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Kato, Masato; Machida, Masahiko; Hirooka, Shun; Nakamichi, Shinya; Ikusawa, Yoshihisa; Nakamura, Hiroki; Kobayashi, Keita; Ozawa, Takayuki; Maeda, Koji; Sasaki, Shinji; et al.
Materials Science and Fuel Technologies of Uranium and Plutonium mixed Oxide, 171 Pages, 2022/10
Innovative and advanced nuclear reactors using plutonium fuel has been developed in each country. In order to develop a new nuclear fuel, irradiation tests are indispensable, and it is necessary to demonstrate the performance and safety of nuclear fuels. If we can develop a technology that accurately simulates irradiation behavior as a technology that complements the irradiation test, the cost, time, and labor involved in nuclear fuel research and development will be greatly reduced. And safety and reliability can be significantly improved through simulation of nuclear fuel irradiation behavior. In order to evaluate the performance of nuclear fuel, it is necessary to know the physical and chemical properties of the fuel at high temperatures. And it is indispensable to develop a behavior model that describes various phenomena that occur during irradiation. In previous research and development, empirical methods with fitting parameters have been used in many parts of model development. However, empirical techniques can give very different results in areas where there is no data. Therefore, the purpose of this study is to construct a scientific descriptive model that can extrapolate the basic characteristics of fuel to the composition and temperature, and to develop an irradiation behavior analysis code to which the model is applied.
Myagmarjav, O.; Iwatsuki, Jin; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Ioka, Ikuo; Kubo, Shinji; Nomura, Mikihiro*; Yamaki, Tetsuya*; Sawada, Shinichi*; et al.
International Journal of Hydrogen Energy, 44(35), p.19141 - 19152, 2019/07
Times Cited Count：16 Percentile：48.9(Chemistry, Physical)Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Yanagihara, Seiji*; Suzuki, Ryosuke*; Matsubara, Masaaki*; Enuma, Yasuhiro
Engineering Failure Analysis, 56, p.484 - 500, 2015/10
Times Cited Count：1 Percentile：11.85(Engineering, Mechanical)Watanuki, Tetsu; Kashimoto, Shiro*; Ishimasa, Tsutomu*; Machida, Akihiko; Yamamoto, Shin*; Tanaka, Yukinori*; Mizumaki, Masaichiro*; Kawamura, Naomi*; Watanabe, Shinji*
Solid State Communications, 211, p.19 - 22, 2015/06
Times Cited Count：7 Percentile：31.9(Physics, Condensed Matter)The thermal expansion of a Au-Al-Yb intermediate-valence quasicrystal has been studied by X-ray diffraction measurements. We have found anomalous thermal expansion behavior, namely zero thermal expansion below 50 K. By comparison with an isostructural Au-Al-Tm quasicrystal, the contribution of the Yb valence variation was extracted, and it was shown that its negative thermal expansion component due to the valence shift toward the divalent state by cooling compensated for the positive thermal expansion of the original lattice.
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Xu, Y.*; Tsukimori, Kazuyuki
Nuclear Engineering and Design, 269, p.88 - 96, 2014/04
Times Cited Count：12 Percentile：67.21(Nuclear Science & Technology)Wakai, Takashi; Machida, Hideo*; Arakawa, Manabu*; Yoshida, Shinji*; Enuma, Yasuhiro
Journal of Pressure Vessel Technology, 135(1), p.011401_1 - 011401_9, 2013/02
Times Cited Count：2 Percentile：13.74(Engineering, Mechanical)This was carried out to establish crack opening displacement (COD) evaluation methods used in Leak-Before-Break (LBB) assessment of sodium pipes of the Japan Sodium cooled Fast Reactor (JSFR). A COD assessment method applicable to thin walled large diameter pipe made of modified 9Cr-1Mo steel was proposed in this study. In this method, COD was calculated by classifying the components of COD; elastic, local plastic and fully plastic. In addition, the verification of this method was performed by comparing with the results of a series of four-point bending tests at elevated temperature using thin wall modified 9Cr-1Mo steel pipe containing a circumferential through wall crack. The rational leak rate evaluation method in LBB assessment was proposed.
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*
Proceedings of 2012 ASME Pressure Vessels and Piping Conference (PVP 2012) (DVD-ROM), 9 Pages, 2012/07
This paper describes the efficiency of the deployment of rotational stiffness evolution model in the critical crack size evaluation for Leak Before Break (LBB) assessment of Sodium cooled Fast Reactor (SFR) pipes. The authors have developed a critical crack size evaluation method for the thin-walled large diameter pipe made of modified 9Cr-1Mo steel. In this method, since the SFR pipe is mainly subjected to displacement controlled load caused by thermal expansion, the stress at the crack part is estimated taking stiffness evolution due to crack into account. The stiffness evolution is evaluated by using the rotational spring model. In this study, critical crack sizes for several pipes having some elbows were evaluated and discuss about the effect of the deployment of the stiffness evolution model at the crack part on critical crack size. As a result, the critical crack size increases by employing the model and LBB range may be expected to be enlarged.
