Glossary - H

Half-life

The time over which the atoms of a particular radioactive nuclide decay to half their original intensity of emitted radiation. The half-life is a characteristic property of each radioactive isotope.

Source: AECL

Heavy Water

Heavy water or deuterium oxide (D₂0) is a natural form of water used to lower the energy of neutrons in a reactor. It is heavier than normal water by about 10%, and occurs in minute quantities (about one part heavy water per 7,000 parts water). CANDU reactors use heavy water as both moderator and coolant. Heavy water is one of the most efficient moderators, and enables the CANDU design to use natural uranium fuel.

Source: AECL