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April 4th, 2014, 12:27 PM
Within a few hundred years these salt caves will collapse In on themselves & the waste will leak all over the earth, contaminating earth for who knows how long. If it is dropped into some active volcanoes with lava bubbling but not exploding it should just dissolve when it hits the lava. Better this than the deserts or oceans. We are already killing our future lets try something new.
Would it stop being radioactive when (if) it's dissolved?Originally Posted by Charles M ODonnell
What happens when/ if that volcano goes off and spreads radioactive lava all over the place?
Where do you get the idea that the waste will leak all over the earth? The repository will be selected based on its geological stability and the waste will be placed in containers which are designed not to leak. Also, the earth is already "contaminated" with radioactive isotopes.
There was a natural fission reactor at Oklo, and there is no evidence that the fission products migrated very far.
Natural nuclear fission reactor - Wikipedia, the free encyclopedia
Some of the barrels are already dissolving. Don't be so naïve, sorry.
Can you provide a source for that? Also, that does not equal: all over the world.
(I haven't done the math, but I wonder if being able to spread the nuclear waste "all over the world" would solve the problem?Even if less acceptable than current proposals to bury it in stable environments.)
Rather than volcanoes, which will tend to spread radioactive lava, it would be better (but even less practical) to drop the waste into subduction zones so it gets taken down to the mantle for a few million years.
Are you referring to this:
Hanford Site - Wikipedia, the free encyclopedia
I guess what you are saying is that tanks from the World War 2 era that were designed to last 20 years are leaking. Therefore all tanks containing radioactive waste will leak no matter how they are designed. Right?On February 15, 2013, Governor Jay Inslee announced a tank storing radioactive waste at the site is leaking liquids on average of 150 to 300 gallons per year. He stressed that the leak poses no immediate health risk to the public, but said that fact should not be an excuse for not doing anything.[57] On February 22, 2013, the Governor stated that "6 more tanks at Hanford site" than previously thought were "leaking radioactive waste"[58] As of 2013, there are 177 tanks at Hanford (149 having a single shell). Older single shell tanks were initially used for storing radioactive liquid waste. The tanks were designed to last 20 years.
good idea. but i think need to get the waste several hundred meters into the subducting plate by drilling and maybe few hundred meterss from where plate goes under other plate. like you said - not as practical.
this might be a very good long term disposal in the future
Last edited by Chucknorium; April 4th, 2014 at 02:26 PM.
One must also consider how the waste would be transported to the volcano. The area surrounding the mouth of an active volcano does not appear to be suitable for heavy equipment.
It's a good idea, but nobody is seriously looking at it because of the international treaties against disposal in the oceans.good idea. but i think need to get the waste several hundred meters into the subducting plate by drilling and maybe few hundred meterss from where plate goes under other plate. like you said - not as practical.
this might be a very good long term disposal in the future
and air drop into a volcano will not be allowed. rarely is radioactive waste transported by air and mostly small amounts.
Transport of Radioactive Materials
- About twenty million consignments of all sizes containing radioactive materials are routinely transported worldwide annually on public roads, railways and ships.
- These use robust and secure containers. At sea, they are generally carried in purpose-built ships.
- Since 1971 there have been more than 20 000 shipments of used fuel and high-level wastes (over 80 000 tonnes) over many million kilometres.
- There have been accidents over the years, but never one in which a container with highly radioactive material has been breached, or has leaked.
let us hope that this will become a non-problem when fusion reactors are built. but like someone said here recently 'it seems like it is alwys 50 years in future'.
It won't become a non-problem for all the existing nuclear waste, which is now stored at nuclear power plants and government facilities. Unfortunately, nobody seems to be doing anything except kicking the can down the road. Remember when Obama killed Yucca Mtn, and set up a "blue ribbon panel." What came out of that? Right. Zero, zip, nada.
Fusion power will not solve our current radioactive waste problem.
But the volcano idea has some advantages over storage in salt mines.
- Radioactivity will drop more quickly at higher temperatures.
- Because lava is usually pretty dense (not counting the foam on top), so it will block radioactivity better than water or air.
However, disadvantages are obvious.
- No control over dispersion or what happens to the waste.
- In an explosion, all land surrounding the volcano will be uninhabitable, a cloud of radioactive dust will travel and lay waste up to 8000 kilometers distance.
