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Yamashiki, Yosuke*; Maehara, Hiroyuki*; Airapetian, V.*; Notsu, Yuta*; Sato, Tatsuhiko; Notsu, Shota*; Kuroki, Ryusuke*; Murashima, Keiya*; Sato, Hiroaki*; Namekata, Kosuke*; et al.
Astrophysical Journal, 881(2), p.114_1 - 114_24, 2019/08
Times Cited Count：31 Percentile：83.73(Astronomy & Astrophysics)The impact of Stellar flares on extrasolar planetary systems has been discussed and argued, especially whether there is a potential impact on their life systems. Here, we propose a comprehensive evaluation system for stellar flares, focusing on Stellar Proton Events (SPE) on selected extrasolar planets with hypothetical atmospheres and oceans. This is done by cross-linking KIC flare-observed and flare-estimated stars by their start pots that are directly linked with the Monte Carlo simulation system PHITS through the exoplanetary database system ExoKyoto. The estimated dose at ground level for each planetary surface did not exceed the critical dose for complex animals.
Muta, Hiroaki*; Nishikane, Ryoji*; Ando, Yusuke*; Matsunaga, Junji*; Sakamoto, Kan*; Harjo, S.; Kawasaki, Takuro; Oishi, Yuji*; Kurosaki, Ken*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 500, p.145 - 152, 2018/03
Times Cited Count：12 Percentile：77.27(Materials Science, Multidisciplinary)Ohashi, Yusuke; Harada, Masayuki*; Asanuma, Noriko*; Ando, Shion; Tanaka, Yoshio; Ikeda, Yasuhisa*
Journal of Radioanalytical and Nuclear Chemistry, 311(1), p.491 - 502, 2017/01
Times Cited Count：1 Percentile：10.62(Chemistry, Analytical)In order to assess the feasibility of method for recovering U from wastes containing uranium (scrap uranium) using polyvinylpolypyrrolidone (PVPP) adsorbent, we have examined the adsorption and desorption behavior of metal species in HCl aqueous solutions dissolving scrap uranium. It was found that the U(VI) species are selectively adsorbed onto PVPP regardless of the presence of a large amount of Na(I) and Al(III), that the adsorbed U(VI) species are desorbed from PVPP column selectively by water. Pure uranium was efficiently recovered from the eluates. From these results, the PVPP resin is expected to be used as the adsorbent in the treatment process of scrap uranium.
ZrPaul, N.*; Corsi, A.*; Obertelli, A.*; Doornenbal, P.*; Authelet, G.*; Baba, Hidetada*; Bally, B.*; Bender, M.*; Calvet, D.*; Ch
teau, F.*; et al.
Physical Review Letters, 118(3), p.032501_1 - 032501_7, 2017/01
Times Cited Count：43 Percentile：88.64(Physics, Multidisciplinary)Ohashi, Yusuke; Nomura, Mitsuo; Tsunashima, Yasumichi; Ando, Shion; Sugitsue, Noritake; Ikeda, Yasuhisa*; Tanaka, Yoshio
Journal of Nuclear Science and Technology, 51(2), p.251 - 265, 2014/02
Times Cited Count：9 Percentile：53.31(Nuclear Science & Technology)Sludge-like uranium-bearing wastes generated from uranium refining and conversion R&D facilities are stored at the Ningyo-toge Environmental Engineering Center. We have proposed an aqueous process for recovering uranium from spent filter aid and CaF
precipitate using hydrochloric acid. The distributions of the dissolved species in the sample solutions at different pH levels were calculated using the chemical equilibrium modeling system. Calculated results of fluorine contents of recovered uranium were compared with the experimental results. The fluorine content in the recovered uranium decreased as the aluminum concentration of the solution increased. On the other hand, uranium of spent filter aid was recovered selectively. The size of the particles of recovered uranium tends to decrease with increasing pH in the precipitation treatments. Also, the uranium concentration of the precipitate generated by the neutralization of the barren solution falls below 1 Bq/g.
Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.
