Nuclear power plants and types of nuclear reactors... Please do comment your suggestions and corrections...

1. NUCLEAR POWER PLANT

2. RADIOACTIVITY
• Nucleus is stable  forces acting on electron and proton are equal.
• Nucleus is unstable  Un equal forces.
• Becomes stable by emitting radiation (particles or EM Waves).
• This phenomenon is called radioactivity.
• Alpha
• Beta
• gamma

3. RADIOACTIVITY
• Alpha particle  nucleus of a Helium atom, 2
4He.
• Beta particles  negatively charged high speed electrons emitted by
the nucleus. They have no mass but posses a charge of -1. They are
denoted by -1
0e.
• Gamma rays are high energy photons travelling with the velocity of
light. They have no mass or charge. They are denoted by 0
0y.

4. NUCLEAR FISSION
• Splitting of nucleus into lighter nuclei by colliding it with a neutron
(projectile).
• Must have an energy equivalent to nuclear binding energy to split the
nucleus.
• Nuclear fission produces heat and electromagnetic radiation.
• E = mc2.

5. NUCLEAR FISSION
• Fission produces additional neutrons (projectiles) which can then be
captured by other atoms to continue the reaction (chain reaction)
• The reaction can get out of control and an explosion can occur.
• To prevent this control rods that absorb the extra neutrons are used.
• Uranium-235 is the most commonly used fuel for fission.

7. • The materials U-235, U-233 and Pu-239 are called fissionable
materials.
• The only fissionable nuclear fuel occurring in nature is uranium
• 99.3 % is U-238
• 0.7% is U-235
• U-234 is only a trace.
• Out of these isotopes only U-235 will fission in a chain reaction.
NUCLEAR FISSION

8. • The materials U-235, U-233 and Pu-239 are called fissionable
materials.
• The only fissionable nuclear fuel occurring in nature is uranium
• 99.3 % is U-238
• 0.7% is U-235
• U-234 is only a trace.
• Out of these isotopes only U-235 will fission in a chain reaction.
NUCLEAR FISSION

11. • REACTOR CORE
• Contains nuclear fuel – U 235
• MODERATOR
• To reduce the speed of the neutrons (projectile) so as to maintain reaction
• Hydrogen, Deuterium, Helium, Lithium, Berylium, Boron, Carbon, Nitrogen,
Oxygen
• CONTROL RODS
• Absorb neutrons to control the reaction
• boron-10, cadmium, graphite.

12. • COOLANT
• Transfer heat to water
• GAS - Air, helium, hydrogen and CO2
• LIQUID - light and heavy water
• METAL - molten sodium and lithium
• REFLECTOR
• Confines the neutrons within the reactor.
• SHIELDING
• Lead or thick concrete.
• Protection from alpha, beta and gamma rays

13. Boiling Water Reactor (BWR )
Ordinary water is used as coolant and moderator

14. Pressurized Water Reactor (PWR )
Water under pressure is used as coolant and moderator

15. Heavy Water Cooled And Moderated (CANDU Type) Reactor
CANDU  Canadian Deuteriurn Uranium.
Heavy water is moderator and coolant

16. Fast-Breeder Reactor.
• Uranium or plutonium is surrounded by a blanket of U-238 or Th-232.
• U-238 or Th-232 absorbs neutrons produced by the fissioning of U-235 and produces fissile material Pu-239 or U-233
• Thus secondary fuels (U-233 and Pu-239) results in reduction of fuel cost.
• Two heat exchangers are used to prevent the possibility of a sodium-water reaction with the radio-active sodium.

17. GAS COOLED REACTOR
• Uses CO2 and Helium as coolant.
• Graphite as the moderator.
• A large quantity of gas is required, due to poor heat transfer qualities.