Calculation of Equipment Fragility under Various Influencing Factors

The seismic margin assessment (SMA) is one of methods of earthquake safety assessment for nuclear power plants. It is an important step in SMA to calculate the high confidence of low probability of failure (HCLPF) value by seismic fragility analysis. The fragility calculation of equipment affected by multiple failure modes was studied in this paper. The Monte Carlo sampling method and Latin hypercube sampling method were used and discussed in the fragility calculation of equipment, and the efficiency and accuracy of the two methods were evaluated. The results show that the Latin hypercube sampling method has better computational efficiency and convergence rate in the small sampling calculation. If the sample size reaches 1 000, two sampling methods can achieve convergence results.