JAEA-Research 2010-019, 194 Pages, 2010/08
JAEA-Research-2010-019-01.pdf:48.47MBJAEA-Research-2010-019-02.pdf:19.4MB
This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m
. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Kawashima, Hisato; Kurita, Genichi; Tanigawa, Hiroyasu; Nakamura, Hirofumi; Honda, Mitsuru; Saito, Ai*; Sato, Satoshi; et al.
Nuclear Fusion, 49(7), p.075029_1 - 075029_10, 2009/07
Times Cited Count：137 Percentile：97.72(Physics, Fluids & Plasmas)Recent design study on SlimCS focused mainly on the torus configuration including blanket, divertor, materials and maintenance scheme. For vertical stability of elongated plasma and high beta access, a sector-wide conducting shell is arranged in between replaceable and permanent blanket. The reactor adopts pressurized-water-cooled solid breeding blanket. Compared with the previous advanced concept with supercritical water, the design options satisfying tritium self-sufficiency are relatively scarce. Considered divertor technology and materials, an allowable heat load to the divertor plate should be 8 MW/m or lower, which can be a critical constraint for determining a handling power of DEMO (a combination of alpha heating power and external input power for current drive).
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Sato, Masayasu; Isono, Takaaki; Sakurai, Shinji; Nakamura, Hirofumi; Sato, Satoshi; Suzuki, Satoshi; Ando, Masami; et al.
Fusion Engineering and Design, 81(8-14), p.1151 - 1158, 2006/02
Times Cited Count：123 Percentile：99.01(Nuclear Science & Technology)no abstracts in English
Takahashi, Hiroyuki*; Kudo, Yusuke; Tsuchiya, Katsuhiko; Kizu, Kaname; Ando, Toshinari*; Matsukawa, Makoto; Tamai, Hiroshi; Miura, Yukitoshi
Fusion Engineering and Design, 81(8-14), p.1005 - 1011, 2006/02
Times Cited Count：2 Percentile：17.18(Nuclear Science & Technology)This paper presents dependence of the stress intensity factor, around the defect in the butt joint welding of a superconducting conductor conduit, on a geometrical factor estimated by fracture mechanics analysis. The stress intensity factor can be estimated by the Newman-Raju equation about CICC section, but the effect of the difference between the geometry assumed in the equation and CICC has not been clarified yet. Therefore, the three-dimensional finite element method (3D-FEM) is performed to estimate the geometrical factor. As a result, the Newman-Raju equation is considered to be available for the assessment of the fracture toughness of the conduit of rectangular shape because the maximum stress intensity factor by 3-D FEM is only 3% larger than that by the Newman-Raju equation in the maximum postulated defect.
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
no abstracts in English
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
Times Cited Count：7 Percentile：22.95(Physics, Fluids & Plasmas)no abstracts in English
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-
. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Ohashi, Yusuke; Ando, Shion; Tsunashima, Yasumichi; Harada, Masayuki*; Ikeda, Yasuhisa*; Asanuma, Noriko*
no journal, ,
Sludge like uranium bearing waste and adsorbent were dissolved using hydrochloric acid. Uranium in the solution is recovered using PVPP. Recovered uranium was desorbed from PVPP using pure water and then uranium was recovered as uranium peroxide. As a result, it was confirmed that highly pure uranium was recovered.
Ohashi, Yusuke; Tsunashima, Yasumichi; Murashita, Shinji; Ando, Shion; Tanaka, Yoshio; Ikeda, Yasuhisa*
no journal, ,
The sludge - like uranium generated by neutralization of the acid water used for decontamination of metal wastes contains much iron. We have examined the aqueous method for recovering uranium from sludge - like uranium containing iron using N-cyclohexyl-2-pyrrolidone (NCP). Precipitation ratio of uranium in the solution prepared by dissolving sludge - like uranium containing iron using HNO
increases as additive amount of NCP increases and it became 97%. The precipitation ratio of iron, aluminum, fluorine and sulfate are less than 1% at all additive amounts of NCP investigated, which indicates that uranium can be selectively recovered by NCP.
