Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 39

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Research and development of three-dimensional isolation system for sodium cooled fast reactor, 7; Development summary of three-dimensional isolation system

Watakabe, Tomoyoshi; Yamamoto, Tomohiko; Okamura, Shigeki; Miyazaki, Masashi; Miyagawa, Takayuki; Uchita, Masato*; Hirayama, Tomoyuki*; Somaki, Takahiro*; Yukawa, Masaki*; Fukasawa, Tsuyoshi*; et al.

Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 10 Pages, 2024/07

To secure the seismic safety of the thin-walled mechanical components and piping under a severe design earthquake level, employing a three-dimensional (3D) seismic isolation system has been planned in a sodium-cooled fast reactor. The development results of the 3D isolation system have been reported in previous papers so far. Its update is reported in Part 7 to Part 9. Part 7 describes the overview of the development, the test plan of the isolation system in the assembled state of each element, and the performance of individual isolation elements. In part 8, the performance of the isolation device that each element was assembled into was investigated through loading tests. Part 9 reports analytical studies by an analysis model validated based on the insight of the test results.

Journal Articles

Seismic design and applications using 3-dimensional seismic isolation system

Yamamoto, Tomohiko; Okamura, Shigeki; Hirayama, Tomoyuki*; Somaki, Takahiro*

Haikan Gijutsu, 65(13), p.1 - 4, 2023/11

The authors are conducting research and development on three-dimensional seismic isolation devices to improve the earthquake resistance of future sodium-cooled fast reactors. This paper introduces an overview of the device and how to use it.

Journal Articles

Research and development of three-dimensional isolation system for SFR (Experimental study on static characteristics using half scale size model)

Fukasawa, Tsuyoshi*; Hirayama, Tomoyuki*; Yokoi, Shinobu*; Hirota, Akihiko*; Somaki, Takahiro*; Yukawa, Masaki*; Miyagawa, Takayuki; Uchita, Masato*; Yamamoto, Tomohiko; Miyazaki, Masashi; et al.

Nihon Kikai Gakkai Rombunshu (Internet), 89(924), p.23-00023_1 - 23-00023_17, 2023/08

no abstracts in English

Journal Articles

Study on vertical restoring force device using disc springs; Examination of optimum combination of disc spring units and identification method of hysteresis loop

Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Miyagawa, Takayuki*; Uchita, Masato*; Yamamoto, Tomohiko; Ishizuka, Futoshi*; Suzuno, Tetsuji*; Okamura, Shigeki*; Fujita, Satoshi*

Kozo Kogaku Rombunshu, B, 68B, p.462 - 475, 2022/04

Journal Articles

Research and development of thick rubber bearing for SFR; Aging properties tests of semi full-scale thick rubber bearing

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.

Journal Articles

Development on rubber bearings for sodium-cooled fast reactor, 4; Aging properties of a half scale thick rubber bearings based on breaking test

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.

Journal Articles

Development on rubber bearings for sodium-cooled fast reactor, 1; Examination plan

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.

Journal Articles

Development on rubber bearings for sodium-cooled fast reactor, 2; Fundamental characteristics of half-scale rubber bearings based on static test

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.

Journal Articles

Conceptual design for Japan Sodium-cooled Fast Reactor, 4; Developmental study of steel plate reinforced concrete containment vessel for JSFR

Negishi, Kazuo; Hosoya, Takusaburo; Sato, Kenichiro*; Somaki, Takahiro*; Matsuo, Ippei*; Shimizu, Katsusuke*

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9418_1 - 9418_7, 2009/05

An innovative containment vessel, namely Steel plate reinforced Concrete Containment Vessel (SCCV) is developed for Japan Sodium-Cooled Fast Reactor (JSFR). Reducing plant construction cost is one of the most important issues for commercialization of fast reactors. This study investigated construction issues including the building structure and the construction method as well as design issues in terms of the applicability of SCCV to fast reactors. An experimental study including loading and/or heating tests has been carried out to investigate the fundamental structural features, which would be provided to develop methodology to evaluate the feasibility of SCCV under the severe conditions. In this paper, the test plan is described as well as the first test results.

Journal Articles

Development of vertical component isolation system with coned disk springs for FBR plant

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.

JAEA Reports

The Investigation about embodiment of vertical isolation structure

Somaki, Takahiro*; Miyamoto, Akinori*

JNC TJ9410 2005-001, 101 Pages, 2004/11

JNC-TJ9410-2005-001.pdf:5.17MB

In this study, supporting structure for the seismic horizontal force and the common deck structure were taken concrete shapes, and the feasibility studies were carried out. Furthermore, the influence on design method of coned disk spring by creep phenomenon was investigated, test pieces for investigating the long-range stability of friction coefficient were manufactured.

