The CANDU reactor
All nuclear power plants in Canada are powered by CANDU reactors.
But why are they called CANDU?
CANDU stands for CANada Deuterium Uranium.
Canada: because that’s where this machine was invented.
Uranium: because that’s the fuel source
Deuterium: well, that needs a bit of an explanation.
Deuterium refers to a special type of water used to slow down the fission process in CANDU reactors: heavy water.
Heavy water is slightly heavier than regular water.
Why is it heavier?
All water molecules contain one atom of oxygen and two atoms of hydrogen. In heavy water, some of the hydrogen atoms are different. While hydrogen atoms only have a proton and no neutron in their most common form, in heavy water they contain a neutron at their centre. We call this unusual type of hydrogen atom “deuterium”.