A framework for analyzing a whole nuclear plant consisting of over 10 million parts has been developed by preparing model data for each part, then distributing them to numerous supercomputers inter-connected by Grid, and finally simulate an entire by considering the connecting condition among the parts. Numerous supercomputers on the Grid are powerful enough to meet the demands on memory and disk capacities in visualization of gigantic analytics data. By distributing all the simulation processes such as the model data preparation, analysis execution, and the data visualization among multiple supercomputers located inside and outside of JAEA opens up the possibility of structural analysis of a whole extra large-scale nuclear plant.