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Watakabe, Tomoyoshi; Yamamoto, Tomohiko; Fukasawa, Tsuyoshi*; Okamura, Shigeki*; Somaki, Takahiro*; Morobishi, Ryota*; Sakurai, Yu*; Kato, Koji*
Nihon Kikai Gakkai Rombunshu (Internet), 83(850), p.16-00444_1 - 16-00444_14, 2017/06
A seismic isolation system composed of a thick rubber bearing and an oil damper has been developed for Sodium-Cooled Fast Reactor. This paper focused on the aging properties of thick rubber bearings, such as basic mechanical properties and ultimate strength. Aging of the rubber bearings was reproduced using thermal degradation based on Arrhenius law.
Watakabe, Tomoyoshi; Yamamoto, Tomohiko; Fukasawa, Tsuyoshi*; Okamura, Shigeki*; Somaki, Takahiro*; Morobishi, Ryota*; Sakurai, Yu*; Kato, Koji*
Proceedings of 2016 ASME Pressure Vessels and Piping Conference (PVP 2016) (Internet), 8 Pages, 2016/07
A seismic isolation system composed of a thick rubber bearing and an oil damper has been developed for Sodium cooled Fast Reactor. One of the advantages of the isolation system is employing the thick rubber bearing in order to realize the longer vertical natural period of a plant, and it leads to mitigation of seismic loads to mechanical components. Rubber bearing technology has progressed based on many past studies, but test data regarding an aging effect is not enough. Also, there is no data of linear strain limit and breaking behavior for the thick rubber bearing after aging. This paper focuses on aging properties of the thick rubber bearing, such as basic mechanical properties and ultimate strength. An aging promote test of the thick rubber bearing was performed by using 1/2 scale and 1/8 scale rubber bearings. Aging of the rubber bearing was reproduced by thermal degradation, where the target aging period was 30 years and 60 years. The load deflection curves of the thick rubber bearing after aging were obtained through the horizontal and vertical static loading tests, and the aging effect was evaluated by comparing with the initial mechanical properties.
Yamamoto, Tomohiko; Kawasaki, Nobuchika; Fukasawa, Tsuyoshi*; Okamura, Shigeki*; Somaki, Takahiro*; Samejima, Yusuke*; Masaki, Nobuo*
Proceedings of 2015 ASME Pressure Vessels and Piping Conference (PVP 2015) (Internet), 7 Pages, 2015/07
Since a SFR (Sodium-cooled Fast Reactor) has thin-walled component structures, a seismic isolation system is employed to mitigate the seismic force. Seismic isolation system for applying the SFR consists of the laminated rubber bearing considering characteristics of SFR structures. This paper describes a basic mechanical characteristic examination with a 1/8 scale model and a characterization examination plan of half-scale laminated rubber.
Fukasawa, Tsuyoshi*; Okamura, Shigeki*; Yamamoto, Tomohiko; Kawasaki, Nobuchika; Somaki, Takahiro*; Sakurai, Yu*; Masaki, Nobuo*
Proceedings of 2015 ASME Pressure Vessels and Piping Conference (PVP 2015) (Internet), 10 Pages, 2015/07
This paper described the results of static loading tests using a half-scale rubber bearing model to investigate the fundamental characteristics such as restoring force of a rubber bearing applied to a Sodium-Cooled-Fast-Reactor (SFR). Since the SFR has thin-walled structures, a seismic isolation system is employed to mitigate the seismic force. The static loading tests were performed using the half-scale rubber bearing with a diameter of 800 mm in the range which exceeds a linear limit of horizontal direction and a yield stress of vertical direction to investigate the horizontal and vertical of each stiffness and damping ratio. The fundamental characteristic of rubber bearing employed to the SFR and the validity of a design formula became clear through the static tests.
Sakurai, Eiko*; Yanai, Kazuhiko*; Ishii, Keizo*; Fujiki, Kota*; Hiraishi, Shingo*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Okamura, Nobuyuki*; Yokoyama, Akihito; Kada, Wataru; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 84, 2012/01
Makida, Yasuhiro*; Ohata, Hirokatsu*; Okamura, Takahiro*; Ogitsu, Toru*; Nakamoto, Tatsushi*; Kimura, Nobuhiro*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 34, 2007/02
A string of superconducting magnets is to be set at an arc section of the J-PARC neutrino beam line. To keep the magnets at superconducting condition, a helium cryogenic facility is to be constructed. Parts of cryogenic devices are located beside the magnets, so thier resistance to radiation with predicted dose of 1 MGy in maximum must be assured. A cryogenic control valve is one of the active devices used in the radio-active area, and its radio-proof characteristics is improved by (1) exchaging intolerant materials by proof ones, (2) moving the feed back control circuit unit including electronics from the valve body to a low radio-active area. Two prototype valves, a tuning valve and a Gauzky relief valve, have been prepared and have been tested by using the Cobalt 60 irradiation facility in JAEA. Actual operations of the both prototypes have been checked at the irradiation test bench, and they were successfully operated after irradiation of 1 MGy.
Kitamura, Seiji; Okamura, Shigeki; Takahashi, Kenji; Kamishima, Yoshio*; Somaki, Takahiro*; Morishita, Masaki
Proceedings of 9th World Seminar on Seismic Isolation, Energy Dissipation and Active Vibration Control of Structures (CD-ROM), p.209 - 216, 2005/00
A structural concept of a vertical component isolation system for fast reactors, assuming a building adopting a horizontal base isolation system, has been studied. In this concept, a reactor vessel and major primary components are suspended from a large common deck supported by vertical isolation devices consisting of large coned disk springs. We designed the isolation device, which could be achieved vertical isolation frequency of 1 Hz and damping ratio of 20 %. Full scale coned disk spring and damper performance tests were carried out to verify the validity of design equations. And a series of shaking table test using a 1/8 scale model was performed. The test results fit well the simulation analysis results, so the validity of the design methods was able to be verified. The prospect that the vertical component isolation system applied to the FBR plant could technically realize was obtained.
