The pressurized-water reactor is similar to a boiling-water reactor, except that the coolant water is pumped through the reactor under

Question

Question

This question was previously asked in

UPSC ESE (Prelims) Electronics and Telecommunication Engineering 19 Feb 2023 Official Paper

Answer 1

The correct option is High-pressure

Concept:

In a Pressurized Water Reactor (PWR), the water that passes over the reactor core to act as a coolant and moderator is kept under high pressure to prevent it from boiling. This high pressure is maintained by a pressurizer and is one of the main characteristics that differentiate a PWR from a Boiling Water Reactor (BWR).
In the BWR, the water in the reactor core is allowed to boil and the steam directly drives the turbine, while in the PWR, the water kept under high pressure is prevented from boiling. The heated water from the PWR reactor core is then passed through a heat exchanger (steam generator) where it transfers its heat to another loop of water, which is under lower pressure and is allowed to boil, producing steam that drives the turbine.
The high pressure in PWR provides certain safety benefits. If a loss-of-coolant accident occurs, the high pressure can expel the coolant and expose the fuel. However, the release of pressure reduces the boiling point of the coolant, causing it to flash to steam and cool the fuel.