Method for Setting up the Truncation Limit of Probabilistic Safety Assessment

  • Marko Čepin
Conference paper


Truncation defines cutting off the negligible contribution of the results of the probabilistic safety assessment. A method is developed, which defines truncation limit in probabilistic safety assessment. The new method specifies the truncation limits with more requirements. The results show that application of the new method largely reduces the large relative errors of importance measures in probabilistic safety assessment. Evaluation of examples shows that application of the method can reduce the relative errors for more than one order of magnitude. It is recommended that users of probabilistic safety assessment consider the method and its findings for setting up the truncation limits in order to have probabilistic safety assessment results, which can serve as a standpoint for decisions.


Fault Tree Importance Measure Electric Power Research Institute Pressurize Water Reactor Diesel Generator 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Roberts N. H., W. E. Vesely, D. F. Haasl, F. F. Goldberg, Fault Tree Handbook, NUREG-0492, US NRC, Washington, 1981Google Scholar
  2. 2.
    Čepin M., B. Mavko, Probabilistic Safety Assessment Improves Surveillance Requirements in Technical Specifications, Reliability Engineering and Systems Safety, 1997, Vol. 56, pp. 69–77CrossRefGoogle Scholar
  3. 3.
    Čepin M, B. Mavko, A Dynamic Fault Tree, Reliability Engineering and System Safety, 2002, Vol. 75, No. 1, pp. 83–91CrossRefGoogle Scholar
  4. 4.
    Jordan Cizelj R., B. Mavko, I. Kljenak, Component Reliability Assessment Using Quantitative and Qualitative Data, Reliability Engineering and System Safety, 2001, Vol. 71, pp. 81–95CrossRefGoogle Scholar
  5. 5.
    Čepin M., Optimization of Safety Equipment Outages Improves Safety, Reliability Engineering and System Safety, 2002, Vol. 77, pp.71–80CrossRefGoogle Scholar
  6. 6.
    Probabilistic Risk Assessment Procedures Guide, NUREG/CR-2300, Vol. 1,2, US NRC, Washington DC, April 1982Google Scholar
  7. 7.
    PSA Applications Guide, EPRI, 1995Google Scholar
  8. 8.
    Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications, ASME RA-S-2002, 2002Google Scholar
  9. 9.
    Regulatory Guide 1.174, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, US NRC RG 1.174, Rev. 1. 2002Google Scholar
  10. 10.
    Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, US NRC RG 1. 177, August 1998Google Scholar
  11. 11.
    Čepin M., Insights about Truncation in Probabilistic Safety Assessment, Proceedings of NENE2003, Portorož, 2003Google Scholar
  12. 12.
    Bronstein I. N., K. A. Semendjajew, G. Musiol, H. Muhlig, Taschenbuch Der Mathematik, 1995Google Scholar

Copyright information

© Springer-Verlag London 2004

Authors and Affiliations

  • Marko Čepin
    • 1
  1. 1.Reactor Engineering DivisionJožef Stefan InstituteLjubljanaSlovenia

Personalised recommendations