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Ono, Hirokazu; Takayama, Yusuke*
Geomechanics for Energy and the Environment, 41, p.100636_1 - 100636_14, 2025/03
Times Cited Count：0 Percentile：0.00(Energy & Fuels)Wakui, Takashi; Saito, Shigeru; Futakawa, Masatoshi
Materials, 17(23), p.5925_1 - 5925_14, 2024/12
Times Cited Count：0 Percentile：0.00(Chemistry, Physical)The ductile properties of irradiated materials are one of the important indicators related to their structural integrity. Indentation tests are used for evaluating the ductile properties easily and rapidly. Constants in the material constitutive equation were identified via inverse analysis using the Kalman filter, such that the numerical experimental results reproduced the indentation test results. Numerical tensile experiments were conducted using stress-strain curves with the identified constants to obtain nominal stress-strain curves. Furthermore, two methods were proposed for evaluating the total elongation. Evaluated minimum total elongation was 10 %. The evaluation results of ion-irradiated materials were similar to the tensile test results of irradiated materials.
Kitamura, Yasunori*; Fukushima, Masahiro
Nuclear Science and Engineering, 186(2), p.168 - 179, 2017/05
Times Cited Count：1 Percentile：9.41(Nuclear Science & Technology)An inconsistency between the reactivity worth of short-size samples measured by the critical-water-level (CWL) method and that conventionally analysed for validating the nuclear data and the nuclear calculation methods has been known. The present study investigated this inconsistency in terms of a simple theoretical framework and proposed a simple and practical technique for correcting the measured sample reactivity worth without making supplementary experiments. A series of Monte Carlo calculations that simulated typical sample reactivity worth measurement by the CWL method showed that this inconsistency is effectively reduced by the present correction technique.
Kobayashi, Takuya; Chino, Masamichi; Togawa, Orihiko
Journal of Nuclear Science and Technology, 43(5), p.569 - 575, 2006/05
Times Cited Count：4 Percentile：29.88(Nuclear Science & Technology)A dissolved radionuclide migration code system that consists of a ocean circulation model, Princeton Ocean Model, and a particle random-walk model, SEA-GEARN, has been developed. The oceanic migration of 
Cs discharged from a nuclear submarine in a hypothetical accident at the Tsushima Strait was calculated in the southwestern area of the Japan Sea as a model application. The calculations for instantaneous releases every 10 days were carried out for one year to study the seasonal differences of migration process of the dissolved radionuclides. The migration tendencies of dissolved radionuclides were divided into two patterns. For the releases started from January to September, all of the high concentration areas migrated to the northeast along the coastline of the Main Island of Japan from the release point. As for the releases from October to December, some high concentrations areas migrated to the west from the release point and the concentrations of Cs along the coastline of the Main Island of Japan were comparatively low.
Inaba, Yoshitomo; Zhang, Y.*; Takeda, Tetsuaki; Shiina, Yasuaki
Heat Transfer-Asian Research, 34(5), p.293 - 308, 2005/07
Water cooling panels have been adopted as the vessel cooling system of the HTTR to cool the reactor core indirectly by natural convection and thermal radiation. In order to investigate the heat transfer characteristics of high temperature gas in a vertical annular space between the reactor pressure vessel and cooling panels of the HTTR, we carried out experiments and numerical analyses on natural convection heat transfer coupled with thermal radiation heat transfer in an annulus between two vertical concentric cylinders with the inner cylinder heated and the outer cylinder cooled. In the present experiments, Rayleigh number based on the height of the annulus ranged from 2.0
10
to 5.410 for helium gas and from 1.210
to 3.510 for nitrogen gas. The numerical results were in good agreement with the experimental ones regarding the surface temperatures of the heating and cooling walls. As a result of the experiments and the numerical analyses, the heat transfer coefficient of natural convection coupled with thermal radiation was obtained.
Inaba, Yoshitomo; Nishihara, Tetsuo; Groethe, M. A.*; Nitta, Yoshikazu*
Nuclear Engineering and Design, 232(1), p.111 - 119, 2004/07
Times Cited Count：27 Percentile：82.81(Nuclear Science & Technology)It is important to grasp the explosion characteristics of object gases: natural gas and methane, in order to evaluate the influence of a gas explosion accident in the HTTR hydrogen production system on the reactor. Thus, we carried out explosion experiments of the object gases in semi-open space, and verified a numerical analysis code for the simulation of the explosion accident. It was confirmed that NG-air mixture or methane-air mixture in semi-open space didn't result in DDT although 10 g of C-4 explosive was used as an ignition source, and the numerical results agreed relatively with the experimental results. As a result, we could have the prospects for predicting the influence of the explosion accident on the reactor.
