Overview of Nuclear Piping Seismic Verification

Abstract

Nuclear power has gone through several transitional phases worldwide with early development, design, and construction in 1960s, 1970s, and 1980s, particularly in Japan and U.S. A relatively less active period followed in U.S. in 1990s followed by resurgence of interest and activities in 2000s. Currently, some countries are focusing on advanced reactor technology and smaller modular reactors instead of large light water reactors. Along with the transition in the need for power and technological advances, one other major change has occurred. Most of the workforce that participated in development, design, research, construction, and operation of currently operating plants is no longer active. There were some major research programs conducted during those years to develop methodology and prove the technology. Much of this knowledge is still very relevant and applicable and would be useful to young engineers and new professionals coming to the nuclear industry. One of such programs is seismic verification of major structures, systems, and components (SSCs) by tests in Japan during the period of 1981–2004 at a large shaking table facility. Opportunities for conducting such large tests are not likely in the current environment of the industry and, therefore, one of the objectives of this paper is to summarize some earlier tests to raise awareness for the newcomers to the industry. This paper discusses piping tests conducted in Japan at the era. In particular, this paper focuses on: insights obtained from the test results; comparisons of test results with responses during actual earthquakes; collaboration of Japan and U.S. in these tests; observations on robustness of Japanese seismic design; how the results relate to current issues; and use of these results from the future perspectives.