JAEA Reports

The Investigation about embodiment of vertical isolation structure

Somaki, Takahiro*; Miyamoto, Akinori*

JNC TJ9420 2003-005, 129 Pages, 2003/02

JNC-TJ9420-2003-005.pdf:4.62MB

In order to realize the concept of a vertical isolation system called common deck system, research and development on the vertical isolation structure is now underway. In its first step, structure plans of each of the isolation element and the damper element will be drawn up, and in the next step, tests on these elements will be planed, executed, analyzed, and evaluated, to be reflected to the structure plan. In this report, the study of analysis, the structure plan and test plan of vertical isolation devices is reported. /The appropriateness of analysis was confirmed by comparison between test results and analysis results. And the loading mechanism and the stress condition of dish spring as piling five lines were analyzed./The formula of Creep was examined on creep test results. And the influence of amount of deformation by creep behavior was made clear on the life of building./The characteristic of loading in actual typical model was presumed by test results, design formula and FEM analysis. These results were mostly coincided and the appropriateness of design method was confirmed./Response displacement of a vertical isolation and response acceleration of primary instruments were analyzed and confirmed beyond restriction values by dynamic analysis./The total fabrication of isolation device and each component were drowned on the result of these studies./The scale of test model was estimated and the map of test model was drowned. And several test plans reflects design guideline were made.

JAEA Reports

The Investigation about embodiment of vertical isolation structure; An Embodiment of the structural plan of damper element

Somaki, Takahiro*; Miyamoto, Akinori*;

JNC TJ9420 2003-001, 341 Pages, 2003/01

JNC-TJ9420-2003-001.pdf:1.18MB

In order to realize the concept of a vertical isolation system (common deck system), research and development on the vertical isolation structure is now underway. In its first step, structure plans of each of the isolation element and the damper element will be drawn up, and in the next step, tests on these elements will be planed, executed, analyzed, and evaluated, to be reflected to the structure plane. In this report, the structure plan and test plan of damper element is reported. At first, it was concluded in the previous work that the steel-materials damper which can be evaluated by Ramberg-Osgood type is applicable to the vertical isolation system required performance.

Oral presentation

Research and development of three-dimensional seismic isolation system, 32; Results of seismic response analysis for reactor building

Morobishi, Ryota*; Somaki, Takahiro*; Fukasawa, Tsuyoshi*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Okamura, Shigeki*

no journal, , 

no abstracts in English

Oral presentation

Research and development of oil damper with high allowable velocity for seismic isolation, 4; Feasibility study for 2.7 m/s of allowable velocity

Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Endo, Naoki*; Okamura, Shigeki*; Fujita, Satoshi*

no journal, , 

no abstracts in English

Oral presentation

Research and development of three-dimensional seismic isolation system, 35; Study summary of three-dimensional isolation system and horizontal oil damper

Okamura, Shigeki*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Miyazaki, Masashi; Hirayama, Tomoyuki*; Fukasawa, Tsuyoshi*; Fujita, Satoshi*; Somaki, Takahiro*; Endo, Naoki*

no journal, , 

no abstracts in English

Oral presentation

Research and development of three-dimensional seismic isolation system, 36; Test plan of three-dimensional seismic isolation system

Hirayama, Tomoyuki*; Somaki, Takahiro*; Nakamura, Misaki*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Miyazaki, Masashi; Fukasawa, Tsuyoshi*; Fujita, Satoshi*

no journal, , 

no abstracts in English

Oral presentation

Research and development of three-dimensional seismic isolation system, 39; Integrated test results of three-dimensional seismic isolation system (1)

Yukawa, Masaki*; Somaki, Takahiro*; Hirayama, Tomoyuki*; Miyagawa, Takayuki*; Yamamoto, Tomohiko; Miyazaki, Masashi; Fukasawa, Tsuyoshi*

no journal, , 

no abstracts in English

Oral presentation

Research and development of three-dimensional seismic isolation system, 44; Study summary of three-dimensional isolation system and horizontal oil damper

Okamura, Shigeki; Uchita, Masato*; Yamamoto, Tomohiko; Miyazaki, Masashi; Watakabe, Tomoyoshi; Hirayama, Tomoyuki*; Fukasawa, Tsuyoshi*; Fujita, Satoshi*; Somaki, Takahiro*; Endo, Naoki*

no journal, , 

no abstracts in English

Oral presentation

Research and development of three-dimensional seismic isolation system, 45; Integrated test plan of three-dimensional seismic isolation system

Hirayama, Tomoyuki*; Somaki, Takahiro*; Nakamura, Misaki*; Uchita, Masato*; Yamamoto, Tomohiko; Miyazaki, Masashi; Watakabe, Tomoyoshi; Fukasawa, Tsuyoshi*; Fujita, Satoshi*

no journal, , 

no abstracts in English

39 (Records 1-20 displayed on this page)