Places in a power station where drying is recommended during shut down include:

GENERATOR - it is important to keep the windings dry to prevent corrosion and ensure a shorter starting time. Dry air can also supplement generator heaters.
CONDENSER - must be kept dry after flushing to allow recoating of water boxes and tube plates.
RE-HEATER - tubes are thinner than super heater tubes and more susceptible to corrosion. Inter-granular attacks on austenic stainless steel can be minimised using dry air.
FEED & CONDENSATE PIPES - important to eliminate internal corrosion on pipes as oxides can contaminate feed water. BOILER - surface temperatures of fireside boiler tubing drop below the dew-point and form condensate. The condensate reacts with sulphurous parts of the ash and acid deposits and hydrolyses, forming a highly acidic solution. The end result is rapid, localized attack of the metal surface.
REACTOR VESSEL - Where access is required, dry air is required to purge out CO2, eliminate corrosion and to dry the graphite prior to refilling with CO2.