Nuclear Reactor

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Nuclear Energy, energy released during the splitting or fusing of atomic nuclei. The energy of any system, whether physical, chemical, or nuclear, is manifested by the system’s ability to do work or to release heat or radiation. The total energy in a system is always conserved, but it can be transferred to another system or changed in form

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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 completely uncontrolled). Currently all commercial nuclear reactors are based on nuclear fission, and are considered by some to be a safe and pollution-free method of generating electricity.

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The key components common to most types of nuclear power plants are: Nuclear fuel Neutron moderator Coolant Control rods Pressure vessel Emergency Core Cooling Systems (ECCS) Reactor Protective System (RPS) Steam generators (not in BWRs) Containment building Boiler feedwater pump Turbine Electrical generator Condenser

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Fuel:- The nuclear reactors uses Uranium-235 as its main fuel . The neutrons of Uranium-235 move in equilibrium . When these neutrons strike a uranium-235 nucleus (in blue in figure below) in the Fuel, sometimes the nucleus will split, or fission, into 2 unequally sized nuclei called fission fragments (in green in figure below). The fission products are large positively-charged particles of elements like Strontium or Iodine. These fission products slow down quickly in the fuel . They are the major contributor to heat production in the fuel (~80%). This heat gets transmitted to the coolant outside the fuel.

Govt. Girls High School Dasuya Hoshiarpur http://www.nucleartourist.com/basics/basic.htm

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Control Rods :- The control rods are very important in the working of the nuclear reactor. They usually made up of cadmium. The main function of the control rods is to slow down the rate of reaction to a controllable limit . Other wise it would turn to be chain reaction blows up like a nuclear bomb. Raising and lowering the control rods allow operators to control the rate of the nuclear reaction. When an operator wants the uranium core to produce more heat, the rods are raised out of the uranium bundle. To create less heat, the rods are lowered into the uranium bundle. Coolant The purpose of the nuclear fission process is to produce heat. The fission fragments that are produced by the fission then slow down in the fuel losing most of their energy. The energy is converted to heat in the fuel. A Coolant is used to remove the heat and maintain the temperature of the fuel within acceptable limits. Sometimes the coolant is used to cool the moderator which, in turn, can be used to cool the fuel. Sometimes the coolant cools the fuel by passing around the rods containing the fuel. Sometimes the moderator and the coolant are the same material (e.g. water).

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Courtesy :-College of Engineering University of Wisconsin - Madison

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•Nuclear power: •Heat for electricity generation •Heat for domestic and industrial heating •Hydrogen production •Desalination •Nuclear propulsion: •Nuclear marine propulsion •Proposed nuclear thermal rockets •Proposed nuclear pulse propulsion rockets •Transmutation of elements: •Production of plutonium, often for use in nuclear weapons •Creating various radioactive isotopes, such as americium for use in smoke detectors, and cobalt-60, molybdenum-99 and others, used for imaging and medical treatment •Research applications including: •Providing a source of neutron and positron radiation (e.g. Neutron activation analysis and Potassium-argon dating) •Development of nuclear technology

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In India Nuclear Reactors are governed by a government body Nuclear Power Corporation Power of India .Its mission is to develop Nuclear Power Technology and to produce Nuclear Power, as a safe, environmentally benign and an economically viable source of electrical energy to meet the increasing electricity needs of the country Some of the Major Nuclear Power Plants in India are:•

Tarapur, Maharashtra

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Rawatbhata, Rajasthan

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Kakrapar, Gujarat

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