NUCLEAR POWER PLANT

NUCLEAR POWER PLANT

Nuclear power or nuclear energy is the use of exothermic nuclear processes, to generate useful heat and electricity. The term includes the nuclear fission and nuclear fusion. Presently the nuclear fission of elements in the actinide series of the periodic table produce the vast majority of nuclear energy in the direct service of humankind. Nuclear power is a low carbon power generation method of producing electricity.

INTRODUCTION OF NUCLEAR ENERGY:-

Actinium Thorium 

Protactinium Uranium

Neptunium Plutonium

 Americium Curium

 Berkelium  Californium Einsteinium

Fermium Mendelevium

Nobelium Lawrencium 

89 90 91 92 93 94 95 96 97 98 99 100

101

102

103

Ac Th Pa U Np Pu Am Cm

Bk Cf Es Fm Nd No Lr

ACTINIDE SERIES AND NUCLEAR ELEMENT:-

Nuclear fusion is the reaction in which two or more nuclei combine together to form a newelement with higher atomic number (more protons in the nucleus). The energy released in fusion is related to E = mc 2 (Einstein’s famous energy-mass equation). On earth, the most likely fusion reaction is Deuterium–Tritium reaction. Deuterium and Tritium are bothisotopes of hydrogen.

2 1Deuterium + 3 1Tritium = 42He + 1

0n + 17.6 MeV

Nuclear Fusion and Nuclear fission :-

Fusion of deuterium with tritium creating helium-4, freeing a neutron, and releasing 17.59 MeV of energy.

NUCLEAR FUSION REACTION

Nuclear fission is the splitting of a massive nucleus into photons in the form of gamma rays, free neutrons, and other subatomic particles. In a typical nuclear reaction involving 235U and a neutron. 236

92U = 14456Ba + 89 36Kr + 3n + 177 MeV

NUCLEAR FISSION REACTION

FISSIONDefinition Fission is the

splitting of a large atom into two or more smaller ones.

Natural occurrence of the process

Fission reaction does not normally occur in nature.

Energy Released

The energy released by fission is a million times greater than that released in chemical reactions.

Energy production

Fission is used in nuclear power plants.

FUSIONDefinition Fusion is the

fusing of two or more lighter atoms into a larger one.

Natural occurrence of the process

Fusion occurs in stars, such as the sun.

Energy Released

The energy released by fusion is three to four times greater than the energy released by fission.

Energy production

Fusion is an experimental technology for producing power.

NUCLEAR POWER PLANT CONSTRUCTION:

STUCTURE OF NUCLEAR POWER PLANTNuclear plant consist of nine major parts.The reactor is the main part of this power plan.

A gas-tight shell or other enclosure around a nuclear reactor to confine fission products that otherwise might be released to the atmosphere in the event of an accident. Such enclosures are usually dome-shaped and made of steel-reinforced concrete. It has maximum pressure in the range of 40 to 80 ps( 410 to 1400 kPa). The containment building itself is typically an airtight steel structure enclosing the reactor normally sealed off from the outside atmosphere. The steel is either free-standing or attached to the concrete missile shield. In India the design and thickness of the containment and the missile shield are governed by federal regulations (10 CFR 50.55a), and must be strong enough.

CONTAINMENT STRUCTURE:

CONTAINMENT DIAGRAM:

These are rods used in specific materials (silver, indium, cadmium or boron carbide) to control fission inside the core. Since they absorb neutrons, they are capable of controlling the chain reaction which - depending on how deep down the rods are inserted into the core - can be accelerated, slowed down or even stopped, thus changing the capacity of the reactor. Indeed, if necessary, the reactor can be immediately stopped when they are fully inserted.

CONTROL RODS:

A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation and in propulsion of ships. Heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines. These either drive a ship's propellers or turn electrical generators.

REACTORS:

A kilogram of uranium-235 (U-235) converted via nuclear processes releases approximately three million times more energy than a kilogram of coal burned conventionally (7.2 × 1013 joules per kilogram of uranium-235 versus 2.4 × 107 joules per kilogram of coal).

Heat generation: The reactor core generates heat in a number of ways: The kinetic energy of fission products is converted to 

thermal energy when these nuclei collide with nearby atoms.

The reactor absorbs some of the gamma rays produced during fission and converts their energy into heat.

Cont.

Steam generators are heat exchangers used to convert water into steam from heat produced in a nuclear reactor core. They are used in pressurized water reactors (PWR)between the primary and secondary coolant loops. That water flowing through the steam generator boils water on the shell side to produce steam in the secondary loop that is delivered to the turbines to make electricity

STREAM GENERATOR:

The Main Steam System used in any power plant has 1 major purpose:

Provide steam from the source (reactor, steam generator, or steam separator) to the turbine

The system may have several other functions Provide the ability to prevent overpressurization

of the steam source (if the source puts out more heat than the turbine can accept)

Provide the ability to prevent overcooling of the reactor coolant system (if the steam system draws off more heat than the source can provide)

STREAM LINE:

The major components in most Main Steam Systems are: Steam Line from the Reactor (if a BWR) , Steam generator (if a

PWR), Steam Separator (if a GCR) to the turbine. Main Steam Isolation Valve - usually an air operated or motor

operated valve used to isolate the steam source from the turbine.

