PLUTONIUM
Alchemists dreamed of turning lead into gold, but physicists regularly turn one element into another. They bombard uranium-238 with neutrons in a nuclear reactor.
The uranium absorbs a neutron to become uranium-239. Beta decay changes this to neptunium-239.
This emits another beta-particle to become plutonium-239 - a metal that does not occur naturally.
All uranium reactors produce plutonium in their fuel rods. Breeder reactors have a jacket of uranium-238 to increase the amount of plutonium produced. They produce more fuel than they consume.
The plutonium is mixed up with highly radioactive fission products.
The spent fuel rods are stored under water for some time until the radioactivity has died down - at first it is powerful enough to give the water a blue glow.
The rods are then dissolved in acid and the plutonium and unused uranium are recovered.
All this has to be done by remote control because of the radiation and the dangerous chemicals involved.
Plutonium-239 has a half-life of 24 000 years, so it is not intensely radioactive.
However, even a tiny amount inside someone's body can eventually cause cancer, because it emits alpha-particles.
There is also the problem that terrorists might steal it, and use it to make weapons.
Plutonium-238 is strongly radioactive, with a half-life of 88 years.
The heat that it produces can be used to warm a thermocouple and generate electricity.
It can be used to power equipment such as heart pacemakers and space probes, where an ordinary battery might not last long enough.
(SOURCE: www.sciencenet.org.uk/database/Physics/Atomic/p00418b.html)
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