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Kanai, Akihiko*; Kasada, Ryuta*; Nakajima, Motoki; Hirose, Takanori; Tanigawa, Hisashi; Enoeda, Mikio; Konishi, Satoshi*
Journal of Nuclear Materials, 455(1-3), p.431 - 435, 2014/12
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)Kanai, Akihiko*; Park, C.*; Noborio, Kazuyuki*; Kasada, Ryuta*; Konishi, Satoshi*; Hirose, Takanori; Nozawa, Takashi; Tanigawa, Hiroyasu
Fusion Engineering and Design, 89(7-8), p.1653 - 1657, 2014/10
Times Cited Count：4 Percentile：31.54(Nuclear Science & Technology)Konishi, Satoshi*; Enoeda, Mikio
Purazuma, Kaku Yugo Gakkai-Shi, 90(6), p.332 - 337, 2014/06
Test Blanket Module (TBM) program is to evaluate important functions of prototypical modules of DEMO breeding blankets in the real DT fusion plasma environment of ITER. Therefore, it is regarded as one of the most important milestones toward DEMO blanket. Japan is proposing a Water Cooled Ceramic Breeder (WCCB) TBM as the primary option of TBM program. Japan Atomic Energy Agency (JAEA) is performing the development of the WCCB blanket as the candidate breeding blanket of Japan, with a collaboration of universities and National Institute for Fusion Science (NIFS). Regarding the TBM development, the engineering R and Ds are ongoing, aiming at the demonstration of fabrication technology and structural integrity of the full size mockup of the WCCB TBM. Regarding the test blanket module fabrication technology development, the real scale back wall mockup was successfully fabricated. Also, the design activities are being performed to show the soundness under various loading conditions of electromagnetic force and thermo-mechanical loading. The evaluation of shutdown dose rate behind the TBM test port is also carried out as one of most important design requirement. Furthermore, key technologies toward DEMO blanket, such as, the development of advanced breeder and multiplier pebbles for DEMO blanket, fabrication technology development of Li rich Li
TiO
pebble and BeTi pebble was performed.
Sumita, Junya; Shibata, Taiju; Fujita, Ichiro*; Kunimoto, Eiji*; Yamaji, Masatoshi*; Eto, Motokuni*; Konishi, Takashi*; Sawa, Kazuhiro
Nuclear Engineering and Design, 271, p.314 - 317, 2014/05
Times Cited Count：11 Percentile：65.32(Nuclear Science & Technology)In this study, in order to develop evaluation method for material properties and to evaluate the irradiation-induced property changes under higher neutron doses for IG-430, the oxidation and densification effects on elastic modulus of IG-430 were investigated. Moreover, the correlation of the microstructure based on the X-ray tomography images and the material properties was discussed. It was shown that the elastic modulus of the densified graphite depends on only the closed pores and it is possible to evaluate the material properties of graphite by using X-ray tomography method. However, it is necessary to take into account of the change in the number and shape of closed pores in the grain to simulate the elastic modulus of the highly oxidized and irradiated materials by the homogenization analysis.
Kwon, S.*; Sato, Satoshi; Kasada, Ryuta*; Konishi, Satoshi*
Fusion Science and Technology, 64(3), p.599 - 603, 2013/09
Times Cited Count：2 Percentile：18.91(Nuclear Science & Technology)Tritium production/breeding behavior in LiPb blanket module was evaluated by neutron transport code MCNP with nuclear cross-section data from FENDL-2.1 libraries. The calculation results were suggested that the sufficient TBR can be obtained in the SiC-LiPb blanket concept. A proper integral experiment on LiPb with DT neutrons in a small test module was evaluated. Also, tritium breeding ratio, tritium production ratio, proper neutron shielding material and nuclear heating in the module were evaluated. With the results of TPR and actual neutron generation devices, we have proposed the plan of the integral experiment and measurable tritium amount.
Fujita, Ichiro*; Eto, Motokuni*; Osaki, Hirotaka; Shibata, Taiju; Sumita, Junya; Konishi, Takashi; Yamaji, Masatoshi; Kunimoto, Eiji
JAEA-Research 2013-004, 20 Pages, 2013/07
JAEA-Research-2013-004.pdf:2.4MB
Graphite components in HTGR and VHTR may be oxidized by impurities in coolant helium-gas even at normal operation, as well as by air at air-ingress accident. In this study, by air-oxidation test at 520-900
C, oxidation characteristics of IG-110 and IG-430 graphites, and associated decrease in compressive strength were examined. The following results were obtained. (1) The activation energy of the air-oxidation for IG-430 is 176 kJ/mol being almost same as for IG-110, though the oxidation rate for IG-430 is less than a half of that for IG-110. (2) There are correlations between density change and decrease in compressive strength. Decrease in strength is the largest in case that the oxidation temperature is lower than 600 C where the homogenous oxidation occurs. (3) In the process of oxidation, amorphous binder regions are predominantly oxidized. It suggests that peeling-off of cokes grains is necessary to be considered for oxidation weight loss, as well as gasification.