Makida, Yasuhiro*; Iida, Masahisa*; Ohata, Hirokatsu*; Okamura, Takahiro*; Ogitsu, Toru*; Kimura, Nobuhiro*; Tanaka, Kenichi*; Nakamoto, Tatsushi*; Yamamoto, Akira*; Idesaki, Akira; et al.
no journal, ,
A Superconducting magnet system will be adopted for the J-PARC neutrino beam line. Since the magnet system will be exposed to high radiation field, the radiation resistance of a cryostat is very important. We have developed radio-proof control valve and relief valve by selection of some parts and separation of the positioner. In this work, the developed valves were worked under the 
ray irradiation, and it was found that the valves show the radiation resistance above 1MGy.
Kitamura, Seiji; Okamura, Shigeki; Somaki, Takahiro*
no journal, ,
The three dimension seismic isolation system by the vertical component seismic isolation system with the coned disk springs is developed. In this report, the behavior of the coned disk spring with damage in loading test is described.
Makida, Yasuhiro*; Ohata, Hirokatsu*; Okamura, Takahiro*; Ogitsu, Toru*; Nakamoto, Tatsushi*; Kimura, Nobuhiro*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio
no journal, ,
A Superconducting magnet system will be adopted for the J-PARC neutrino beam line. Since the magnet system will be exposed to high radiation field, the radiation resistance of a cryostat is very important. We have developed radio-proof control valve and relief valve by selection of some parts and separation of the positioner. In this work, the developed valves were worked under the ray irradiation, and it was found that the valves show the radiation resistance above 1 MGy.
Sakurai, Eiko*; Ishii, Keizo*; Yamanaka, Kentaro*; Okura, Satoru*; Fujiki, Kota*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Kamiya, Tomihiro; Sato, Takahiro; Arakawa, Kazuo*; et al.
no journal, ,
Cognitive degradation and behavior disorder occur under the mental disease caused by stimulant drugs. In this study, it was continuously administered to mice. After that, neuropoiesis of dentate gyrus and trace elements in its brain were analyzed by in-air micro-PIXE. As a result, the distribution of trace elements was different from that of normal mice.
Sakurai, Eiko*; Ishii, Keizo*; Okamura, Nobuyuki*; Sato, Takahiro; Kamiya, Tomihiro; Yanai, Kazuhiko*
no journal, ,
The brain section of the mouse which prescribed methamphetamine was analyzed using micro-PIXE. When bromine in the hippocampal dentate gyrus of a mouse which caused the behavioral change, and other amounts of elements were measured, the amount of bromine accumulation was on the decrease, but the accumulation of zinc, iron, and calcium were on the increase. It was suggested that the medicine which gives change to the amount of actions has also affected distribution of the trace element within a brain.
Sakurai, Eiko*; Yanai, Kazuhiko*; Okamura, Nobuyuki*; Ishii, Keizo*; Fujiki, Kota*; Hiraishi, Shingo*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Yokoyama, Akihito; Kada, Wataru; et al.
no journal, ,
no abstracts in English
Sakurai, Eiko*; Yanai, Kazuhiko*; Okamura, Nobuyuki*; Ishii, Keizo*; Hiraishi, Shingo*; Yamauchi, Shosei*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Yokoyama, Akihito; Kada, Wataru; et al.
no journal, ,
no abstracts in English
Yamamoto, Tomohiko; Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Hirokawa, Atsushi*; Miyagawa, Takayuki*; Okamura, Shigeki*
no journal, ,
High speed type horizontal oil damper is developed for three dimensional seismic isolation system for SFR. This paper describes the experimental plan of this oil damper.
Okamura, Shigeki*; Kinoshita, Takahiro*; Nishino, Hiroyuki; Yamano, Hidemasa; Kurisaka, Kenichi; Futagami, Satoshi; Fukasawa, Tsuyoshi*
no journal, ,
A Sodium-Cooled Fast Reactor (SFR) has thin-walled structures compared to the LWRs, because its thermal stress due to elevated temperature is much higher and its internal pressure is much lower than that of the LWRs. A seismic isolation system is employed to reduce the seismic force, because the thin-walled structure is strongly affected by severe earthquakes. The thicker laminated rubber bearings are adopted for SFR. The laminated rubber bearing with thickness rubber is adopted for SFR. The characteristic of the laminated rubber bearing has been grasped by the static test with 1/2scale model. The analysis model, which improved non-linear characteristic, has suggested. On the other hand, the earthquake PRA has carried out in the seismic isolation plant of SFR. In this study, the seismic response analysis with the improved analysis model was carried out. The acceleration response in the floor response spectrum was grasped. The damage probability of the reactor with the non-linear characteristic of the laminated rubber bearing is improved.
Yamamoto, Tomohiko; Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Hirokawa, Atsushi*; Miyagawa, Takayuki*; Okamura, Shigeki*
no journal, ,
no abstracts in English
Adachi, Yoshihiko*; Endo, Naoki*; Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Okamura, Shigeki*
no journal, ,
no abstracts in English
Endo, Naoki*; Adachi, Yoshihiko*; Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Okamura, Shigeki*
no journal, ,
no abstracts in English
Somaki, Takahiro*; Morobishi, Ryota*; Fukasawa, Tsuyoshi*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Okamura, Shigeki*
no journal, ,
no abstracts in English
