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Watakabe, Tomoyoshi; Yamano, Hidemasa; Futagami, Satoshi
Transactions of the 28th International Conference on Structural Mechanics in Reactor Technology (SMiRT28) (Internet), 10 Pages, 2025/08
The fragility evaluation method of the RV in the SFR has been developed for both failure mode buckling and fatigue. The past studies showed the fragility using the RV of a loop-type SFR: radius R / thickness t is about 100. Recently, Japan Atomic Energy Agency together with Japanese industrial partners has been conducting a pool-type SFR design. The fragility of the pool-type RV has never been evaluated by the proposed method, which is based on the fatigue failure mode instead of the buckling. To investigate the basic behaviour of the pool-type RV under excessive seismic loading, this report investigated the fragility by using a simple cylindrical model with a wall thickness close to the design of the pool-type RV: R/t is 200, as the first trial.
Okafuji, Takashi*; Miura, Kazuhiro*; Sago, Hiromi*; Murakami, Hisatomo*; Watakabe, Tomoyoshi; Ando, Masanori; Miyazaki, Masashi
Proceedings of the ASME 2025 Pressure Vessels & Piping Conference (PVP2025) (Internet), 8 Pages, 2025/07
Tsukimori, Kazuyuki; Yada, Hiroki
Journal of Pressure Vessel Technology, 147(3), p.031901_1 - 031901_9, 2025/06
Times Cited Count：0 Percentile：0.00(Engineering, Mechanical)After the accident at the Fukushima Daiichi Nuclear Power Plant, very strict safety measures were implemented for nuclear power plants in Japan. It thus becomes a crucial issue if the safety of a plant is maintained or not at beyond design basis events. In this study, head plates and bellows were examined as components that compose the parts of the boundary of vessels that contain the primary coolant of a prototype fast breeder reactor. The behaviors of buckling, post-buckling deformation, and penetration failure, that is, loss of boundary function of these components with increasing pressure were investigated. The series of this research program started in FY2013 and the research proceeded step by step. The new result in this paper is the application of the proposed criteria to head plates and bellows, and a conservative estimation of penetration failure of these components is obtained.
Okafuji, Takashi*; Miura, Kazuhiro*; Sago, Hiromi*; Murakami, Hisatomo*; Watakabe, Tomoyoshi; Ando, Masanori; Miyazaki, Masashi
Proceedings of the ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 8 Pages, 2024/07
We have developed the buckling strength equations of vessels for fast reactors with seismic isolation system. The applicability of the buckling equations was confirmed by a series of buckling tests and analyses under monotonic or cyclic axial compressive load accompanied with constant horizontal load in the previous reports. In this report, we proposed a correction factor to reduce the buckling strength calculated by the buckling equations for large initial imperfections. A series of elastic-plastic buckling analyses considering large displacement and large strain theories was conducted to Grade 91 steel and austenitic stainless steel vessels which has a wide range of dimensions, initial imperfection amplitude, and vertical/horizontal load ratio. The simulation results showed that the correction factor generally shows a reduction tendency of buckling strength corresponding to initial imperfection amplitude, and the modified buckling equations are applicable to the vessels in fast reactors even for large initial imperfection amplitude which exceeds half the wall thickness.
Ishihara, Masahiro; Yamaji, Masatoshi*; Baba, Shinichi; Hanawa, Satoshi
Key Engineering Materials, 297-300, p.201 - 206, 2005/11
no abstracts in English
Kojima, Kensuke; Okajima, Shigeaki; Yamane, Tsuyoshi; Ando, Masaki; Kataoka, Masaharu*; Iwanaga, Kohei
JAERI-Tech 2004-016, 38 Pages, 2004/03
JAERI-Tech-2004-016.pdf:1.46MB
To investigate the void coefficient in the Reduced-Moderation Water Reactor (RMWR), an infinite multiplication factor was measured in the FCA-XXII-1 (65V) core. Axial and radial fission rate distributions were measured by micro fission chambers with four different kinds of nuclides. The infinite multiplication factor was derived from the material buckling, which was obtained from both the axial and radial fission rate distributions, and the migration area calculated. The value of it in the test region of the FCA-XXII-1 (65V) core was 1.344
0.034. It was compared with the calculation, the ratio of the calculation to the measurement was 1.0080.026. The improvement in measurement accuracy was also considered.
