nuclear reactor is a device to obtain nuclear energy in controlled way to be used for peaceful purposes.

1. NUCLEAR
REACTORS
BY:
WISHAL
BUTT

2. INTRODUCTION:-
A nuclear reactor, or atomic
pile.
It is designed & operated for
the purpose of sustaining a
nuclear fission chain reaction
at controlled predetermined
rate.
Helpful in production of heat,
mechanical & electrical
energy, radioactive isotopes,
weapons materials & nuclear
research.

3. INSTRUMENTATIONS:-

4. COMPONENTS:-
FUEL ELEMENTS:-
 Material containing
the fissile isotopes, called
reactor fuel or nuclear
fuel.
Varied composition,
natural uranium to highly
enriched in U²³⁵, Pu²³⁹ or
U²³³.
Basic source are uranium
& thorium.
U²³⁵ 0.71% by wt. produce
the nuclear energy.

5. FUEL RODS:-
A long, slender,
zirconium metal tube
containing pellets of
fissionable material,
which provide fuel for
nuclear reactors.
 Fuel rods are
assembled into bundles
called fuel assemblies,
which are loaded
individually into the
reactor core.

7. MODERATORS:-
Rapidly reduce the high
energy of fission
neutrons.
Neutrons ejected by he
fission must be slow
down by the collision
with the atom of
comparable mass that
do not absorb them.
E.g.
Ordinary water,
graphite, helium, heavy
water,

8. CORE:-
A nuclear reactor core is the portion of a nuclear
reactor containing the nuclear fuel components
where the nuclear reactions take place and the
heat is generated.

9. COOLANT:-
Heat generated in the
core is removed by the
coolant.
Ordinary & heavy
water.
Liquid metals like Na, K
at high temp .
Benzene, polyphenyls ,
air, CO₂ , CH₄, H₂ & He.

10. CONTROL RODS:-
The power level of
neutron is controlled by
controlling the neutron
flux, that is achieved by
using some neutron
absorbing material.
BORON , most
commonly used due to
high M.P & absorption.
Cadmium is also used.

11. SHIELDING:-
Consist up of layer
of concrete that
surrounds the core.
Absorbs both
gamma rays &
neutrons.
Good structural
material & have
enough hydrogen
to moderate the
fast neutrons.

12. WORKING:-
Working consist up of
following steps.
Nuclear fission
Heat generation
cooling

13. FISSION:-
Fissile isotopes present in the fuel rods receives
the neutron & undergo fission reaction.
Releases two lighter nuclei & three more neutrons.
So the chain of fission reaction starts & goes on
increasing.
Produces heat (K.E) , gamma rays, free neutrons.

14. HEAT PRODUCTION:-
The reactor core generates heat in a
number of ways:
The K.E of fission products is
converted to thermal energy when
these nuclei collide with nearby
atoms.
The reactor absorbs some of the
gamma rays produced during fission
and converts their energy into heat.
Heat is produced by the radioactive
decay of fission products and
materials that have been activated by
neutron absorption.

15. Moderator may slow down the speed of fission
reaction by decreasing the energy of neutrons.

16. Control rods will absorbs the excess of
neutrons & hence will control the rate of
fission reaction & heat production.

17. COOLING:-
A nuclear reactor coolant,
usually water but
sometimes a gas
circulated the reactor
core to absorb the heat
generated.
 This heat is then used to
generate steam.
Steam turns on the
turbine, & produces the
electricity.
Water being cold is
collected side by &
transfers again in the
reactor’s core & works as
moderator

19. TYPES:-

23. ADVANTAGES:-
 Produces no polluting
gases.
 Does not contribute to
global warming.
 Very low fuel costs.
 Low fuel quantity reduces
mining and transportation
effects on environment.
 High technology research
required benefits other
industries.
 Power station has very
long lifetime.

24. DISADVANTAGES:-
Waste is radioactive and safe
disposal is very difficult and
expensive.
Local thermal pollution from
wastewater affects marine life.
Large-scale accidents can be
catastrophic.
Public perception of nuclear
power is negative.
Costs of building and safely
decommissioning are very high.
Cannot react quickly to
changes in electricity demand.