Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tc separation/concentration technology from 
Mo by (n, 
) methodFujita, Yoshitaka; Hu, X.*; Takeuchi, Tomoaki; Takeda, Ryoma; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; Hori, Junichi*; Suzuki, Tatsuya*; Suematsu, Hisayuki*; Ide, Hiroshi
KURNS Progress Report 2022, P. 110, 2023/07
no abstracts in English
Uehara, Akihiro*; Akiyama, Daisuke*; Ikeda, Atsushi; Numako, Chiya*; Terada, Yasuko*; Nitta, Kiyofumi*; Ina, Toshiaki*; Takeda-Homma, Shino*; Kirishima, Akira*; Sato, Nobuaki*
Journal of Nuclear Materials, 559, p.153422_1 - 153422_11, 2022/02
Times Cited Count：3 Percentile：50.96(Materials Science, Multidisciplinary)Nakashima, Yosuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Oki, Kensuke*; Sakamoto, Mizuki*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; Imai, Tsuyoshi*; et al.
Journal of Nuclear Materials, 463, p.537 - 540, 2015/08
Times Cited Count：20 Percentile：83.66(Materials Science, Multidisciplinary)Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.
Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10
He neutron spin filters on the small-angle neutron scattering spectrometer SANS-J-IISakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Aizawa, Kazuya; Arai, Masatoshi; Noda, Yohei; et al.
Journal of Physics; Conference Series, 294(1), p.012017_1 - 012017_7, 2011/06
Times Cited Count：2 Percentile：65.41(Physics, Applied)He neutron spin filter cellsSakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.
Journal of Physics; Conference Series, 294(1), p.012004_1 - 012004_7, 2011/06
Times Cited Count：2 Percentile：65.41(Physics, Applied)He neutron spin filtersSakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.
Physica B; Condensed Matter, 406(12), p.2443 - 2447, 2011/06
He neutron spin filtersSakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.
Physica B; Condensed Matter, 406(12), p.2443 - 2447, 2011/06
Times Cited Count：3 Percentile：16.18(Physics, Condensed Matter)He neutron spin filter cellsSakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Arai, Masatoshi; Takeda, Masayasu; et al.
Nuclear Instruments and Methods in Physics Research A, 634(1, Suppl.), p.S122 - S125, 2011/04
Sekioka, Yasushi*; Takeda, Seiji; Kimura, Hideo
JAEA-Research 2009-062, 68 Pages, 2010/03
JAEA-Research-2009-062.pdf:3.62MB
In safety assessment for geological disposal, release of radionuclides from vitrified waste is dependent on dissolution rate of glass matrix. It is assumed that the alteration and dissolution of glass in an engineered barrier system proceeds by a mechanism not related by the chemical affinity for dissolution reaction of glass matrix. Recent studies indicate that the glass dissolution rate is likely to decrease as time passed, but scientific basis on the dissolution process has not been necessarily understood. We estimate uncertainty of the glass dissolution rate represented by not only a model of constant dissolution rate but also a model of decreasing dissolution rate. In order to estimate the parameter uncertainty of the glass dissolution rate, we carried out the statistical analysis of the appropriate release rate data of boron for a hypothetical condition of disposal system, based on investigating the relation between published data of glass dissolution and those experimental conditions. As a result of the model of constant dissolution rate, the uncertainty of the glass dissolution rate is estimated to be a variance with about 3 orders and logarithmic mean of 0.004 g/m
/day. The glass dissolution rate by the decreasing model changes in the range of 10
to 10
g/m/day by 1000 years and is lower than the minimum value estimated by the model of constant dissolution rate. The result indicates that the difference of two models may lead to large variance of the glass dissolution rate in safety assessment.
Takeda, Seiji; Yamaguchi, Tetsuji; Nagasawa, Hirokazu; Watanabe, Masatoshi; Sekioka, Yasushi; Kanzaki, Yutaka; Sasaki, Toshihisa; Ochiai, Toru; Munakata, Masahiro; Tanaka, Tadao; et al.
JAEA-Research 2009-034, 239 Pages, 2009/11
JAEA-Research-2009-034.pdf:33.52MB
In safety assessment for geological disposal of high level radioactive waste, it is of consequence to estimate the uncertainties due to the long-term frame associated with long-lived radionuclides and the expanded geological environment. The uncertainties result from heterogeneity intrinsic to engineered and natural barrier materials, insufficient understanding of phenomena occurring in the disposal system, erroneous method of measurement, and incomplete construction. It is possible to quantify or to reduce the uncertainties according to scientific and technological progress. We applied a deterministic and a Monte Carlo-based probabilistic method simulation techniques to the uncertainty analysis for performance of hypothetical geological disposal system for high level radioactive waste. This study provides the method to evaluate the effects of the uncertainties with respect to scenarios, models and parameters in engineering barrier system on radiological consequence. The results also help us to specify prioritized models and parameters to be further studied for long-term safety assessment.
