Typical fission events release about two hundred million eV of energy for each fission event. By contrast, most chemical oxidation reactions (such as burning coal or TNT ) release at most a few eV per event, so nuclear fuel contains at least ten million times more usable energy than does chemical fuel. The energy of nuclear fission is released as kinetic energy of the fission products and fragments, and as electromagnetic radiation in the form of gamma rays ; in a nuclear reactor, the energy is converted to heat as the particles and gamma rays collide with the atoms that make up the reactor and its working fluid , usually water or occasionally heavy water . 1 electron volt = 1.60217646 × 10-19 joules 1 electron volt = 1.60217646 × 10-19 joules
In nuclear physics and nuclear chemistry , nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts, often producing free neutrons and lighter nuclei , which may eventually produce photons (in the form of gamma rays ). 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 ( heating the bulk material where fission takes place). For fission to produce energy, the total binding energy of the resulting elements has to be higher than that of the starting element. Fission is a form of nuclear transmutation because the resulting fragments are not the same element as the original atom. The atomic number, Z , should not be confused with the mass number , A , which is the total number of protons and neutrons in the nucleus of an atom. The number of neutrons, N , is known as the neutron number of the atom; thus, A = Z + N . Since protons and neutrons have approximately the same mass (and the mass of the electrons is negligible for many purposes), the atomic mass of an atom is roughly equal to A .
NPP, Nuclear Power Plant,
Nuclear Power Plants <ul><li>Seventeen Nuclear Reactors </li></ul><ul><li>Production – 4120.00MW </li></ul><ul><li>Energy from atomic nuclei via controlled nuclear reactions(Fission) </li></ul><ul><li>Uranium-235 and plutonium-239. </li></ul>
Advantages of NPP <ul><li>Fuel is inexpensive and easy to transport. </li></ul><ul><li>Energy generated is very efficient and and the remaining waste is compact. </li></ul><ul><li>Nuclear reactors need little fuel. </li></ul><ul><li>Amount of waste produced is much smaller than that produced in coal burning plant </li></ul><ul><li>Chance of a nuclear accident is 1 in 250 years. </li></ul><ul><li>Clean source of energy. </li></ul>
Disadvantages <ul><li>Actual cost of producing energy is more because of containment, radioactive waste storage system </li></ul><ul><li>The mining of the fuel itself can cause serious problems </li></ul><ul><li>The meltdown of reactor can cause serious disaster. </li></ul>
Main Components Of A Reactor <ul><li>Fuel Rods – Tube filled with pellets of Uranium </li></ul><ul><li>Shielding - Protection against alpha, beta and Gamma Rays </li></ul><ul><li>Moderator - Slow down the neutron release(Heavy water, Beryllium, Graphite) </li></ul><ul><li>Control Rods - neutron absorbing material(boron Carbide, cadmium) </li></ul><ul><li>Coolant - To transfer the heat generated inside the reactor to a heat exchanger for utilization of power generation </li></ul><ul><li>Steam Separator - steam from the heated coolant is fed to the turbines to produce electricity from generator. </li></ul><ul><li>Containment - concrete lined cavity acting as a radiation shield </li></ul>
Selection of Site <ul><li>Availability of water - NPP requires ample amount of water for cooling and steam generation. </li></ul><ul><li>Disposal of Waste – Dangerous waste/residue obtained </li></ul><ul><li>It needs to be disposed deep under the ground in sea so that radioactive effect is eliminated. </li></ul><ul><li>Away from populated area – For health safety </li></ul><ul><li>Nearest to the load centre </li></ul><ul><li>Other Factors – Accessibility to the road and rail are general considerations. </li></ul>
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