A nuclear reactor that uses water as the primary coolant and moderator, with slightly enriched uranium as fuel. There are two types of commercial light-water reactors--the boiling-water reactor (BWR) and the pressurized-water reactor (PWR).
A thermal reactor using ordinary water both as a moderator and as a coolant with enriched uranium as fuel.
The typical commercial nuclear power reactor. It uses ordinary water (light water) to produce steam. The steam turns turbines and generates electricity.