Guest Post by Willis Eschenbach
For many people the sticking point for nuclear power is, what do we do with the waste? We can “vitrify” the waste, but what do we do with it after that?
Figure 1. The process of “vitrification”. Liquid nuclear waste (solid fuel rods dissolved in acid) is converted into a solid glass like substance. Image Source
Unfortunately, the people in almost every country of the world have not been able to make up their minds what to do with the solidified nuclear waste. As a result, in almost every country it’s just sitting around. And nuclear material sitting around is dangerous. So here’s my brilliant plan. Nuclear lawn darts.
We have a pretty good idea what was happening on the bottom of the ocean millions of years ago. This is because there are places in the ocean where what you might think of as the local underwater climate never changes. It’s always cold. It’s always dark. There’s not much current. There is a continuous rain of very fine particles from the upper ocean. And it’s been like that for the last X million years.
We know that this has been the case for millions of years because we can take a core sample of the top layers of the thousands of feet of silt up at the top, and we can see that it has been undisturbed for that time. The conditions have not changed much year after year for millions of years. Every year a tiny amount is added to the thickness of the primordial ooze at the ocean floor.
Those spots in the mud at the ocean bottom seem to me to be ideally suited for the storage of nuclear waste. We know these areas are geologically stable on the multi-million year scale. It also gives us multiple layers of protection both from human interference, as well as from accidental release.
It is isolated from humans for the most obvious of reasons—it is way down at the bottom of the ocean.
It isolates any leak through the use of several redundant mechanisms. First the nuclear waste is already solidified. So in order for it to escape it would have to leach out of the solid glass. At that point it finds itself inside a sealed welded stainless steel container. However even the best of steels may develop some chemical corrosion. At that point it is encased in concrete. Suppose it gets through the concrete. Then it is still contained by the stainless steel outer container. Again, perhaps the outer container cracks. At that point the leaking radioactivity finds itself buried under 50 feet of silt and mud. And if somehow it manages to make it to the environment, it comes out in the best spot, the spot where radioactivity will do the least damage. That spot is the bottom of the ocean. Here’s why.
On land there are a number of scarce elements that are necessary for life. One of them is calcium. We needed for our bones and our teeth. So the bodies of land animals have developed special mechanisms that gather up these various scarce elements like calcium and concentrate them so we can use them in our bodies.
This makes for trouble. When radioactive elements enter the environment, our bodies avidly seek them out. We concentrate these radioactive elements, and they then damage our bodies.
The ocean, on the other hand, is a veritable stew of all kinds of chemical compounds. Take iodine as an example. Radioactive iodine on land is concentrated by our bodies and stored in our thyroid glands. And since there is so little iodine around on land, any radioactive iodine in the environment stands a good chance of being picked up by some living animal. Thus, it is dangerous.
In the ocean, however, iodine is quite common. It’s responsible for the “medicinal” smell of seaweed. There’s lots and lots of iodine in the ocean.
So where will a spill of radioactive iodine cause more damage? Obviously, the answer is on land. In the ocean, at the very bottom of the ocean, that radioactive iodine will be immediately diluted among millions and millions of atoms of iodine which are already there. This has two effects. First, the sea creatures use iodine as well—but they have no special mechanisms to pick it up and concentrate it because it exists all around them. Second, because of the large amount of natural iodine in the ocean, the concentration of radioactive iodine in the ocean is very low compared to natural abundance. So between the animals not concentrating the iodine, and the low and well-diluted levels of radioactive iodine within the reservoir of natural iodine, any release is much less dangerous in the ocean than on land. And for the obvious reasons of dilution and separation from the larger surface biosphere, a release is much less dangerous at the bottom of the ocean than at the top.
Now, how to get the nuclear waste down to the ocean bottom and bury it there? I propose a very low-tech method, using nuclear lawn darts. The plan is to seal two or three of the canisters of vitrified nuclear waste into what is in essence a giant stainless steel tuna fish. This tuna would be loaded aboard a large vessel. At a predetermined spot in the ocean it would be dropped over the side. If sophisticated steering is desired, that can be achieved through the use of steerable vanes. With proper hydrodynamic design, they should be capable of reaching reasonable speeds. This should be enough to bury them entirely in the mud at depth. (Naturally, a suitable site with appropriately soft silt, will need to be chosen.)
