In general, seismic adequacy of the safety related equipment in Nuclear Power Plants (NPPs) is verified by Shake Table Test. Regarding Beyond Design Basis Seismic Event (BDBSE), directly performing Shake Table Test for all equipment again do not seem to be an efficient and economical approach because seismic design margin of some equipment is sufficient to BDBSE.
NARI has established an applicable technology of Seismic Margin Assessment (SMA) which contains a systematic seismic evaluation process for NPPs in Taiwan. In addition to verifying the seismic adequacy of safety related equipment in NPPs, the reliability of safety related system can be efficiently improved by implementing the corresponding retrofit of seismic inadequate items from the SMA insight.
SMA for the safety system of pressure control within the containment of the NPP in Taiwan has been performed successfully by NARI. Furthermore, equipment with potential inadequacy to seismic concerns are also identified. Finally, NARI has assisted the NPP in Taiwan to make resources for retrofitting the equipment more efficiency in improving the reliability of the safety system instead of repurchasing equipment that shall meet the requirement of BDBSE.