Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kaji, Yoshiyuki; Gu, W.*; Ishihara, Masahiro; Arai, Taketoshi; Nakamura, Hitoshi*
Nuclear Engineering and Design, 206(1), p.1 - 12, 2001/05
Times Cited Count：9 Percentile：56.04(Nuclear Science & Technology)no abstracts in English
Shimo, Michito*; *
JNC TJ7400 2000-008, 157 Pages, 2000/03
JNC-TJ7400-2000-008.pdf:4.02MB
no abstracts in English
Ijiri, Yuji; ; *; Watari, Shingo; K.E.Web*; *; *
JNC TN8400 99-092, 91 Pages, 1999/11
JNC has been developed the performance assessment approaches for both fractured rock and porous rock. An equivalent continuum model is incorporated for solving the radionuclide migration in porous rock, while a discrete fracture network model is incorporated for solving the radionuclide migration in fractured rock (see more detail in Sawada et al. [1999]). This report describes the methodology, the data and the results of the performance assessment of porous rock. From the results of radionuclide migration analyses that were based on the hydrogeological properties obtained from the Neogene sedimentaly rock at the Tono mine, it was found that the release rate of selenium-79 and cesium-135 are dominant in porous rock. The sensitivity analyses using one-dimensional porous model revealed that hydraulic conductivity has more influences on the results than porosity does. In addition, it was found that smaller distribution coefficients of sandstone yield higher release rate than mudstone and tuff, and smaller distribution coefficients of saline water conditions yield higher release rate than fresh water conditions. The radionuclide migration in Neogene sedimentaly rock, where flow in rock matrix as well as in fractures are significant, was evaluated by superposing the results of porous model and fracture model. Since fracture model tends to yield more conservative results than porous model, it is obvious that the performance of Neogene sedimentary rock can be conservatively assessed by fracture model alone. The nuclide migration analyses performed in this report were based on the hydrogeological properties obtained at the depth between 20 meters and 200 meters frrom the ground surface. Therefore, it should be noted that the release rate at the depth of a future repository in Neogene sedimentary rock, 500 m, will be smaller than that shown in this report due to peemeability decrease from 200 m to 500 m.
Kaji, Yoshiyuki; Arai, Taketoshi; Gu, W.*; Nakamura, Hitoshi*
JAERI-Review 99-016, 61 Pages, 1999/06
JAERI-Review-99-016.pdf:2.37MB
no abstracts in English
Kaji, Yoshiyuki; Gu, W.*; Ishihara, Masahiro; Arai, Taketoshi; Nakamura, Hitoshi*
Transactions of 15th Int. Conf. on Structural Mechanics in Reactor Technol. (SMiRT-15), 2, p.133 - 139, 1999/00
no abstracts in English
; Yokokawa, Mitsuo
Proc. of the Joint Int. Conf. on Mathematical Methods and Supercomputing in Nuclear Applications,Vol. 1, p.260 - 270, 1993/00
no abstracts in English
Igarashi, Takahiro
no journal, ,
Corrosion of metal in solution is electrochemical reaction that is influenced by both material and environmental factors. For example, move of chemical species due to change of valence charge and diffusion of chemical species in solution (long time, macro scale), electrochemical reaction corresponding to metal surface condition (short time, nano scale), changes in surface molphorogy by chemical reaction (long time, macro scale). In order to carry out computational simulation taking into consideration all these factors, it is necessary to conduct several years of quantum calculation for a system with size that can express surface roughness, and even with recent high-performance computers it is quite difficult to do. We apply different computational approaches to each phenomenon and try to comprehensively understand corrosion phenomena. In this presentation, we introduce various computational simulation examples on the micro to macro scale conducted in our group.
Tagawa, Yoichi*; Onoe, Hironori*; Esaki, Taichi*; Hane, Koji*; Ishibashi, Masayuki*; Namikawa, Tadashi*; Tabei, Kazuto*; Saegusa, Hiromitsu*; Ishida, Keisuke*; Sawada, Atsushi
no journal, ,
no abstracts in English
