posted on Jan, 11 2014 @ 06:03 PM
reply to post by ikonoklast
I would think a controlled meltdown is an oxymoron.
I could be mistaken, I'm an engineer not a nuclear physicist. But here is how I understand it to normally work...
Any given fuel rod would not sustain a chain reaction by itself, you need the stray particles from adjacent fuel rods. Control rods are inserted
between fuel rods to prevent or control the particles from going between fuel rods. The rate of the chain reaction can be controlled by pulling out
or pushing in control rods to control how much particle interaction there is between fuel rods. The chain reaction generates a lot of heat, and water
is used to dissipate enough heat so that the fuel rods do not melt.
If something fails and the fuel rods get so hot as to melt down, the melted fuel pools at the bottom of the reactor. If the mass of this is
sufficient to sustain a chain reaction, that's really bad. Control rods cannot be inserted because the fuel has melted into one mass at the bottom.
You now have an uncontrolled chain reaction that you pretty much can't do anything about. This is apparently what is currently happening at