Prelims Science and Technology

PWR (Pressurized Water Reactor)

A PWR is a reactor where ordinary water is used both as coolant and moderator, and it is kept under very high pressure so that it does not boil.

Example: Reactors used by Nuclear Power Corporation of India Limited in several projects are based on this concept.

Key points:

1)Uses enriched uranium

2) Water does not boil inside the reactor

3) Heat is transferred to another water system to produce steam

4) Most common reactor type in the world

PHWR (Pressurized Heavy Water Reactor)

A PHWR uses heavy water (D₂O) instead of normal water.

Example: Many reactors at Kakrapar Atomic Power Station and Rajasthan Atomic Power Station are PHWR type.

Key points:

1) Uses natural uranium (no enrichment needed)

2) Heavy water is used as moderator and coolant

3) Widely used in India