The present invention relates to a nuclear power plant defense-in-depth safety apparatus having diversity, comprising: an analog type first control unit for generating an operation signal for a safety system; a digital type second control unit for generating an operation signal for the safety system; and a device interface module for receiving the operation signal of the first control unit and the operation signal of the second control unit and applying the operation signal of the first control unit to the safety system as a top priority.

An event analyzing device includes an event collector configured to collect log data of a manual operation event performed by an operator of a plant, an event analyzer configured to analyze a manual operation method or a manual operation intention of the manual operation event based on the log data, a manual operation sequence extractor configured to extract the manual operation method or the manual operation intention for each predetermined period as manual operation sequences in order of time, a manual operation sequence classifier configured to classify the manual operation sequences in which manual operations are in a similar order from among the manual operation sequences, a manual operation procedure constructor configured to construct a manual operation procedure of the operator based on the manual operation sequences, a process data collector configured to collect process data of the plant, and a manual operation condition estimator configured to estimate an execution condition under which manual operations of the manual operation procedure constructed are performed.

An event analyzing device includes an event collector configured to collect log data of a manual operation event performed by an operator of a plant, an event analyzer configured to analyze a manual operation method or a manual operation intention of the manual operation event based on the log data, a manual operation sequence extractor configured to extract the manual operation method or the manual operation intention for each predetermined period as manual operation sequences in order of time, a manual operation sequence classifier configured to classify the manual operation sequences in which manual operations are in a similar order from among the manual operation sequences, a manual operation procedure constructor configured to construct a manual operation procedure of the operator based on the manual operation sequences, a process data collector configured to collect process data of the plant, and a manual operation condition estimator configured to estimate an execution condition under which manual operations of the manual operation procedure constructed are performed.