this is the Mechanical presentation on nuclear power plant

1. Summer Training Presentation By-
YOGESH SHARMA
N.P.C.I.L Narora

2. Contents
 Introduction of NAPS
 Layout of NAPS
 Working of Nuclear Power Plant
 Principal of Nuclear Power Plant
 Uranium Fuel Bundle
 Calandria
 Heavy Water
 Moderator System
 Shut Down System
 Compressed Air System
 Cooling Water
 CWPH(Circulating Water Pump House)
 Feed Water System

3. INTRODUCTION OF NAPS
• Narora atomic power station is situated at the bank of
river Ganga in Bulandshahr district of Uttar Pradesh.
• Naps is involved in generating electricity by utilizing
nuclear energy.
• Naps is laid down on 4th January 1974.
• The heat generated due to fission of Natural Uranium is
removed by circulating D2O Coolant.
• Naps has 2 Natural draft cooling tower and 2 Induced draft
cooling tower.

4. LAYOUT OF NAPS
 Administration building
 Overhead water tank
 Natural draft cooling tower
 220KV Switch yard
 Stack
 Service building
 Reactor building
 Purification building
 Turbine building
 Pump House
 Station Training centre
 Waste Management plant

5. WORKING OF NUCLEAR PLANT

6. Working of Nuclear Power Plant :-
Nuclear power plants generated electricity from
nuclear heat.
The nuclear heat converts water to steam ,which in
turn drives the turbine and generator to produce
electricity.
Inside a nuclear power station, energy is released by
nuclear fission in the core of nuclear reactor.
1kg of Uranium U-235 produce as much energy as
the burning of 4500 tones of high grade variety of
coal or 2000 tones of oil.

7. Principal of Nuclear Reactor
 A Nuclear Power reactor is only a source of heat.
 The heat being produced when the uranium atom splits
(fission).
 Natural uranium consist of two types (isotopes) of uranium
namely U-235 and U-238 in the ratio of 1:139.
 Naturally occurring uranium contains only 0.71% U-235,the
remainder is the non feasible U-238.
 When a U-235 atom is struck by a slow (or thermal)
neutron, it splits into two or more fragments.

8. Principle Continued(fission)

9. URANIUM FUEL BUNDLE

10. Uranium Fuel Bundle
Uranium fuel bundles are 49.53 cm long & has
8.17cm dia.
Each bundle consists of 19 hermetically seal
zircaloy tubes containing compact & sintered
pallets of natural uranium.
Twelve such bundles are located in each fuel
channel.

11. CALANDRIA

12. Calandria
Calandria is the heart of reactor and it is the source
of heat.
Calandria is a cylindrical vessel having 306 Calandria
tubes.
One coolant tube passes through each calandria
tube, and this Coolant tube has 12 fuel Bundles in it
which undergo fission reaction.

14. HEAVY WATER
 Heavy water is used as both coolant and
moderator.
 Heat energy is transported by coolant from
reactor to the vertical, integral U-tubes in
shell type of heat exchangers.
 The absorption of heavy water for neutron is
far less than the ordinary water.
 This helps in neutron economy.

15. Moderator System
 Moderator system is a
heavy water and helium
system.
 Calandria is always full of
moderator up to 96% and
remaining volume is
covered by helium gas.
 Working pressure and
temperature of
moderator system are
8Kg/cm 2 and 63℃.
respectively.

16. SHUTDOWN SYSTEM
1. PRIMARY SHUTDOWN SYSTEM
-This system will response in just 2.3 sec.
-This is slow down acting system.
-primary shutdown system has shutoff mechanism at 14
locations in the reactor.
2.SECONDARY SHUTDOWN SYSTEM
-This will used when primary system is fail to shutdown the system.
- This is the fast acting system and respond in 1.4sec.
-secondary shutdown system is a fast acting back up system to the primary
shutdown system.

17. Compressed Air System
The compressed air system has been provided
for the supply of compressed air for the
purpose of-
• Instrumentation(Instrument Air).
• Control service(Service Air).
• Mask air requirement(Mass Air).

18. CWPH(CIRCULATING WATER PUMP HOUSE)
 Circulating water system is mainly for removing the latent
heat from the turbine exhaust and maintains the desired
exhaust pressure in condenser.
 Some portion of circulating water is supplied -
1. Turbine oil coolers
2. Hydrogen coolers
 plant consists of six horizontal opposed balanced type air
compressors, each having nominal capacity of 14.85M3/min.
(Free air delivery = 18.0M3/min) at a pressure 8.5 Kg/cm2 .

20. FEED WATER SYSTEM
Feed water system main function:-
1. Supply adequate high quality water to steam
generator.
2.heat the water from about 49℃ to 170℃.
Feed water pump:-
1.Feed water pump is used to increased the
pressure 350 psi to 1200 psi.
2.Each unit typically will have 2 or 3 Feed
water pumps.

21. Feed Water Pump
Feed pumps usually rotate at about 5000 revolutions per
minute and have an oil lubricating system.