Seismic margin analysis of switch cabin based on the aseismic qualification test

It is necessary to evaluate the seismic margin of the equipment to identify the weak links of nuclear power plants after the earthquake beyond Design Basic Earthquake occurs in the plant site. The seismic margin may be quantified with High Confidence Low Probability Failure (HCLPF). The methods to determine the HCLPF of equipment are Conservative Deterministic Failure Margin (CDFM) and Fragility Analysis (FA). This paper introduces the steps of two methods and the scope of key parameters value. The HCLPF of the switch cabinet is calculated by the two methods. (authors)