Inaba, Yoshitomo; Zhang, Y.*; Takeda, Tetsuaki; Shiina, Yasuaki
Nihon Kikai Gakkai Rombunshu, B, 70(694), p.1518 - 1525, 2004/06
no abstracts in English
Kishimoto, Yasuaki
Purazuma, Kaku Yugo Gakkai-Shi, 80(5), p.390 - 395, 2004/05
High performance magnetically confined plasma is realized by having structures in plasmas, where different elementary processes with different time and spatial scales are deeply contributing with each other. A research based on large scale simulation is then essential to understand such hierarchical complex plasmas. We discuss the underlying physical process of the structural plasma and present a prospect for future numerical simulations covering a wide dynamical range.
Kishimoto, Yasuaki; Idomura, Yasuhiro; Li, J.
Purazuma, Kaku Yugo Gakkai-Shi, 79(5), p.478 - 488, 2003/05
This is a collection of review article related to the "Multiple Time and Spatial Scale Plasma Simulation" of various fields including fundamental research area of self-organization, magnetic and laser fusion field, space and astrophysics field where a plasma plays an essential roles.
Koarashi, Jun*; Iida, Takao*; Atarashi-Andoh, Mariko; Yamazawa, Hiromi; Amano, Hikaru
Fusion Science and Technology, 41(3), p.464 - 469, 2002/05
no abstracts in English
Kobayashi, Takuya; Lee, S.; Chino, Masamichi
Journal of Nuclear Science and Technology, 39(2), p.171 - 179, 2002/02
Times Cited Count：3 Percentile：22.66(Nuclear Science & Technology)A three-dimensional model system was developed to predict oceanic dispersions of radionuclides released into the eastern area of Shimokita Peninsula. This system is a combination of the Princeton Ocean Model (POM) for predicting ocean currents and a particle random walk model for oceanic dispersion of radionuclides. The model was verified by using measured currents, temperature and salinity at the coastal area of Shimokita, Aomori-ken, Japan, where a nuclear fuel reprocessing plant is under construction. The results obtained from simulations area as follows; (1) Wind and the Tsugaru Warm Current entering into the objective region through the Tsugaru Strait significantly affect the structure of current over the region. (2) POM can represent seasonal variations of the Tsugaru Warm Current well with hypothetical oceanographic data. The calculation succeeded to reproduce the coastal mode from winter to spring and the gyre mode from summer to autumn.
Suzuki, Yoshio; Kishimoto, Yasuaki; NEXT Group
Purazuma, Kaku Yugo Gakkai-Shi, 78(1), p.59 - 69, 2002/01
From the year 2000 to 2001, the computer system located on Naka Fusion Research Establishment, Japan Atomic Energy Research Institute has been replaced. Since the main computer is the scalar parallel computer, which is about 40 times superior to the previous one, the amount of data outputted from the numerical simulations becomes much larger. In this paper, which scientific visual analysis system is more useful to extract the physical phenomena from such a large amount of data is investigated and the performance of the established visual analysis system is estimated.
Inaba, Yoshitomo; Takeda, Tetsuaki
JAERI-Research 2000-062, 73 Pages, 2001/02
JAERI-Research-2000-062.pdf:2.83MB
no abstracts in English
Yamazawa, Hiromi
KURRI-KR-61, p.100 - 105, 2000/00
no abstracts in English
Nakamura, Hideo; Ito, Kazuhiro*; Kukita, Yutaka*; ; ; Maekawa, Hiroshi; Katsuta, Hiroji
Journal of Nuclear Materials, 258-263, p.440 - 445, 1998/00
Times Cited Count：7 Percentile：53.28(Materials Science, Multidisciplinary)no abstracts in English
Tokuda, Shinji
Purazuma, Kaku Yugo Gakkai-Shi, 72(9), p.916 - 919, 1996/09
no abstracts in English
;
Physical Review Letters, 74(8), p.1434 - 1437, 1995/02
Times Cited Count：12 Percentile：61.00(Physics, Multidisciplinary)no abstracts in English
Takase, Kazuyuki
Nucl. Eng. Des., 154, p.345 - 356, 1995/00
Times Cited Count：4 Percentile：42.81(Nuclear Science & Technology)no abstracts in English
Takase, Kazuyuki
JAERI-Research 94-034, 28 Pages, 1994/11
JAERI-Research-94-034.pdf:1.12MB
no abstracts in English
H.-W.Bartels*; Kunugi, Tomoaki; A.J.Russo*
Atomic and Plasma-Material Interaction Data for Fusion, Vol. 5, 0, p.225 - 244, 1994/00
no abstracts in English
