Creating Usable EnergyResearchers use uranium 235, an isotope of uranium, in many nuclear reactors (In some cases, they use plutonium instead). The uranium comes to the reactor in small pellets. Those pellets then go into fuel rods. The fission reaction produces heat, and the entire reactor has to be cooled by water, so nuclear plants are built near rivers, lakes, etc. Since the reaction keeps growing, and since no one wants a reactor to melt, they have to do more than just cool things off. Since the number of neutrons controls the size of the reaction, you can control the reaction by controlling the neutrons. Reactors use control rods, which absorb neutrons, and insert them into the reactor to keep it under control. The further they insert the rods, the slower/smaller the reaction. When most of the fuel pellets have changed from U-235 to other atoms, the rods are removed and kept in a big pool of water for a year. Then new fuel rods are inserted in their place.
After enough time has gone by, and the radioactive materials have cooled down, officials have to bury the nuclear waste deep underground. They bury them so that the radioactivity will not contaminate the surrounding water or land.
When biological substances become irradiated by very powerful radiation, they can no longer survive. The result is something called radiation poisoning and nuclear plant workers have to be very careful.
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Advanced Test Reactor Tour (Idaho Nat’l Labs Video)
Useful Reference MaterialsEncyclopedia.com (Nuclear Reactor):