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CoSiYamauchi, Hiroki; Sari, D. P.*; Yasui, Yukio*; Sakakura, Terutoshi*; Kimura, Hiroyuki*; Nakao, Akiko*; Ohara, Takashi; Honda, Takashi*; Kodama, Katsuaki; Igawa, Naoki; et al.
Physical Review Research (Internet), 6(1), p.013144_1 - 013144_9, 2024/02
Kamide, Hideki; Shibata, Taiju
NREL/TP-6A50-77088 (Internet), p.35 - 38, 2020/09
Watanabe, So; Sano, Yuichi; Okada, Makoto*; Matsuura, Haruaki*; Hagura, Naoto*; Kada, Wataru*
Nuclear Instruments and Methods in Physics Research B, 477, p.60 - 65, 2020/08
Times Cited Count：4 Percentile：38.59(Instruments & Instrumentation)IBIL and EXAFS analyses were applied on strucutral analysis of Eu complex formed in adsorbent developed for extraction chromatography. Those analyses revealed slight structural difference between adsorbent and solvent systems.
Goto, Minoru; Okumura, Keisuke; Nakagawa, Shigeaki; Inaba, Yoshitomo; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Katayama, Kazunari*
Fusion Engineering and Design, 136(Part A), p.357 - 361, 2018/11
Times Cited Count：7 Percentile：53.34(Nuclear Science & Technology)A High Temperature Gas-cooled Reactor (HTGR) is proposed as a tritium production device, which has the potential to produce a large amount of tritium using 
Li(n,
)T reaction. In the HTGR design, generally, boron is loaded into the core as a burnable poison to suppress excess reactivity. In this study, lithium is loaded into the HTGR core instead of boron and is used as a burnable poison aiming to produce thermal energy and tritium simultaneously. The nuclear characteristics and the fuel temperature were calculated to confirm the feasibility of the lithium-loaded HTGR. It was shown that the calculation results satisfied the design requirements and hence the feasibility was confirmed for the lithium-loaded HTGR, which produce thermal energy and tritium.
Kubo, Katsunori; Hotta, Takashi
Journal of the Physical Society of Japan, 75(1), p.013702_1 - 013702_4, 2006/01
Times Cited Count：12 Percentile：57.79(Physics, Multidisciplinary)Effects of orbital degeneracy on magnetic susceptibility in paramagnetic phases are investigated within a mean-field theory. Under certain crystalline electric fields, the magnetic moment consists of two independent moments, e.g., spin and orbital moments. In such a case, the magnetic susceptibility is given by the sum of two different Curie-Weiss relations, leading to the deviation from the Curie-Weiss law. Such behavior may be observed in 
- and 
-electron systems with 
and 
ground states, respectively. As a potential application of our theory, we attempt to explain the difference in the temperature dependence of magnetic susceptibilities of UO
and NpO. Then, we find that the difference in the temperature dependence can be naturally explained by considering the effects of the octupole moments in NpO.
Nakamura, Hiroo; Takemura, Morio*; Yamauchi, Michinori*; Fischer, U.*; Ida, Mizuho*; Mori, Seiji*; Nishitani, Takeo; Simakov, S.*; Sugimoto, Masayoshi
Fusion Engineering and Design, 75-79, p.1169 - 1172, 2005/11
Times Cited Count：6 Percentile：39.75(Nuclear Science & Technology)In the IFMIF, activated erosion/corrosion materials of Li target back wall deposits on a surface of the Li loop. Therefore, accessibility during maintenance of the Li loop pipings will depend on the activation level of the deposition materials. This paper evaluates effect of target activation on the accessibility of the Li loop pipings. Activation level is calculated by the ACT-4 code. High energy cross section above 15 MeV is introduced using IEAF-2001 data. In this calculation, target material is stainless steel 316. Area of the erosion/corrosion in the back wall is 100 cm
. The erosion/corrosion rate is 1 micron/y. Dose rate around the Li loop after one year IFMIF operation is evaluated assuming 1% deposition of the erosion/corrosion materials and uniform deposition on surface area of 33 m. Permissible level for hands-on maintenance is 10 microSv/hr. As the results, after 1 week from shutdown, close maintenance work 8 cm to the Li loop is possible. Also, after 1 month, hands-on maintenance becomes possible.
