nuclear power plant presentation

8/10/2019 Nuclear Power Plant Presentation

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NUCLEAR POWER PLANTS


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INTRODUCTION

All Conventional thermal power plants have a fuel source to provide

heat. For a nuclear power plant, this heat is provided by nuclear

fission inside the nuclear reactor's core.

When a relatively large fissile atomic nucleus is struck by a neutron it

forms two or more smaller nuclei as fission products, releasing energy

and neutrons in a process called nuclear fission. The neutrons then

trigger further fission, and so on.

When this nuclear chain reaction is controlled, the energy released

can be used to heat water, produce steam and drive a turbine that

generates electricity.


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NUCLEAR REACTORS

The basic parts of a reactor are the core, a moderator, control rods,

a coolant, and shielding. The core of a reactor contains the uranium

fuel.

The neutrons produced by fission are travelling at great speeds, and

in most reactors, they are deliberately slowed down by a material

known as a moderator. A moderator is composed of light atoms and

the materials most commonly used are carbon in the form of

graphite, and water.


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NUCLEAR REACTORS

For more precise control of the chain reaction, control rods are

inserted into the core of the reactor. Pushed in, they absorb

neutrons and slow down the reaction - pulled out they allow it

to speed up again. In this way the chain reaction is controlled.

Fissions occurring in the reactor generate an enormous

amount of heat. A liquid or gas coolant carries this heat away

from the reactor to a boiler where steam is made.

Shielding, typically made of steel and concrete about two

metres thick, is an outer casing that prevents radiation from

escaping to the environment.

It may be noted that concrete outershielding are designed ti

withstand aircraft crash.


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PRESSURISED WATER REACTOR


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PRESSURISED WATER REACTORS

The most common type of reactor is the Pressurized Water Reactor

(PWR)

In the PWR, there are two main water cycles. One is the water inside

the core that is highly radioactive. This water's heat is transferred to

other, non-radioactive water inside the second loop. This water is

then used to turn a turbine.


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BOILING WATER REACTOR


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BOILING WATER REACTORS

The second most popular reactor type is the Boiling Water Reactor

(BRW). This type of reactor differs from the PWR in that there is only

one water cycle.

Radioactive water is used to turn the turbine. The major

disadvantage of this is that the radioactive nuclides in the water

that cause its radioactivity can be transferred to the turbine, thus

causing it to become radioactive too.

This produces more hazardous material that needs to be disposed

off when a reactor is dismantled.


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PRESSURISED HEAVY WATER REACTOR


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PRESSURIZED HEAVY WATER REACTOR

Fuel assemblies are placed horizontally in a tank called a calandria.

Heavy water coolant is pumped through tubes containing the fuel

assemblies to pick up the heat generated from the nuclear reaction. The coolant then moves to the steam generators to produce steam

from ordinary water and back to the reactor.

Heavy water is a rare but natural form of water and is the most

effective moderator used in nuclear reactors to maintain continuous

fissioning. Ordinary water is a combination of one oxygen and two

hydrogen atoms (H2O).

Heavy water is virtually identical, except each of the hydrogen atoms

have an extra neutron. This hydrogen isotope is called deuterium

(D). Since heavy water (D2O) has almost all the extra neutrons it

wants, it slows neutrons in the reactor without significantly

absorbing them. The advantage of heavy water is that it permits the

use of unenriched uranium as fuel.


12/16FAST BREEDER REACTOR


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FAST BREEDER REACTOR

The Fast Breeder Reactor (FBR) has a core of plutonium surroundedby rods of U-238. The U-238 nuclei absorb neutrons from the core

and are transformed into plutonium (P-239).

For every four atoms of plutonium that are used up in the core of

the breeder, five new plutonium atoms are made from the U-238.Therefore, FBRs "breed" plutonium.

Fast breeder reactors work at such a high temperature that they

need a special coolant such as liquid sodium.

In addition, they are not equipped with a moderator to slow downneutrons, and for this reason are called "fast" breeders.


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LIST OF INSTALLATION IN INDIA

Power plant Location Country Start date Type & Gross

power

Kaiga-2 Karnataka India 1999 PHWR, 220MW

Kakrapar-1 Gujarat India 1992 PHWR, 220MW

Kakrapar-2

Gujarat

India

1995

PHWR, 220MW

Kalpakkam - 1 Tamilnadu India 1983 PHWR, 170MW

Kalpakkam - 2 Tamilnadu India 1985 PHWR, 170MW

Narora-1 Uttar Pradesh India 1989 PHWR, 220MW


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LIST OF INSTALLATION IN INDIA

Power plant Location Country Start date Type & Gross

power

Narora-2

Uttar

Pradesh

India

1992

PHWR,

220MW

Rajasthan-1 Rajasthan India 1972 PHWR,

100MW

Rajasthan-2

Rajasthan

India

1980

PHWR,200MW

Tarapur-1 Maharastra India 1969 BWR, 160MW

Tarapur-2 Maharastra India 1969 BWR, 160MW

Kaiga-1

Karnataka

India

2000

PHWR,

220MW


220MW


200MW

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