Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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A hybrid approach of partially applying BDD for seismic PSA quantification

  • Sang Hoon Han (Risk Assessment Research Division, Korea Atomic Energy Research Institute)
  • Received : 2023.12.13
  • Accepted : 2024.05.25
  • Published : 2024.10.25
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Abstract

The binary decision diagram (BDD) method provides a means to calculate the exact probability of a fault tree, but cannot solve large fault trees for nuclear power plant PSAs. However, the BDD method can be used as a supplementary means to increase the accuracy of PSA quantification, especially for a seismic PSA which includes many non-rare events. Since it is difficult to solve a large PSA model using BDD method, several approaches have been developed that partially apply the BDD technique to small-sized branches of a large PSA model. This paper proposes an approach of partially applying BDD technique to large-sized branches. The results from the pilot application to a seismic PSA model shows that the partial BDD approach of this paper provides a relatively accurate way to quantify each sequence as well as the overall core damage in a seismic PSA model.

Keywords

Acknowledgement

This work was supported by the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety (KoFONS) using financial resources granted by the Nuclear Safety and Security Commission (NSSC) of Korea (No. RS-2023-00240452).

References

  1. R.E. Bryant, Graph-based algorithms for boolean function manipulation, IEEE Trans. Comput. C-35 (No.8) (1986). 
  2. Antoine Rauzy, New algorithms for fault trees analysis, Reliab. Eng. Syst. Saf. 40 (1993) 203-211. 
  3. Jung Han Kim, et al., Overview of development of PRASSE: probabilistic risk assessment of systems for seismic events, in: Transact Kor. Nuclear Soc. Autumn Meet, Gyeongju, Korea, 2011 Oct., pp. 27-28. 
  4. EQE International Inc, EQESRA Reference Document Version 3, 1995. 
  5. Ji Suk Kim, Man Cheol Kim, Insights gained from applying negate-down during quantification for seismic probabilistic safety assessment, Nucl. Eng. Technol. 54 (2022) 2933-2940. 
  6. FTREX 2, 0 Software Manual, EPRI 3002018234, 2020. 
  7. Hak Kyu Lim, A Simple approach to calculate CDF with non-rare events in seismic PSA model of Korean nuclear power plants, J. Korean Surg. Soc. 36 (5) (2021) 86-91. 
  8. Woo Sik Jung, A method to improve cutset probability calculation in probabilistic safety assessment of nuclear power plants, Reliab. Eng. Syst. Saf. 134 (2015) 134-142. 
  9. Sang Hoon Han, Enhancement of the FTeMC Software for Fault Tree Top Event Probability Evaluation Using Monte Carlo Approach, Transactions of the Korean Nuclear Society Spring Meeting, Jeju, Korea, 2018. May. 17-18. 
  10. Tetsukuni Oikawa, et al., Development of systems reliability analysis code SECOM-2 for seismic PSA, Reliab. Eng. Syst. Saf. 62 (1998) 251-271.