Matsumoto, Taro; Naito, Hiroshi*; Tokuda, Shinji; Kishimoto, Yasuaki
Physics of Plasmas, 12(9), p.092505_1 - 092505_7, 2005/09
Times Cited Count：2 Percentile：6.66(Physics, Fluids & Plasmas)The behavior of the collisionless magnetohydrodynamics modes is investigated by the gyro-kinetic particle simulation in a cylindrical tokamak plasma in the parameter region where the effects of electron inertia and electron parallel compressibility are competitive for magnetic reconnection. Although the linear growth of the 
internal kink-tearing mode is dominated by the electron inertia, it is found that the growth rate can be nonlinearly accelerated due to the electron parallel compressibility proportional to the ion sound Larmor radius 
. It is also found that, as decreasing the electron skin depth 
, the maximum growth rate before the internal collapse saturates independently of the microscopic scales such as and . The acceleration of growth rate is also observed in the nonlinear phase of the 
double tearing mode.
Yutani, Toshiaki*; Nakamura, Hiroo; Sugimoto, Masayoshi
JAERI-Tech 2005-036, 10 Pages, 2005/06
JAERI-Tech-2005-036.pdf:2.06MB
In the high flux region of the International Fusion Materials Irradiation Facility (IFMIF), the neutron irradiation damage for iron-based alloys will exceed 20 dpa/ year. An accurate specimen temperature measurement under a large amount of nuclear heating is a key issue but the change of heat transfer of gap between irradiation specimens and specimen holder during irradiation test is inevitable, if gap is filled with an inert gas and temperature is monitored by a thermocouple buried in the specimen holder. A solution to make heat transfer predictable is to fill the gap with a liquid metal (sodium or sodium-potassium alloy). An issue of compatibility between Reduced Activation Ferritic/Martensitic steels and the liquid metalsis addressed in this paper, and some recommendations for designing irradiation rig are presented, such as a purification control before filling liquid metals, or a careful selection of material of rig to avoid carbon mass transfer.
Galatanu, A.; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo; Yamamoto, Etsuji; Aoki, Dai*; Takeuchi, Tetsuya*; Onuki, Yoshichika
Journal of the Physical Society of Japan, 74(5), p.1582 - 1597, 2005/05
Times Cited Count：39 Percentile：79.95(Physics, Multidisciplinary)We investigated the magnetic property of typical uranium compounds by measuring the magnetic susceptibility in an extended temperature range up to about 800 K. The magnetic susceptibility follows the Curie-Weiss law for a localized 5
-electron compound UPd and a ferromagnetic insulator UFe
P
. In most of the investigated compounds we observed a crossover effect of the 5 electrons from a low-temperature itinerant nature to a high-temperature localized one. This is found to be characteristic for ferromagnetic superconductors such as UGe
and UIr, and also for antiferromagnets like USb or UNiSb. To assess an extension of this characteristic property in the uranium compounds we also investigated typical 5-itinerant compounds like UGa
and UPtGa
. The crossover effect is essentially important in heavy fermion compounds such as UPt, UPdAl and URuSi. Even in the paramagnetic compound of UB, the magnetic susceptibility is not temperature-independent, but approaches a 5-localized tendency at high temperatures. Since the samples were single crystals, we were also able to trace the evolution of the magnetic anisotropy. The high-temperature anisotropic susceptibility data were analyzed on the basis of the crystalline electric field scheme.
SiMatsuda, Tatsuma; Haga, Yoshinori; Ikeda, Shugo; Galatanu, A.; Onuki, Yoshichika
Physica B; Condensed Matter, 359-361, p.1069 - 1071, 2005/04
Times Cited Count：3 Percentile：16.39(Physics, Condensed Matter)We have succeeded in growing a high-quality single crystal of UCuSi with the tetragonal structure by the Sn-flux method and measured the magnetic susceptibility and magnetization. UCuSi is confirmed to order antiferromagnetically below 
= 106 K, and follows a successive ferromagnetic ordering at 
= 100 K. The magnetic properties are highly anisotropic, reflecting the crystal structure. An easy-axis of magnetization is found to be the [001] direction (
-axis), while the [100] direction (
-axis) corresponds to the hard-axis in magnetization. The saturation moment is determined as 1.8
/U.
