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.
Huh, what an intriguing idea.
Actually, my preferred target areas are the subduction trenches. Add a few 10s of millions of years recycling through the mantle.
No immediate objections. Alternatively you could play darts in outback South Australia with just as much success.
Also, the development of new nuclear technologies and processes like the Thorium cycle will end up producing far less (~1%) stuff that has to be stored in the first place, as well as generating more energy to start with.
Willis – check out Synroc. About 30 year ago it was invented and has a far better ability to resist leaching compared to vitrified glass.
The biggest problem you will have is the wailers who cry “oooh but its in the ocean and will spread everywhere”.
You also don’t really need to worry about the iodine very much, its half-life is too short. Its the strontium and caesium you need to be concerned about. Provided your proposal can lock stuff up for about 4 to 10 half-lives its probably got some legs.
Makes perfect sense to me…
An ingenious but appealingly simple solution.
But the biggest objection to this solution, without a doubt?
The fact that neither the politicians, nor their green activist chums, want a solution. They see it as more useful to have the nuclear waste sitting about, so they can point to it and scare people about how dangerous it is.
Excellent article. This is exactly (to a spooky level of detail!) what I have been saying for years.
In 1988 I was involved in an oceanography expedition off New Guinea and we took core samples from depths of 10km. The boffin on board told me all about the subbottom layers of sludge and how much time passes with nothing happening down there.
I think that this is such a perfect solution.
I can imagine the knee jerk reaction but have yet to hear a serious criticism of the idea.
Point out also that every cubic kilometre of sea water already contains 200 tons of Uranium…
This is an excellent, redundantly safe, economic and rational solution to nuclear disposal.
Sadly, it is certain to be rejected because nuclear-phobia is a state religion, not a rational belief system. Anti-nuclear superstitious dread is so strong among the majority population of most industrial countries that reason will not be listened to. Concerning science and public opinion, we are in an absolute dark age with no light at the end of the tunnel.
Great article, do your best to avoid being burned at the stake!
A simple concept, simply communicated. Seems OK to this non-scientist. In my view, too much stuff is way too complicated and makes my head hurt thinking about it. Never any brain pain from Willis’ ideas!
What’s wrong with a cave in Nevada? That way we can retrieve it for reprocessing once we get over our pc horror of clean green nuke power.
Aside from being totally brilliant, no objections. Why do I appear to object to the brilliance? You be the judge. The panicking juggernaut of bureaucracy surrounding nuclear waste is incapable of comprehending simplicity.
The transponder & grapple? Omit it. We want this stuff to be gone. No means of getting it back. If dropped in a subduction zone, it will either get swallowed up in the trench or buried in the scraped-off accretionary wedge on the overlying plate. Either way, it’s gone. By the time it gets digested to the point of being shot out of an andesitic stratovolcano, it will have decayed to nothing.
Either way, it can’t be used as a dirty bomb…even if it DID get hot and metamorphose some adjacent ooze, in 35,000 feet of water the cold and crushing pressure would keep it safe.
But good luck getting the whole brilliant, simple, elegant, and ultimately achievable idea past the usual screeching herd of dissenters who want us to get quickly back to the dark ages.
Interesting solution. But building thorium reactors capable of burning highly active nuclear waste still sounds more like a win-win solution to me!
Appealing idea, but on first sight it would seem to breach Marpol 73/78 (disposal at sea of harmful substances in packaged form) – see
http://en.wikipedia.org/wiki/International_Convention_for_the_Prevention_of_Pollution_from_Ships
I think the concept (and the target areas for the dumping) would need further international agreement before it is lawful in international waters – and some governments may well object simply on principle, so it may not be feasible whatever the merits.
Nice idea. I’d rather keep the stuff on land where we could get the usable fuel back out of it, though. (Most reactors today leave most of the fuel unused. The “waste” is largely usable uranium fuel…)
But if folks are determined to dump the stuff, this seems like a reasonable way. I’d suggest using waters deeper than any fishing trawl will ever go…
BTW, we lost a nuclear bomb of the Carolina coast. It is believed to have self buried into the mud and folks have never been able to find it.
There are somewhere over 4 Billion Tons of Uranium disolved in the ocean. It’s a very big place. If one of these things (or all of them, even) did leak, I suspect it would be of no consequence at all…
http://nextbigfuture.com/2007/11/two-proposals-for-mining-ocean-for-720.html
So it would take one heck of a lot of ‘waste’ to have an impact on the radioactive levels… Or you could drop them into a subducting trench. In a few hundred million years they would be recycled into new mineral deposits on the new mountains formed. At least that way the resource would eventually be recycled 😉
An interesting possible solution. Somtimes the simplist ideas are the most practical and once a practical way of completly getting rid of waste is found then the darts could be retrived. I am sure there will be the usual ‘instant’ objections to the idea, but it could be a good place to start, after all, most other solutions seem to be more dngerous.
Just feeding the craziness. Nuclear waste is toxic waste, but toxic waste that happens to “get better” after some number of half lifes. Carcinogenic, mutagenic heavy metal poisons like mercury *never* “get better” when buried away, yet somehow no one plan perpetual vigils for the disposal sites. Not only that, but the portions are immensely larger.
The whole nuclear waste controversy is an absurd crock.
