Heavy-water reactor

Heavy-water reactor is a type of nuclear reactor that uses heavy water (deuterium oxide D2O) as its coolant and neutron moderator. This type of reactor has a unique feature that allows it to use natural uranium as its fuel, making it a valuable resource for countries without access to enriched uranium.

History

The concept of the heavy-water reactor was first proposed in the 1930s, following the discovery of neutrons and the realization that they could cause nuclear fission in certain elements. The first operational heavy-water reactor, the NRX reactor in Canada, began operation in 1947.

Design and Operation

In a heavy-water reactor, the core is composed of fuel rods containing natural uranium or sometimes slightly enriched uranium. The fuel rods are immersed in heavy water, which acts as both a coolant and a neutron moderator. The heavy water slows down the fast neutrons produced by fission in the fuel rods, turning them into thermal neutrons that are more likely to cause further fission in the uranium nuclei.

Advantages and Disadvantages

One of the main advantages of heavy-water reactors is their ability to use natural uranium as fuel. This makes them attractive for countries without access to enrichment facilities. They also have a high neutron economy, which makes them suitable for producing plutonium for use in nuclear weapons.

However, heavy-water reactors also have several disadvantages. The main one is the cost of heavy water, which is significantly more expensive than ordinary water. They also have a lower power density than light-water reactors, which means they need to be larger to produce the same amount of power.

Examples

Several countries have built heavy-water reactors, including Canada, India, and Argentina. The most well-known example is the CANDU reactor, a Canadian design that has been exported to several other countries.

See also

• Nuclear power
• Nuclear fission
• Nuclear fuel cycle
• Nuclear proliferation