- Basically, if it erupts, nearly half of the planet would be uninhabitable. (a slight disadvantage)
I have looked into fusion power for a while, but it should already have given better results than it has now. It keeps disappointing everyone. They only just generated a surplus power. But this is just nothing compared to the energy it costed to harvest the deuterium..
yes. yes.you are both right. i should have said something like 'after fusion reactors are successful and the current fission plants are decommisioned and the current nuclear waste is buried or destroyed safely...' then it will be non-problem because there will be no more waste created. i know. i know. we are talking hundreds of years probably.
and i am sure that just like fission reactors have failed a fusion reactor will also fail. that is sure. not sure what a fusion reactor failure would look like. hopefully not like a thermonuclear explosion. that would be hard on the neighbors.
Nope. It's a nuclear process - doesn't have much if anything to do with temperature.
Blocking radiation is not a problem. The problem is the potential for radioactive isotopes leaking out into the environment where they could be ingested.- Because lava is usually pretty dense (not counting the foam on top), so it will block radioactivity better than water or air.
If you want to dissolve it in something, dissolve it in seawater. There's a lot more seawater in the sea than there is lava in a volcano.
No, it won't.
Water is a far better shield against fast neutrons than rock. Gamma radiation shielding is about the same. Both shield alpha and beta radiation 100%.- Because lava is usually pretty dense (not counting the foam on top), so it will block radioactivity better than water or air.
Definitely!
Would be pretty boring. It's very hard to maintain a fusion reaction. (Compared to a fission reaction, which not only keeps running if you do nothing, but can't be completely shut down due to decay products for months.)not sure what a fusion reactor failure would look like.
Hmm, actually i was thought that half life of some radioactive compounds (manmade) was dependant on the temperature, but i found opposite references to this, so you seem to be correct on that. However i found this.No, it won't.
Water is a far better shield against fast neutrons than rock. Gamma radiation shielding is about the same. Both shield alpha and beta radiation 100%.- Because lava is usually pretty dense (not counting the foam on top), so it will block radioactivity better than water or air.
In the last few years, however, a number of new results have threatened to overturn this picture. Various groups have shown that the rate of alpha, beta, and electron capture decays all depend on temperature and whether they are placed in an insulating or a conducting material. That’s exciting because it raises the possibility of treating radioactive waste products. But it also raises a problem for particle physicists whose entire standard model assumes that decay rates cannot be influenced by external factors.
The anomalous results are puzzling. One group found that the alpha emitter polonium-210, when placed in a copper container at 12 degrees Kelvin had a half-life that was six percent shorter than at room temperature. Another report claimed that the half-life of the beta(-) emitter, gold -198, was 3.6 percent longer at 12 degrees Kelvin than at room temperature. And yet another group showed that the half-life of beryllium-7, which decays by electron capture, depends on the material in which it is placed, increasing by 0.9 percent in palladium at 12 degrees Kelvin and at 0.7 percent in indium at 12 degrees Kelvin. There is even a theory to explain what is going on: that a temperature-dependent screening effect inside metallic containers influences electron capture. This, of course, ought to affect all nuclei that decay in this way.
Next to that, nearly everything shields agains alpha and beta radiation, even 30 cm of air stops most alpha/beta.. I was thought a piece of paper blocks 90% of alpha rays..
- Alpha particles (helium nuclei) are the least penetrating. Even very energetic alpha particles can be stopped by a single sheet of paper.
When the petroleum industry first blossomed in the U.S. in the last third of the nineteenth century, the primary product it produced was kerosene. The advertising campaigns stressed kerosene lanterns as a safe and inexpensive method of home lighting compared to available alternatives, with space heating and cooking being secondary uses. Unfortunately, extracting kerosene from crude oil left a noxious byproduct, a smelly residue high in volatile fractions, poisonous and dangerously flammable, that had to be disposed of. This stuff was called gasoline.
With today's petroleum industry focused primarily on gasoline production, it seems strange that in its early years, the petroleum threw this stuff away as a useless, dangerous waste product. But that's what happened. Only after decades of experimentation did gasoline come to be seen as a more useful fuel than kerosene, and only then did safe methods of handling and storing it come to be developed.
