What are the basic components of a nuclear power plant in nuclear reactors in points?
Answers
There are several components common to most types of reactors:Fuel. Uranium is the basic fuel. Usually pellets of uranium oxide (UO2) are arranged in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core.* In a 1000 MWe class PWR there might be 51,000 fuel rods with over 18 million pellets.* In a new reactor with new fuel a neutron source is needed to get the reaction going. Usually this is beryllium mixed with polonium, radium or other alpha-emitter. Alpha particles from the decay cause a release of neutrons from the beryllium as it turns to carbon-12. Restarting a reactor with some used fuel may not require this, as there may be enough neutrons to achieve criticality when control rods are removed.Moderator. Material in the core which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite.Control rods. These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it.* In some PWR reactors, special control rods are used to enable the core to sustain a low level of power efficiently. (Secondary control systems involve other neutron absorbers, usually boron in the coolant – its concentration can be adjusted over time as the fuel burns up.) PWR control rods are inserted from the top, BWR cruciform blades from the bottom of the core.* In fission, most of the neutrons are released promptly, but some are delayed. These are crucial in enabling a chain reacting system (or reactor) to be controllable and to be able to be held precisely critical.Coolant. A fluid circulating through the core so as to transfer the heat from it. In light water reactors the water moderator functions also as primary coolant. Except in BWRs, there is secondary coolant circuit where the water becomes steam. (See also later section on primary coolant characteristics.) A PWR has two to four primary coolant loops with pumps, driven either by steam or electricity – China’s Hualong One design has three, each driven by a 6.6 MW electric motor, with each pump set weighing 110 tonnes.Pressure vessel or pressure tubes. Usually a robust steel vessel containing the reactor core and moderator/coolant, but it may be a series of tubes holding the fuel and conveying the coolant through the surrounding moderator.Steam generator. Part of the cooling system of pressurised water reactors (PWR & PHWR) where the high-pressure primary coolant bringing heat from the reactor is used to make steam for the turbine, in a secondary circuit. Essentially a heat exchanger like a motor car radiator.* Reactors have up to six 'loops', each with a steam generator. Since 1980 over 110 PWR reactors have had their steam generators replaced after 20-30 years service, 57 of these in USA.* These are large heat exchangers for transferring heat from one fluid to another – here from high-pressure primary circuit in PWR to secondary circuit where water turns to steam. Each structure weighs up to 800 tonnes and contains from 300 to 16,000 tubes about 2 cm diameter for the primary coolant, which is radioactive due to nitrogen-16 (N-16, formed by neutron bombardment of oxygen, with half-life of 7 seconds). The secondary water must flow through the support structures for the tubes. The whole thing needs to be designed so that the tubes don't vibrate and fret, operated so that deposits do not build up to impede the flow, and maintained chemically to avoid corrosion. Tubes which fail and leak are plugged, and surplus capacity is designed to allow for this. Leaks can be detected by monitoring N-16 levels in the steam as it leaves the steam generator.Containment. The structure around the reactor and associated steam generators which is designed to protect it from outside intrusion and to protect those outside from the effects of radiation in case of any serious malfunction inside. It is typically a metre-thick concrete and steel structure.
I would simply agree!
Most of the science we learn we forget quickly . The purpose for which you are suggesting science course may not be much useful . In the engineering course one subject used to be Engineering economics . Even the best option will not be used if the cost is not competitive .
India imports 80% of petroleum it burns in the transport sector . The petrol can be mixed with ethanol upto 20% without any change to the engines . Ethanol is a byproduct of sugar industry and they can increase the production of ethanol without much problem . The sugar production is in surplus not only in India but world over . The oil industry will not pay Rs 5 per liter (7 cents ) extra for the ethanol and the sugar industry will not increase production . Ethanol reduces air pollution also and it is renewable energy.
Nuclear Energy was reasonably cheap in the beginning . In order to reduce cost further the plant size was made larger . Now to cool the bigger core in case of power loss we are trying various methods not acceptable to regulators . The cost has gone up three times and the market is lost .
Life is not static . what the environmentalists found that the Hydro Dams are against ecology has gone full circle and now we cannot live a peaceful life without dams controlling the floods due to global warming .While constructing dams place enough generators to utilize 100% water stored to run the turbines .Even in the old dams we should do this to generate the green power . This power will be useful as standby for solar power when the sun is not there in the evening peak load and night . Without this arrangement you have to spend money on thermal or Nuclear power and double the fixed cost of generation .
With proper Hydro power and solar we may not need thermal or Nuclear power and we achieve 100% green energy and flood control to alleviate the annual misery of thousands of people .
What we need is not the deep knowledge in science and engineering which the schools are trying to pack in the brains of all the students but wide general knowledge in science and engineering so that people will make knowledgeable decisions in their life .