nuclear power plant

NUCLEAR POWER PLANT

CONTENTS

Introduction

Nuclear fuel

Nuclear fission process

Nuclear chain reaction

Constituents of Nuclear power plant

Types of power reactors commonly used

Advantages and Disadvantages

World’s Nuclear power program

India’s Nuclear power program

Design features of Reactor containment

Presented By : Omraj Singh

NUCLEAR FUEL

Nuclear fuel is any material that can be consumed to derive nuclear energy.

The most common type of nuclear fuel is fissile 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.

NUCLEAR FISSION

When a neutron strikes an atom of Uranium, the Uranium splits into 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.


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.

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.


NUCLEAR CHAIN REACTIONPresented By : Omraj Singh

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 explosion.


NUCLEAR POWER PLANT


MAIN COMPONENTS OF NUCLEAR POWER PLANT

Fuel Rods -

• Tube filled with pellets of Uranium

Shielding -

• Protection against alpha, beta and Gamma Rays

Moderator -

• Slow down the neutron release(Heavy water, Beryllium, Graphite)

Control Rods -

• Control rods made of a material material (boron Carbide, cadmium) that absorbs neutrons are inserted into the bundle using a mechanism that can rise or lower the control rods.

• The control rods essentially contain neutron absorbers like, boron, cadmium or indium.



Coolant -

• To transfer the heat generated inside the reactor to a heat exchanger for utilization of power generation

• Either ordinary water or heavy water is used as the coolant

Containment -

• Concrete lined cavity acting as a radiation shield

Steam Generator s -

• Steam generators are heat exchangers used to convert water into steam from heat produced in a nuclear reactor core

Steam Separator -

• Steam from the heated coolant is fed to the turbines to produce electricity from generator



Steam Turbine -

• A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical

• Various high-performance alloys and super alloys have been used for steam generator tubing

Coolant Pump -

• The coolant pump pressurizes the coolant to pressures of the order of 155bar

• The pressure of the coolant loop is maintained almost constant with the help of the pump and a pressurizer unit.



Feed Pump -

• Steam coming out of the turbine, flows through the condenser for condensation and re-circulated for the next cycle of operation

• The feed pump circulates the condensed water in the working fluid loop.

Condenser -

• Condenser is a device or unit which is used to condense vapor into liquid

• The objective of the condenser are to reduce the turbine exhaust pressure to increase the efficiency and to recover high quality feed water in the form of condensate & feed back it to the steam generator without any further treatment.



Cooling Towers -

• Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere

• Water circulating through the condenser is taken to the cooling tower for cooling and reuse


TYPES OF POWER REACTORS COMMONLY USED

Boiling water Reactor(BWR)

Pressurized water Reactor(PWR)

Pressurized Heavy Water Reactors(PHWR) OR CANDU Type

Reactor

Gas Cooled Reactor

Liquid Metal Cooled Reactor


BOILING WATER REACTOR (BWR)

Heat generated in the core is used to generated steam through a

heat exchanger

The steam runs a turbine just like a normal power plant

Fuel used is rich in uranium oxide

Ordinary water is used as both moderator and coolant

Low thermal efficiency

Can’t meet sudden increase

of load


PRESSURIZED WATER REACTOR (PWR)

Water in the core heated top 315°C but is not turned into steam due

to high pressure in the primary loop

Heat exchanger used to transfer heat into secondary loop where

water is turned to steam to power turbine power plant

Steam used to power turbine never comes directly in contact

with radioactive materials

Strong pressure vessel is

required

High loss from heat exchanger


PRESSURIZED HEAVY WATER REACTOR

(PHWR) OR CANDU TYPE REACTOR

It makes use of heavy hydrogen (deuterium oxide D2 O) as moderator

Primary and secondary circuits are similar to PWR

It’s very expensive to separate

Control rods are not required

It has high multiplication factor and low level fuel consumption


ADVANTAGES Nuclear power generation does emit relatively low amounts of carbon dioxide

(CO2). The emissions of green house gases and therefore the contribution of

nuclear power plants to global warming is therefore relatively little.

This technology is readily available, it does not have to be developed first.

It is possible to generate a high amount of electrical energy in one single plant.

Highly Concentrated Source of Energy1 kg wood: 1 kW·h1 kg coal: 3 kW·h1 kg oil: 4 kW·h1 kg uranium: 50 000 kW·h(3 500 000 kW·h with reprocessing)

Nuclear Power: a Compact SourceTypical Fossil & Nuclear Sites : 1–4 km² Solar thermal or photovoltaic (PV ) parks : 20–50 km² Wind fields : 50–150 km²Biomass plantations : 4000–6000 km² (a province)


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.

Nuclear power plants as well as nuclear waste cloud be preferred targets for

terrorist attacks.

During the operation of nuclear power plants, radioactive waste is

production, which in turn can be used for production of nuclear weapons.


WORLD’S NUCLEAR POWER PROGRAM


Source: International Energy Outlook 2010 Presented By : Omraj Singh

NUCLEAR POWER PLANT STATUS IN TH E WORLD

Present Status (As of Aug 2011)

*No of Units in Operation:432

* Total Installed Capacity: 365837 (MWe)

*No of Units under Construction: 62

* Total Installed Capacity: 62862 (MWe)(Source: IAEA)


(Source: IAEA)Presented By : Omraj Singh

INDIA’S NUCLEAR POWER PROGRAM


INIDA’S NUCLEAR POWER PROGRAM

India now envisages to increase the contribution of nuclear power to overall electricity generation capacity from 4.2% to 9% within 25 years. In 2010, India's installed nuclear power generation capacity will increase to 6,000 MW. Indian nuclear power industry is expected to undergo a significant expansion in the coming years in part to the passing of the U.S.-India Civi l Nuclear Agreement . This agreement will allow India to carry out trade of nuclear fuel and technologies with other countries and significantly enhance its power generation capacity. When the agreement goes through, India is expected to generate an additional 25,000 MW of nuclear power by 2020, bringing total estimated nuclear power generation to 45,000 MW.


