Probabilistic safety analysis methods (PSA) and deterministic safety analysis methods (DSA) are classical safety analysis methods for nuclear power plant (NPP). However they can’t do a comprehensive analysis for epistemic uncertainty and aleatory uncertainty. This problem can be solved by Risk-Informed Safety Margin Characterization method (RISMC) which combines PSA and DSA.
Due to Best-Estimate plus uncertainty analysis (BEPU) analysis method quantify the epistemic uncertainty in safety analysis accurately, BEPU is used for DSA. The dynamic event tree (DET) analysis method can branch the event tree according to the number of successfully invested devices, which can provide a more detailed component accident sequence, which is of great significance for serious aleatory uncertainty. In order to improve the analysis efficiency, the RAVEN platform is used for safety analysis.
The uncertainty of NPP safety analysis is analyzed more accurately by using the RISMC analysis method which combines PSA and DSA. The CDF calculated by the BEPU analysis method coupled with the DET method is 3.59e−12, and the CDF obtained by the DET analysis method is 2.59E−15. Moreover, the efficiency of the analysis is greatly improved by using the RAVEN platform and the method of selecting significant sequence analysis.