Abstract: NPP Main Steam Line Break (MSLB) plus Steam Generator Tube Rupture (SGTR) and Safety Injection (SI) failure is severe accident (SA) process with complex phenomena in reactor vessel. The severe accident process serial was analyzed using the latest version of Modular Accident Analysis Program 5 (MAAP5). The whole trends of the simulation result agreed well with the anticipated process serial, which could provide training material to the full scope simulator and the related evidence to make detailed severe accident management guidelines (SAMG).

Key words: severe accident, simulation analysis, SI failure, failure process of the reactor core, time serial