Why seawater is so damaging in a steam plant

How badly does seawater contamination damage boilers and turbines?

It can cause severe corrosion, deposits and component damage, dramatically shortening machinery life depending on operating conditions.

Salt contamination in a steam plant is far more than an inconvenience. Hot saline water can corrode components, damage boiler tubes and leave deposits in narrow passages. Salt can clog or calcify nozzles and contribute to damage inside the turbines themselves. The severity varies with operating pressure and the purity demanded by the system, but machinery life can fall dramatically. This is a historian's explanation rather than a marine engineer's calculation.