Nuclear power plant parmmax

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nuclear power plant

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  • 1. Assignment no. 01 Submitted to: Mr. Amrit Pal Singh Submitted by: Mr. Parmjeet Singh 10UME043
  • 2.  NUCLEAR FUEL  Nuclear fuel is any material that can be consumed to derive nuclear energy. The most common type of nuclear fuel is fissile elements that can be made to undergo nuclear fission chain reactions in a nuclear reactor  The most common nuclear fuels are 235U and 239Pu. Not all nuclear fuels are used in fission chain reactions  NUCLEAR FISSION  When a neutron strikes an atom of uranium, the uranium splits in to two lighter atoms and releases heat simultaneously.  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
  • 3.  Operating Principles of Nuclear Power Plants  A nuclear power plant is a facility at which energy released by the fissioning of atoms is converted to electrical energy under strictly regulated operating conditions.  The major processes are the same as those in nonnuclear (conventional) power plants except that the coal or oil fired boiler is replaced by a nuclear reactor.
  • 4.  NUCLEAR REACTOR  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 uncontrolled causing an explosion.  CONTROL RODS  Control rods made of a material that absorbs neutrtons are inserted into the bundle using a mechanism that can rise or lower the control rods.  The control rods essentially contain neutron absorbers like, boron, cadmium or indium.  STEAM GENERATORS  Steam generators are heat exchangers used to convert water into steam from heat produced in a nuclear reactor core.  Either ordinary water or heavy water is used as the coolant.
  • 5.  COOLANT PUMP  The coolant pump pressurizes the coolant to pressures of the order of 155bar.  The pressure of the coolant loop is maintained almost constant with the help of the pump and a pressurize unit.  FEED PUMP  Steam coming out of the turbine, flows through the condenser for condensation and recirculated for the next cycle of operation.  The feed pump circulates the condensed water in the working fluid loop.
  • 6.  CONDENSER  Condenser is a device or unit which is used to condense vapor into liquid.  The objective of the condenser are to reduce the turbine exhaust pressure to increase the efficiency and to recover high quality feed water in the form of condensate & feed back it to the steam generator without any further treatment.  COOLING TOWER  Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere.  Water circulating through the condenser is taken to the cooling tower for cooling and reuse .
  • 7. MODERATOR Thermal reactors need a “moderator” a component where neutrons are slowed down thus avoiding (or minimizing) loosed due to capture in 238U. The ideal moderator has to be:  light (atomic mass comparable to neutron mass, for efficient slowing down)  Not neutron thirsty (i.e. does not capture neutrons)  cheap  Not inflammable Most common used materials are  light water (H20)  heavy water (D2O)  graphite
  • 8.  The reactor core consists of fuel rods and control rods ◦ Fuel rods contain enriched uranium ◦ Control rods are inserted between the fuel rods to absorb neutrons and slow the chain reaction  Control rods are made of cadmium or boron, which absorb neutrons effectively
  • 9.  A nuclear reactor is a device which initiates and controls a sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for generating electricity. A nuclear power plant can have several reactors
  • 10.  A steam generator is a machine where chemical energy is transformed into heat energy. Generators differ from steam boilers in the fact that they are much larger and more complicated.
  • 11.  STEAM TURBINE  A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical  Various high-performance alloys and super alloys have been used for steam generator tubing.
  • 12.  99.99% of water molecules contain normal hydrogen (i.e. with a single proton in the nucleus)  Water can be specially prepared so that the molecules contain deuterium (i.e. hydrogen with a proton and a neutron in the nucleus)  Normal water is called light water while water containing deuterium is called heavy water  Heavy water is a much better moderator but is very expensive to make
  • 13.  NUCLEAR CHAIN REACTIONS  A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. If the process is controlled it is used for nuclear power or if uncontrolled it is used for nuclear weapons.
  • 14. Nuclear reactions During a nuclear reaction the change in mass of particle represents the release or an absorption of energy, consequently, in the mass of the resultant particle, will cause the absorption of energy. A nuclear reaction can be written as follows: 1. The bombarded nuclei is written first from left hand side. 2. In the middle with in brackets, first is the incident particle and second one is ejected . 3. On the right side the resultant nucleus is placed . Examples: 11 na23 +1H1 ____ 12Mg23 0n1 U235 + n → fission + 2 or 3 n + 200 MeV If each neutron releases two more neutrons, then the number of fissions doubles each generation. In that case, in 10 generations there are 1,024 fissions and in 80 generations about 6 x 10 23 (a mole) fissions.
  • 15.  The radioactive half-life for a given radioisotope is the time for half the radioactive nuclei in any sample to undergo radioactive decay. After two half-lives, there will be one fourth the original sample, after three half-lives one eight the original sample, and so forth.
  • 16. The government wants to build new nuclear power stations. If their plan succeeds, it will be at the cost of blocking the real solutions to climate change and a reliable future energy supply. It will also result in the continued production of dangerous nuclear waste and an increased risk from terrorism, radioactive accident and nuclear proliferation. Climate change  New nuclear power stations would not stop climate change. Even at the most optimistic build rate - 10 new reactors by 2024 – our carbon emissions would only be cut by four per cent: far too little, far too late. Given the nuclear industry’s poor track record it's highly unlikely that ten reactors could be built within two decades. The most contemporary example of building a new reactor is in Finland; just one year into construction, the completion date has been delayed by 18 months and its costs have spiralled by up to 2 billion Euros over budget.  Worse still, new investment in nuclear power and its infrastructure will block development of renewable energy and energy efficiency – the real solutions to climate change. Energy security  Nor would new nuclear power stations address the anticipated gap in our future energy supply. This is because nuclear power only produces electricity and so only marginally deals with our need for services like hot water and central heating which are mainly met by gas. Its overall contribution to total energy demand is too small to make a difference to the UK's energy security.
  • 17. Terrorism  Aside from the risk of a terrorist strike directly onto a nuclear power station, the nuclear industry transports thousands of tonnes of radioactive waste around the UK by road, rail and sea. Every week, communities up and down the country are put at risk from potential radioactive contamination as these trains trundle through our cities, towns and villages. There are no police or security personnel on board and there are no local plans in place to deal with an emergency. If a nuclear waste train was involved in a terrorist attack, tens of thousands of people could be exposed to cancer causing radiation and whole regions might have to be evacuated. Safety  Over twenty years since the world’s worst nuclear disaster, Chernobyl, the human and environmental consequences are still being suffered internationally. Nuclear power is inherently dangerous and, despite claims of improvements in safety, scientists agree that another catastrophe on the scale of Chernobyl could still happen any time, anywhere. Reprocessing and nuclear proliferation  Nuclear waste is taken from wherever it is produced, across the country, to Sellafield in Cumbria for reprocessing. During reprocessing, plutonium is separated from other wastes for supposed re-use in nuclear reactors. In reality none of this plutonium is reused for electricity generation. The UK now has a stockpile of over a hundred tonnes of deadly plutonium - and no plans for what to do with it. Cost  The nuclear industry is hugely expensive.