Sumita, Junya; Shibata, Taiju; Fujita, Ichiro*; Kunimoto, Eiji*; Yamaji, Masatoshi*; Eto, Motokuni*; Konishi, Takashi*; Sawa, Kazuhiro
Proceedings of 6th International Topical Meeting on High Temperature Reactor Technology (HTR 2012) (USB Flash Drive), 6 Pages, 2012/10
In this study, in order to develop evaluation method for material properties and to evaluate the irradiation-induced property changes under higher neutron doses for IG-430, the oxidation and densification effects on elastic modulus of IG-430 were investigated. Moreover, the correlation of the microstructure based on the X-ray tomography images and the material properties was discussed. It was shown that the elastic modulus of the densified graphite depends on only the closed pores and it is possible to evaluate the material properties of graphite by using X-ray tomography method. However, it is necessary to take into account of the change in the number and shape of closed pores in the grain to simulate the elastic modulus of the highly oxidized and irradiated materials by the homogenization analysis.
Sumita, Junya; Shibata, Taiju; Kunimoto, Eiji*; Yamaji, Masatoshi*; Konishi, Takashi*; Sawa, Kazuhiro
IOP Conference Series; Materials Science and Engineering, 18(16), p.162012_1 - 162012_4, 2011/09
Times Cited Count：1 Percentile：53.4For control rod element of Very High Temperature Reactor, carbon fiber reinforced carbon matrix composite (C/C composite) is one of the major candidate materials for its high strength and thermal stability. The development of a property prediction model of the two-dimensional (2D)-C/C composite is one of the most important subjects for the design methodology for control rod. Since the property of the 2D-C/C composite is strongly dependent on its microstructure, fiber/matrix, it would be possible to evaluate the properties of the 2D-C/C composite from its microstructure. In this study, in order to develop the property prediction model of the 2D-C/C composite base on its microstructure, pore distribution was investigated by using the X-ray computed tomography (X-ray CT) images and developed image based voxcel model. The compressive strength of the 2D-C/C composite was measured and evaluated by the voxcel model. This study shows that the pore distribution in the 2D-C/C composite can be confirmed visually and the volume and shape of the pores can be estimated from X-ray CT images. It is also shown that evaluation of the compressive strength by using the voxel model is useful to simulate the trend of the stress distribution of the 2D-C/C composite. However, it is necessary to characterize the property of the 2D-C/C composite and to set up the appropriate mesh to simulate the absolute stress value precisely.
Isobe, Kanetsugu; Yamanishi, Toshihiko; Konishi, Satoshi*
Fusion Engineering and Design, 85(7-9), p.1012 - 1015, 2010/12
Times Cited Count：9 Percentile：53.38(Nuclear Science & Technology)The measurement of tritium permeation behavior of NITE-SiC/SiC composites in both low tritium partial pressure and tritium diluted with hydrogen was carried out. Steady-state tritium permeation fluxes of NITE-SiC/SiC that has low permeability of hydrogen could be measured successfully by using tritium, even though low partial pressure (0.6 Pa). Steady-state tritium permeation fluxes were estimated to be 9.5
10
[mol/m
sec]. In the experiment of tritium diluted with hydrogen, it was found that steady-states permeation fluxes was decreased with the increase of distillation rate, although the partial pressure of tritium in all condition was same (0.6 Pa).
Sumita, Junya; Shibata, Taiju; Kunimoto, Eiji*; Yamaji, Masatoshi*; Konishi, Takashi*; Sawa, Kazuhiro
Journal of Nuclear Science and Technology, 47(4), p.411 - 420, 2010/04
Times Cited Count：4 Percentile：30.83(Nuclear Science & Technology)Two dimensional carbon fiber reinforced carbon composite (2D-C/C composite) is one of the candidate materials for a reactor internals, e.g. control rod element, of Very High Temperature Reactor (VHTR) because of its high strength at high temperature and thermal stability. From the viewpoint of its application to the reactor internals of VHTR, it is important to investigate the anisotropy effect on its properties for the design and safety analysis of VHTR. Moreover, the property of 2D-C/C composite is strongly related to its microstructure, therefore, it is necessary to observe the internal microstructure to investigate the relationship between the microstructural change and the property change. This study has shown that the X-ray tomography could be applied to observe the microstructural change of thermally 2D-C/C composite. The relationship between the thermal conductivity and the coefficient of thermal expansion (CTE) change and burn-off of thermally oxidized 2D-C/C composite could be expressed by the empirical exponential decay formula in both directions perpendicular and parallel to lamina. It could be explained the direction of hexagonal graphite crystal structure from carbon atoms and microstructural change of 2D-C/C composite.
