The generic objective of the activity is to achieve an estimation of the maximum thermal power removable by NC in PWR systems. As already mentioned, no care is given to the thermohydraulics-neutronics interaction and, therefore to the actual possibility of generating the considered fission power. The analysis is carried out into two parts the former related to ITF, to give more realism to the calculated results, the latter related to a PWR. In all cases, the primary system pressure and the SG conditions (pressure, level and feedwater temperature) are kept constant at the nominal values if not differently specified. The main circulation pumps are at zero speed and the locked rotor hydraulic resistance of the impeller is taken into account. The core power and the feedwater flowrate levels are consistently modified.