When steam that does not contain any impurities and external particles, expands in the turbines and crosses the saturation line, it is not instantly condensed, but rather first enters supersaturated or supercooled conditions. The supercooled steam is in unstable state and during a time period, which depends on the supercooling degrees, by way of nucleation, i.e. the sudden formation of numerous minute liquid droplets and growth, returns to stable state, and consequently, equilibrium two-phase flow is reached. The modeling of this two-phase vapor-liquid flow, which starts with droplet formation (nucleation) and continues with rapid droplet growth and condensation shock, is highly dependent on the understanding of nucleation and defining its main thermo-physical properties. Despite numerous research conducted in this area, there still exists a great deal of uncertainty around the value of the influential parameters affecting the nucleation, in particular the droplet surface tension, which require further investigation. The factors which most .....

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