Probabilistic Safety Assessment of Station Blackout Accident and 5th Emergency Diesel in Daya Bay NPP

In this paper, probabilistic safety assessment （PSA） of the station blackout （SBO） and 5th emergency diesel in Daya Bay NPP has been carried out, the calculation method of non-recover factors of power supplies is given, and sensitivity analysis on the connection duration of 5th emergency diesel has been executed. It is concluded that the core damage frequency （CDF） induced by SBO is relatively large, the addition of 5th emergency diesel is very helpful for the CDF reduction, and the connection duration of this diesel has great effect on the CDF reduction.