This document provides an overview of different types of nuclear reactors, including pressurized water reactors, boiling water reactors, CANDU reactors, gas cooled reactors, and fast breeder reactors. It describes the basic design and functioning of each type of reactor, and highlights some of their key advantages and disadvantages. The document was prepared by an electrical engineering student as part of an active learning assignment on electrical power generation topics.

1. Active Learning Assignment
Semester : 4th
Branch : Electrical Engineering
Subject : Electrical Power Generation ( )
Topic : “Types of Nuclear Reactor”
Prepared by : Soham Gajjar(160120109007)
Guided by : Prof. Piyush Pandya
Gandhinagar Institute of Technology 1

2. INTRODUCTION
• TYPES OF NUCLEAR REACTOR :
• Pressurised Water Reactors (PWR)
• Boiling Water Reactor (BWR)
• CANDU Reactor
• Gas Cooled Reactors
• Fast Breeder Reactor (FBR)

3. Water is used as coolant and moderator.
The water in the primary circuit gets heated by absorbing the
fission energy in the core and same energy is given in the
heat exchanger to generate the steam.
The water coming out of the heat exchanger is circulated by
the pump to maintain pressure in the circuit in the range of
100 to 130 atm.
The water becomes radioactive when passing through the
reactor ; therefore entire primary circuit including heat
exchanger must be shieldedto protect the operating persons.
The radioactive coolant does not make the steam radioactive
in the boiler.From the pressure water flows to the steam
turbine. The electrical generator coupled with steam turbine
generates electrical power.
Pressurised Water Reactors (PWR)

4. Pressurised Water Reactors (PWR)
• Advantages :
• The water which is used as coolant,moderator and reflector is cheap and easily available.
• Requirement of control rods are less.
• Secondary circuit is not affected by radiation, so normal turbine maintenance technique can be
used.
• Operation is safe and stable.
• Disadvantages :
• High primary circuit pressure requires strong pressure vessel.
• High capital cost.
• Corrosion problem.

5. Boiling Water Reactor (BWR)
• In this type of reactor
enriched Uraniumis used
as fuel and water is used
as coolant.
• Ain this type of reactor
steam is generated in
reactor core itself and this
steam is expanded in
turbine.
• After expansion steam is
condensed in condenser.
Feed pump is used to
circulate water back into
reactor core.

6. Boiling Water Reactor (BWR)
• Advantages :
• The pressure inside the reactor vessel is considerably smaller than P.W.R.
• The metal surface temperature is lower than P.W.R.
• The boiling water reactor is more stable than any other type of reactor.
• The thermal effiency of this reactor is 30%.
• Disadvantages :
• The steam leavine the reactor is slighty radioactive therefore, light shielding of turbine
and piping is neccessary,.
• More safety precautions needed which are costly.

7. CANDU Reactor
• This type of reactor was first design & developed in Canada.
• The long form of CANDU is Canadian Deuterium Uranium.
• In this type of reactor the natural Uranium (0.7%U235) is used as a fuel and heavy water
as moderator.
• The Coolant , heavy water is passed through the fuel pressure tubes and heat exchanger.
• The heavy water is circulated in primary circuit in the same way as a P.W.R and ordinary
water.
• The control of the reactor is archived by varying the moderator level in the reactor and
therefore, control roads are not required.

8. CANDU Reactor
• Advantages:
• No control rods are required, so control is much easier.
• Enriched fuel is not required.
• A short time is needed to construct the reactor compared wit P.W.R and B.W.R.
• Heavy water being good moderator.
• Disadvantages :
• The cost of heavy water is extremely high.
• The leakage is major problem.
• Very high standard of design, manufacture,inspection and maintenance are required.

9. Gas Cooled Reactors
• These reactor use gas as a coolant.
• There are two types of gas cooled reactor developed.
• 1 : The gas cooled graphite moderated (GCGM) reactor &
• 2 : High temperature gas coolant (HTGC) reactor.
• The first type uses carbon dioxide as a coolant and second type uses
helium as a coolant.

10. Fast Breeder Reactor (FBR)
• This reactor uses enriched uranium or plutonium as fuel.
• It is surrounded by blanket of uranium.
• The fertile material absorbs neutrons from the fisible material and gets
converted into fissible material, U235 is converted in PU239 or TH232 into
U233.
• This new material produced can used for other reactors.
• Coolant is liquid sodium.

11. REFERANCES
• ATUL PRAKASHAN
• IMAGE : GOOGLE.COM