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Yoshikawa, Akira; Tanigawa, Hisashi; Seki, Yohji; Hirose, Takanori; Tsuru, Daigo; Ezato, Koichiro; Yokoyama, Kenji; Nishi, Hiroshi; Suzuki, Satoshi; Tanzawa, Sadamitsu; et al.
JAEA-Technology 2009-077, 23 Pages, 2010/03
JAEA-Technology-2009-077.pdf:2.62MB
In the side wall of TBM, parallel flow channels are considered. In the cooling channels structure, the flow distribution probably arises from the pressure drop in the channels. The purpose of this study is to clarify the water flow distribution in the side wall and design the cooling channels structure so that structural material of the side wall can be kept under the allowable temperature. The structural material for assumed flow rates and the flow distribution were estimated, and then the cooling channels structure was designed. The design was verified using the mockup made of the vinyl chloride pipe. For the verified design, the mockup made of F82H is manufactured, and the water flow distribution and the pressure drop were measured. It was found that the heat removal capability was sufficient in this design. From these results, the design for the cooling channels structure in the side wall is established so that enough water flow to cool the structural material is kept.
Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu
Nuclear Reactors, Nuclear Fusion and Fusion Engineering, p.367 - 403, 2009/09
In recent large tokamak machines, the vacuum leak detection technology is highly important due to mainly a safety reason. However, such machines are huge, complicated, and inaccessible, so the conventional 
He leak detection method is not applicable in many cases. In this chapter, the essential technologies developed in JAEA are exhibited. The high-resolution quadrupole mass spectrometer (HR-QMS) has been developed, where 10
of the He
/D
peak ratio could be obtained. An improved method with fully circulating the water has been demonstrated, where krypton (Kr) was dissolved in water. For 10
Pa-m
/s of two water leaks, the positional accuracy of 12.6% was obtained. Another valuable method has been developed, namely, a unidirectional in-vacuum movable total pressure gauge could detect the minimum 10
Pa-m/s level of air leaks. A special in-vacuum movable QMS head could detect the argon (Ar) leak of 1.9
10
Pa-m/s.
Tanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya; Shimizu, Katsusuke*; Inoue, Masahiko*; Watanabe, Mitsunori*; Iguchi, Masashi*; Sugimoto, Tomoko*; Inohara, Takashi*; Nakamura, Junichi*
JAEA-Technology 2008-076, 99 Pages, 2008/12
JAEA-Technology-2008-076.pdf:35.19MB
The primary vacuum pumping system of the International Thermonuclear Experimental Reactor (ITER) exhausts a helium (He) ash resulting from the DT-burn with excess DT fueling gas, as well as performing a variety of functions such as pump-down, leak testing and wall conditioning. A mechanical based vacuum pumping system has some merits of a continuous pumping, a much lower tritium inventory, a lower operational cost and easy maintenance, comparing with a cryopump system, although demerits of an indispensable magnetic shield and insufficient performance for hydrogen (H) pumping are well recognized. To overcome the demerits, we newly fabricated and tested a helical grooved pump (HGP) unit suitable for H pumping at the ITER divertor pressure of 0.1-10 Pa. Through this R&D, we successfully established many design and manufacturing databases of large HGP units for the lightweight gas pumping. Based on the databases, we conceptually designed the ITER vacuum pumping system mainly comprising the HGP with an optimal pump unit layout and a magnetic shield. We also designed conceptually the reduced cost (RC)-ITER pumping system, where a compound molecular pump combining turbine bladed rotors and helical grooved ones was mainly used. The ITER mechanical based primary pumping system proposed has eventually been a back-up solution, whereas a cryopump based one was formally selected to the ITER for construction.
Seki, Yohji; Tanigawa, Hisashi; Tsuru, Daigo; Enoeda, Mikio; Akiba, Masato; Ezato, Koichiro; Tanzawa, Sadamitsu; Nishi, Hiroshi; Hirose, Takanori; Homma, Takashi; et al.
JAEA-Technology 2007-067, 34 Pages, 2008/01
JAEA-Technology-2007-067.pdf:14.41MBJAEA-Technology-2007-067(errata).pdf:0.08MB
This report is result of one-dimensional nuclear and thermal analyses on Test Blanket Module (TBM) for ITER emphasizing on optimized layer structures of a ceramic tritium breeder (
) and a beryllium neutron multiplier 
. Taking into account increment of Tritium Breeding Ratio (TBR), the radial widths of the breeder and multiplier layers are optimized. The main results of our study are as follows: (1) In multilayered structures of pebble beds, the peak of the TBR exists within the range of the volume ratio 
(2) In the case of the single packing, the R stayed in the range of 
by setting the two layers of Be behind a layer of . This database of TBR for optimized layer structures contributes to the estimation of TBR at the design stage of the TBM and demonstration blanket.
