Nuclear reactor seminar

1. Seminar on Nuclear Reactors
By Mahesh Patil
M.Tech. (Thermal Science )
NIT Calicut

2. Nuclear Fission
 Nuclear Fission is either a nuclear reaction or
radioactive decay in which nucleus of atom splits into
smaller parts thereby producing neutrons, photons
(gamma rays) and a very large amount of energy.
 Discovered in 1938 by Lise Meitner, Otto Hahn, Fritz
Strassmann & Otto Robert Frisch.

3. The stages of binary fission in a liquid drop model. Energy input
deforms the nucleus into a fat "cigar" shape, then a "peanut"
shape, followed by binary fission as the two lobes exceed the
short-range strong force attraction distance, then are pushed
apart and away by their electrical charge. Note that in this
model, the two fission fragments are the same size.

4. Nuclear chain reaction
 Nuclear fuel is bombarded with fission neutron to
produce fission reaction thereby producing nuclear
power.
 In-turn it emit neutrons when they break apart.
Controlled Nuclear
chain reaction
Uncontrolled
Nuclear chain
reaction (Nuclear
Bomb)

6. The mushroom cloud of the atom bomb dropped on
Nagasaki, Japan in 1945 rose some 18 kilometres
(11 mi) above the bomb‘s hypocenter. The bomb
killed at least 60,000 people.

7. Nuclear Power plant
 16 Dec, 1951- First time electricity was generated using
nuclear reactor at Arco, Idaho (U.S.)
 First commercial scale power station: Calder Hall,
England- October 21, 1956
 As on 16 Jan, 2013 there are 439 Nuclear Power Plant all
over the world (Source: IAEA)

11. Mechanism
Nuclear Fission
• U-235 or P-239 absorbs neutron & undergoes fission
reaction
• Releases Kinetic energy, gamma radiation & netrons
• Neutron poisons or Moderators are used to control
chain reaction.
Heat generation
• Reactor core generates heat
• Kinetic energy of fission converted into thermal energy

12. Cooling
• Coolant usually water sometimes gas or liquid metal is circulated past the
reactor core to absorb heat .
• The heat is carried away from reactor & used to generate steam.
• Pressurized Water Reactor (PWRs): Cooling system is physically
separated from the water that will be boiled to produce pessurized steam
for turbines.
• Boiling Water Reactor (BWRs) : Water is boiled directly by reactor core
Reactivity Control
• Control rods

13. Components
 Nuclear Fuel
 Nuclear Reactor Core
 Neutron moderator
 Neutron poison
 Coolant
 Control rods
 Reactor vessel
 Boiler feed water pump
 Steam generators
 Steam turbine
 Electrical generator
 Condenser
 Radiation-waste system
 Nuclear safety system
 Essential service water
system (ESWS)

16. Classification by type of nuclear
reaction
Nuclear Fission
• Thermal reactors
• Fast Neutron reactors
Nuclear Fusion
• Experimental Technology

17. Classification by moderator
material
Graphite moderated reactors
Water moderated reactors
• Heavy water reactors
• Light water moderated reactors
Light element moderated
• Molten salt Reactors (MSRs)
• Liquid Metal Cooled Reactors
Organically moderated reactors (OMRS)

18. Classification by Coolant
Water cooled reactors
• Pressurised water reactors
• Boiling water reactors
• Pool type reactors
Liquid metal cooled reactors
• Sodium cooled fast reactor
• Lead cooled fast reactor
Gas cooled reactors
Molten salt reactors (MSRs)

19. Classification by Generation
Generation I
Generation II
Generation III
Generation IV

20. Classification by Use
Electricity generation
propulsion
• Nuclear marine propulsion
• Rocket propulsion
Other uses of heat
• Desalination
• Domestic & Industrial heating
• Hydrogen production in ‘hydrogen economy’
Transmutation of Elements
• Breeder Reactors
• Radioactive isotopes
• Nuclear Weapons
Research reactors

22. Enegetics
Output ~
200 meV
Input
~
7-8
meV

23. Indian Atomic Energy programme
 Atomic energy program developments started during
Independence- Homi J. Bhabha
 First Nuclear reactor- APSARA- Aug 4, 1956
 Followed by CIRUS (Canada India Reseach U.S.)
reactor, 1960: used natural Uranium as fuel & heavy
water as moderator capacity: 40 MW
 research reactors: ZERLINA, PURNIMA(I, II & III),
DHRUVA & KAMINI.

24.  KAMINI: U-233 as Fuel
 limited reserves of uranium but abundant reserves of
Thorium
 3-stage strategy
1. Obtain Pu-239 from natural uranium
fission
2. Pu-239 fuel for ‘fast breeder’ Reactors
3. Produce fissile U-233 from Thorium-232

27. Nuclear Accidents
 Chernobyl Reactor, Ukraine, 1986

28. Chernobyl mishap

30. Fakushima, Japan Nuclear Disaster

31. Quetions
 Why we use specific nuclear fuels like uranium-235 &
plutonium-238?
 When we say a reactor achieved criticality, what does
it mean?


32. References
 WNA (World Nuclear Association)
 IAEA (International Atomic Energy Association)
 BARC (Bhabha Atomic Research Centre)
 Wikipedia

33. Next Seminar Scope Topics in
context with nuclear reactors
 Current technologies
 Future and developing technology
 Nuclear disaster: Case study
 Nuclear energy a Savior or Killer : Debate
 Conclusion