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The Effects of Seismic Failure Correlations on the Probabilistic Seismic Safety Assessments of Nuclear Power Plants

지진 손상 상관성이 플랜트의 확률론적 지진 안전성 평가에 미치는 영향

  • Eem, Seunghyun (Major in Plant System Engineering, Department of Convergence and Fusion System Engineering, Kyungpook National University) ;
  • Kwag, Shinyoung (Department of Civil and Environmental Engineering, Hanbat National University) ;
  • Choi, In-Kil (Smart Structural Safety and Prognosis Research Division, Korea Atomic Energy Research Institute) ;
  • Jeon, Bub-Gyu (Seismic Research and Test Center, Pusan National University) ;
  • Park, Dong-Uk (Seismic Research and Test Center, Pusan National University)
  • 임승현 (경북대학교 융복합시스템공학과 플랜트시스템전공) ;
  • 곽신영 (한밭대학교 건설환경공학과) ;
  • 최인길 (한국원자력연구원 스마트안전진단연구부) ;
  • 전법규 (부산대학교 지진방재연구센터) ;
  • 박동욱 (부산대학교 지진방재연구센터)
  • Received : 2021.01.07
  • Accepted : 2021.02.09
  • Published : 2021.03.01

Abstract

Nuclear power plant's safety against seismic events is evaluated as risk values by probabilistic seismic safety assessment. The risk values vary by the seismic failure correlation between the structures, systems, and components (SSCs). However, most probabilistic seismic safety assessments idealized the seismic failure correlation between the SSCs as entirely dependent or independent. Such a consideration results in an inaccurate assessment result not reflecting real physical phenomenon. A nuclear power plant's seismic risk should be calculated with the appropriate seismic failure correlation coefficient between the SSCs for a reasonable outcome. An accident scenario that has an enormous impact on a nuclear power plant's seismic risk was selected. Moreover, the probabilistic seismic response analyses of a nuclear power plant were performed to derive appropriate seismic failure correlations between SSCs. Based on the analysis results, the seismic failure correlation coefficient between SSCs was derived, and the seismic fragility curve and core damage frequency of the loss of essential power event were calculated. Results were compared with the seismic fragility and core damage frequency of assuming the seismic failure correlations between SSCs were independent and entirely dependent.

Keywords

References

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