What characterizes a Pressurized Water Reactor?

• A. A nuclear reactor system that pressurizes the coolant water to prevent boiling in the core; the heated water leaves the core and flows through a steam generator where steam is produced and used to drive turbines
• B. A reactor that uses a gas as the primary coolant which directly turns a turbine
• C. A reactor that relies on molten salt as a coolant and heat transfer medium
• D. A reactor that operates with no moderator present to slow neutrons

Answer: (A)

In a Pressurized Water Reactor, the coolant water is kept under high pressure so it stays liquid inside the reactor core. That liquid removes heat from the fuel without boiling. The heated primary coolant then transfers its energy to a separate secondary loop through a steam generator. In that secondary loop, water boils to steam, and the steam drives the turbines. The radioactive primary coolant remains isolated from the turbine system, which is a key safety and design feature. The other designs described—gas as the primary coolant, molten salt as the coolant, or operation without a moderator—do not describe a PWR, which relies on liquid water under high pressure in the primary circuit and steam generation in a secondary loop.