But some of what goes down in plate subduction comes back out in volcanoes.
Posted on 02/20/2010 11:09:33 PM PST by ErnstStavroBlofeld
Dumping all our nuclear waste in a volcano does seem like a neat solution for destroying the roughly 29,000 tons of spent uranium fuel rods stockpiled around the world. But there’s a critical standard that a volcano would have to meet to properly dispose of the stuff, explains Charlotte Rowe, a volcano geophysicist at Los Alamos National Laboratory. And that standard is heat. The lava would have to not only melt the fuel rods but also strip the uranium of its radioactivity. “Unfortunately,” Rowe says, “volcanoes just aren’t very hot.”
Lava in the hottest volcanoes tops out at around 2,400F. (These tend to be shield volcanoes, so named for their relatively flat, broad profile. The Hawaiian Islands continue to be formed by this type of volcano.) It takes temperatures that are tens of thousands of degrees hotter than that to split uranium’s atomic nuclei and alter its radioactivity to make it inert, Rowe says. What you need is a thermonuclear reaction, like an atomic bomb—not a great way to dispose of nuclear waste.
Volcanoes aren’t hot enough to melt the zirconium (melting point that encases the fuel, let alone the fuel itself: The melting point of uranium oxide, the fuel used at most nuclear power plants, is ;. The liquid lava in a shield volcano pushes upward, so the rods probably wouldn’t even sink very deep, Rowe says. They wouldn’t sink at all in a stratovolcano, the most explosive type, exemplified by Washington’s Mount St. Helens. Instead, the waste would just sit on top of the volcano’s hard lava dome—at least until the pressure from upsurging magma became so great that the dome cracked and the volcano erupted. And that’s the real problem.
(Excerpt) Read more at popsci.com ...
Here’s another stupid question: why not shoot it off into space? Is the threat of a launch accident too great?
Do you have a background in geology? Sounds like it.
Bingo. In fact the US is unique in that we don’t reprocess our spent fuel by statute. The annual amount of actual hot isotopes that can’t be used for anything would fit inside a thimble, and the great bulk of actual non-fuel rod “nuclear waste” disposed of in places like WIPP are contaminated nuclear facility clothing like smocks and gloves, and hospital radiological wastes.
“Here’s another stupid question: why not shoot it off into space? Is the threat of a launch accident too great”
Some planet in a galaxy far, far, away, isn’t going to be happy with you.
Solid radioactive waste from reactors (3% enriched uranium pellets) become plutonium rich and can be processed into fuel for a second burn. There is no reason, other than Jimmy Carter made it illegal, that we can’t do that.
The resulting solid rad waste is the stuff I think should be recycled via deep-sea trenches into subduction zones.
But some of what goes down in plate subduction comes back out in volcanoes.
Studied geology in college and worked in the nuclear power industry for eight years.
Very interesting. :)
I was a geology major. Never completed the degree however. :(
Well, we could put the waste on boxes labelled “CARE” & drop them in Terhran.
There was a news item from about 15-20 years ago about a child's playground jungle gym/swing set which was associated with symptoms of radiation sickness in the children who played on and around it. It turned out that the metal swing set was radioactive. Further investigation yielded the information that the swing set had been manufactured out of recycled dental office X-ray machines.
I minered in Geology. Pun intended.
Failed Stratigraphy. I couldn’t do the math to dig a coal mine in the side of a mountain. Today I would be an environmental wacko’s hero.
Fossils Rule!
“Well, we could put the waste on boxes labelled “CARE” & drop them in Terhran.”
Great idea, but I’d label the boxes “CAIR”, just to confuse them.
Build some large booster rockets, load up radioactive waste, fire out of Earth orbit in the general direction of the sun. The sun’s the biggest gravity sink within several light-years - the waste will get there sooner or later, and will fall into a thermonuclear explosion far larger than the entire Earth. Perfectly safe disposal and probably more economical than building and securing some huge underground repository.
We've got a strange case of synchronicity here with the thread on the Brookhaven quark plasma experiment. The temperature there, confined to a nuclear radius or so, of a fireball induced by collisions of gold nuclei, is a few trillion degrees Kelvin ... enough to "melt protons" , as noted.
You wouldn't have to melt protons to get rid of radioactive nuclei, but you would have to melt the nuclei. This would require a temperature of a few MeV, vs. the 100 MeV corresponding to the trillion degrees. So we're talking a few billion degrees Kelvin. Compare this to the mere 10 million degrees Kelvin at the center of the sun.
“But some of what goes down in plate subduction comes back out in volcanoes.”
Yeah, but millions of years later.
Lol! Duh! Good point! Been a very long day...not thinking too clearly right now. 3AM here.
We have the ability to dig holes that are miles and miles deep, not only that we have many abandoned mines which are empty and pose no threat to any water table. throw the waste down there and fill it up with concrete and dirt.
Ok...so where is the down side?
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