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Tochio, Daisuke; Fujimoto, Nozomu
Journal of Nuclear Science and Technology, 53(3), p.425 - 431, 2016/03
Times Cited Count：1 Percentile：10.6(Nuclear Science & Technology)The future HTGR is now designed in JAEA. The reactor has many merging points of helium gas with different temperature. It is needed to clear the mixing characteristics of helium gas at the pipe in the HTGR from the viewpoint of structure integrity and temperature control. Previously, the reactor inlet coolant temperature was controlled lower than specific one in the HTTR due to lack of mixing of helium gas in the primary cooling system. Now the control system is improved to use the calculated bulk temperature of reactor inlet helium gas. In this paper, thermal-hydraulic analysis on the primary cooling system of the HTTR was conducted to clarify the mixing behavior of helium gas. As the result, it was confirmed that the mixing behavior of helium gas in the primary cooling system is mainly affected by the aspect ratio of annular flow path, and it is needed to consider the mixing characteristics of helium gas at the piping design of the HTGR.
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Sakai, Takuro; Arakawa, Kazuo
JAERI-Review 2003-033, TIARA Annual Report 2002, p.270 - 272, 2003/11
A snow crystal scavenges earozol particles and trasfer various elements in atomosphere through heterogenious nucleation. The snow has many complicated crystal shapes which results in difficulty in comparison of its environmental purification function directly with that of raindrops. The replica of individual snow crystal grain was prepared by their immobilization on the collodion film. The replica samples were analized by micro-PIXE at JAERI and PIXE st Kyoto university. The following results are obtained: (1) Size(circumscribed diameter) of individual snow crystal are in the range of 0.12-2.5mm, (2)snow crystal grows from hexagnal plate to dendritic sectored plate, (3) major elements captured by a snow crystal are Si,S,K,Ca,Fe,S, (4)there is relation between snow crystal size and captured-element masses. The result leads us to presume the chemical inner-structure and the elemental mixing state in/on single snow crystal.
Yamazawa, Hiromi; Furuno, Akiko; Chino, Masamichi
Atmospheric Environment, 32(24), p.4343 - 4349, 1998/00
Times Cited Count：5 Percentile：17.41(Environmental Sciences)no abstracts in English
Yamazawa, Hiromi; Chino, Masamichi; Furuno, Akiko
ETEX Symp. on Long-Range Atmospheric Transport,Model Verification and Emergency Response, p.191 - 194, 1997/00
no abstracts in English
1.0m, P/D: 1.1261.2, number of rods: 47Iwamura, Takamichi; Okubo, Tsutomu; *; ; Murao, Yoshio
JAERI-M 90-044, 158 Pages, 1990/03
no abstracts in English
Inagaki, Yoshiyuki; Kunugi, Tomoaki;
Nucl. Eng. Des., 123, p.77 - 86, 1990/00
Times Cited Count：9 Percentile：67.09(Nuclear Science & Technology)no abstracts in English
Iwamura, Takamichi; Okubo, Tsutomu; *; ; Murao, Yoshio
JAERI-M 89-127, 47 Pages, 1989/09
no abstracts in English
Fujimoto, Nozomu; Maruyama, So; Sudo, Yukio
JAERI-M 89-049, 53 Pages, 1989/05
no abstracts in English
