Light-water reactor

LWR

The family of reactors that use ordinary water as both coolant and moderator: pressurised water reactors and boiling water reactors. Together they make up about 85% of the world's operable power reactors, 376 of 441 units in the World Nuclear Association's count of 5 August 2026. Because ordinary water absorbs some neutrons, they need uranium enriched to a few percent uranium-235. 'Light' distinguishes ordinary water from heavy water, whose hydrogen is deuterium.

Vocabulary id

concept:light-water-reactor

Scheme

Concepts

Back to the glossary.