Figure 2 shows a cross-section drawing of what such a disposal system might look like. It is modeled after the shape of an oceanic tuna, which are capable of speeds up to 45 miles an hour (70 km/h). This should give it plenty of speed to be able to bury itself deeply in the ocean floor.
Figure 2. Cross section of a Nuclear Lawn Dart. The illustration shows the outer stainless steel shell, the inner concrete, and the stainless steel casks containing vitrified nuclear waste. Three individual containers are shown inside the dart. Background Graphic.
This design gives great strength and durability, and provides redundant levels of containment for the nuclear waste.
Figure 3. The process of dropping a nuclear dart.
Each nuclear dart will have a buoy to mark the location, attached to a short length of cable which will deploy automatically when the nuclear tuna strikes the ocean bottom. Each buoy will contain a transponder that can report back the condition (temperature, pressure) of the dart. These will allow that particular nuclear tuna to be located, identified, and retrieved as necessary. This would allow all nuclear darts to be retrieved quite simply by hooking onto the cable. That cable is connected to a lifting ring at the stern of the nuclear dart and which would serve to hoist directly up out of its resting place. If there were to be any radioactive leakage, it could be detected and the leaking and nuclear dart could be retrieved and fixed. Anyhow, that’s my bozo solution for how to deal with nuclear waste. Put it into a streamlined projectile, drop it over the side of a ship, and let it bury itself in the bottom of the ocean. What could be simpler?
Possible objections? One I can think of is the issue of heat. Radioactive decay gives off heat. How well this will be dispersed by the surrounding mud is an interesting question. However it doesn’t seem to be an unsolvable question. Simple experimentation will bring that to a quick resolution. That will give us the limitations on the number and amount and density of these kind of disposal units that the ocean floor can sustain. In addition, since each dart will be (relatively) cheap, we can reduce the concentration of the fuel in each dart and increase the number of darts. This will reduce the heat generated in each dart.
Another is the deceleration when the dart hits the ocean floor. Again, this can be measured (it will differ for each site) and the darts suitably engineered to resist the forces involved.
So. What are the possible objections to this scheme? All submissions gratefully accepted.
My best to all,
w.
[UPDATE] A number of people have said in comments that if I can retrieve them, someone else can too … a valid point. Scratch the retrieval cable, bury them and forget about them.
But it’s not waste! Bottom of the ocean? Do you know how much project Azorian cost?
As TimC mentions there are treaties trying to prevent pollution of the oceans. In itself this method is probably safe, but it sets a dangerous precedent. Our current mechanisms for protection of the oceans are so fragile that you have to be careful about weakening them at all.
I imagine that you could find some rather unsavory people going on fishing expeditions for these canisters too. I don’t know if “dirty bombs” are very practical, but someone might be inclined to try. It would probably be a good idea to make the range of that transponder rather short so only someone who knows exactly where to look can find it.
My brother explained this concept to me almost 30 years ago. I’ve mentioned it now and then on the blogs, to almost complete silence. I’ve wondered why such a simple idea simply had no legs.
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Set the controls for the heart of the sun
Set the controls for the heart of the sun
Kasmir says:
May 6, 2011 at 1:05 am
Just feeding the craziness. Nuclear waste is toxic waste, but toxic waste that happens to “get better” after some number of half lifes.
So nuclear waste is a waste of time!
It would seem that these ‘lawn darts’ with a convenient lifting eye would be an ideal target fot terrorists to get hold of nuclear material. This would supply material for a Dirty Bomb to contaminate a city for thousands of years.
Not a well thought out solution I am afraid.
Not a bad idea. You don’t want to use stainless steel for the canisters though, because it corrodes in an anoxic environment.
I figure, better the ‘waste’ sitting many km beneath the sea – and in metres of ooze – is preferable to it sitting in something not much bigger than an Olympic swimming pool.
One (solvable) problem with the ‘Willis’ Uranium Waste Tuna’ (hmmm….a familiar acronym…) would be the tremendous water pressure on the tuna casing. But, would that we had the people to make these things work instead of telling us why they won’t.
