Page 11 - Sources of Energy

Nuclear power reactors located at Tarapur (Maharashtra), Rana Pratap Sagar
(Rajasthan), Kalpakkam (Tamil Nadu), Narora (UP), Kakrapar (Gujarat) and Kaiga
(Karnataka) have the installed capacity of less than 3% of the total electricity generation
capacity of our country. However, many industrialised countries are meeting more
than 30% of their electrical power needs from nuclear reactors.

The major hazard of nuclear power generation is the storage and
disposal of spent or used fuels – the uranium still decaying into harmful
subatomic particles (radiations). Improper nuclear-waste storage and
disposal result in environmental contamination. Further, there is a risk
of accidental leakage of nuclear radiation. The high cost of installation
of a nuclear power plant, high risk of environmental contamination and
limited availability of uranium makes large-scale use of nuclear energy
prohibitive.
Nuclear energy was first used for destructive purposes before nuclear
power stations were designed. The fundamental physics of the fission
chain reaction in a nuclear weapon is similar to the physics of a controlled
nuclear reactor, but the two types of device are engineered quite
differently.

Nuclear fusion
Currently all commercial nuclear reactors are based on nuclear fission. But there
is another possibility of nuclear energy generation by a safer process called nuclear
fusion. Fusion means joining lighter nuclei to make a heavier nucleus, most commonly
hydrogen or hydrogen isotopes to create helium, such as
Do You Know? the mass of the product is little less than the sum of the masses of the original individual
H + H → He (+ n)
2
3
2
It releases a tremendous amount of energy, according to the Einstein equation, as
nuclei.
Such nuclear fusion reactions are the source of energy in the Sun and other stars. It
takes considerable energy to force the nuclei to fuse. The conditions needed for this
process are extreme – millions of degrees of temperature and millions of pascals of
pressure.
The hydrogen bomb is based on thermonuclear fusion reaction. A nuclear bomb based
on the fission of uranium or plutonium is placed at the core of the hydrogen bomb.
This nuclear bomb is embedded in a substance which contains deuterium and lithium.
When the nuclear bomb (based on fission) is detonated, the temperature of this substance
7
is raised to 10 K in a few microseconds. The high temperature generates sufficient
energy for the light nuclei to fuse and a devastating amount of energy is released.

Activity 14.7
Activity 14.7
Activity 14.7
Activity 14.7
Activity 14.7
 Discuss in class the question of what is the ultimate source of
energy for bio-mass, wind and ocean thermal energy.
 Is geothermal energy and nuclear energy different in this respect?
Why?
 Where would you place hydro electricity and wave energy?

252 Science