Add an aluminum accordion style or telescopic style extension on to the tip that will act as a crumple zone, then you will then have a known maximum deceleration.
You will also need active steering and a gyro (inertial guidance) to maintain the 90 degree impact angle through the unknown currents and eddies of decent.
Make it nose heavy, steering fins at the front.
Design the delivery vessel such that the launch is from the bottom of the hull through a tube that extends to above the water line inside the ship, inside the ship. That thing looks heavy and would likely drag a Zodiac full of Greenpeace people to the bottom of the sea.
I will make a very boring video if you can not actually see anything enter the water. Boring is good.
The idea of ‘mining’ sea water is a bit ‘theoretical’ -it will still be more economical to simply dig it up for a while yet.
Willis,
Technically, the ‘problem’ of nuclear waste is a solved problem, and has been for decades. The only problem that exists is a political problem, and is as intractable as all such are.
Firstly, the amounts involved are tiny, and as E.M. Smith notes above, for the transuranic and similar stuff, reprocess it to remove anything useful, and shove the rest into an undersea subduction zone – send it back to where it came from. Or just dump it unprocessed. With the atomic weights involved, it’s not going to float to the surface.
Remember also that much of the supposed nuclear waste is ‘low level waste’, and is absolutely anything used at the nuclear facility – used paper towels and the like. The NRC on their ‘low level waste’ page says – ‘This waste typically consists of contaminated protective shoe covers and clothing, wiping rags, mops, filters, reactor water treatment residues, equipments and tools, luminous dials, medical tubes, swabs, injection needles, syringes, and laboratory animal carcasses and tissues.’
I suspect that ‘contaminated’ here means ‘used in a nuclear facility’ regardless of any actual exposure to nuclear material?
One other thing, you will need to have a set of hard plate sonar reflectors or controllable active sonar transmitter(s) on the seabed in the target area to make certain that there are no whales in the area during delivery. If one blue whale bobs to the surface or washes up on a beach somewhere with that thing stuck in it your investment is lost. You would also need to publish well in advance when and where you are going to deliver so that there is no chance of sinking a submarine.
Thanks again Willis for A Great Thought!
If we have to have Uranium reactors then this is the best solution for waste disposal I have heard of yet. However, Thorium sounds like a better, longer term solution to me – I’m with Espen here. Please look it up and let us have your thoughts on it!
As ever, Stu.
Perhaps we should sink these darts in the North Arabian Sea where the heat generated will remind Osama Bin Laden that that he has not gone to the place where there are 72 virgins.
Willis – you are straying out of your competence field. Radioactive iodine is not a problem – by the time you get to vitrify the waste, it is long decayed away. Most liquid nuclear waste is old and the long-lived nuclides dominate – like caesium-137 and the actinides (plutonium, etc). Neptunium is interestingly, given its name, the most problematic, with a long half-life and great solubility – also an alpha emitter.
In the UK we have a plant that vitrifies liquid waste – and it has had no end of engineering problems (I know because I was actively engaged in pressing the British authorities to vitrify the waste – by the Irish government – because the storage of the liquid is such a high risk). But you would not want to go through the whole reprocessing of solid spent fuel and turning it into liquid in the first place – the contamination problems are immense, and it is not economic to recover the unused uranium nor use the plutonium in mixed-oxide fuel – apart from the higher risks of accidents, discharges and worker exposure. The ‘best’ solution is to do what most non-weapon countries have done – store the spent fuel.
The oceans are a global commons (treated badly I know) – and there are many people – simple fishermen, who regard it as a sacred place. They are not easy to convince (nor should they be) that what technocratic experts tell them is a safe dumping operation that solves a lot of rich-country energy-supply problems (apparently) is actually safe. And safety may not be their main concern – but then sanctity is not something westerners much understand, especially where the Earth (or Ocean) is concerned.
I spent 15 years on this case – from being on the editorial board of the Journal of Environmental Radioactivity to the Research Advisory Group at the UK’s department of Environment, plus a seat on a government commission that eventually banned low-level dumping operations – advising also the governments of Spain and Ireland and several oil-companies who developed drilling technologies for territorial waters (the free-falling penetrators into international mud are an old idea from the 1980s that was not preferred). I also acted as Greenpeace’s chief advocate at the UN.
So I have seen all of this from both sides of the argument. You are wasting your intellect on this one. There is no ‘solution’ to nuclear waste – anymore than there is a fail-safe reactor in current usage or a reprocessing plant that does not present enormous risks (far greater than Chernobyl or Fukushima – and on the latter, there would have been far more severe problems if the wind had not been out-to-sea for the larger releases).
What’s the terminal velocity likely to be in water? Will it be going fast enough to penetrate very far?
Also, what happens if one dart rams into the previous one?
There’s a very interesting book out, Nuclear Transmutation of Stable and Radioactive Isotopes in Biological Systems, by Vladimir Vysotskii and Alla Kornilova. Prof Vysotskii is Head of Department of Theoretical Radiophysics at Kiev National Shevchenko University, Ukraine. I suspect that this is is one of the important ways forward, eventually. Russians are far less coy than Westerners about investigating unusual scientific matters – thank goodness.
Reminds me I need to do a review for Amazon.