Abstract
Seismically isolated nuclear power plants (NPPs) can provide substantial benefits towards reducing the failure probability of NPPs, especially for beyond design basis earthquake shaking. One risk posed by seismic isolation is the potential for pounding to a stop or moat wall, with currently little guidance provided by design standards on how to address this concern. In this paper, a structural model of an isolated NPP based on the Advanced Power Reactor 1400 MW is enveloped with moat walls and advanced bearing models. The bearing models account for large strain behavior through failure based on full-scale experiments with lead rubber bearings (LRBs). Using these analytical models and a measured ultimate property diagram from LRB failure tests, the range of clearance to the stop considering the performance criteria for the NPP is investigated. Although the analysis results are dependent on the particular models, ground motions, and criteria employed, this research provides an overview of the seismic response and performance criteria of an isolated NPP considering the clearance to the stop.
Highlights
Seismic isolation systems represent a promising strategy to improve the seismic performance of a structure under strong ground motions that reduces the vibration transferred to the structure by inserting a flexible isolation layer at the base that can sustain large displacements [1]
The key objective of this paper is to examine the performance criteria of seismically isolated nuclear power plants (NPPs), the clearance to the stop (CS), as suggested by NUREG [15] and ASCE [16]
Clearance to the stop of an isolated NPP based on given performance criteria
Summary
Seismic isolation systems represent a promising strategy to improve the seismic performance of a structure under strong ground motions that reduces the vibration transferred to the structure by inserting a flexible isolation layer at the base that can sustain large displacements [1]. There are some remaining issues in the application of seismic isolation systems to nuclear power plants(NPPs), such as the durability of the isolators and design- and construction-related issues, the use of seismic isolation has increased gradually from the first seismically isolated NPP in Koeberg, South Africa in the 1970s [2,3]. With stricter safety regulations than other structures, it is critical that NPPs maintain their structural integrity against severe external hazards, including earthquakes. The application of seismic isolation to NPPs can allow for designs to meet the requirements in high seismic zones or increase the margin of safety for unexpected motions in regions with lower seismic risk.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
