3 Responses

1. You can know more about it here

   http://en.wikipedia.org/wiki/Nuclear_power

2. A nuclear bomb is an uncontroled fission reaction whereas a reactr is a highly controlled fission reaction. A nuclear fission reaction is basically taking a heavy atom, hitting it with something, and generating two smaller atoms.Now, in most A-bombs/reactor they use Uranium-235 because it is big, easy to split and has a very desirable property. Basically, what happens is a neutron hits a uranium atom, temporarily making it a Uranium-236 atom which is incredibly unstable. The U-236 atom immediately breaks apart, forming Krypton-92 and Barium-141, and 3 more neutrons. Thoe 3 neutrons move on to hit other U-235 atoms, which generate more neutrons, which hit more U-235 atoms and so on. In an A-bomb, this chain reaction is allowed to happen without any control, resulting in a chain reaction and the explosive power of an A-bomb.In a nuclear reactor, rather then letting those extra neutrons to keep on going and striking more Uranium, most of the excess neutrons are instead absorbed using control rods (made of Boron or some other material that can absorb alot of neutrons). Ideally, you want a U-235 fission to generate only one extra neutron so only one more U-235 atom can be split, thus keeping the reaction safely under control.

3. Both nuclear reactors and fission weapons use Uranium-235 or Plutonium-239 as fuel (other actinide isotopes may be used as well), which is fissioned or split by neutrons to release energy.

   In a reactor, thermal neutrons (velocity 2200 m/s) fission the fuel nuclei to release energy (200 MeV) and extra, fast, neutrons. These neutrons are moderated by control rods, etc…, and so a nuclear reactor uses controlled fission to maintain a steady and, near, continuous energy supply at (say) several mega watts.

   A fission bomb uses a rapidly built-up chain reaction (over a few milliseconds) to release an uncontrolled explosion. The build up of the chain reaction is held in place by an implosion, created by shaped explosives, and initiated with a neutron source that releases neutrons at the key moment. A nuclear bomb releases all of its energy in a few milliseconds in a yield of between 1 and 300 kilotons of TNT explosive power – depending upon its design and or efficiency!