, 2005/03
JAERI-Review-2005-005.pdf:3.52MB
The International Fusion Materials Irradiation Facility (IFMIF) is being jointly planned to provide an accelerator-based Deuterium-Lithium (Li) neutron source to produce intense high energy neutrons (2 MW/m
) up to 200 dpa and a sufficient irradiation volume (500 cm
) for testing the candidate materials and components up to about a full lifetime of their anticipated use in ITER and DEMO. To realize such a condition, 40 MeV deuteron beam with a current of 250 mA is injected into high speed liquid Li flow with a speed of 20 m/s. In target system, radioactive species such as 7Be, tritium and activated corrosion products are generated. In addition, back wall operates under severe conditions of neutron irradiation damage (about 50 dpa/y). In this paper, the thermal and thermal stress analyses, the accessibility evaluation of the IFMIF Li loop, and the tritium inventory and permeation of the IFMIF Li loop are summarized as JAERI activities on the IFMIF target system performed in FY2004.
range for International Fusion Materials Irradiation Facility (IFMIF)Nakamura, Hiroo; Ida, Mizuho*; Nakamura, Hideo; Takeuchi, Hiroshi; IFMIF International Team
Fusion Engineering and Design, 65(3), p.467 - 474, 2003/04
Times Cited Count：4 Percentile：31.64(Nuclear Science & Technology)IFMIF is an accelerator-based neutron source for development of fusion materials. The Li target system consists of a target assembly, a Li purification system and various diagnostics. An intense deuterium beam power up to 10 MW in a footprint of 20
5 cm corresponds to ultra high heat flux up to 1 GW/m. To handle such an ultra high heat flux, the high-speed liquid Li flow with a velocity of 20 m/s and a concave flow configuration are necessary. According to thermal-hydraulic analysis, an induced centrifugal force (160 G) under the concave back wall of a radius of 25 cm is sufficient for IFMIF operation. To confirm the hydraulic characteristics of Li flow, water jet experiment has been done. Moreover, validation experiment in Li loop is planned. In addition, to control tritium and impurities such as C, N, O below permissible levels, a cold trap and two hot traps are used. These technologies have similarities in plasma facing components in fusion reactor. In presentation, the IFMIF Li target technology and its application of to the plasma facing component will be discussed.
Nakamura, Hiroo; Burgazzi, L.*; Cevolani, S.*; Dell'Ocro, G.*; Fazio, C.*; Giusti, D.*; Horiike, Hiroshi*; Ida, Mizuho*; Kakui, Hideo*; Loginov, N.*; et al.
Journal of Nuclear Materials, 307-311(Part.2), p.1675 - 1679, 2002/12
Times Cited Count：4 Percentile：29.25(Materials Science, Multidisciplinary)This paper describes the latest design of the IFMIF liquid Li target system reflecting the KEP results. Future prospects will be also summarized. To handle an averaged heat flux of 1 GW/m2 under a continuous 10 MW D beam deposition, a high-speed Li flow of 20 m/s, a double reducer nozzle and a concaved flow are applied to the target design. Hydraulic characteristics of the Li target design have been validated in a water jet experiment. To obtain a control scenario of the Li loop in an accident of the D beam trip, a transient analysis has been done. To control tritium and impurities in Li, a cold trap and two kinds of hot trap are adopted in Li purification loop. To maintain reliable continuous operation, various diagnostics are attached to the target assembly. To exchange the target assembly and back wall, a remote handling system with a multi axis arm and welding/cutting tool are designed. As an option, design of a replaceable back wall with a mechanical seal is being in progress. In a next phase of IFMIF beyond 2004, a Li test loop will be constructed for engineering validation.
Nakamura, Hiroo; Ida, Mizuho*; Sugimoto, Masayoshi; Yutani, Toshiaki*; Takeuchi, Hiroshi
Fusion Science and Technology, 41(3), p.845 - 849, 2002/05
This paper presents the design considerations on removal and control of tritium generated in liquid lithium target of International Fusion Materials Irradiation Facility (IFMIF). In the IFMIF, intense neutrons simulating fusion condition are produced by injecting deuterium beam with a maximum energy of 40 MeV and a maxim current of 250 mA into the liquid lithium flow with a speed of 20 m/s. Tritium is produced by direct reactions of the beam with the lithium. Total production rate is estimated to be about 10 g/year.As a reference method of the tritium removal, a cold trap with a swamping method is used. As an option, yttrium getter hot trap is considered. The concentration of hydrogen isotopes in the Li flow is detected by measuring their partial gas pressure which comes through a Nb or Nb-Zr membrane. To distinguish the isotopes from the other, a quadrupole mass spectrometer is used. The off-line sampling system is also used to measure the tritium concentration in the lithium.
IFMIF International Team
JAERI-Tech 2002-022, 97 Pages, 2002/03
JAERI-Tech-2002-022.pdf:9.17MB
Activities of International Fusion Materials Irradiation Facility (IFMIF) have been performed under an IEA collaboration since 1995. IFMIF is an accelerator- based deuteron (D+)-lithium (Li) neutron source designed to produce an intense neutron field (2 MW/m, 20 dpa/year for Fe) in a volume of 500 cm for testing candidate fusion materials. In 2000, a 3year Key Element technology Phase (KEP) of IFMIF was started to reduce the key technology risk factors. This interim report summarizes the KEP activities until mid 2001 in the major project work-breakdown areas of accelerator, target, test cell and design integration.
Nakamura, Hideo; Ito, Kazuhiro*; Kukita, Yutaka*; *; ; Maekawa, Hiroshi; Katsuta, Hiroji
Journal of Nuclear Materials, 258-263, p.440 - 445, 1998/00
Times Cited Count：7 Percentile：53.8(Materials Science, Multidisciplinary)no abstracts in English
Nakamura, Hideo; *; Kukita, Yutaka*; *; ; Maekawa, Hiroshi
Eighth Int. Topical Meeting on Nuclear Reactor Thermal-Hydraulics (NURETH-8), 3, p.1268 - 1275, 1997/00
no abstracts in English
Shinohara, Nobuo; *
Nuclear Instruments and Methods in Physics Research A, 362, p.114 - 116, 1995/00
Times Cited Count：0 Percentile：0.01(Instruments & Instrumentation)no abstracts in English
Kondo, Tatsuo; Ono, Hideo; R.A.Jameson*; J.A.Hassberger*
Fusion Engineering and Design, 22, p.117 - 127, 1993/00
Times Cited Count：6 Percentile：55.97(Nuclear Science & Technology)no abstracts in English
; Watanabe, Katsutoshi; Kondo, Tatsuo
Journal of Nuclear Materials, 191-194, p.1428 - 1431, 1992/00
Times Cited Count：3 Percentile：35.32(Materials Science, Multidisciplinary)no abstracts in English