Hiroki, Seiji; Tanzawa, Sadamitsu; Arai, Takashi; Abe, Tetsuya
Fusion Engineering and Design, 83(1), p.72 - 78, 2008/01
Times Cited Count：6 Percentile：39.22(Nuclear Science & Technology)A water leak detection method using krypton as a water soluble tracer has been proposed for fusion reactors with fully circulating the in-vessel cooling water. This method is targeted for applying to the ITER. The water leaks are effused into the vacuum vessel evacuated with a cryopump and the water dissolved Kr is detected with a quadrupole mass spectrometer. When two leak valves with 1 m distance are attached to the test pipe with 30 
C heating, two distinct 
/
= 84 peak current rises caused by the water leak are successfully detected with the time interval of 39 sec. On the other hand, the water accession length as a function of the traveling time is calculated by considering a natural convection flow caused by the 30 C heating, where the traveling time is 44.6 sec for the 1 m length. This means that the observed positional accuracy is 12.6%, based on the calculation. This method can be applied to the ITER condition.
/He mixed gas under room temperatureTanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya
Shinku, 46(3), p.154 - 157, 2003/03
no abstracts in English
Tanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya; Futatsuki, Takashi*; Tajima, Yoshinori*
Shinku, 46(1), p.44 - 48, 2003/01
no abstracts in English
Abe, Tetsuya; Kanari, Moriyasu; Tanzawa, Sadamitsu; Hiroki, Seiji
JAERI-Tech 2002-093, 17 Pages, 2002/12
JAERI-Tech-2002-093.pdf:3.04MB
no abstracts in English
Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Junichi*; Obayashi, Tetsuro*
JAERI-Tech 2002-056, 11 Pages, 2002/07
JAERI-Tech-2002-056.pdf:0.79MB
no abstracts in English
Kanari, Moriyasu; Abe, Tetsuya; Kosaku, Yasuo; Tanzawa, Sadamitsu; Hiroki, Seiji
Nihon Genshiryoku Gakkai-Shi, 43(12), p.1228 - 1234, 2001/12
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
/He mixture gasTanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya; Inohara, Takashi*
Shinku, 44(7), p.667 - 670, 2001/07
no abstracts in English
Abe, Tetsuya; Hiroki, Seiji; Tanzawa, Sadamitsu; Kosaku, Yasuo; Takauchi, Hisao*; Yamakawa, Akira*
JAERI-Research 2001-029, 13 Pages, 2001/05
JAERI-Research-2001-029.pdf:3.39MB
no abstracts in English
Hiroki, Seiji; Tanzawa, Sadamitsu; Arai, Takashi; Abe, Tetsuya; Shimizu, Katsusuke*; Nakatani, Junnosuke*; Kuribayashi, Shizuma*
Shinku, 44(3), P. 329, 2001/03
no abstracts in English
Kanari, Moriyasu*; Abe, Tetsuya; Tanzawa, Sadamitsu; Shimizu, Katsusuke*; ;
JAERI-Research 99-012, 21 Pages, 1999/02
JAERI-Research-99-012.pdf:2.26MB
no abstracts in English
Fuketa, Toyoshi; Sasajima, Hideo; ; ; Tanzawa, Sadamitsu; Ishijima, Kiyomi; ; ;
JAERI-Research 95-078, 194 Pages, 1995/11
JAERI-Research-95-078.pdf:17.91MB
no abstracts in English
Fuketa, Toyoshi; ; Sasajima, Hideo; ; Tanzawa, Sadamitsu; Ishijima, Kiyomi; ; Kikuchi, Teruo;
JAERI-Research 95-013, 230 Pages, 1995/03
JAERI-Research-95-013.pdf:24.22MB
no abstracts in English
Fuketa, Toyoshi; Ishijima, Kiyomi; Tanzawa, Sadamitsu; Nakamura, Takehiko; Sasajima, Hideo; Kashima, Yoichi; ;
JAERI-Research 95-005, 53 Pages, 1995/01
JAERI-Research-95-005.pdf:1.96MB
no abstracts in English
Fuketa, Toyoshi; Sasajima, Hideo; ; ; Tanzawa, Sadamitsu; Ishijima, Kiyomi; ; ; Kikuchi, Teruo;
JAERI-Research 94-006, 96 Pages, 1994/07
JAERI-Research-94-006.pdf:6.19MB
no abstracts in English
Tanzawa, Sadamitsu; ;
Journal of Nuclear Science and Technology, 30(4), p.281 - 290, 1993/04
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
Tanzawa, Sadamitsu
JAERI-M 93-011, 32 Pages, 1993/02
no abstracts in English