Safety valves - large relief valves that will open if steam pressure gets too high (same purpose as the pop valve on your hot water heater).

Power Operated Relief Valves - large air or motor operated valves that usually lift at a setpoint lower than the safety valves - in order to keep the steam pressure from getting too high.

Non-return Valve - a large valve that prevents backward steam flow in the steam line

Major Components Of Stream Line:

A boiler feedwater pump is a specific type of pump used to pump feedwater into a steam boiler. The water may be freshly supplied or returning condensate produced as a result of the condensation of the steam produced by the boiler. These pumps are normally high pressure units that take suction from a condensate return system and can be of the centrifugal pump type or positive displacement type.

PUMP:

The generator converts kinetic energy supplied by the turbine into electrical energy. Low-pole AC synchronous generators of high rated power are used.

GENERATOR:

A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. it is particularly suited to be used to drive an electrical generator. An ideal steam turbine is considered to be an isentropic process, or constant entropy process, in which the entropy of the steam entering the turbine is equal to the entropy of the steam leaving the turbine. No steam turbine is truly isentropic, however, with typical isentropic efficiencies ranging from 20–90% based on the application of the turbine.

TURBINE:

A surface condenser is a commonly used term for a water-cooled shell and tube heat exchanger installed on the exhaust steam from a steam turbine in thermal power stations.[1][2]

[3] These condensers are heat exchangers which convert steam from its gaseous to its liquid state at a pressure below atmospheric pressure. Where cooling water is in short supply, an air-cooled condenser is often used. An air-cooled condenser is significantly more expensive and cannot achieve as low a steam turbine exhaust pressure as a water-cooled surface condenser.

COOLING WATER CONDENSER:

In Nuclear power plants, the primary purpose of a surface condenser is to condense the exhaust steam from a steam turbine to obtain maximum efficiency, and also to convert the turbine exhaust steam into pure water (referred to as steam condensate) so that it may be reused in the steam generator or boiler as boiler feed water.

PURPOSE OF WATER CONDENSER:

The steam turbine itself is a device to convert the heat in steam to mechanical power. The difference between the heat of steam per unit mass at the inlet to the turbine and the heat of steam per unit mass at the outlet from the turbine represents the heat which is converted to mechanical power. Therefore, the more the conversion of heat per pound or kilogram of steam to mechanical power in the turbine, the better is its efficiency. By condensing the exhaust steam of a turbine at a pressure below atmospheric pressure, the steam pressure drop between the inlet and exhaust of the turbine is increased, which increases the amount of heat available for conversion to mechanical power. Most of the heat liberated due to condensation of the exhaust steam is carried away by the cooling medium (water or air) used by the surface condenser

Cont..

WATER CONDENSER DIAGRAM:

Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature. With respect to the heat transfer mechanism employed, the main types are:

Dry cooling towers operate by heat transfer through a surface that separates the working fluid from ambient air, such as in a tube to air heat exchanger, utilizing convective heat transfer. They do not use evaporation.

Wet cooling towers or open circuit cooling towers operate on the principle of evaporative cooling. The working fluid and the evaporated fluid (usually water) are one and the same.

Fluid coolers or closed circuit cooling towers are hybrids that pass the working fluid through a tube bundle, upon which clean water is sprayed and a fan-induced draft applied. The resulting heat transfer performance is much closer to that of a wet cooling tower, with the advantage provided by a dry cooler of protecting the working fluid from environmental exposure and contamination.

COOLING TOWER:

Fuel rods are the containers for the uranium used in nuclear power plants. A fuel rod is typically a long, slender, zirconium metal tube containing pellets of fissionable material, which provide fuel for nuclear reactors. Fuel rods are assembled into bundles called fuel assemblies, which are loaded individually into the reactor core. 

FUEL RODS:

It used in Nuclear power plant to step up the generated voltage.Generaly maximum 50KVA rating of Transformer can used in Nuclear power plant.

TRANSFORMER:

Electrical power generation: The energy released in the fission process

generates heat, some of which can be converted into usable energy. A common method of harnessing this thermal energy is to use it to boil water to produce pressurized steam which will then drive a steam turbine that turns an alternator and generates electricity.

WORKING PRINCIPLE:

As of 2012, India has 20 nuclear reactors in operation in six nuclear power plants,having an installed capacity of 5780 MW[2]

[3] and producing a total of 29,664.75  GWh of electricity[4] while seven other reactors are under construction and are expected to generate an additional 6,100 MW.

To be cont..

INDIAN NUCLEAR POWER PLANT:

TOTAL=5780

Power station

Operator

State Type Units Total capacity(MW)

Kaiga NPCIL Karnataka

PHWR 220*4 880

KaKrapar

NPCIL Gujurat PHWR 220*2 440

Kalpakkam

NPCIL Tamil Nadu

PHWR 220*2 440

Narora NPCIL Uttar pradesh

PHWR 220*2 440

Rawatbhata

NPCIL Kota,Rajasthan

PHWR 200*1 118

Tarapur NPCIL Maharashtra

BWR 400*2 140

Kudankulam

NPCIL Tamil Nadu

WER-1000

1000*1 1000

NAME-PANKAJ KUMAR NAYAKBRANCH-ELECTRICAL

ROLL NO-11-EE-10

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