Dear Mr Eschenbach,
as someone professionally involved in the nuclear back end business, let me state first that most everybody I know will agree that deep ocean disposal would be one of the cleanest and most elegant way to get rid of highly active nuclear waste, if you never wanted to see the stuff again. Two caveats, however. You state in your second paragraph:
“Unfortunately, the people in almost every country of the world have not been able to make up their minds what to do with the solidified nuclear waste. As a result, in almost every country it’s just sitting around. And nuclear material sitting around is dangerous.”
First, and as others have already stated, nuclear waste storage is not a technical problem, but a political one. And in a political discussion, deep ocean disposal is a hard sell because it looks careless, irresponsive and sloppy. And won’t somebody think of the dolphins? Furthermore, the attempt to move the discussion forward by offering yet another technical solution is, in my opinion, just participation in a game that the anti-nuclear interest groups have thoroughly rigged in their favor by falsely calling nuclear waste disposal as an unsolved problem.
That you might have fallen for their trap is indicated by your flat statement “And nuclear material sitting around is dangerous”. My flat answer would be “No, it’s not” or, maybe, “Dangerous compared to what?”. A more involved answer is that the body count from the production, handling, transport and storage of vitrified nuclear waste is zero, to the best of my knowledge. How is this dangerous?
This ties to my second caveat, which is purely technical: retrieval of vitrified waste might be desirable even though it does not contain any uranium or other fissile material, contrary to what some of the comments indicate (vitrified waste is what you get after the spent fuel is recycled – all the uranium and plutonium is processed into MOX fuel to be reused in a normal reactor). The reason is this: among the fission products that get created during power production, there are a lot of stable elements that are otherwise very hard to find anywhere. Some of them, like rubidium, already have technical applications, others might have some in the future.
So potentially, today’s waste is tomorrow’s treasure lode, and it would be a shame if you had to hunt for that treasure on the ocean bottom when you could have stowed it away in a more accessible place where, and this is the kicker, it would have done just as little harm to anybody.
Hope this helps, and please let me use this occasion to humbly thank you for the incredible work you’ve done in your many articles here, which are always intriguing, and often astoundingly brilliant.
The “vitrify” link is incorrect. At the time of this comment it’s http://www.ricllc.com/pr1_3_20.htm%20it, but the final ‘%20it’ needs to be removed.
Just make sure that the darts are retrievable. You never know when we might need them to fuel thorium reactors once we’ve mined out all the available uranium and used it up.
Then again, some nations would actively do just that: steal your stored UO2 rods that you are counting on for a reserve. You put that stuff down there, and somebody will go get it.
LFTR plus transmutation?
I’ll bet the Chinese and/or others are already doing this.
Because I think the decay of the radioactive material will pulverize the glass and over time the stainless steal will fail and radioactive material *will* be release.
Now where did I read that the waste can be recycled in the Thorium process?
Obviously the best solution if it is feasible.
I like it. Nice design. And the retrieval cable can also be used as a handy attachment point for greenpeace activists who might want to chain themselves to it and accompany it on its journey.
Unfissioned uranium and tranuranic elements are valuable enough to be separated and put back into the fission process. This is a lot of uranium/thorium ore that wont have to be mined. Its also the long-lived isotopes that will be burned up with neutrons.
Fission products are much shorter lived. They could be sequestered in ocean trenches or probably far more easily in surface geological formations. Iodine-131 does not matter much because its half life is only 8 days. Cesium-137 and strontium-90 are the nucleatides that must isolated from the biosphere. They are potassium and calcium chemical analogs and can do immense damage.
I think any attempt to concentrate the waste and then dispose of it out of reach is doomed to failure. By definition there is a danger that some of these darts will not bury themselves in the mud, may then be damaged and release waste into the ocean such that it can be detected. Then its game over for that plan – fears over contamination of the food chain and possible terrorist activity related to getting hold of the waste darts would take hold and bring the plan to a halt.
I favour vitrifying the waste in particles as fine as ball-bearings, then spreading the waste “ball-bearings” very thinly over the mid-Atlantic ridge. Lots of volcanoes in the mid-Atlantic ridge which are already radioactive, so if you spread the waste very thinly you won’t even notice it, and retrieval of the waste by terrorists and rogue states would be impossible.
Generally speaking it isn’t really the radioactivity that is the problem – the uranium was itself radioactive before being mined, just not so concentrated. The problem is the spent fuel rods are 1% Plutonium which is highly toxic as well as being radioactive. That needs to be kept well away from the human food chain and a volcano at the bottom of the deep ocean sounds like a great place.
