Prediction of wet steam conditions in steam turbine

In most conventional power plants, the turbines are supplied with superheated steam but, during the course of its expansion, the condition of the steam enters the two-phase region and the last few low-pressure (LP) stages operate in the wet regime. For nuclear plants, the steam supplied from the reactors is often already wet or, at best, only slightly superheated, so wetness effects may be relevant throughout the entire machine.
In either case, the main practical consequences of operating in the wet regime are blade erosion and corrosion damage, and deterioration in thermal efficiency due to a variety of two-phase effects collectively known as wetness losses.
The subcooling reaches a maximum at the so-called Wilson point, in the vicinity of which vast numbers of tiny liquid droplets are formed by spontaneous association of vapor molecules.