Nuclear reactor

First of all, to know what is a nuclear reactor you need to have some knowledge about this nuclear thing,please read my other posts in my blog so that you can develop a slight insight of what i am going to share with you now.
So the question is what is a nuclear reactor???
Here's the answer:-
In a simple language a nuclear reactor is a device in which nuclear reactions are carried out in a controlled manner,i.e there is no uncontrolled chain reaction.The main components you must know about are as follows:

• Source of neutrons:-Before starting anything a source must be created and this source must be kept in the vicinity of the fissionable material;how this source acts as a trigger will be explained .
• Fissionable material:- Uranium-235 is mainly used as a fissionable material,now what happens is that a moderator is used to slow down the neutrons coming out from the source,generally heavy water (D20) is used as a moderator ,the neutrons are made to pass through a block of moderator which in turn absorb energies by elastic collision and slows down the velocity of neutrons,now this neutrons have become capable of causing fission.
• Control Rods-Now the most important fact is about how to control chain reaction,materials like Cadmium or Boron are used to control the chain reaction.This materials have the capability to absorb neutrons without having themselves being disintegrated .And also by controlling the length of this rods we can limit the number of neutrons taking part .
• Coolant:This is arguably most important part in this nuclear reactor ,as the name suggests you can imagine that this is required to absorb excess heat generated in the process.Heavy water is most commonly used as a coolant .This coolant takes up the heat and exchanges this with water which in turn you know transforms the  water into a super- heated steam.This steam is used to run the turbine which in turn operates the machines ,so you can imagine how in this process not a single damn thing is wasted.
• Protective shield:-Since this process helps us to create loads of energy,but also has some demerits,i.e,in this process huge amount of radiations are emitted,so for that a shield is created around a nuclear reactor ,the shield is mainly mainly made up of massive amount of concrete and it is 10 m thick.

My aim is to create this subject interesting to you,and i have tried to make it interesting.Though i may fail,so i am open to criticism,feel free to hit me up with your comments.I won't object and it will in turn make me a good writer.