This is how I view so-called "nuclear waste". This stuff is dangerous precisely because it releases large quantities of energy in the form of radiation. But from an engineering standpoint, a substance high in energy content is something you want to look at as a potential fuel. There is no theoretical reason the dangerous isotopes in the nuclear waste we sorry so much about disposing of cannot be separated out, formed into fuel elements, and burned in a reactor designed to use that energy to make electricity. We already know how to do this with Pu-239. To be sure, plutonium extraction methods were developed by the military for the purposes of making bombs with the plutonium, but there is no reason we can't work out methods for doing the same thing for other isotopes for peaceful purposes.
It is my view that a century from now people will look back at the "nuclear waste" problem and scratch their heads wondering: "They threw the stuff away? What were they thinking?"
>This stuff is dangerous precisely because it releases large quantities of energy in the form of radiation.
Well, no. It is useful to us because, during certain critical nuclear reactions, it produces a lot of heat. The gamma radiation that the decay products emit do not produce a lot of heat (which is why you can shut down a nuclear reactor at all, although it takes a while) - but they often produce a lot of gamma radiation. A dose of gamma radiation that would raise your core temperature only a few degrees would be almost instantly fatal.
However, nuclear waste reprocessing does indeed make a lot of sense as long as we can deal with the proliferation issues, since most of the 'active' material in nuclear waste is still there.
Energy wise, gamma radiation that would increase your body temperature by only 0,01 degree, would also be fatal, albeit not instantly. You will suffer from severe radiation poisoning before dying in excruciating agony. But danhanegan raises a nice point here, in the future, if we could use the radiation, say by direct radiation to energy transfer, we would bitch-slap our ancestors, for trying to toss it, and not utilizing it. I think there is much potential in this type of energy. This could possibly provide us with 30% extra energy (or fewer coal power plants).
??? Decay products produce energies in the range of (at most) a few watts per kilogram TOTAL. Only part of that is gamma radiation. That means you have a very, very low energy density compared to any other form of power. Heck, even solar panels will give you 200 watts per square meter. Even if they only provide power 25% of the time, that's far more power than you'd get from 100 kilograms of nuclear waste, even if you could somehow convert gamma radiation directly to energy. (And of course solar panels are a lot more pleasant to work with.)
However there is one application that that nuclear waste might work very well for - RTG's. These are devices that convert decay heat into usable power. They are often used to provide small amounts of power for space probes, rovers etc and medium amounts of power for things like remote lighthouses and Antarctic science emplacements. Get a better radiation to energy converter and you might be able to get a little more power out of them. They'll never power your toaster but they might someday power the weather station that gives you your weather reports.
You're telling me that radiatioactive waste has no real energy potential? There is more to power then just heating a surface. A kilogram of Cesium, may only have about 2 kW of potential energy, but it is relatively unaffected by aging, independent from solar rays, wind, clouds or tides, and the waste just lies there. If we could utilize the power of this, we would have a unsurpassed stable power-source. the 2 kW was an estimate btw. I still have to calculate it, but i'm struggling with how to face off the Becquerel value to watts. There is no table for this anywhere, nor is there a formula.??? Decay products produce energies in the range of (at most) a few watts per kilogram TOTAL. Only part of that is gamma radiation. That means you have a very, very low energy density compared to any other form of power. Heck, even solar panels will give you 200 watts per square meter. Even if they only provide power 25% of the time, that's far more power than you'd get from 100 kilograms of nuclear waste, even if you could somehow convert gamma radiation directly to energy. (And of course solar panels are a lot more pleasant to work with.)
However there is one application that that nuclear waste might work very well for - RTG's. These are devices that convert decay heat into usable power. They are often used to provide small amounts of power for space probes, rovers etc and medium amounts of power for things like remote lighthouses and Antarctic science emplacements. Get a better radiation to energy converter and you might be able to get a little more power out of them. They'll never power your toaster but they might someday power the weather station that gives you your weather reports.
* Could anyone provide me with a formula to calculate wattage from the becquerels.
A kilowatt is a unit of power; a kilowatt-hour is a unit of energy. While nuclear waste has a lot of latent energy, releasing it when you want is the challenge.
Radioactive waste has a tremendous energy potential. You can reprocess it and get about 230 megawatt-hours per kilogram from the remaining U-235 in a reactor over the course of a few years. Or you could let it decay and get the same 230 megawatt-hours over the course of a few hundred million years due to natural decay. (That ends up being a few milliwatts of power per kilogram.)
