Nuclear Reactor - Understanding how it works | Physics Elearnin

nuclear reactor in this video are going

to learn about the nuclear reactor

nuclear reactors are the modern-day

devices extensively used for power

generation as the traditional fossil

fuels like coal are at the breech of

extinction a nuclear reactor is the

source of intense heat which is in turn

used for generation of power in nuclear

power stations its mechanism is similar

to that of a furnace in a steam

generator the steam is used to drive the

turbines of the electric generator

system the nuclear reactor consists of

three crucial components fuel elements

moderator and control rods fuel elements

come usually in the shape of thin rods

of about one centimeter in diameter and

contain fissionable nuclei like

uranium-235 or uranium 238 these rods

vary a number according to the size of

the reactor in large power reactors

thousands of fuel elements are placed

close to each other this region where

these fuel elements are placed is called

the reactor core these fuel elements are

normally immersed in water which acts as

a moderator the objective of a moderator

is to slow down the energy neutrons a

nuclear reactor which are produced

during the nuclear fission process by

the fuel elements thermal neutrons which

are the neutrons with energy of about

0.04 electron volts are capable of

producing fission reaction with


during the fission reaction process new

neutrons are given out which have

energies of about 1 MeV this is 1 mega

electron volts these neutrons typically

escape from participating in another

fission process as they are accompanied

by enormous energy release in fact the

probability of these neutrons produce

another fission reaction is 500 times

less than that compared to a thermal


this is where a moderator is extremely

useful moderators have the capability to

slow down or in other words moderate the

speeds of these high-energy neutrons so

that they can in turn be used for a

chain reaction to trigger multiple

fission reactions of other uranium-235

nuclei commonly ordinary or heavy water

is used as a moderator in nuclear

reactors because of the deuterons

present in them which are capable of

slowing down the neutrons speed water

molecules in the moderator are useful in

slowing down the high-energy neutrons

which leave the fuel element after

nuclear fission these high-energy

neutrons collide with water molecules

thereby losing out on some energy with

every collision and therefore slowing

down substantially a new fission

reaction can now be triggered using this

slow Neutron by striking it with a fuel

element the third and most prominent

part of a nuclear reactor are the

control rods in order to get a steady

output of energy from the nuclear

reactor every single fission reaction

should trigger another fission reaction

and ensure the availability of spare

neutrons released to trigger the chain

reactions by controlling the number of

spare neutrons available at any given

time the rate of nuclear fission chain

reactions can be controlled

this control on the fission reaction can

be maintained using control rods the

main function of the control rods is to

absorb any excess or spare Neutron in

the moderator in order to prevent any

further fission reactions usually such

control rods are made of boron or

cadmium to increase the rate of fission

reactions these rods can be removed from

the moderator a steady output of energy

can must be maintained by inserting or

removing the control rods in the nuclear

reactor now that we know the components

of a nuclear reactor let's understand

the working of a nuclear reactor it's

usually enclosed in a shield made of

thick concrete walls it can

of a reactor core pump and heat

exchanger the reactor core and pump are

placed in contact with the water which

is usually the heat exchanger in these

reactors due to the enormous amount of

heat released during the fusion reaction

the surrounding water gets heated up and

changes to steam which is in turn used

to turn the turbines so huge heat energy

gets converted into electrical energy

water is continuously flown in and out

of the nuclear reactor using the pump so

a nuclear reactor successfully generates

nuclear energy from fission reactions