E.M.Smith 0052 hrs,
Thanks. I never realised how much uranium is disolved in sea water. I’ll bet Helen Caldicott, resident Australian anti-nuclear campaigner, doesn’t know that. Otherwise she would be trying to ban surfing. Then again, how many ardent surfers have suffered from radiation poisoning? The Greens must be really cheezed with mother nature. Everything they come up with is eventually nullified by Gaia herself.
It does go to show that the only way these green ideas get legs is as a result of the profound ignorance of the public and their politicians. The failure of education systems to teach history and science has lead to the current malaise. No wonder older people are more likely to reject AGW. Most had a decent education.
In the 1970s my then boss, John Elliston, proposed encased burial in soft sediments at places like the mouth of the Mississippi or Ganges. His idea and yours are so similar that one would think you had discussed it.
By using a sedimentary pile, the penetration of the “darts” would be deeper. There would be less exposure to water and hence a lower possibility of spreading if corrosion reached the core. The sedimants, being softer, would also exert less physical force on the container during movement – and of course, they accumulate to far greater thicknesses than open sea floor in the same geological time.
It does not really matter much where you put the waste. Depending on prior reactor management and the dilution factor in glassification or Synroc, the waste has about the same radioactivity as the original ore in something like 100 to 1,000 years. We live very safely with ore in the mine and processing plants. There is no reason why we cannot live safely with Synroc 1,000 years old. It does not require human management for 25,000 or 250,000 years as the common Green mantra chants.
The other factor is distance. As we note about Australia’s poisonous snakes, more people are bitten by trying to kill the snake than by calmly walking away from it. It’s sound advice to keep a small distance away from nuclear waste as well. A mile or so is a rule of thumb for a strong source among the public.
Usual Willis standard – excellent and well written.
Liquid Fluoride Thorium Reactors are the way to go – visit “Energy from Thorium”.
The reporting of the recent Japanese disaster was remarkable in that there was almost no mention of ‘units’ of radioactivity nor the relevant 1/2 lives and dangers of released products.
50 years ago the idea of even just simply re-processing spent fuel rods was unimagined. Nowadays in France they use re-processing on their spent fuel rods all the time. People today can’t imagine the idea of de-radioactivating radioactive materials – but I can imagine it -and it’s really just a matter of time before some Genius Physicist discovers some property of some sub-atomic particle which can be used to de-radioactivate stuff …. then we won’t have any problems with Nuclear Power because the stuff coming out will be fully neutralised …. and we already know how to make stuff radioactive …. so we have a fully renewable cycle 🙂
Infallible thinking. Brilliant! You’re a genius! You might need to reinforce the outer shell at potential imapct sensitive points though. What about fitting an auger head to it so it self-drills into the sea floor?
However, me thinks you’ll never get it off the drawing board old fruit, as the anti-nuclear brigade, who have correctly predicted every disaster that has occurred (not, as with everything else!) will never permit it, after all, they know best what’s good for Gaia. Besides, Willis, think of what the Silurians will do once they realise that we humans have taken over the planet above them poisoning their sub-terranean world beneath us, I know what they’re like, I’ve watched every episode of Dr Who. Oh, must go there are some fellas in white coats at my door beckoning me to come with them & one has a very strange jacket & the other a large syringe!!!! Sarc off:-))
Actually, ol’ bean, I hate to break the news to you, but this basic idea has been around for a while. You havent heard of it, of course, because it has one basic flaw, it works, and it’s cheap and easy. it is important to the anti nuclear crowd, who pretty much control the press, that nuclear waste be around and dangerous, so as to prevent the creation of nuclear plants. This idea would pretty much remove the last reason for nuclear plants, therefore, it must be censored.
The idea of lawn darts however may be new. The old idea, which I understand works just as well, is just make the big glass bricks, and drop it in a suduction trench. Only problem with that is, if you later want it back, you can’t have it.
Or you could just use a Canadian reactor which can actually use nuclear waste as feul, and can even use raw urainium as feul, why waste it?
A brilliant idea, and probably no serious research/design needed as the engineering solution has already been produced… Just model the darts on Barnes Wallis’s “Tallboy” or “Grand Slam” earthquake bombs.