The objective of this study was to develop an emergency database search system for nuclear power plants during nuclear incidents / accidents. Image data reported from nuclear power plants to the regulatory body and other related data will be stored systematically in the computer. The data will be utilized during nuclear emergency to prevent the accident from spreading out and to minimize its effect. It will also be used in exchanging information on accident or incidents with the foreign countries. The operational documents in the Kori-4 nuclear power plant are used as the major source for the categorization and analysis in performing this research. It was not easy to access the detailed operational data due to its unique characteric for the security. Therefore, we strongly suggest to increase manpower for this project in Korea Institute of Nuclear Safety (KINS) and archive involvement from Korea Electric Power Company to establish better database retrieval system.