Sensitivity study on severe accident core melt progression for advanced PWR using MELCOR code

A LBLOCA scenario for an advanced pressurized water reactor, call APR1400, developed in Korea is analyzed in order to obtain an overall insight into a severe accident progression from an initiating event to the reactor vessel failure in detail by using the MELCOR computer code Versions 1.8.5 and 1.8.6. The present results (the amount of molten corium and vessel failure timing) would be used as input for the establishment of severe accident management strategies or for the design of a core catcher for the APR1400. The MELCOR results showed that the lower head instrumentation tube penetration failure model and internal structure in the reactor vessel had influence on the amount of corium ejected and the timing of reactor vessel failure.