It is the gist of accidents managing and the important basis for safety management to analyze and evaluate the accident loss.

In this paper the main content is the analysis of the information asymmetry of the accident loss and the several incidents asymmetric types are summed up in order to make better of the analysis of the accident loss.

PWR LOCA Analysis with Condensation Reflux Model;

Simulation of LOCA in the auxiliary primary loop system of nuclear power plant;

Realistic Analysis of Intermediate and Small LOCA;

Loss of coolant accident is considered as design basis accident in the design of nuclear power plant.

The momentum integral method is applied in the frame of safety analysis of pressure water reactors under hypothetical loss of coolant accident(LOCA) conditions to simulate numerically film condensation, rewetting and vaporization on the inner surface of a pressure water reactor containment.

To evaluate the safety characteristics of pulsed reactor under LOCA (loss of coolant accident), an analytical model of LOCA is developed and an advanced code XPRLOCA with friendly interactive interface and real time simulation function is coded for simulating LOCA.

In order to construct a proper black start scenario,accelerate system recovery after fault and minimize outage loss,this paper proposes a method for determining the number,capability and location of the generating units in the black start of power systems according to technical performance index of black start and the characteristics of the generators.