Energy from nuclear fission reaction

A nuclear reactor is a device for generating energy from nuclear fission reactions. Nuclear fission is the process in which large atoms are split, releasing large amounts of energy and smaller atoms. In a nuclear reactor, it is essential that just the right number of neutrons are present. Too many neutrons can cause a fission reaction to get out of control. Too few neutrons and a fission reaction stops. 

Hafnium has only a few applications. Probably its most important use is in nuclear power plants. A nuclear power plant is a facility where energy released from nuclear fission reactions is used to generate electricity. 

A simple nuclear weapon derives its energy from nuclear fission. A mass of fissionable material is rapidly assembled into a critical mass, in which a chain reaction develops and releases tremendous amounts of energy. This is known as an atomic bomb. Nuclear fusion can be used to make a more powerful weapon. In such a weapon, the X-ray thermal radiation from a nuclear fission explosion is used to heat and compress a small amount of tritium, deuterium, or hthium, causing nuclear fusion, releasing even more energy. Such a weapon is called a hydrogen bomb and can be hundreds of times more powerful than an atomic bomb. 

Nuclear installations are provided with a pressure explosion suppression and containment shell as an accommodation system against any sudden energy release resulting from an uncontrolled nuclear fission reaction. The internal air pressure is maintained at a level lower than the external atmosphere. 

Nuclear energy in almost inconceivable quantities can be obtained from nuclear fission and fusion reactions according to Einstein s famous equation. 

Fission weapons or bombs They derive their power from nuclear fission when heavy nuclei such as uranium (U) or plutonium (Pu) are bombarded by neutrons and split into lighter elements, more neutrons and energy. The newly generated neutrons then bombard other nuclei which then split and bombard other nuclei and so on. This process continues and leads to a nuclear chain reaction which releases large amount of energy. These are also historically called atomic bombs or atom bombs or A-bombs. 

NATURE OF NUCLEAR FISSION REACTIONS The energy of a nuclear fission reaction can be computed from the change in mass between reactants and products according to Einstein s law ... 

The tremendous release of energy from nuclear reactions makes possible a unique family of applications for long-lived radioisotopes that are important to health, science, and industry. Whereas fission and fusion occur almost instantaneously, other radioactive decay processes occur in times ranging from a few minutes to thousands of years. The general areas of application may be grouped into irradiation, thermal energy generation, and tracer applications.57... 

The production of power from controlled nuclear fission of heavy elements is the most important technical application of nuclear reactions at the present time. This is so because the world s reserves of energy in the nuclear fuels uranium and thorium greatly exceed the energy reserves in all the coal, oil, and gas in the world [HI], because the energy of nuclear fuels is in a form far more intense and concentrated than in conventional fuels, and because in many parts of the world power can be produced as economically from nuclear fission as from the combustion of conventional fuels. 

Neutrons in a nuclear reactor have velocities, and energies, distributed over a wide range. Neutrons are bom from the fission reaction at an average energy of about 2 MeV... 

The production of energy by nuclear fission in a nuclear reactor must be a controlled process. Neutrons released from the fission of lose most of their kinetic energy by passage through a moderator (graphite or D2O). They then undergo one of two nuclear reactions. The first is capture by leading to further fission the second... 

The nuclear fission reactions operate most readily with neutrons whose energies have been reduced from the high energies at their formation. The material which accomplishes this is a moderator which can be graphite or ordinary or heavy water. The role of coolant and moderator can be combined when water is used. The assembly of fuel elements and moderator is called the reactor core . 

There is a huge difference between the amount of energy liberated in an ordinary chemical reaction, like the burning of methane in air, and the energy liberated in a nuclear fission reaction. If you compared the energy from the burning of only 16 g of methane with that from the fission of an equivalent amount of uranium-235, the fission reaction would produce almost 25 million times more energy. 

Nuclear fission reactions release a lot of energy. Where does the energy come from Well, if you make very accurate measurements of the masses of all the atoms and subatomic particles you start with and all the atoms and subatomic pcirticles you end up with, you find that some mass is missing. Matter disappectfs during the nuclear reaction. This loss of matter is called the mass defect. The missing matter is converted into energy. 

Because the fission of one uranium-235 atom releases enormous amounts of energy and produces neutrons that can split other uranium-235 atoms, the energy from these collective reactions can be harnessed in an atomic bomb or nuclear reactor. 

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