Heavy water reactor

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It has been suggested that Pressurised heavy water reactor be merged into this article or section. (Discuss)

Heavy water reactors use heavy water as a neutron moderator. Heavy water is deuterium oxide, D₂O. Neutrons in a nuclear reactor that uses uranium must be slowed down so that they are more likely to split other atoms and get more neutrons released to split other atoms. Light water can be used, as in a light water reactor, but since it absorbs neutrons the uranium must be enriched for criticality to be possible. The most common pressurised heavy water reactor is the CANDU reactor.

Opponents of heavy water reactors suggest that because such reactors can be fueled with unenriched uranium there is much greater risk of nuclear proliferation; since once a country has such a reactor, it only needs uranium as it is found in nature. Therefore, the oversight by international institutions of uranium enrichment is bypassed. While there is no need for fuel enrichment, heavy water reactors produce more plutonium and tritium as a by-products of normal use than light water reactors. Both plutonium and tritium are hazardous radioactive substances, used in the production of modern nuclear weapons such as fission, boosted fission, and neutron bombs as well as in the primary stages of thermonuclear weapons. India produced its plutonium for Operation Smiling Buddha, its first nuclear weapon test from plutonium extracted from a heavy water research reactor known as "CIRUS". Heavy water reactors require a set of safeguards to prevent their exploitation in such a fashion.

The reactors are used in nuclear power plants to produce nuclear power from nuclear fuel.

See also

• Pressurised Heavy Water Reactor
• NRX
• CIRUS
• MIT Nuclear Research Reactor
• CANDU
• KS 150