Nuclear Energy and Hydroelectric Power Plant

Nuclear Energy

The energy released during a nuclear reaction is called nuclear energy. Nuclear energy can be obtained from two types of reaction: nuclear fission and nuclear fusion.

Nuclear fission

The process in which the heavy nucleus of a radioactive atom splits up into smaller nuclei when bombarded low energy neutrons is called nuclear fission. A tremendous amount of energy is released from nuclear fission which is converted into electric energy.

When uranium 235 atoms are bombarded with slow neutrons, the heavy uranium nucleus breaks up to produce two medium weight atoms, barium -139 and krypton-94, with emission of 3 neutron.

\begin{align*} _{92}U^{235} + _0n^1 \rightarrow + _{56}Ba^{139} + _{36}Kr^{94} + _0n^1 + \:\text {Tremendous amount of energy} \end{align*}

Nuclear Fusion

The process in which two nuclei of light elements combine to form a heavy nucleus, is called nuclear fusion.The nuclear reactions which occur at extremely high temperature are called thermonuclear energy.

When deuterium atoms are heated to an extremely high temperature under extremely high pressure, then two deuterium nuclei combine together to form the heavy nucleus of helium, and a neutron is emitted.

\begin{align*} _1H^2 + _1H^2 \rightarrow _2He^3 + _0n^1 + \:\text {Tremendous amount of energy} \end{align*}

Thermal Power Plant

A thermal power plant produces electricity by burning coal or oil.

Working of a Thermal Power Plant

Coal or oil is burnt in a furnace to produce heat energy. This heat energy is used to boil water in order to produce steam. The steam produced in the water reservoir is allowed to fall in the turbine rotates it with high pressure. The steam falling on the turbine rotates it with high speed. A generator or dynamo connected with the turbine through an axis rotates with high speed and produce electricity. The electricity so produce is transmitted to a distant place through transmission wires.

Hydroelectric Power Plant

The electricity produced by the flowing water is known as hydro-electric power.

For the construction of hydro-electric power plant, a dam or water reservoir is made over a river. The energy stored in a dam which has potential energy is allowed to fall on the water wheel or turbine. Flowing water with potential energy makes turbine rotate with an axle and the armature of the generator. The armature of the generator between two poles of a strong magnet. The rotation of the armature of the generator rotates within two poles of a strong magnet. The rotation of the armature of the generator between two poles of a strong magnet gives rise to electric current or electricity. This electricity is transmitted to the sub-stations through a transformer for further distribution to the houses factories.

Principle of Generation of Hydroelectricity

The potential energy of water stored in a dam is converted into kinetic energy of the falling water. The water falls on the turbine, so kinetic energy of the flowing water is converted into kinetic energy of armature of the generator connected to the turbine. Then kinetic energy is converted into electrical energy known as hydroelectricity.

Advantage

1. It does not cause any environmental pollution.
2. Hydroelectricity is a cheap and renewable source of energy.
3. The hydroelectric power plant can be set up anywhere at a suitable place.

Disadvantage

1. Hydroelectric power is generated only near the rivers having water throughout the year. The electric power has to be carried to the sub-stations for distribution to the house and factories situated far off from the sites of hydroelectric power stations. This is done through the transmission wires, so a lot of money has to spend on this process.
2. A large area of fertile land submerged at the site of the dam constructed for tapping energy from the flowing water.
3. A large number of people residing near the site of a dam are dislocated. So, a lot of problems are to be faced in rehabilitating.
4. Large ecosystems are destroyed when land is submerged under the water reservoir of a dam.

Applications of Hydroelectricity

1. Hydroelectricity can be used in transportation.
2. It can be used for various household purposes such as cooling, heating, lighting etc.
3. It can be used to irrigate agriculture land.
4. Hydroelectricity can be used in industries to operate various machines.

Reference

Manu Kumar Khatry, Manoj Kumar Thapa, Bhesha Raj Adhikari, Arjun Kumar Gautam, Parashu Ram Poudel.Principle of Physics. Kathmandu: Ayam publication PVT LTD, 2010.

S.K. Gautam, J.M. Pradhan. A text Book of Physics. Kathmandu: Surya Publication, 2003.