Summer Training Presentation By-

ASHISH KUMAR(1313340033)

B.Tech 4th year Mechanical BranchN.I.E.T. Greater Noida

Contents Introduction of NAPS Layout of NAPS Important data 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 Feed Water System

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 a twin unit module which develope totally 440MWe by using uranium as a fuel and heavy water as a moderator

• 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

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

IMPORTANT DATA OF NAPSSr.No Data Specification1. Transmission Lines

a)220 kV Narora-Moradabadb)220kV Narora-Harduaganjc)220kV Narora-Simbholid)220kV Narora-Khurja

Five:Single lineSingle lineSingle lineDouble line

2. Stack Height 142 Meters

3. NDCT Height 128 Meters4. NDCT Top Dia. 58 Meters5. NDCT Base Dia. 107 Meters6. NDCT Throat Dia. 53 Meters7. Steam Flow 1314 Ton/hr8. PHT Flow 12700 Ton/hr9. Steam Pressure 48-40 kg/cm2

10. PHT Pressure 87 Kg/cm2

11. CCW Flow 39000 Ton/hr12. Coolant Tubes 30613. Fuel Bundle in 1 channel 1214. Fuel Bundle Weight 15 Kgs15. Condenser Pressure 680mm of hg16. R B Design Pressure 1.25 Kg/cm2

17. Station Load 18-20 Mwe18. Generator Power 220 MWe19. Grid Voltage 220 Kv

WORKING OF NUCLEAR PLANT

working of nuclear power plant continued...

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 tonnes of high grade variety of coal or 2000 tonnes of oil

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 occuring uranium contains ony 0.71% U-235,the

remainder is the non fissible U-238 When a U-235 atom is struck by a slow (or thermal)

neutron, it splits into two or more fragments

Principal continued(fission)...

URANIUM FUEL BUNDLE

Uranium fuel bundle continued...Uranium fuel bundles are 49.53 cm long & has

8.17cm diaEach bundle consists of 19 hermetically seal

zircaloy tubes containing compact & sintered pallets of natural uranium

Twelve such bundles are located in each fuel channel.

CALANDRIA

calandria continued...Calandria is the heart of reactor and it is the source

of heatCalandria is a cylindrical vessel having 306 Calandria

tubesOne coolant tube passes through each calandria

tube, and this Coolant tube has 12 fuel Bundles in it which undergo fission reaction

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

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/cm2 and 63 oC respectively

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

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)

CWPH 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 coolers2. 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

FEED WATER SYSTEMFeed 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 Feedwater pumps.

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