Re: Ooooo, aren't we feeling arrogant today
This is true for a man-made reactor. Our reactors are carefully constructed and don't have the right geometry or material distribution to be a bomb. That's why they melt down instead of exploding. For the scale we're talking about, such considerations go out the window. The limiting factor in how big we can make a fission bomb is how big a mass (well, two masses) of concentrated fissile nuclei (Pu-239, U-235, et al) we can make before the masses are bombs themselves.
I have no reason to believe that there would be anything but VERY uniform material distribution in the core, given how old the earth is. Heat and material movement might matter on a human scale reactor, but not this size. I'm sure there's some very interesting natural mechanisms for material transport, but nothing that would regulate the reactor as you're suggesting.
There are a shitload of rules for doing this and they're followed quite rigidly. Don't get these ideas of leaky barrels of waste killing children at playgrounds get to your head. The only irresponsible waste disposal done that I know of was by the government (for weapons development and production during the cold war) before people started getting on their asses. Such messes have nothing to do with present nuclear power production and are nothing I wish to associate myself with.
This is me.
What's ridiculous? Ok: Scale, stability (there is none), spikes of energy dissipated out from the core, fuel burnout, reaction poisons.Originally posted by overdoze
What's so ridiculous about it? It doesn't even have to be a single fission reactor; there could be many at any one time down there, arising from local chance concentrations of radioactivity.
Why would there be any low Z elements in the core when they would've, according to you and suggestions of buoyancy, floated to outside the core?There are plenty of moderators (it's all suspended in molten iron), and as for refueling you're right. However, we aren't talking about your normal functional fission reactor. Rather, we're talking about a "fission reactor" in a state of continuous meltdown.
This is a BIG point. It wouldn't be steady state because steady state is not the nature of nuclear reactions. Given conditions suggested here, you'd have a giant supercritical reactor that would reach some ridiculously large power output in a matter of nanoseconds. This is because power increases in a fission reactor exponentially. This is why it'd be a giant bomb.And why wouldn't it be? (steady state)
Fission reactor meltdowns are not the same as nuke explosions. If you know as much about nuclear processes as you claim, you at least ought to know this much.
This is true for a man-made reactor. Our reactors are carefully constructed and don't have the right geometry or material distribution to be a bomb. That's why they melt down instead of exploding. For the scale we're talking about, such considerations go out the window. The limiting factor in how big we can make a fission bomb is how big a mass (well, two masses) of concentrated fissile nuclei (Pu-239, U-235, et al) we can make before the masses are bombs themselves.
Eventually they would, but they would be a poison for as long as they're there, and that could be awhile. Creation of such poisons on such a scale would (at best) yield some seriously squirrley (spikey) behavior that would be violently shaking the planet quite often.They would float up by virtue of being lighter. And the "goal" of the "reactor" is not optimal output. It simply generates a lot of heat over long periods of time, gradually losing its useful nuclear energy stored when the heavy elements were created in a supernova explosion a long time before Earth's formation.
Moreover, the material in the core cannot become so concentrated as to produce a catastrophic explosion, because that very heat will tend to disperse the material as soon as it becomes too concentrated. The heat generated by fission would act on radioactive atoms like the charge on positive ions, preventing them from getting too close to each other and tending to distribute them outward around the surface of the core while gravity and currents work to counter that effect. So you have a more or less steady-state, sustained, low-level fission reaction churning within the currents of molten iron in the core for millions and billions of years.
I have no reason to believe that there would be anything but VERY uniform material distribution in the core, given how old the earth is. Heat and material movement might matter on a human scale reactor, but not this size. I'm sure there's some very interesting natural mechanisms for material transport, but nothing that would regulate the reactor as you're suggesting.
It really all depends on if and how you mix waste. Generally, nuclear power doesn't generate much besides some high level waste (spent fuel) and some short lived low level wastes from reactor operation. The reason it is impossible to exactly determine what's in those mixes is because decay chains have more than one possible path. However we can tell with pretty good certainty what should and shouldn't be there.Nobody knows enough. Barrels of radioactive waste, after a few years, contain a mixture of elements and chemicals that is currently unpredictable. Nuclear waste managers actually have to sample the brew to determine what's in it at any particular moment in time; it's impossible to predict the contents theoretically at this stage. Moreover, even low-grade nuclear waste tends to heat up dangerously if it becomes too concentrated or there is too great of a volume. This is not due to any standard nuclear reaction used in fission power plants.
There are a shitload of rules for doing this and they're followed quite rigidly. Don't get these ideas of leaky barrels of waste killing children at playgrounds get to your head. The only irresponsible waste disposal done that I know of was by the government (for weapons development and production during the cold war) before people started getting on their asses. Such messes have nothing to do with present nuclear power production and are nothing I wish to associate myself with.
No problem. How's this:You'll have to show us all where your certainty comes from. I hope the answer is not hubris.
This is me.