This application calculates the thermal efficiency of a steam turbine cycle in a Nuclear Power Plant (NPP) with a Pressure Water reactor (PWR).

Pressurized water flows from the nuclear reactor (NPP primary circuit) to the steam generator (SG) and transfers heat to the boiling water of the second circuit. Saturated steam is supplied from the steam generator to the high pressure cylinder (HPC) of the steam turbine. Part of the live steam from the steam generator enters the superheater. Before being superheated, the exhaust steam from the HPC is partially dried in the separator (S), where some water is separated from the wet steam, and then returned to the circuit with bypass of the low pressure cylinder (LPC) of the steam turbine.

The thermal circuit of an NPP introduces a risk factor not found in fossil fuel power plant. In an NPP, If saturated steam is supplied to a turbine, whose outlet pressure is 5-4 kPa, moisture in the last stages of the turbine will be unacceptably high; this may lead to steam turbine failure.