Nuclear Reactor (Radioactivity-Nuclear)

RADIOACTIVITY NUCLEAR

A nuclear reactor produces tremendous amount of energy through nuclear fission. The energy liberated from the fusion of nuclear fuel heats the surrounding water. As a result, steam is generated to drive turbines which in turn drive the electrical generators. In the nuclear reactor, the neutrons released through a nuclear fission move with very high speeds and are slowed down to increase the chances of colliding with the Uranium-235.

General Structure of a Nuclear Reactor

Graphite Moderator
Fast moving neutrons are slowed down by collisions with nuclei in the moderator so that they can cause further fissions. In some nuclear power plant, the moderator is water.

Uranium Rod
Fission reactions occur in the uranium rod to produce nuclear energy. The uranium used is often enriched by increasing the proportion of the isotope uranium-235 above the natural value of 0.7% to 3%.

Control Rod
The rate of the fission reaction is controlled by inserting or withdrawing these rods. The nuclei in the rods absorb neutrons without undergoing any reaction. Sometimes the rod is made of cadmium.

Coolant
Coolant is used to take away the heat from the nuclear reactor. Substances with high specific heat capacity such as heavy water and carbon dioxide are used.

Thick Concrete Wall
Thick concrete wall prevent the escape of harmful radiations.

Steam Generator
Water in the generator is heated and changed into steam. The steam then drives the turbines.

Turbine
Turbine is used to turn the dynamo in the electrical generator to produce electricity.

To prevent any damage to the plant which causes serious environment pollution, normally the site of a nuclear power plant is far away from the zones of volcanic eruption. The nuclear power plant is normally built near the sea or the river to ensure that there is enough water supplies to cool the plant in an emergency.