In order to increase the seismic safety of nuclear power plant (NPP) structures, a technique to reduce the seismic load transmitted to the NPP structure by using a seismic isolation device such as a lead-rubber bearing has recently been actively researched. In seismic design of NPP structures, three directional (two horizontal and one vertical directions) artificial synthetic earthquakes (G0 group) corresponding to the standard design spectrum are generally used. In this study, seismic analysis was performed by using three directional artificial synthetic earthquakes (M0 group) corresponding to the maximum-minimum spectrum reflecting uncertainty of incident direction of earthquake load. The design basis earthquake (DBE) and the beyond design basis earthquakes (BDBEs are equal to 150%, 167%, and 200% DBE) of G0 and M0 earthquake groups were respectively generated for 30 sets and used for the seismic analysis. The purpose of this study is to compare seismic responses and seismic fragility curves of seismically isolated NPP structures subjected to DBE and BDBE. From the seismic fragility curves, the probability of failure of the seismic isolation system when the peak ground acceleration (PGA) is 0.5 g is about 5% for the M0 earthquake group and about 3% for the G0 earthquake group.

A B S T R A C T
 1. 서 론
 2. 면진된 원전구조물의 지진해석모델
  2.1 원전구조물 모델링
  2.2 면진장치 모델링
  2.3 입력지진의 특성
 3. 원전구조물의 지진응답 비교
  3.1 지진하중에 따른 면진장치와 격납구조물의 변위응답의 비교
  3.2 지진하중에 따른 면진장치와 격납구조물의 가속도 응답의 비교
  3.3 지진하중에 따른 격납구조물의 전단력 응답의 비교
 4. 면진된 원전구조물의 지진취약도 해석
 5. 결 론
 REFERENCES

• 김현정(강원대학교 건축·토목·환경공학부 토목공학전공) | Kim Hyeon-Jeong (Department of Civil Engineering, Kangwon National University)
• 송종걸(강원대학교 건축·토목·환경공학부 토목공학전공) | Song Jong-Keol (Department of Civil Engineering, Kangwon National University) Corresponding author