In a PWR, where are the moisture separators located?

• A. In the top part of the steam generators.
• B. Inside the reactor core.
• C. In the turbine housing.
• D. In the cooling tower basin.

Answer: (A)

Moisture separators are placed where the steam has just left the steam generator and is about to go to the turbine, to remove droplets before they reach the turbine. In a PWR, steam is produced in the steam generator, and even after generation some liquid water remains entrained in the steam. Locating the separator in the top part of the steam generator uses gravity to encourage the droplets to coalesce and drain away, delivering drier steam to the main steam line and then to the turbine. This protects the turbine from moisture-related erosion and reduces moisture-induced losses. Placing separators inside the reactor core, in the turbine housing, or in the cooling tower basin would not accomplish effective dry-out of the steam fed to the turbine, and would miss the practical, gravity-assisted separation step right after generation.