PROBLEM TO BE SOLVED: To assess a damage of a plant when a disaster occurs and maintain plant monitoring even after the disaster has occurred.SOLUTION: A soundness support device at disaster 1a is connectable to a plant monitoring system 2 for monitoring a plant. The soundness support device at disaster 1a includes: a disaster information reception part 11 for receiving disaster information 121; a seismic intensity information reception part 12 for receiving seismic intensity information 122 from a seismic intensity meter installed in the plant; a plant information reception part 13 for receiving plant information 123; a disaster assessment part 15 for determining an assumed accident level of the plant on the basis of the disaster information 121 and the seismic intensity information 122 and generating disaster assessment data 141; and a disaster monitor information transmission part 16 for transmitting the plant information 123 and the disaster assessment data 141 to the plant monitoring system 2.
