1. NUCLEAR POWER PLANT

2. NUCLEAR FUEL  Nuclear fuel is any material that can be consumed to derive nuclear energy. The most common type of nuclear fuel is fissible elements that can be made to undergo nuclear fission chain reactions in a nuclear reactor  The most common nuclear fuels are 235U and 239Pu. Not all nuclear fuels are used in fission chain reactions

3. NUCLEAR FISSION  When a neutron strikes an atom of uranium, the uranium splits ingto two lighter atoms and releases heat simultaneously.  Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments

5. NUCLEAR CHAIN REACTIONS  A chain reaction refers to a process in which neutrons released in fission produce an 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 weapons

7. U235 + n → fission + 2 or 3 n + 200 MeV  If each neutron releases two more neutrons, then the number of fissions doubles each generation. In that case, in 10 generations there are 1,024 fissions and in 80 generations about 6 x 10 23 (a mole) fissions.

9. features does not depend on seasonal variations Transportation cost is less Partially independent of geographical factors Radioactive waste management is the main problem. Large amount of power is released with the consumption of only a small amount of fuel Nuclear pp resembles to a conventional thermal pp because the energy is utilized to produce steam to drive a turbine & hence a generator

10. parts fuel – It should be a fissionable material & produce fission chain reaction.It can be U235, U233 & Pu239 The fuel should be protected from corrosion.It should be able to withstand high temp within the reactor.Moderator- to control the speed of neutrons. Graphite, heavy water beryllium etc are used Control rods- It is cylindrical or sheet form. It can be moved in & out of the reactor vessel.It is used to control fission by absorbing neutrons It should be stable under heat & radiation corosion resistant strong to shut down the reactor instantly under all conditions Reflector- to reflect back the neutrons that are trying to escape from the reactor & hence improve the Neutron economy of the reactor It is made of graphite & berillium

11. Parts cont. Reactor vessel – It is a strong walled container housing the core.It contains moderator,reflector,thermal shielding & control rods Biological shielding – for shielding the radioactive zones from possible radiation hazard is essential to protect operating men from harmful effects Thick layers of lead or concrete are provided to block gamma rays Thick layers of metal or plastic are sufficient to stop beta & alpha particles Coolant – it is circulated thro’ and around the reactor core to cllect heat generated.If it is water it takes heat & gets converted into steam & directly sent to turbine coolant should not corrode the material that comes in contact be stable under thermal conditions

12. Parts cont. High heat transfer coefficient the radio activity induced in the coolant should be nil power required for pumping should be min Coolants are water (light or heavy),gas (air,Co2,H,He ) etc Site selection Avilability of water,distance from load centres, distance from populated areas,accessibility to site (by road or rail), waste disposal,safety against earth quakes etc

16. NUCLEAR REACTOR  A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate, as opposed to a nuclear bomb, in which the chain reaction occurs in a fraction of a second and is uncontrolled causing an explotion.

17. 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.

18. DISADVANTAGES  Nuclear power plants as well as nuclear waste could be preferred targets for terrorist attacks..  During the operation of nuclear power plants, radioactive waste is produced, which in turn can be used for the production of nuclear weapons.

19. Radiation and Health Health effects as a result of radiation exposure: -increased likelihood of cancer -birth defects including long limbs, brain damage, conjoined stillborn twins -reduced immunity -genetic damage 19

20. 20 Risk of terrorism (new challenge to industry) 9/11 jet passed near Indian Point

21. Thank you