Development of failure mitigation technologies for improving resilience of nuclear structures, 1; Failure mitigation by passive safety structures without catastrophic failure

Kasahara, Naoto*; Yamano, Hidemasa; Nakamura, Izumi*; Demachi, Kazuyuki*; Sato, Takuya*; Ichimiya, Masakazu*

Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 8 Pages, 2024/03

In this study, we propose failure mitigation methods by application of passive safety structures. The idea of the passive safety structures was applied to next generation fast reactors under high temperature conditions and excessive earthquake conditions.

Uncertainty assessment of structural modeling in the seismic response analysis of nuclear facilities

Choi, B.; Nishida, Akemi; Muramatsu, Ken*; Takada, Tsuyoshi*

Transactions of the 24th International Conference on Structural Mechanics in Reactor Technology (SMiRT-24) (USB Flash Drive), 10 Pages, 2017/08

In order to clarify the influence of the modeling method on the result of seismic response analysis of nuclear facility, seismic response analysis using various simulated input ground motions was carried out and the uncertainty of response results were statistically analyzed. In particular, we focused on the difference of the response due to the structural modeling method (a conventional sway-rocking model and 3D FE model), and the relations among the input level, floor position, and response results were described and discussed.

Integrity check of Tokai Reprocessing Plant after the Tohoku Region Pacific Coast Earthquake

Nakano, Takafumi; Sato, Fuminori; Shirozu, Hidetomo; Nakanishi, Ryuji; Fukuda, Kazuhito; Tachibana, Ikuya

Nihon Genshiryoku Gakkai-Shi ATOMO, 57(1), p.14 - 20, 2015/01

https://doi.org/10.3327/jaesjb.57.1_14

no abstracts in English

A Study of structure of base-isolated

; ; Yamazaki, Toshihiko; ; ; Kondo, Toshinari*; *

JNC TN8400 2001-030, 99 Pages, 2002/01

JNC-TN8400-2001-030.pdf:13.24MB

There is a great deal of that we build a Base-Isolated building with the quaternary deposit ground. In an atomic energy institution, a study request is strong. When we build a Base-Isolated building with the quaternary deposit ground, evaluation of earthquake vibration of a vertical direction is an important problem. In an atomic energy institution, we design it by big earthquake load, and therefore examination is necessary. And, in this study, we do examination to build a Base-Isolated building with the quaternary deposit ground, we report it about an evaluation method of a design. Furthermore, we report that we estimated pipe laying and machinery to put in a building of Base-lsolated.

Shaking table test and dynamic response analysis of 3-D component base isolation system using multi-layer rubber bearings and coil springs

Tsutsumi, Hideaki*; Yamada, Hiroyuki; Ebisawa, Katsumi; Shibata, Katsuyuki; Fujimoto, Shigeru*

JAERI-Tech 2001-033, 124 Pages, 2001/06

JAERI-Tech-2001-033.pdf:9.98MB

no abstracts in English

Dynamic behavior and base isolation effect of three dimensional base isolation test system for nuclear components

Tsutsumi, Hideaki*; Yamada, Hiroyuki; Ebisawa, Katsumi; Shibata, Katsuyuki; Fujimoto, Shigeru*

Doboku Gakkai Dai-2-Kai Menshin, Seishin Korokiumu Koen Rombunshu, p.75 - 82, 2000/11

no abstracts in English

Study on optimaI vertical isolation characteristics

;

JNC TN9400 2000-060, 168 Pages, 2000/05

JNC-TN9400-2000-060.pdf:4.09MB

Optimal vertical isolation characteristics were studied for the structural concept of vertical seismic isolation system, which uses a common deck and a set of large coned dish springs. Four kinds of earthquake wave and three kinds of artificial seismic wave were used. The earthquake response analysis of a base isolated building was carried out considering some ground conditions and some vertical vibration characteristics of the building isolator. Floor response and acceleration time history at the vertical isolation level were arranged. Using the acceleration time history as a seismic input, the earthquake response analysis of the vertical isolation system according to single degree of freedom model was carried out. Linear analysis and non-linear analysis were made. ln the linear analysis, vertical isolation frequency was examined within 0.8 to 2.5 Hz, and damping ratio was examined within 2 to 60%. ln the non-linear analysis, it was examined within vertical isolation frequency 0.5 to 5Hz, which depended only on the rigidity of the coned disk spring, rigidity ratio of the damping devise 1 to 20 and yield seismic intensity of the damping devise 0.01 to 0.2. As the optimal vertical isolation characteristics of the system, the criterion of largest relative displacement, maximum acceleration and maximum value of the floor response acceleration between 5 to 12Hz was set, the combination region of the appropriate parameter were examined. ln case of largest relative displacement 50mm, acceleration response magnification of 0.75, floor response magnification of 0.33 were used as a criterion, from the result of the linear analysis, vertical frequency was set at 0.8 to l.2 Hz, and by combining the damping ratio over 20 %, it was proven that appropriate vertical isolation characteristics were obtained. The result of the non-linear analysis showed that the combination of the coned disk spring of vertical frequency 0.8 to 1.0 Hz and the damping element of rigidity ...

Development of seismic isolation system in vertical direction; Coupled response analysis of reactor building and common deck isolation system

PNC TN9410 97-032, 126 Pages, 1997/04

PNC-TN9410-97-032.pdf:4.62MB

Study was made on the effect of dynamic interaction between reactor building and common deck isolation structure. Dynamic response analyses were made with a coupled and a decoupled model of the reactor building and the isolation structure. The effect of the dynamic interaction was evaluated by comparing these analysis results. The results of the study can be summarized as below; (1)Dynamic coupling effect between reactor building and the common deck isolation structure is not significant. This can be attributed to the fact that the isolation frequency is sufficiently lower than the fundamental frequency of the soil-structure system. (2)The decoupled analysis model was found to give response results with practically sufficient accuracy and slight conservatism. (3)The effect of the response of common deck isolation structure on the response of the reactor building is also negligible.

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Mori, Koji*; Neyama, Atsushi*; *; Nishimura, Kazuya*

PNC TJ1458 97-003, 179 Pages, 1997/02

PNC-TJ1458-97-003.pdf:5.75MB

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*; Neyama, Atsushi*; Nishimura, Kazuya*; *

PNC TJ1458 96-001, 190 Pages, 1996/02

PNC-TJ1458-96-001.pdf:4.12MB

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