2007-06-08 01:51:57 · 3 answers · asked by chol B 1 in Science & Mathematics ➔ Physics
In a fission reaction, a Uranium nucleus is struck by one neutron and disintegrates. The disintegration releases several (typically 2 or 3) new neutrons (of course it also releases energy). These new neutrons then go on and strike more Uranium nuclei causing more disintegrations etc. Since only one neutron gets consumed and 2 or 3 neutrons get produced per disintegration , the reaction "snowballs" (ie. a chain reaction) (I am leaving out details). So to control the reaction it is necessary to control the number of neutrons around. Control rods are made of materials specifically chosen for their ability to absorb neutrons.
2007-06-08 02:07:00 · answer #1 · answered by ontheroad 2 · 0⤊ 0⤋
The control rods absorb radiation. The idea of the reactor is to keep the amount of radiation created sufficient to only continue the reaction. It there's too much the rods are inserted deeper and absorb more. If there's too little they pull out. That's a pretty simplified answer but I think that's what you wanted.
2007-06-08 08:58:07 · answer #2 · answered by Charlie P 4 · 0⤊ 0⤋
The rods are lowered into the reactor to absorb more neutrons to slow the chain reaction or raised out of the reactor to allow more neutrons to speed up the chain reaction.
2007-06-08 08:56:26 · answer #3 · answered by physandchemteach 7 · 0⤊ 0⤋