Fujii, Yasuhiko
Koatsuryoku No Kagaku To Gijutsu, 14(2), p.113 - 118, 2004/05
no abstracts in English
photocatalystsChoi, Y.; Umebayashi, Tsutomu; Yoshikawa, Masahito
Journal of Materials Science, 39(5), p.1837 - 1839, 2004/03
Times Cited Count：231 Percentile：97.82(Materials Science, Multidisciplinary)Carbon (C)-doped anatase TiO photocatalysts have been prepared by the oxidative annealing of TiC powders at 623 K for 50-100 hrs. From XRD and XPS analysis, it is clear that C is incorporated into O site of the TiO lattice. Diffuse reflectance spectroscopy (DRS) showed that the optical absorption edge of the C-doped anatase TiO shifted to lower energy compared with that of pure anatase TiO. The decomposition of methylene blue (MB) adsorbed on the C-doped sample was observed under a visible light range of 420-500 nm. We conclude that substitution of C for O in the TiO leads to a photocatalytic decomposition of MB under visible light irradiation.
Lu
BC(0
x0.31) compoundsTobo, Aya*; Ishimoto, Kenichi*; Konno, Junya*; Oyama, Kenji*; Kaneko, Koji; Yamaguchi, Yasuo*; Onodera, Hideya*
Journal of the Physical Society of Japan, 72(12), p.3231 - 3236, 2003/12
Times Cited Count：1 Percentile：12.72(Physics, Multidisciplinary)no abstracts in English
IShirasu, Yoshiro; Minato, Kazuo
Journal of Nuclear Materials, 320(1-2), p.25 - 30, 2003/09
Times Cited Count：4 Percentile：31.21(Materials Science, Multidisciplinary)no abstracts in English
Onuki, Akira; Takase, Kazuyuki; Kureta, Masatoshi; Yoshida, Hiroyuki; Tamai, Hidesada; Liu, W.; Akimoto, Hajime
Nihon Kikai Gakkai 2003-Nendo Nenji Taikai Koen Rombunshu, Vol.3, p.247 - 248, 2003/08
We start R&D project to develop the predictable technology for thermal-hydraulic performance of Reduced-Moderation Water Reactor (RMWR) in collaboration with power company/reactor vendor/university since 2002. The RMWR can attain the favorable characteristics such as effective utilization of uranium resources, multiple recycling of plutonium, high burn-up and long operation cycle, based on matured BWR technologies. MOX fuel assemblies with tight lattice arrangement are used to increase the conversion ratio by reducing the moderation of neutron energy. Increasing the in-core void fraction also contributes to the reduction of neutron moderation. The confirmation of thermal-hydraulic feasibility is one of the most important R&D items for the RMWR because of the tight lattice configuration. This series presentation focuses on the feasibility study and shows the R&D plan using large-scale test facility and advanced numerical simulation technology.
Ito, Masashi; Shiraishi, Akemi; Murakami, Hiroyuki
JAERI-Tech 2001-048, 20 Pages, 2001/07
JAERI-Tech-2001-048.pdf:1.27MB
In Japan Atomic Energy Research Institute, a new type radiophotoluminescent(RPL) glass dosimeter is recently adopted replaced film badge for external personal monitoring. Some fundamental characteristics of this dosimeter, such as dose dependence linearity, energy dependence, dose evaluation accuracy against mixed irradiation condition,fading, etc.,were examined at the Facility of Radiation Standard(FRS),JAERI. The results have proved that the RPL glass dosimeter has sufficient characteristics in practical use as a personal dosimeter for all of the items examined.
Araya, Fumimasa; Kureta, Masatoshi; Akimoto, Hajime
Proceedings of 2nd Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-2), p.309 - 314, 2000/00
no abstracts in English
Onuki, Akira; Yoshida, Hiroyuki; Akimoto, Hajime
Proceedings of ANS International Meeting on Best Estimate Methods in Nuclear Installations Safety Analysis (BE-2000) (CD-ROM), 17 Pages, 2000/00
no abstracts in English
H.H.Mai*; N.D.Duong*; Kojima, Takuji
IAEA-TECDOC-1070, p.345 - 351, 1999/03
no abstracts in English
Sm
TiO(0≦x≦1)Yoshii, Kenji; Nakamura, Akio; Abe, Hideki*
Journal of Alloys and Compounds, 290(1-2), p.236 - 243, 1999/00
Times Cited Count：11 Percentile：61.06(Chemistry, Physical)no abstracts in English
