Question by Audrey: Is nuclear fusion used in nuclear power plants to produce energy, or just nuclear fission?
I read that nuclear fission is used to split atoms and produce heat for nuclear power plants, but what does nuclear fusion do then? Does it have anything to do with that?
Best answer:
Answer by Kes
Nuclear energy can be obtained either by splitting heavy atoms such as uranium (fission) or by joining light atoms such as hydrogen to form helium (fusion). Presently, all operating nuclear power plants use fission. Plants that use fusion are under development but none create more energy output than must be supplied to run the experimental plants.
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2 Responses
“…nuclear fission is used to split atoms…”
Not exactly. Nuclear fission uses atoms that have a natural tendency to split all by themselves, and when they do, they release energy. Nuclear fission is like a fire—the energy released by one splitting atom can cause its neighbors to split too. The “control rods” in a nuclear reactor regulate the rate of the “fire” by interfering with the ability of the atoms to transfer energy to one another.
The atoms in nuclear fission fuel are uranium or plutonium or (in some experiments) thorium. All solid metals at room temperature. The fuel in commercial nuclear power stations usually is in the form of ceramic pellets made from oxides of uranium and plutonium. Those remain solid even when red hot.
Nuclear fusion uses extreme temperatures (millions of degrees) and immense pressures to force lightweight atoms (usually different isotopes of hydrogen) to combine with one another, again releasing energy. Nuclear fusion occurs in the sun and in nuclear weapons, and controlled nuclear fusion has been achieved in laboratories, but only on a very small scale. Nobody has yet solved the problem of how to build a container for the incredible temperatures and pressures that (as far as we know) would have to be maintained in reactor core of a commercial fusion power plant.
Current research focuses on two different methods. Magnetic containment would use powerful magnetic fields to continuously confine and squeeze a high temperature plasma of fusion fuel. Inertial containment uses pulses of light from powerful lasers to heat and compress pellets of fuel, one at a time. Both kinds of reactor have been built and tested, but so far, they both require more energy to operate than they produce.
Fusion really only happens in nuclear bombs called Hydrogen Bombs, or H-bombs. These weapons actually use nuclear fission to start a fusion reaction between Hydrogen and Lithium.
On the other hand nuclear reactors currently in use just operate on fission, or the splitting of atoms giving off heat, Nazi nuclear scientists actually referred to this process during WW2 as Uranium burners, or Uranium furnaces, although a nuclear reactor can use other fission “fuel” besides Uranium.