Kobayashi, Yasuhiko; Funayama, Tomoo; Hamada, Nobuyuki*; Sakashita, Tetsuya; Konishi, Teruaki*; Imaseki, Hitoshi*; Yasuda, Keisuke*; Hatashita, Masanori*; Takagi, Keiichi*; Hatori, Satoshi*; et al.
Journal of Radiation Research, 50(Suppl.A), p.A29 - A47, 2009/03
Times Cited Count：37 Percentile：72.38(Biology)Konishi, Satoshi*; Glugla, M.*; Hayashi, Takumi
Fusion Engineering and Design, 83(7-9), p.954 - 958, 2008/12
Times Cited Count：16 Percentile：71.21(Nuclear Science & Technology)Ushigusa, Kenkichi; Seki, Masahiro; Ninomiya, Hiromasa; Norimatsu, Takayoshi*; Kamada, Yutaka; Mori, Masahiro; Okuno, Kiyoshi; Shibanuma, Kiyoshi; Inoue, Takashi; Sakamoto, Keishi; et al.
Genshiryoku Handobukku, p.906 - 1029, 2007/11
no abstracts in English
Yamamoto, Yoshihiko*; Yamanishi, Toshihiko; Kawamura, Yoshinori; Isobe, Kanetsugu; Yamamoto, Yasushi*; Konishi, Satoshi*
Fusion Science and Technology, 52(3), p.692 - 695, 2007/10
Times Cited Count：1 Percentile：11.4(Nuclear Science & Technology)A solid electrolyte (ionic conductor) cell has been developed for measurement and control of hydrogen and oxygen density in liquid metal blanket with LiPb. The ceramic tubes of the SrCe
Yb
O
(proton conductor) and Yttria Stabilized Zirconia (oxygen ion conductor) that can be used at operating temperature of LiPb blanket have been utilized for electrolytes of the devices, which enable the continuous measurement of respectively hydrogen and oxygen in liquid LiPb. Fundamental electrochemical data such as EMF for a partial pressure and ion conductivity were measured, and the results were used to evaluate the feasibility of these devices.
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
Isobe, Kanetsugu; Nakamura, Hirofumi; Kaminaga, Atsushi; Tsuzuki, Kazuhiro; Higashijima, Satoru; Nishi, Masataka; Kobayashi, Yasunori*; Konishi, Satoshi*
Fusion Engineering and Design, 81(1-7), p.827 - 832, 2006/02
Times Cited Count：11 Percentile：60.62(Nuclear Science & Technology)Exhaust gas from JT-60U during experimental operation has been measured with Gas Chromatography (GC), and the gas exhaust characteristic from JT-60U on plasma discharge conditions has been investigated during the JT-60U experimental campaign in 2003-2004. During experimental operation of JT-60U, hydrogen isotope concentration strongly depended on the type of discharges such as high performance, long pulse and so on. On the other hand, impurity species, such as helium, hydrocarbon and carbon oxide, were detected during plasma discharges occasionally. During the experimental operation, plasma disruption remarkably tended to produce high concentration impurities. Glow discharge and Taylor discharge for wall conditioning also produced impurities. In the case of normal plasma, impurity was detected and high performance plasma, such as high 
plasma, tended to produce high concentration impurities. This result indicated that impurities concentration might be higher in the case of normal plasma in ITER, because of its high performance.
Enoeda, Mikio; Akiba, Masato; Tanaka, Satoru*; Shimizu, Akihiko*; Hasegawa, Akira*; Konishi, Satoshi*; Kimura, Akihiko*; Koyama, Akira*; Sagara, Akio*; Muroga, Takeo*
Fusion Engineering and Design, 81(1-7), p.415 - 424, 2006/02
Times Cited Count：62 Percentile：96.5(Nuclear Science & Technology)no abstracts in English
Takatsu, Hideyuki; Konishi, Satoshi*
Purazuma, Kaku Yugo Gakkai-Shi, 81(11), p.837 - 902, 2005/11
Technology research and development issues, other than Breeding Blankets and Structural Materials, nesessary to be developed toward a fusion DEMO plant are introduced. Taking five critical technologies (Divertor, Superconducting Magnets, Tritium System, Heating and Current Drive system and Remote Maintenance System), target specifications and current status of technology research and development are outlined.
Tobita, Kenji; Konishi, Satoshi*; Tokimatsu, Koji*; Nishio, Satoshi; Hiwatari, Ryoji*
Purazuma, Kaku Yugo Gakkai-Shi, 81(11), p.875 - 891, 2005/11
no abstracts in English
Isobe, Kanetsugu; Nakamura, Hirofumi; Kaminaga, Atsushi; Higashijima, Satoru; Nishi, Masataka; Konishi, Satoshi*; Nishikawa, Masabumi*; Tanabe, Tetsuo*
Fusion Science and Technology, 48(1), p.302 - 305, 2005/07
Times Cited Count：5 Percentile：36.02(Nuclear Science & Technology)no abstracts in English
