DOI QR코드

DOI QR Code

Influence Analysis of Seismic Risk due to the Failure Correlation in Seismic Probabilistic Safety Assessment

다중기기 손상 상관성에 의한 지진리스크 영향 분석

  • Eem, Seung-Hyun (Structural and Seismic Safety Research Team, Korea Atomic Energy Research Institute) ;
  • Choi, In-Kil (Structural and Seismic Safety Research Team, Korea Atomic Energy Research Institute)
  • 임승현 (한국원자력연구원, 구조지진안전연구실) ;
  • 최인길 (한국원자력연구원, 구조지진안전연구실)
  • Received : 2018.07.13
  • Accepted : 2019.01.10
  • Published : 2019.03.01

Abstract

The seismic safety of nuclear power plants has always been emphasized by the effects of accidents. In general, the seismic safety evaluation of nuclear power plants carries out a seismic probabilistic safety assessment. The current probabilistic safety assessment assumes that damage to the structure, system, and components (SSCs) occurs independently to each other or perfect dependently to each other. In case of earthquake events, the failure event occurs with the correlation due to the correlation between the seismic response of the SSCs and the seismic performance of the SSCs. In this study, the EEMS (External Event Mensuration System) code is developed which can perform the seismic probabilistic safety assessment considering correlation. The developed code is verified by comparing with the multiplier n, which is for calculating the joint probability of failure, which is proposed by Mankamo. It is analyzed the changes in seismic fragility curves and seismic risks with correlation. As a result, it was confirmed that the seismic fragility curves and seismic risk change according to the failure correlation coefficient. This means that it is important to select an appropriate failure correlation coefficient in order to perform a seismic probabilistic safety assessment. And also, it was confirmed that carrying out the seismic probabilistic safety assessment in consideration of the seismic correlation provides more realistic results, rather than providing conservative or non-conservative results comparing with that damage to the SSCs occurs independently.

Keywords

References

  1. Ravindra MK. Sensitivity studies of seismic risk models. Report NP-3562. Electric Power Research Institute. Palo Alto, CA. c1984.
  2. US Nuclear Regulatory Commission. Reactor Safety Study. Wash 1400. Washington, DC. c1975.
  3. Smith PD, Dong RG, Bernreuter DL, Bohn MP, Chuang TY, Cummings GE, Smith PD, Dong RG, Bernreuter DL, Bohn MP, Chuang TY, Cummings GE, Johnson JJ, Mensing RW, Wells JE. Seismic safety margins research program. Phase I final report-Overview (No. NUREG/CR-2015 (VOL. 1)). Lawrence Livermore Laboratory. c1981.
  4. Budnitz RJ, Hardy GS , Moore DL, Ravindra MK. Correlation of Seismic Performance in Similar SSCs (Structures, Systems, and Components) (No. NUREG/CR-7237). U.S. Nuclear Regulatory Commission. c2017.
  5. US Nuclear Regulatory Commission. Procedures for the External Event Core Damage Frequency Analyses for NUREG-1150 (NUREG/CR-4840). Washington, DC. c1990.
  6. Reed JW, McCann MW, Iihara J, Hadidi-Tamjed H. Analytical Techniques for Performing Probabilistic Seismic Risk Assessment of Nuclear Power Plants. ICOSSAR '85, 4th International Conference on Structural Safety and Reliability, Kobe, Japan. c1985 May;3: 253-261.
  7. Ellingwood B. Validation studies of seismic PRAs. Nuclear Engineering and Design. 1990;123(2-3):189-196. https://doi.org/10.1016/0029-5493(90)90237-R
  8. Kim JH, Choi IK, Park JH. Uncertainty analysis of system fragility for seismic safety evaluation of NPP. Nuclear Engineering and Design. 2011;241(7):2570-2579. https://doi.org/10.1016/j.nucengdes.2011.04.031
  9. Severe accident risk assessment - Limerick Generation Station (in 2 vols.). Prepared for Philadelphia Electric Co. by NUS Corporation. c1983.