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Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Proceedings of 1st International Forum on Heat Transfer (IFHT 2004), p.207 - 208, 2004/11
no abstracts in English
; *
JNC TN8400 2001-010, 25 Pages, 2001/03
Performance assessment in geosphere for the JNC's 2nd progress report was based on nuclide migration calculation results by discrete fracture network model. The channel network model approximated from fracture network model with considering fracture connectivity was applied for nuclide migration analysis, since fracture network model had too large data to calculate nuclide migration. However, there are many options in the process of approximation from fracture network model to channel network model. In case of analyzing nuclide migration for above report, so-called "base case", one option was chosen from many options, arbitrarily. In this report, the sensitivity of these options to nuclide migration calculation results was studied. As a result, there was no significant impact to nuclide migration although connectivity of channel and flow characteristics of the model slightly changed among different options. Based on above studies, we concluded that an option used for the base case was appropriate.
Tanaka, Satoru*
JNC TJ8400 2000-003, 62 Pages, 2000/02
For the safety assessment of radioactive waste disposal, it is important to elucidate the effect of colloids on radionuclide migration, which are released with dissolution of cementitious materials composing engineered barricr. In the previous work, we identified and characterized the colloidal particles in the solutions contacting cement hydrates, OPC and low-alkaline cement paste, and observed the release of the colloid particle. In the present work, we performed same experiments as the last year to confirm the reproducibility of the colloid release. We studied the leaching behavior of the colloid when OPC and low-alkaline cement past contact water flow. Furthermore, the effect of an alumina particle was studied, which is used as a barrier material for colloid migration. The following conclusions were derived: (1)In the solution contacting cement paste, the small amount of particles, which are considered as CaCO or silicate colloids were observed. Thus, the reproducibility of the last work was confirmed. (2)The leaching of colloid in the solution was confirmed by water flow through the cement paste. The concentration of particle was as low as 1010 mL. (3)Al0 powder, with the diameter of 200150m, was found to be effective to some extent as a barrier for a colloid migration from low-alkaline cement paste.
Ijiri, Yuji; ;
JNC TN8400 99-091, 69 Pages, 1999/11
It is crucial for the performance assessment of geosphere to evaluate the characteristics of fractures that can be dominant radionuclide migration pathways from a repository to biosphere. This report summarizes the charactelistics of fractures obtained from broad literature surveys and the fields surveys at the Kamaishi mine in northern Japan and at outcrops and galleries throughout the country. The characteristics of fractures described in this report are fracture orientation, fracture shape, fracture frequency, fracture distribution in space, transmissivity of fracture, fracture aperture, fracture fillings, alteration halo along fracture, flow-wetted surface area in fracture, and the correlation among these characteristics. Since granitic rock is considered the archetype fractured media, a large amount of fracture data is available in literature. In addition, granitic rock has been treated as a potential host rock in many overseas programs, and has JNC performed a number of field observations and experiments in granodiorite at the Kamaishi mine. Therefore, the characteristics of fractures in granitic rock are qualitatively and quantitatively clarified to some extent in this report, while the characteristics of fractures in another rock types are not clarified.
Fujii, Yoshio; Suzuki, Katsuo
JAERI-Tech 98-054, 65 Pages, 1998/12
no abstracts in English
Fujii, Yoshio; Suzuki, Katsuo
JAERI-Tech 97-071, 42 Pages, 1998/01
no abstracts in English
Sato, Shinji; Amemiya, Kiyoshi*; Yamagata, Junji*; Hirose, Ikuro; Ishikawa, Hirohisa; Yusa, Yasuhisa; Sasaki, Noriaki
PNC TN8410 90-060, 106 Pages, 1990/06
None
Shibamoto, Yasuteru; Yonomoto, Taisuke
no journal, ,
no abstracts in English