You'd need tons of waste to provide 2kW of _heat_ power - and then an engine to convert that heat power to useful power. That means you need active cooling, a protected primary loop, the heat engine itself etc. In other words, you need about 40% of a nuclear power plant. And you'd still have to 'refuel' periodically as decay heat drops off.but it is relatively unaffected by aging, independent from solar rays, wind, clouds or tides, and the waste just lies there. If we could utilize the power of this, we would have a unsurpassed stable power-source. the 2 kW was an estimate btw.
In addition you'd need to get the waste a lot sooner, when it is still "hot." Right now spent nuclear fuel is stored in on-site pools until it is cool enough to transport. To get a lot of energy out of the waste you'd have to move them a lot sooner, which adds risk to the transportation process.
I discussed how to deal with nuclear waste with a relative of mine some years ago. The relative was a department of energy nuclear waste containment researcher who had a security clearance. What he told me covered several facets of the conversation of this thread so I'll keep it short by summarizing.
1) The containers are degrading and their contents transferred to new containers periodically. They are kept in geologically stable areas underground to minimize exposure (to both people and natural resources like water.
2) There is no such thing as dissolve into nothingness (remember those scientific laws about how matter can't be destroyed) so a volcano is a no go. These materials are usually liquids, even at those high temperatures. If the volcano goes off, that radioactive material gets spread as far as the ash clouds go. Remember Mt. St. Helens or more recently Iceland where the cloud was over Europe interrupting air traffic? You'd be looking at radioactive contamination affecting millions of people over a massive goegraphic area that would last longer than your lifetime. In short, a very bad idea.
3) The best option from a cost benefit analysis would be to launch the waste into the sun or perhaps an uninhabitable nearby planet like Mercury or Venus. The risks to this are the same as the volcano. If the shuttle taking the material up explodes, that radioactive material gets spread all over the place.
When the technologies are sufficiently reliable we'll probably transition to relocating the waste to another celestial entity. But until we can make affordable containers that would maintain their integrity from being in a mid air explosion, terminal volocity fall into the planet where they could be recovered (remember how much trouble we had with the Air France black box, and we knew the impact zone in that case) and re-launched...underground is best.
When the technologies are sufficiently reliable we will:
1) not be creating new nuclear waste
2) be transmuting the wastes we have to harmless materials
Others have pointed out the snags with your volcano idea. But I think I read one related idea was to bury the waste in ocean trenches, i.e. at active subduction zones. The concept would be that over millennia these would be entrained beneath the continental margins and go down into the tectonic circulation for a few million years, long enough to decay away or join the other radioactivity down there in the mantle. The catch, I suppose, would be the long time to entrain them (plate margins move at 3-5 cm/yr at most) and the crushing of the material as it was incorporated into the rocks. I suppose if the stuff was in the form of an insoluble glass it might be OK though. I imagine you would drill holes in the sea bed and place the stuff down in it and refill the holes, then let geology do its work. Quite taxing engineering though, drilling fat holes at the depths involved.
Why not just drop them on the seafloor nearby and let nature take its course? By the time any "crushing" happens they will be covered with meters of sediment and thus contained.
I'm not talking about turning it into heat, because that ship has passed. This was done in the nuclear reactors. Now this process could not be maintained efficiently, so there has to be another way to collect the energy, which is not heat, but kinetic impact of gamma rays, hitting electrons loose, and making a current.
Actually, there is a fair amount of fissile fuel left in spent fuel, which can be recovered by re-processing. The heat from radioactive decay isn't much though, after long periods of time.I'm not talking about turning it into heat, because that ship has passed. This was done in the nuclear reactors. Now this process could not be maintained efficiently, so there has to be another way to collect the energy, which is not heat, but kinetic impact of gamma rays, hitting electrons loose, and making a current.
Decay heat - Wikipedia, the free encyclopedia
After one year, typical spent nuclear fuel generates about 10 kW of decay heat per tonne, decreasing to about 1 kW/t after ten years.[13] Hence effective active or passive cooling for spent nuclear fuel is required for a number of years.
That's been tried. One of the more promising ways is to use a phosphor that effectively converts the high energy gamma photons into lower energy photons that can be absorbed by photovoltaic cells. But again, outputs are on the order of milliwatts.
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