6.2.1 Production of Nuclear Energy and Its Uses
Nuclear energy can be produced in nuclear reactors through the following two methods:
(a)  Nuclear fission
(b)  Nuclear fusion

6.2.1 Nuclear Fission
1. Nuclear fission is a process involving the splitting of a heavy nucleus into two nuclei of roughly equal mass and shooting out several neutrons at the same time.


Nuclear fission of uranium to produce nuclear energy


2. 
Nuclear fission occurs when a high energy neutron bombards a uranium nucleus. The nucleus becomes unstable and splits into two (or more) lighter nuclei with the release of two or three neutrons and a large amount of nuclear energy.
 
3. The nuclear fission can only occur in some types of heavy and unstable nuclei such as uranium-235 and plutonium-239.
 
4. A chain reaction occurs as the process of nuclear fission keeps on repeating. The neutrons produced will bombard more uranium-235. The chain reaction produces more neutrons and releases more nuclear energy.
 
5. Uncontrolled chain reaction occurred when atomic bombs exploded in Hiroshima and Nagasaki in Japan during Second World War. Thousands of lives were lost and properties destroyed.