How does a nuclear reactor work?
814757
A nuclear reactor contains uranium and a moderator, such as water or carbon (as graphite).  If struck by a neutron, U-235 is likely to fission, yielding fragments and two or three neutrons, which can, if you do things right, cause more fissions -- it's called a chain reaction.  Unfortunately, most uranium is U-238, which does not like to fission nearly as much as U-235 does -- but it does eat neutrons, becoming U-239 which decays to Np-239 and Pu-239.  The appetite of U-238 for neutrons is considerably reduced if the neutrons are slowed down before they have a chance to interact with it, and that is what a moderator does: it slows them down so that instead of traveling near the speed of light, they are traveling at about the speed of sound.  When the slow neutrons encounter a uranium fuel rod, they are more likely to be captured by U-235 to produce fission than by U-238, so the chain reaction can continue.  It is important that not all neutrons created by a fission are released immediately -- some are delayed, and that permits the reactor to be controlled by inserting rods of a neutron-absorptive material to keep the reaction from getting out of hand. \n In an atomic bomb, U-235 (or Pu-239) in nearly pure form is quickly assembled into a mass of such size that more neutrons cause fission than escape through the sides of the material, and so that delayed neutron release is overwhelmed by quick release, so a kilogram or more of uranium can fission before the device blows itself to pieces.
7743
It depends on the mass.  Take a look at the graph in the source link. Elements with an atomic mass lower than that of Iron (or there abouts) generally must have energy added to the system to split it.  Conversely, those same atoms lighter than iron will release enegy when you fuse them together.  This is the property of nuclear fission.  It is how the sun works to create heat and light by fusing hydrogen atoms into helium atoms, and it is also the principle behind the H-bomb (the hydrogen bomb, or the fusion bomb, which is much more powerful than the fission bombs dropped on Nagasaki and Hiroshima).\n\nIf the atom is heavier than iron, it will release energy when you split it.  Heavy elements like uranium and plutonium are unstable, and will naturally decay, releasing particles and energy.  If these high-energy particles hit other unstable elements--like more uranium--you can get a chain reaction, which makes decay happen more quickly.  Under controlled levels of uranium density, you can make this heat useful to boil water and run turbines and generate energy.  But if the density of the unstable element is really high, the chain reaction can take off uncontrolably, causing a nuclear explosion.  this is the principle behind fission bombs, like those dropped on Nagasaki and Hiroshima.\n\nHydrogen bombs require tritium, which is a rare isotope of hydrogen that has two neutrons.  the technology behind nuclear fusion is more complicated than that behind fission.  Power plants currently use fission, but fission has the problem of producing radioactive waste.  Hydrogen fusion has the problem of being hard to control, although people are working on developing a fusion reactor to generate energy, which would be advantageous.
118189
Nuclear power is a 'clean' power in that, under normal circumstances, the only emisson is steam from the reactor. However, if there is a meltdown, like the one in Russia a while ago, the effect could be very threatning.
426649
To get a nuclear explosion, you need to have an uncontrolled  chain reaction: whenever an atom fissions (and emits neutrons), other fissionable atoms have to be available to capture the neutrons and also fission themselves. The chain reaction occur because one atom fissions, emitting two neutrons; these two cause two more atoms to fission, emitting four, then eight, sixteen, thiry-two ...\n\nCritical mass is also necessary to have enough fissionable material around that enough of the neutrons are absorbed to continue the chain reaction. \n\nBarium-133 decays by electron capture (one of the protons in the nucleus actually combines with  an inner-shell electron to form a neutron. This emits a X-ray instead of a neutron, so it's not suitable for building a bomb. Gotta have those neutrons, and more than one of them.
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It's the theoretical relationship between energy and mass.  Albert Einstein's famous equation.  It is what nuclear power is based on.
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The basics....\n\n1. Burn something\n2. Whatever is burnt, boils water that turns into steam.\n3. The steam is used to turn turbines \n4. the turbines generate electricity\n\nFor a more detailed answer, go to howstuffworks.com or wikipedia.
45782
In most electric power plants, water is heated and converted into steam, which drives a turbine-generator to produce electricity. Fossil-fueled power plants produce heat by burning coal, oil, or natural gas. In a nuclear power plant, the fission of Uranium atoms in the reactor provides the heat to produce steam for generating electricity.\n\nHeat is produced in a nuclear reactor when neutrons strike Uranium atoms causing them to fission in a continuous chain reaction. Control elements, which are made of materials that absorb neutrons, are placed among the fuel assemblies. When the control elements, or control rods as they are often called, are pulled out of the core, more neutrons are available and the chain reaction speeds up, producing more heat. When they are inserted into the core, more neutrons are absorbed, and the chain reaction slows or stops, reducing the heat. \n  Most commercial nuclear reactors use ordinary water to remove the heat created by the fission process. These are called light water reactors. The water also serves to slow down, or "moderate" the neutrons. In this type of reactor, the chain reaction will not occur without the water to serve as a moderator.
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The one I run into most is that everyone that operates a nuclear reactor is like Homer J. Simpson, a moron, or like some kind of evil scientist. \n\nWhen I tell people I teach at a reactor site, they are amazed. "What do you teach?" They ask. When I tell them nuclear physics, radiation protection, radiation chemistry and techwriting, they scratch their heads in bewilderment. "Never thought there were classes out there."  \n\nFunny how folks really have no idea what the 1200 people working right nearby them do or are like. Of course  many could not get a job there: we do close background checks on employment and credit history, we test for illegal drug use, we do hire folks with special skills. Even so, the workers are just folks who wind up being scout leaders, church members, football coaches in their spare time. Good solid citizens.
