Session: SE-02-01 Seismic Isolation and Structural Dynamics-1

Paper Number: 122430

122430 - Research and Development of Three-Dimensional Isolation System for Sodium Cooled Fast Reactor: Part 7 Development Summary of Three-Dimensional Isolation System 

A Sodium-cooled-fast-reactor (SFR) has been developed as one option for energy de-carbonization in 2050 in Japan. The SFR is operated under an elevated temperature and a low-pressure condition compared with existing light water reactors (LWRs). The mechanical components and piping in the SFR are consequently designed as thin-walled structures from the perspective of the elevated temperature design. In addition, seismic design earthquake level is to be severe more and more by regulatory requirements based on past earthquake disaster experiences.  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 the SFR. The development outcome of the 3D isolation system has been reported in previous papers so far. Its update is reported in Part 7 to Part 9.

The proposed isolation system consists of a thicker laminated rubber bearing for reducing horizontal seismic load, coned disk springs for reducing vertical seismic load, oil dampers for horizontal and vertical damping components, and a support structure for the integration of each isolation component. Part 7 describes the overview of the 3D isolation system, the development plan, and the performance of individual isolation components which was confirmed through a series of loading tests by an actuator. In part 8, the performance of the isolation unit that each component was integrated into was investigated through some tests. Part 9 reports analytical studies by an analysis model validated based on the insight of the test results.

Presenting Author: Tomoyoshi Watakabe Japan Atomic Energy Agency

Presenting Author Biography: Tomoyoshi Watakabe received a Doctorate degree in Mechanical Engineering, in Tokyo denki university in Japan, in 2009. He is a researcher at the Japan Atomic Energy Agency. His main research interests include the development of seismic isolation devices and seismic design methods of mechanical components and piping in sodium-cooled fast reactors.

Authors:

Tomoyoshi Watakabe Japan Atomic Energy Agency
Tomohiko Yamamoto Japan Atomic Energy Agency
Shigeki Okamura Japan Atomic Energy Agency
Masashi Miyazaki Japan Atomic Energy Agency
Takayuki Miyagawa Japan Atomic Energy Agency
Masato Uchita Japan Atomic Power Company
Tomoyuki Hirayama Mitsubishi FBR Systems, Inc.
Takahiro Somaki Obayashi Corporation
Masaki Yukawa Obayashi Corporation
Tsuyoshi Fukasawa Tokyo Denki University
Satoshi Fujita Tokyo Denki University