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Xu, Y.*; Tsukimori, Kazuyuki
Transactions of the 21st International Conference on Structural Mechanics in Reactor Technology (SMiRT-21) (CD-ROM), 8 Pages, 2011/11
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Kawashima, Fumiko*; Kikuchi, Koichi*; Xu, Y.*; Tsukimori, Kazuyuki
Proceedings of 2011 ASME Pressure Vessels and Piping Conference (PVP 2011) (CD-ROM), 10 Pages, 2011/07
This paper describes the improved COD assessment method and verifies the validity of the method based on the results of a series of four-point bending tests at elevated temperature using thin wall modified 9Cr-1Mo steel pipe containing a circumferential through wall crack. As a result, COD values calculated by the proposed method were in a good agreement with the experimental results for the uniform pipe without weld. In the case that the crack was machined at weld metal or heat affected zone (HAZ), proposed method predicted relatively larger COD than the experimental results. The causes of such discrepancies were discussed comparing with the results of finite element analyses. Based on these examinations, the rational leak rate evaluation method in LBB assessment was proposed.
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Tokiyoshi, Takumi*; Kikuchi, Koichi*; Xu, Y.*; Tsukimori, Kazuyuki
Proceedings of 2011 ASME Pressure Vessels and Piping Conference (PVP 2011) (CD-ROM), 8 Pages, 2011/07
This paper studies the master curve to estimate the crack length when a postulated initial crack unexpectedly grows and penetrates the pipe thickness. In order to obtain the fatigue crack and creep crack growth characteristics of modified 9Cr-1Mo steel pipes, fatigue crack and creep crack growth tests were conducted using compact tension (CT) specimens and crack growth rates for both fatigue and creep at elevated temperature were obtained. Based on the obtained material characteristics and the results of a series of crack growth calculations, a relationship between the penetrated crack length and the ratio of membrane to total stress, so called as master curve, was proposed. In this study, master curves were proposed for pipes made of modified 9Cr-1Mo steel as a function of pipe geometry, i.e. the ratio of radius to thickness.
Wakai, Takashi; Machida, Hideo*; Yoshida, Shinji*; Enuma, Yasuhiro*; Asayama, Tai
Proceedings of 2010 ASME Pressure Vessels and Piping Conference (PVP 2010) (CD-ROM), 10 Pages, 2010/07
Wei, J.*; Okamoto, Hiromi*; Ochi, Shuta*; Yuri, Yosuke; Sessler, A. M.*; Machida, Shinji*
Proceedings of 10th European Particle Accelerator Conference (EPAC 2006) (CD-ROM), p.2841 - 2843, 2006/00
Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams. On the other hand, crystalline beams can only be formed at energies below the transition energy of the circular accelerators. In this paper, we investigate the formation of crystals in two types of high-transition-energy lattices, one realized by three-cell missing dipole modules and the other with negative bends. The latter type satisfies the maintenance condition for a crystalline beam.
Hotchi, Hideaki; Noda, Fumiaki*; Tani, Norio; Kishiro, Junichi*; Machida, Shinji*; Molodojentsev, A. Y.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.916 - 918, 2005/00
no abstracts in English
Saha, P. K.; Noda, Fumiaki*; Irie, Yoshiro; Hotchi, Hideaki; Takayanagi, Tomohiro; Hayashi, Naoki; Machida, Shinji*; Sakai, Izumi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.3739 - 3741, 2005/00
The RCS(rapid cycling synchrotron) of J-PARC(Japan proton accelerator research complex) acts as an injector to the main ring as well as a high-power beam for the spallation neutron source at a repetition rate of 25 Hz, where at present the injection and the extraction beam energy are chosen to be 0.181 GeV and 3.0 GeV, respectively. The present work concerns on the present design and calculations for the injection-dump line of the RCS, which includes, (1) an accurate aperture list of all elements taking into account a wide range of the betatron tune, effect of changing injection modes, multiple trajectories of different particles after the charge-exchange foil(like H0 from the H- and H- beam itself)and (2) an accurate estimation of the uncontrolled beam losses especially from the H0-excited states, multiple coulomb scattering at the charge-exchange foil and also the lorentz stripping loss at the septum magnets so as to optimize them concerning mainly the radiation issues as well as for the hands-on maintenance.
Noda, Fumiaki*; Hotchi, Hideaki; Saha, P. K.; Shobuda, Yoshihiro; Yamamoto, Kazami; Hayashi, Naoki; Kishiro, Junichi; Machida, Shinji*; Molodojentsev, A. Y.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2759 - 2761, 2005/00
no abstracts in English
Ikegami, Masanori; Machida, Shinji*; Uesugi, Tomonori*
Physical Review Special Topics; Accelerators and Beams, p.124201_1 - 124201_10, 1999/12
no abstracts in English
Machida, Shinji*; Ikegami, Masanori
Proceedings of 6th European Particle Accelerator Conference (EPAC98) (CD-ROM), p.282 - 284, 1998/01
no abstracts in English
Machida, Shinji*; Ikegami, Masanori*
Workshop on Space Charge Physics in High Intensity Hadron Rings, p.73 - 84, 1998/00
no abstracts in English
Idomura, Yasuhiro; Kano, Takuma; Ida, Masato; Tokuda, Shinji; Machida, Masahiko
no journal, ,
no abstracts in English
Wakai, Takashi; Machida, Hideo*; Arakawa, Manabu*; Yoshida, Shinji*; Enuma, Yasuhiro*; Asayama, Tai
no journal, ,
no abstracts in English