Three Stage Nuclear Power Program

Closed Fuel Cycle

First Stage has reached a level of maturity

540 MW and 700 MW reactors of Indigenous design

Second Stage: 500 MW PFBR under construction

3rd Stage AHWR : Construction expected to start in next 1 to 2 years


INDIA’s THREE STAGE NUCLEAR POWER PROGRAMME


PROPOSED XI PLAN STARTS – NPCIL MAJOR PROJECTS

Project Construction Start

1. KAPP 3&4 (2X700 MWe PHWRs) 2008-09

2. RAPP 7&8 (2X700 MWe PHWRs) 2009-10

3. 7NP 5&6 (2X700 MWe PHWRs) 2011-12

4. 7NP 7&8 (2X700 MWe PHWRs) Pre- Project

Project Construction Start

1. KK 3&4 2007-08

2. JAITAPUR 1&2 2008-09

3. KK 5&6 2010-11

4. LWR 11&12 2010-11

5. JAITAPUR 3&4 2011-12

Indigenous

Imports


3360 41

20 4780 57

80 6780

7280

7280

7280

9280

1268

0 1438

0

1978

0

2318

0

33

60

41

20

47

80 57

80

67

80

72

80

72

80

72

80

72

80 86

80 1

03

80

117

80

13

18

0

0

5000

10000

15000

20000

25000

05-06 06-07 07-08 08-09 09-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18

With international co-operation

Indigenous and ongoing LWRs

NUCLEAR POWER CAPACITY BUILD-UP

(WITH XI PLAN PROPOSALS)


Reactor State Type MWe net , each

Commercial operation

Safeguards status

Tarapur 1 & 2 Maharashtra BWR 150 1969 item-specificKaiga 1 & 2 Karnataka PHWR 202 1999-2000

Kaiga 3 & 4 Karnataka PHWR 202 2007, (due 2011)

Kakrapar 1 & 2 Gujarat PHWR 202 1993-95December 2010

under new agreement

Madras 1 & 2 (MAPS)

Tamil Nadu PHWR 202 1984-86

Narora 1 & 2 Uttar Pradesh PHWR 202 1991-92in 2014 under new

agreement

Rajasthan 1 Rajasthan PHWR 90 1973 item-specificRajasthan 2 Rajasthan PHWR 187 1981 item-specific

Rajasthan 3 & 4 Rajasthan PHWR 202 1999-2000early 2010 under new agreement

Rajasthan 5 & 6 Rajasthan PHWR 202 Feb & April 2010Oct 2009 under new agreement

Tarapur 3 & 4 Maharashtra PHWR 490 2006, 05

Total (20) 4385 MWe

INDIA’S OPERATING NUCLEAR POWER REACTORS


Reactor TypeMWe gross ,

net , each

Project

control

Construction start

Commercial

operation due

Safeguards status

Kudankulam 1 PWR (VVER) 1000, 950 NPCIL March 2002October 2011?

item-specific

Kudankulam 2 PWR (VVER) 1000, 950 NPCIL July 2002 June 2012 item-specific

Kalpakkam PFBR FBR 500, 470 Bhavini Oct 20049/2011, or

2012 -

Kakrapar 3 PHWR 700, 630 NPCIL Nov 2010 June 2015 Kakrapar 4 PHWR 700, 630 NPCIL March 2011 Dec 2015

Rajasthan 7 PHWR 700, 630 NPCIL July 2011 Dec 2016

Total (6) 4260 MWe net, 4600 MWe gross

INDIA’S NUCLEAR POWER REACTORS UNDER CONSTRUCTION


DESIGN FEATURES OF REACTOR CONTAINMENT


EFFECT OF SITE CHARACTERISTICS ON NUCLEAR POWER PLANT

1. Natural Events

(a) Seismic Consideration

Site should not lie in seismic zone V as per IS 1893 ( Part area of J&K , Uttaranchal , North east , Kutch etc.) – rejection criteria

No Capable fault within 5 Km - Seism tectonic evaluation needed – rejection criteria

All lineaments within 300 km radius are studied

Evaluation for Liquefaction – rejection criteria

Effect of Tsunami



( b ) Geological Considerations

Competent strata exist

Adequate sub soil investigation ( 6 boreholes during sitting)

Seismic logging of foundation strata

Evaluate for slope instability ( such as land slide , land erosion)

Evaluate for existence of mines , oil wells , subsidence



(c ) Flooding of Site

All historical rainfall , flood data examined

Flooding due to precipitation

Flooding due to up stream dam break

Finished grade level higher than both these floods

Coastal sites evaluated for combination of high tides , wind effects, wave run up

Studies done at detailed Site Evaluation stage

• – 1000 year return period daily rainfall evaluated from Annual maximum daily rainfall series

• 1000 year return period flood evaluated from annual maximum flood series

• Design Basis Flood calculated from worst combination of events



(d) Extreme Meteorological Events

Two level of wind effects are considered

• - Severe wind 1000 year return period for design purpose

• - Extreme wind 10000 year return period for wind induced missiles

Wind speed and wind rose

Extreme temperatures

(e ) Loss of ultimate heat s ink – Failure of down stream dam – 7 days storage is provided


Distance from small airfields More than 5 km.

Distance from major airports More than 8 km.

Distance from military airfields More than 15 km.


2. Man- Induced Events

Aircraft Crash- Screening Distance Values (SDV) are used


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nuclear power plant

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