Abstract In this study, the stress response of the piping system in the advanced power reactor 1400 (APR 1400) with a base isolation design subjected to seismic loading is addressed. The piping system located between the auxiliary building with base isolation and the turbine building with a fixed base is considered since it can be subjected to substantial relative support movement during seismic events. First, the support responses with respect to the base characteristic are investigated to perform seismic analysis for multiple support excitations. Finite element analyses are performed to predict the piping stress response through various analysis methods such as the response spectrum, seismic support movement and time history method. To separately evaluate the inertial effect and support movement effect on the piping stress, the stress is decomposed into a primary and secondary stress using the proposed method. Finally, influences of the base isolation design on the piping system in the APR 1400 are addressed. The primary stress based on the inertial loading is effectively reduced in a base isolation design, whereas a considerable amount of secondary stress is generated in the piping system connecting a base isolated building with a fixed base building. It is also confirmed that both the response spectrum analysis and seismic support movement analysis provide more conservative estimations of the piping stress compared to the time history analysis.
The nuclear accident due to the recent earthquake in Japan has triggered awareness of the importance of safety with regard to nuclear power plants (NPPs). An earthquake is one of the most important parameters which governs the safety of NPPs among external events. Application of a base isolation system for NPPs can reduce the risk for earthquakes. At present, a soil-structure interaction (SSI) analysis is essential in the seismic design of NPPs in consideration of the ground structure interactio...
#1Jianyun Chen(DUT: Dalian University of Technology)H-Index: 15
#2Chunfeng Zhao(DUT: Dalian University of Technology)H-Index: 8
Last. Chenyang Yuan(DUT: Dalian University of Technology)H-Index: 5
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Abstract Safety and integrity of NPP must be ensured during the plant life in any design conditions, particularly, in the event of a severe earthquake. Base isolation as a popular and powerful technology can drastically reduce the seismic response of the structure and prevent the structure from damage. The objective of this paper is to numerically investigate the dynamic response of the AP1000 Nuclear Island (NI) building with and without isolators under a typical safe shutdown earthquake (SSE)....
#1Chunfeng Zhao(DUT: Dalian University of Technology)H-Index: 8
#2Jianyun Chen(DUT: Dalian University of Technology)H-Index: 15
Abstract Reinforced concrete containment (RCC) is the most significant component of the nuclear power plant (NPP). Therefore, the safety and integrity must be ensured during the plant life in any conditions, in particular, in the event of a severe earthquake. Seismic or base isolation is a proven technology for reducing the effects of earthquake shaking on the building and avoiding failure of structure under earthquake. The aim of this paper is to numerically analyze the dynamic response of the ...
#1Dae Soo Kim(KEPCO: Korea Electric Power Corporation)H-Index: 1
#2Joon Ho Lee(KEPCO: Korea Electric Power Corporation)H-Index: 1
Last. In Yeung Kim(KEPCO: Korea Electric Power Corporation)H-Index: 1
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The steam supply piping connected to the high pressure (HP) turbine of APR1400 (Korea’s advanced power plant 1400 MW-class) is a typical example of multi-supported piping system, and it is routed from the Containment building to the Turbine building via the Main Steam Isolation Valve House in the Auxiliary building. In the seismic analysis of this piping system, using the Enveloped Response Spectrum (ERS) method, a commonly used methodology for seismic analysis of nuclear power plant piping in i...
Conventional response spectrum analysis is used for piping seismic design in Japan. When piping is supported by restraints and structures fixed on multiple buildings or floors, the envelope of the response spectra of all supporting points is typically applied for the piping under multiple excitations. The local vibration mode of long piping is difficult to excite by the far input from the vibrating part, so the analysis will overestimate the response. Considering each input from each building or...
The Advanced Power Reactor 1400 (APR1400) is an evolutionary advanced light water reactor (ALWR) based on the Optimized Power Reactor 1000 (OPR1000), which is in operation in Korea. The APR1400 incorporates a variety of engineering improvements and operational experience to enhance safety, economics, and reliability. The advanced design features and improvements of the APR1400 design include a pilot operated safety relief valve (POSRV), a four-train safety injection system with direct vessel inj...
#1R. E. Spears(INL: Idaho National Laboratory)H-Index: 2
#2S. R. Jensen(INL: Idaho National Laboratory)H-Index: 2
Nonlinearities, whether geometric or material, need to be addressed in seismic analysis. One good analysis method that can address these nonlinearities is direct time integration with Rayleigh damping. Modal damping is the damping typically specified in seismic analysis Codes and Standards [1, 2]. Modal damping is constant for all frequencies where Rayleigh damping varies with frequency. An approach is proposed here for selection of Rayleigh damping coefficients to be used in seismic analyses th...
The objective of the present work is to examine advantages and drawbacks of different types of isolation systems, when seismic isolation is used as a protection strategy against damage to internal equipment and contents. The starting point of the study is the big experimental program of table tests on reduced-scale R/C structural models, carried out within the MANSIDE (Memory Alloys for New Seismic Isolation DEvices) project. Seven identical l:3.3-scaled, 3-storey frames were tested, including t...
Abstract This paper presents the results of a series of numerical simulation studies on seismic responses of secondary systems in base-isolated structures including equipment-structure interactions. A three-storey building is used as the primary structure, while the equipment is modelled as a single-degree-of-freedom linear system. A number of base isolation systems such as the Laminated Rubber Bearing, the Pure Friction, the Resilient-Friction, and the Electricite de France system are considere...
This paper presents a comparison of dynamic responses of piping systems subject to independent-support excitation using the response spectrum and time-history methods. The BNL finite-element computer code PSAFE2 has been used to perform all the analyses. The time-history method combines both the inertia as well as static effect on the piping responses due to independent-support excitations at each time point, thus representing the actual responses. A sample problem is analyzed subjected to two i...