Core cooling success criteria analyses to support PRA study of GE SBWR plant design

In the framework of the cooperation program between ENEL and General Electric in the design of SBWR Light Water Passive Plant, core cooling success criteria for short term have been evaluated by ENEL by performing a thermal-hydraulic LOCA analysis with the TRACG computer code. A number of different break sizes, in the range of large, medium, and small LOCA, and location have been evaluated to define the minimum systems configuration in accordance with the acceptance criteria to limit the PCT (Peak Cladding Temperature) below 2,200 F. Particular attention was given to the efficiency of the main safety and non safety systems (CRD, GDCS, IC, and ADS), with a major interest to the passive ones (GDCS,IC). This paper does not consider the activity of the PCCS (Passive Containment Cooling System) because of its influence on the containment behavior and not specifically on the vessel core cooling. Timing sensitivity analyses for operator actions to operate a specific system or to perform recovery actions have been also evaluated