Icare / Cathare Analysis Of The Core Behavior Of One Million Kw Class Pwr Severe Accident

The safety of nuclear power plant (NPP) should be paid much attention due to an ambitious development policy in China. Severe accident analysis is one of the essential techniques to assure safety of NPP. The report describes an application of ICARE/CATHARE code to a 900MWe PWR, including the main aspects as follows:Installation of ICARE/CATHARE code under Linux operating system;Modeling of 900MWe PWR;Analyzing accident sequences of LBLOCA and SBLOCA with station blackout, including investigation of the mitigation measures under SBLOCA.The analysis of LBLOCA shows that oxidation of Zr begins at about 500s. The core begins to damage at 1700 seconds and the upper part of the core is observed full damage at 2400s while 270kg hydrogen is generated. A sensitivity study shows that the process of the accident with a cold leg break is faster than that with a hot leg break. The analysis shows that the progress of SBLOCA with station blackout sequence is slower than that of LBLOCA. The core uncovers at about 2400s and begins to damage at 13000s. The analysis shows that the core keeps intact if the inject system could put into operation at about half an hour after initialization of the accident. Whereas, only slight oxidation is found at upper of the core if the inject system could put into operation when the vapor temperature of the core outlet exceeds 650℃(about 2700 seconds).