Once an accident occurs in the Nuclear Power Plant (NPP), operators have to understand what is going on in NPP, to identify the event and to select or search the proper emergency operating procedure. A post-trip monitor is proposed in this paper as the automated event identification system to reduce the workload of operators on one hand with increasing the reliability of the recovery actions on the other hand, in operators¼× upset conditions during NPP accidents. In order to construct the post-trip monitor, three algorithms are considered for the automated event identification to enhance the reliability of the system response by analytic diversity. The result of neural network application is discussed for automated localization of break point and break size on the case of loss of coolant accident in NPP.