Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
권호 표지
DOI QR코드

DOI QR Code

FLOODING PSA BY CONSIDERING THE OPERATING EXPERIENCE DATA OF KOREAN PWRs

  • Published : 2007.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The existing flooding Probabilistic Safety Analysis(PSA) was updated to reflect the Korean plant specific operating experience data into the flooding frequency to improve the PSA quality. Both the Nuclear Power Experience(NPE) database and the Korea Nuclear Pipe Failure Database(NuPIPE) databases were used in this study, and from these databases, only the Pressurized Water Reactor(PWR) data were used for the flooding frequencies of the flooding areas in the primary auxiliary building. With these databases and a Bayesian method, the flooding frequencies for the flooding areas were estimated. Subsequently, the Core Damage Frequency(CDF) for the flooding PSA of the Ulchin(UCN) unit 3 and 4 plants based on the Korean Standard Nuclear Power Plant(KSNP) internal full-power PSA model was recalculated. The evaluation results showed that sixteen flooding events are potentially significant according to the screening criterion, while there were two flooding events exceeding the screening criterion of the existing UCN 3 and 4 flooding PSA. The result was compared with two kinds of cases: (1) the flooding frequency and CDF from the method of the existing flooding PSA with the PWR and Boiled Water Reactor(BWR) data of the NPE database and the Maximum Likelihood Estimate(MLE) method and (2) the flooding frequency and CDF with the NPE database(PWR and BWR data), NuPIPE database, and a Bayesian method. From the comparison, a difference in CDF results was revealed more clearly between the CDF from this study and case (2) than between case (1) and case (2). That is, the number of flooding events exceeding the screen criterion further increased when only the PWR data were used for the primary auxiliary building than when the Korean specific data were used.

Keywords

References

  1. ASME, 'Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications,' ASME RA-S-2002 (2002)
  2. Nuclear Energy Institute Risk-based Applications Task Force, 'Probabilistic Risk Assessment Peer Review Process Guidance' (2000)
  3. KAERI/TR-2509/2003, Review of UCN 3,4 PSA Model based on ASME PRA Standard, Rev.0,' KAERI (2003)
  4. J. E. Yang and J. J. Ha, 'Improving PSA Quality of KSNP Model,' KNS Conf., Korea (2005)
  5. Stoller Power, Inc., 'Nuclear Power Experience,' Bolder, Colorado
  6. KEPCO, 'Ulchin Units 3&4 Final Probabilistic Safety Assessment Report, Rev. 1' Vol. 3 (1997)
  7. KEPCO. 'Individual Plant Examination of External Events for Yonggwang Nuclear Units 3&4' (1993)
  8. KHNP, 'Probabilistic Safety Assessment for Ulchin Units 5&6 (Phase II): External Event Analysis (Final Report),' 98NJ14 (2002)
  9. KAERI/KINS, 'NuPIPE (Korea Nuclear Pipe Failure Database) Program'
  10. S. Y. Choi and J. E. Yang, 'Estimation of Internal Flooding Frequency for Screening Analysis of Flooding PSA,' KNS Conf., Korea (2005)
  11. S. Y. Choi and Y. H. Choi, 'Development of OPDE Piping Failure Database,' KNS Conf., Korea (2002)
  12. Virginia Power, 'Probabilistic Risk Assessment Surry Nuclear Power Plant Unit 1 and 2 for the Individual Plant Examination, Final Report Vol. V, App. E,' August (1991)
  13. S. Y. Choi and Y. H. Choi, 'Application of Piping Failure Database in Korea,' OPDE Database Application Workshop, Korea (2004)
  14. S. Y. Choi and Y. H. Choi, 'Piping Failure Frequency Analysis for the Maint Feedwater System in Domestic Nuclear power Plants,' KNS Journal, 36, 1 (2004)
  15. S. Y. Choi, J. J. Ha, and Y. H Choi, 'Evaluation of Nuclear Piping Rupture in Korean PWRs,' KPVP Conf., Korea (2004)
  16. NUREG/CR-5750J, 'Rates of Initiating Events at U.S. Nuclear Power Plants: 1987-1995,' U.S.NRC (1999)
  17. M. J. Hwang, 'Development of Generic Component Reliability Database considering the dependency among the book data,' KAERI (1997)
  18. Christian P. Robert, 'The Bayesian Choice from Decision Theoretic Foundations to Computational Implementation,' Springer, 2001
  19. Box and Tiao, 'Bayesian Inference in Statistical Analysis,' John Wiley and Sons, Inc. (1992)
  20. Bayesian Reliability Analysis, Harry F. Martz and Ray A. Waller, John Wiley & Sons (1982)
  21. KAERI, 'PRiME-U34'
  22. NUREG/CR-1407, 'Procedural and Submittal Guidance for the Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities,' USNRC (1991)