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Sorry to be late, I didn't see your question till today. It works by creating steam. The core (nuclear material) is exposed and heats water in tubes. That water (steam) is generally used to heat water in a separate set of tubes. that steam is sued to turn turbines to created electricity. In a nutshell that is it. One side issue the "smoke" you see coming from nuclear power plants is steam. The water in the tubes is used over and over and never released.
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Most nuclear weapons rely on fission (the breaking down of a nucleus into smaller nuclei).  This breakdown releases the energy that would otherwise go into holding the nucleus together.  That's not much energy for one nucleus, but breaking a few nuclei releases stray particles that bump into other nuclei and break them  -- which releases more energy, and more stray particles which bump into still more nuclei, and so on.  That's a chain reaction.  This reaction isn't limited to weapons; it also occurs in peaceful uses of nuclear technology such as reactors.  A nuclear weapon simply releases all of the available energy all at once.\n  As to predicting the reaction products, that's largely a function of what fissionable material you start with.  Nuclear physicists (which I am not) know what materials result from the nuclear decay of specific radioactive elements.  How you achieve fission is also a factor; a nucleus will break differently when hit by a fast neutron than it will when hit by a gamma ray.  Fusion is much simpler; if you start with hydrogen, the result is always helium.
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Hi, Kenny. You are asking for a lot of information. I have written a book, on the history of nuclear science and will link you to it to read online. This space here is awfully limited.\n\nThe short answer is that nuclear science allows us to generate electrical power out in space even when we are far away from stars like the sun. \n\nThere are two ways we do that:\n\n1. Nuclear reactors - just like the atomic power plants on earth, reactors depend upon the splitting of uranium or plutonium atoms to generate heat and then the heat is used to boil a liquid and turn a turbine. The turbine moves a coil of wire through a magnetic field and gives you electricity.\n\n2. Thermopyles - plutonium due to its alpha radioactive decay gets pretty hot naturally. If you put two dissimilar wires wrapped around each other in a heat source and then the other end of the wires in somewhere cold (like out in space), electrons will flow through them. This is called a thermocouple. If you put lots of those together, you have what is called a thermopyle. This kind of technology is pretty flawless and is used even for things like heart pacemakers.
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a reactor is a container designed such that a chemical reaction can safely be performed in it.  It usually has many pipes into and out of it for fluid transfer, and gauges to measure temperature and pressure.
1110130
There are a few things you need to know about fissionable materials. One, a good fissionable material goes though a fission reaction when it absorbs a neutron. Two, a good fissionable material releases more than an average of one neutron when it goes through a fission reaction. The material must be able to go through a fission reaction by absorbing a neutron that travels slower than the release speed of the previous reaction. Once you have the a material that fits those requirements the rest is a probability game. If you have a small amount of material within a set space the probability of a neutron from one fission event hitting another fissionable atom is very unlikely, but as more and more material is placed within a set volume the probability increases until a point where on average every reaction will lead to one additional reaction. This point is called critical mass. At this point you have a controlled chain reaction, and generate heat. Then you run some material through the reaction to transfer heat out of the reactor to a generator.
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In a fission bomb, shaped explosives force a weapons-grade plutonium core to undergo fission.\n\nAn a fusion (hydrogen) bomb, the energy comes from the fusion of hydrogen atoms into helium, and is much more powerful that fission bombs.\n\nhttp://en.wikipedia.org/wiki/Nuclear_weapon
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some reactors don't need them b/c they're not cooled by water.  they have liquid metal reactors and also gas cooled reactors.  however.  however, in a boiling water reactor the water that turns the turbines never comes in contact w/the outside, it simply stays in the reactors in a continuous loop.  that heated water is used to boil other water which causes the turbines to turn.  pretty much all of the reactors used in the United States are PWR so they all will have cooling towers.
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Fission.  Nuclear reactors\nFussion. The sun.
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well, the basic idea is that they're kind of like a big propeller inside a tube.  one side of the tube is connected to a sealed tank with some water in it, and the other side of the tube is vented out to the air.  when you light a fire under the water, the water boils and releases steam.  this fire can be powered by coal, oil, or even not be fire at all - in a nuclear reactor, the nuclear reaction is used to heat water that in turn boils and makes steam.\n\nif you've ever done any cooking on the stove, you know that if the container is sealed, the steam can build up to a VERY high pressure.  \n\nif you then open a valve and send the steam down the tube toward the turbine, the high pressure on one side will cause the turbine blades to spin.  just like a propellor working in reverse, essentially.  obviously i'm glossing over some of the details - there are a lot of subtle thermodynamics involved with a real turbine, and "propellor" is only a very rough approximation.\n\nso the shaft of the propeller is then connected via some gearbox to a generator.  a generator is basically a loop of wire that is free to turn in a magnetic field.  usually this field is generated by a permanent magnet.  \n\nif the loop spins, the mechanical energy of the spin is converted into electrical energy via a phenomenon called magnetic induction.  if you then connect the wires of the loop to some circuit, the induced current will power the circuit.\n\nan old roommate of mine was into collecting miniatures steam engines, for some reason, and apparently there are quite a few companies that make them.  here is a representative example of one or you can search on google for "steam turbine toy" or "steam turbine kit":\n\nhttp://www.lilliputmotorcompany.com/steam-turbine-wilesco-p-451.html\n\nas for a generator, lots of science hobby places sell little kit generators.  you don't want to use a big one as your tiny steam engine won't have enough torque to turn one over.  here's an example:\n\nhttp://sciencekit.com/category.asp_Q_c_E_440210\n\nhere are some links about how steam turbines work, and magnetic induction and generators:\nhttp://library.thinkquest.org/C006011/english/sites/dampfturbine.php3?v=2\nhttp://www.sciencejoywagon.com/physicszone/lesson/otherpub/wfendt/generatorengl.htm\nhttp://www.taftan.com/thermodynamics/STURBINE.HTM