Fission is the splitting of a nucleus into smaller parts that releases energy. It can occur through nuclear chain reactions where neutrons produced in one fission induce additional fissions. Uranium-235 is commonly used as it can undergo fission when struck by slow neutrons. This results in fission products like krypton and strontium, more neutrons on average, and a large amount of energy. A controlled chain reaction in a nuclear reactor uses fissionable material as fuel, neutron moderators to slow neutrons, control rods to regulate the reaction, coolants to remove heat, and shielding to protect from radiation. Nuclear power plants generate electricity by using the heat from fission in a reactor to

3. FISSION
Fission is the splitting of a
nucleus into two or more
separate nuclei of comparable
mass
One neutron interacts with one
“fissionable” nucleus
(Uranium for example)

5. A slow moving neutron induces
fission in Uranium 235

6. RESULT OF NUCLEAR FISSION
Fission Products – Two heavy nuclides
One heavier than the other (Average ratio
of ~ 2 : 3 )
Neutrons – 2.43 on average emitted /
fission
Important that more neutrons are
produced than are used to cause one
fission
Gamma rays, beta particles
Energy !! E = mc2

7. CHAIN REACTION
 A chain reaction refer to a process
in which neutron released in fission
produced in additional fission in . At
least one further nucleus. This
nucleus in turn produces neutrons
and the process repeats. If the
process is controlled it is used for
nuclear power or if uncontrolled it is
used for nuclear weapon….

8. In nuclear fission, 3 neutrons are
produced along with large amount
of energy these neutrons further
cause fission producing three
more neutrons. This process
continues for longer time and it is
known as uncontrolled chain
reaction.

9. FISSION OF URANIUM

10. WHAT IS NUCLEAR POWER
PLANT???
• A nuclear power plant is thermal
power station in which the heat source
is a nuclear reactor. As a typical in all
conventional thermal power stations,
the heat is used to generate steam
which drives a steam turbine
connected to an electric generator
which produces electricity.Nuclear
power was developed in 20th century...

11. NUCLEAR REACTOR
•IT IS A DEVICE TO INITIATE AND CONTROL A
SUSTAINED NUCLEAR CHAIN REACTION, THE
MOST COMMON USE OF NUCLEAR REACTORS IS
TO GENERATE ELECTRIC ENERGY. AND FOR
PROPULSION OF SHIPS
•The nuclear reactor is contained inside the
spherical containment building in the centre. Left
and right are the cooling towers which are common
cooling devices used in all power station.

12. NUCLEAR POWER PLANT

13. PARTS OF NUCLEAR
REACTOR
 Fissionable materials
Moderator
Control material
Coolant
Protective shield

14. FISSIONABLE MATERIAL
It is called a fuel of nuclear reactor.
For examples
1.Uranium
2.Thorium.
3.Plutonium.
These isotopes are most commonly used fuel.

15. World Distribution of Uranium

16. Moderator
 Neutrons are slowed
down by having them
collide with light atoms
(Water in US
reactors).
 Highest level of
energy transfer occurs
when the masses of
the colliding particles
are equal (ex: neutron
and hydrogen)

17. Control Rods
 Control rods are
made of a material
that absorbs excess
neutrons (usually
Boron or Cadmium).
 By controlling the
number of neutrons,
we can control the
rate of fissions

18. Coolent
It is the material used to cool the fuel rods and
the moderator and is capable of carrying away
large amount of heat produced in the fission
process. the coolent transfers heat to the
working liquid like water and produces steam the
steam drives turbine which, in turn, runs a
generator to generate electric power. The
coolent must have boiling point and specific
heat.

19. SHIELDING
The intense neutrons
and the gamma
radiation produced in
nuclear reactor are
harmful for human
body. To protect the
worker from these
radiation the reactor
core is surrounded by
a thick concrete wall

20. NUCLEAR REACTOR

22. ADVANTAGES
 Nuclear power generation does emit relatively low
amounts of carbon dioxide Co2 .
 The emissions of green house gases and
therefore the contribution of nuclear power plants
to global warming is therefore relatively little.
 This technology is readily available, it does not
have to be developed first.
 It is possible to generate a high amount of
electrical energy in one single plant .

23. 23
Nuclear power plants in the world
”Italy is surrouned by nuclear power plants but can’t rely on cheap nuclear
energy”
441 reactors in 29 countries with total capacity of
374,000 MWe – or 14% of global power production
Within 200 km from Italian border, there are 26 reactors
with 24,000 MWe
200 km
Source: International Nuclear Safety Center (INSC) - U.S. Department of Energy (DOE)
Nuclear is safe: power plants have reached 14,000 reactor years of operating
experience

24. DISADVANTAGEs
 The problem of radioactive waste is still an
unsolved one.
 High risks: It is technically impossible to build a
plant with 100% security.
 The energy source for nuclear energy is
Uranium. Uranium is a scarce resource, its
supply is estimated to last only for the next 30 to
60 years depending on the actual demand.

26. KUNDANKULAM POWER
PLANT