Omori, Junji*; Araki, Masanori
JAERI-Tech 2000-006, p.15 - 0, 2000/02
JAERI-Tech-2000-006.pdf:0.66MB
no abstracts in English
Yamane, Yuichi; Miyoshi, Yoshinori
Proceedings of 6th International Conference on Nuclear Criticality Safety (ICNC '99), 1, p.180 - 185, 1999/00
no abstracts in English
Ishihara, Masahiro; Iyoku, Tatsuo; Futakawa, Masatoshi
Nucl. Eng. Des., 148, p.91 - 100, 1994/00
Times Cited Count：4 Percentile：41.50(Nuclear Science & Technology)no abstracts in English
Iyoku, Tatsuo; Shiozawa, Shusaku; Ishihara, Masahiro; ; Oku, Tatsuo*
Nucl. Eng. Des., 132, p.23 - 30, 1991/00
Times Cited Count：25 Percentile：90.25(Nuclear Science & Technology)no abstracts in English
Nishiguchi, Isoharu; Kaji, Yoshiyuki; Ioka, Ikuo; ;
J. Pressure Vessel Technol., 112, p.233 - 239, 1990/08
Times Cited Count：9 Percentile：55.73(Engineering, Mechanical)no abstracts in English
Hoshiya, Taiji; ; ; Harayama, Yasuo
JAERI-M 89-199, 35 Pages, 1989/12
no abstracts in English
Ueda, Shuzo
Nucl.Eng.Des., 85, p.251 - 260, 1985/00
Times Cited Count：10 Percentile：75.67(Nuclear Science & Technology)no abstracts in English
; Yamamoto, Masahiro; ; ; ; ;
Journal of Nuclear Science and Technology, 21(5), p.341 - 355, 1984/00
Times Cited Count：4 Percentile：44.76(Nuclear Science & Technology)no abstracts in English
O assembly; ;
Journal of Nuclear Science and Technology, 5(1), p.1 - 6, 1968/00
Times Cited Count：1no abstracts in English
Pu fueled system from the data of composite Pu-
U fueled fast critical assemblyNihon Genshiryoku Gakkai-Shi, 4(11), p.746 - 753, 1962/00
no abstracts in English
Miura, Kazuhiro*; Okafuji, Takashi*; Sago, Hiromi*; Shimomura, Kenta; Okajima, Satoshi; Sato, Kenichiro*
no journal, ,
Buckling evaluation methods capable of evaluating elasto-plastic buckling under axial compression, bending, and shear loads are required for cylindrical vessels of fast reactors in order to cope with thinning due to the increase in diameter, adoption of new materials, and adoption of seismic isolation design due to the increase in the standard seismic ground motion. Buckling evaluation methods corresponding to the above are being considered in the fast reactor standards of the Japan Society of Mechanical Engineers. In this study, in order to examine the applicability of the proposed buckling evaluation equation, Monte Carlo simulation was carried out using material properties and initial imperfections, which are the fluctuation factors of buckling strength, as parameters, and the effect of the fluctuation of these factors on buckling load was evaluated. When the buckling load was normalized by the buckling critical value according to the proposed formula using the longitudinal elastic modulus and the design yield stress of JSME S NC2-2013, the 95% lower confidence limit exceeded the threshold of the proposed formula for both the vertical single load condition and the horizontal and vertical combined load condition. The results show that the buckling critical value calculated by using the design yield stress in the proposed equation is more conservative than the 95% lower confidence limit of the actual buckling load affected by the scatter of material properties and others.