Obayashi, Hironari; Tasaka, Yuji*; Kon, Seiji*; Takeda, Yasushi*
Flow Measurement and Instrumentation, 19(3-4), p.189 - 195, 2008/06
Times Cited Count：13 Percentile：52.64(Engineering, Mechanical)This paper proposes a new technique that enables the measurement of the velocity vector in multi-dimensions on a line of the flow field. A system to achieve this goal was developed based on ultrasonic velocity profiling by using multiple transducers. A two-dimensional system was constructed and successfully applied to an actual flow field for two-dimensional velocity vector measurements. To estimate the influence of existence of a wall, acoustic field under the developed system was calculated by solving two-dimensional wave equation and then the focal point of an ultrasonic beam was determined to optimize the system. The system was applied to measure two directional velocity components of a periodic velocity fluctuation in a wake of a cylinder as an example of unsteady flow. Temporal variation of velocity vector profiles well represent the velocity fluctuation, and vorticity distribution, which is obtained from the spatial distribution of velocity vector, well represents vertical motion in the wake.
Tasaka, Yuji*; Takeda, Yasushi*; Obayashi, Hironari; Yanagisawa, Takatoshi*
Choompa Techno, 18(6), p.70 - 74, 2006/11
Ultrasonic Velocity Profiler (UVP) enables us to obtain the velocity profiles in liquid metals. It is obvious that any optical method of flow measurement cannot be applied since all the liquid metals are opaque. This meant that non-invasive flow measurement was not possible until the ultrasonic measurement has been established. In this short review, we explain the various measurement relut given by UVP.
Obayashi, Hironari; Tasaka, Yuji*; Takeda, Yasushi*
Kashika Joho Gakkai-Shi, 26(103), p.252 - 257, 2006/10
Ultrasonic velocity profiler (UVP) has been established in fluid mechanics and fluid engineering applications of flow measurement. It is utmost importance to investigate flow structure and behavior of liquid metals when it is used in an active manner not only in heat transportation but also a flowing medium, as is the case for any kinds of situations of fluid flow is involved, and as such, fluid mechanics is applied. It is obvious that any optical method of flow measurement cannot be applied since all the liquid metals are opaque. This meant that non-invasive flow measurement was not possible until the ultrasonic measurement has been established. In the past studies, UVP has been applied to the flow measurement of liquid metal. In this paper, we show some examples which measured the liquid metal flow and introduce a new measurement system based on the UVP techniques.
Kikuchi, Kenji; Takeda, Yasushi*; Obayashi, Hiroo*; Tezuka, Masao*; Sato, Hiroshi
Journal of Nuclear Materials, 356(1-3), p.273 - 279, 2006/09
Times Cited Count：11 Percentile：60.11(Materials Science, Multidisciplinary)Measurements of LBE flow velocity profile were realized in the spallation target model by the ultrasonic Doppler velocity profile technique. Hitherto, it has not yet been done well because both of poor wetting property of LBE with stainless steels and poor performance of supersonic probes at high temperatures. Measurement was made for a return flow in the target model, which has coaxially arranged annular and tube channels. The electromagnetic pump generates LBE flow and the flow rate was measured by the electromagnetic flow meter. Measurement results show that re-circulation occurred near the surface of beam window, which might affect a heat transfer of target container.
Obayashi, Hironari; Yamaguchi, Kohei*; Kon, Seiji*; Takeda, Yasushi*
Nihon Ryutai Rikigakkai Nenkai 2006 Koen Rombunshu (CD-ROM), 4 Pages, 2006/09
The velocity vector of fluid is expressed with the function of the velocity components of three directions, and the function of time. Therefore, in order to understand the flow structure, it becomes very important to measure these components. We propose the new equipment that enables three-dimensional velocity vector measurement of the flow field of the name of Vector-UVP. It consists of a central emitter, symmetrically surrounded by three receivers. If the plane transducer is used for the emitter, the ultrasonic beam will spread in the practical range, consequently measurement volume will become too large. Thus, the characteristic of the ultrasonic beam from the emitter has great influence on the performance of Vector-UVP. For the solution of this problem, and in order to simplify our equipment, we use commercial focused transducer for the emitter. We developed 2D Vecotor-UVP system. And this system successfully applied to an actual flow field for two-dimensional velocity vector measurements.
Kikuchi, Kenji; Tezuka, Masao*; Saito, Shigeru; Oigawa, Hiroyuki; Takeda, Yasushi*
Proceedings of 4th International Symposium on Ultrasonic Doppler Method for Fluid Mechanics and Fluid Engineering (ISUD-4), p.107 - 110, 2004/09
When the steel is submerged into LBE, LBE will contact with the steel except for the interface among LBE, gas and metal where the surface energy controls the shape of the free surface in LBE. It is supposed that LBE will transmit ultrasonic wave into LBE through the contacting area. However, the ultrasonic echo was too low to detect from the steel container filled with LBE. The measurement was improved by coating the interface between the steel and LBE with the SnPb solder. After an immersion test the steel surface was covered with thin LBE layer. The thickness of the layer is only 10 to 20 micron m. So it will not disturb the flow pattern where UVP is applied. Sn was not detected by X ray analyses. This is an evidence how the steel was wetted in LBE and how the ultrasonic wave transmitted though the interface of LBE and the steel.
Ishino, Masahiko; Yoda, Osamu; Haishi, Yasuyuki*; Arimoto, Fumiko*; Takeda, Mitsuhiro*; Watanabe, Seiichi*; Onuki, Somei*; Abe, Hiroaki
Japanese Journal of Applied Physics, Part 1, 41(5A), p.3052 - 3056, 2002/05
Times Cited Count：12 Percentile：45.87(Physics, Applied)no abstracts in English
;
Nuclear Science and Engineering, 214(3), 231 Pages, 2002/00
None
