Canada Deuterium Uranium reactor

The Canada Deuterium Uranium (CANDU) reactor is a type of nuclear reactor developed in Canada. It utilizes natural uranium as fuel, which is abundant domestically, eliminating the need for uranium enrichment services from other countries.1

CANDU reactors are moderated and cooled by heavy water. The core consists of a vessel containing cold heavy water, pierced by pressure tubes made of zirconium alloy. Natural uranium fuel is placed within these tubes, and heavy water coolant circulates through them. Unlike the vertical alignment of many light-water reactors, CANDU vessels are horizontally aligned.1

Heat generated from nuclear fission is transferred to the heavy water coolant, which then flows to a steam generator. This produces steam to drive turbines for electricity generation. A key feature of CANDU reactors is the ability to refuel while the reactor is operating, pushing new fuel assemblies in and extruding spent fuel, which contributes to higher operational efficiency. Heavy water is used as a moderator because it enhances neutron scattering, increasing the probability of fission with natural uranium fuel.123