Originally posted by jadedANDcynical
Originally posted by NowanKenubi
reply to post by aching_knuckles
Then we should all go die in piles on top of their air exchangers... That'll teach them something for next time!
Hey, the bible DOES say survivors will wish to be dead!... ( Or is it from a prophecy of sorts?!? )
Seriously, I read on a previous post it was about the dispersion of Cesium-137? Man, how many types of radio particles can these Japanese reactors
Take the periodic table and multiply it by at least 3.
Radioactivity is "spread" by energetic neutrons. As these neutrons are continually emitted from a nuclear reaction, eventually everything in the
immediate vicinity of a reaction becomes energized and radioactive.
Depending on the amount of neutrons absorbed and how energetic they are will vary the isotope you end up with. This in turn break down (decay) over a
specified period of time (half-life) sometimes to other unstable particles (each with it's own half-life) until eventually a stable state is reached.
That's all off the top of my head and VERY rough but it should give you an idea of what we are dealing with.
edit on 1-4-2011 by
jadedANDcynical because: Typo: more idiocy.
Don't get confused by the difference between radioisotopes, the constituent sub-atomic particles that make up the radioisotopes, and the decay
Radiation is spread", for lack of a better word by whatever is emitted during decay of a radioisotope. Nuclear reactors for the most part, use
uranium and/or plutonium as a fuel. Actually, you don't really want to use the pure metal, since it will burn, so commonly you would use an oxide of
the metal, like uranium dioxide in a salt form. Burning is just a different way to describe oxidation, and if something is already oxidized, it has
Both uranium and plutonium are what are called actinide metals, and both are unstable, decaying through various processes into other isotopes or
elements. Let's take uranium first. A uranium atom has 92 protons, 92 electrons and between 141 and 146 neutrons. How many neutrons determines the
particular isotope. If it has 146 neutrons, you add that 146 to 92 representing the protons, and you get Uranium 238, the most common isotope. Now
if you bombard U-238 with free neutrons, one can be absorbed and you now have uranium 239, but not for long. U-239 decays by beta decay, into
neptunium 239, which in turn, through more beta decay, decays into plutonium 239. Beta decay is when a neutron turns into a proton, and spitting out
an antineutrino and an electron, or a proton turns into a neutron, spitting out a neutrino and a positron, the antimatter version of an electron.
Other elements are created, not as natural decay products, but as fission products. When a neutron, which is not in itself radioactive, hits a
fissile fuel, it can split the element into other atoms, releasing heat. The Cesium 137 and Iodine 129 and 131 in the news are such fission
products, as are Strontium-90, and various radioisotopes of Selenium, Tin, and a few others. Not every element has an unstable (radioactive) isotope
and something doesn't become radioactive by being irradiated. It becomes radioactive by becoming or containing a radioisotope.
There is another kind of radioactive decay, this time having nothing to do with neutrons. Alpha decay, which is a decay process turning U-238 into
Thorium 234, and in the process spitting out an alpha particle, which is the same as a Helium 4 nucleus.
A third form of radioactive decay is gamma decay where a gamma ray (high energy photon) is emitted. You can get gamma radiation from fusion,
fission, matter-antimatter annihilation, pion0 decay, and some other ways irrelevant to nuclear reactors.