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Sato, Ikken; Yamaji, Akifumi*; Li, X.*; Madokoro, Hiroshi
Mechanical Engineering Journal (Internet), 9(2), p.21-00436_1 - 21-00436_17, 2022/04
Sato, Ikken
Journal of Nuclear Science and Technology, 56(5), p.394 - 411, 2019/05
Times Cited Count：10 Percentile：74.6(Nuclear Science & Technology)Water columns were adopted in the pressure measurement system of Fukushima-Daiichi Unit-3. Part of these water columns evaporated during the accident condition jeopardizing correct understanding on actual pressure. Through comparison of RPV (Reactor Pressure Vessel) and S/C pressures with D/W pressure, such water-column effect was evaluated. Correction for this effect was developed enabling clarification of slight pressure difference among RPV, S/C and D/W. This information was then integrated with other available data such as, water level, CAMS and environmental dose rate, into an interpretation of accident focusing on RPV and PCV pressurization/depressurization and radioactive material release to environment. It is suggested that dryout of in-vessel and ex-vessel debris was likely causing pressure decrease. S/C water poured into pedestal heated by relocated debris was the likely cause of pressurization. Cyclic reflooding of pedestal debris and dryout was likely.
Fukaya, Masaaki*; Takeda, Nobufumi*; Miura, Norihiko*; Ishida, Tomoko*; Hata, Koji*; Uyama, Masao*; Sato, Shin*; Okuma, Fumiko*; Hayagane, Sayaka*; Matsui, Hiroya; et al.
JAEA-Technology 2016-035, 153 Pages, 2017/02
JAEA-Technology-2016-035.pdf:37.6MB
The researches on engineering technology in the Mizunami Underground Research Laboratory (MIU) project in FY2016, detailed investigations of the (mechanical) behaviors of the plug and the rock mass around the reflood tunnel through ongoing reflood test were performed as part of (5) development of technologies for restoration and/or reduction of the excavation damage. As the result, particularly for the temperature change of the plug, its analytical results agree fairly well agree with the measurement ones. This means cracks induced by temperature stress can be prevented by the cooling countermeasure works reviewed in designing stage. In addition, for the behaviors of the plug and the bedrock boundary after reflooding the reflood tunnel, comparison between the results obtained by coupled hydro-mechanical analysis (stress-fluid coupled analysis) with the ones by several measurements, concluded that the model established based on the analysis results is generally appropriated.
Onuki, Akira; Yoshida, Hiroyuki; Akimoto, Hajime
Proceedings of ANS International Meeting on Best Estimate Methods in Nuclear Installations Safety Analysis (BE-2000) (CD-ROM), 17 Pages, 2000/00
no abstracts in English
Onuki, Akira; Akimoto, Hajime
Journal of Nuclear Science and Technology, 36(11), p.1021 - 1029, 1999/11
Times Cited Count：1 Percentile：13.15(Nuclear Science & Technology)no abstracts in English
Onuki, Akira; Okubo, Tsutomu; Akimoto, Hajime
Proceedings of 7th International Conference on Nuclear Engineering (ICONE-7) (CD-ROM), 10 Pages, 1999/00
no abstracts in English
Onuki, Akira;
Proc. of 5th Int. Topical Meeting on Nuclear Thermal Hydraulics,Operations and Safety, 00(00), p.1 - 6, 1997/04
no abstracts in English
Iguchi, Tadashi; Onuki, Akira; Iwaki, Chikako*; Kureta, Masatoshi; Akimoto, Hajime
Proc. of 5th Int. Conf. on Nuclear Engineering (ICONE-5), p.1 - 9, 1997/00
no abstracts in English
JAERI 1336, 362 Pages, 1995/09
no abstracts in English
; Onuki, Akira; Murao, Yoshio
Proc. of the 2nd Int. Conf. on Multiphase Flow 95-Kyoto, 0, p.P2_37 - P2_44, 1995/00
no abstracts in English
; Onuki, Akira; Murao, Yoshio
Validation of Systems Transients Analysis Codes (FED-Vol. 223), 0, 8 Pages, 1995/00
no abstracts in English
Onuki, Akira; ; Iguchi, Tadashi; Murao, Yoshio
JAERI-Research 94-012, 59 Pages, 1994/08
JAERI-Research-94-012.pdf:1.75MB
no abstracts in English
Iguchi, Tadashi
JAERI-M 94-008, 32 Pages, 1994/02
no abstracts in English
Abe, Yutaka; ; Kamo, Hideki*; Murao, Yoshio
Journal of Nuclear Science and Technology, 30(12), p.1214 - 1224, 1993/12
Times Cited Count：3 Percentile：38.1(Nuclear Science & Technology)no abstracts in English
Onuki, Akira; ; Murao, Yoshio
JAERI-M 93-139, 85 Pages, 1993/07
no abstracts in English
Onuki, Akira; ; Murao, Yoshio
JAERI-M 93-138, 55 Pages, 1993/07
no abstracts in English
; Onuki, Akira; Abe, Yutaka*; Murao, Yoshio
JAERI-M 93-045, 126 Pages, 1993/03
no abstracts in English
; Onuki, Akira; *; Murao, Yoshio
JAERI-M 93-032, 190 Pages, 1993/03
no abstracts in English
17 type fuel assembly of PWROnuki, Akira; ; Murao, Yoshio
Journal of Nuclear Science and Technology, 30(3), p.187 - 202, 1993/03
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
