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.
Leon Neihouse says:
May 7, 2011 at 4:21 am
I love the web, I always learn so much. Many thanks.
w.
This idea was discussed by Bernard Cohen years ago, in his book called “Before It’s Too Late: A Scientist’s Case for Nuclear Energy”. This is an excellent book to counter a lot of the emotional arguments against nuclear energy.
So………..problem still not solved !
The sensible approach, would now be to ban all uranium mining and processing of these extremely radioactive, toxic & dangerous substances.
When an appropriate solution to render radioactive substances harmless is found, and 100% safe ways of using it are found, then and only then should it be reconsidered as viable.
Of coarse this (future use) would never happen, as before the nuclear industry could find a way to accomplish this, a safe alternative would have already filled the void.
In the 1970’s Mork suggested “nuke away”, so often fact follows fiction, sadly, not in this case.
Fiction abounds about radioactive substances, you deluded people seriously need to do some homework on ionizing radiation, DNA, RNA, the food web and the associated mutations from this disgusting technology.
Myth #1, radiation cures cancer
As pointed out by a number of commenters, deep sea disposal has been a viable proposed solution to radioactive waste for a long time. And yes, it has been done in the past. The main objection to the concept is the “what if it leaks” meme. This notion needs to be disabused because the dilution of the ocean is so huge that the radioactive material would be rendered harmless as long as there is no reconcentration in a biological system.
Dilution is a solution to radioactive materials. The reason for this is related to the concept of half-life. One atom of plutonium-239 has a 50/50 chance of emitting its radiation in within a 24,000 year period and it does so in a split second. What is this atom doing the rest of the 23,999.9999999 years? Answer: It certainly is not emitting radiation.
Let’s say you put a kilogram of the Pu in the ocean. For you chemists and numbers folks, remember Avogadro’s number, and you can calculate the actual number of Pu atoms present in this kilogram. Now calculate the number of atoms of water in the ocean. Divide the number of atoms of Pu by the number of atoms of water. Then calculate how many atoms of the Pu would be in each pint or liter of ocean water. Presuming a uniform dilution of the Pu, I can guarantee that if you can find a single atom in any one pint, you will be lucky.
Let’s presume that a fish drinks a liter of water with one atom of Pu in it and the atom stays in the fish (unlikely as biological systems do not have much use for the chemical form that this Pu would be in). What are the odds that this atom of Pu would happen to emit its radiation during the lifetime of the fish? Really, really, really small. Even if the fish got unlucky, it is only a one time hit from this Pu atom. Given that there are other naturally occurring nuclides (tritium, C-14, uranium, etc) in the fish and in sufficient quantities that they give off emissions by the millions every minute, does anyone really think that one extra potential hit is going to make a big difference to this biological system? One hit from radiation has a one in a quadrillion chance of causing harm such as cancer. That is not a million, not a billion, not a trillion, but a quadrillion chance.
Deep sea disposal is very viable and the concern of leakage becomes laughable when one understands how radioactive atoms work, the half-life concept and the chemistry of the materials that would be disposed. However, Willis, I agree with a number of the obviously more knowledgeable posters that land disposal with decent security provides a means for future humans (hopefully better educated than today’s folks) to retrieve and use the energy still available in this waste. Land disposal can be as safe as sea disposal, but with this added benefit to future generations.
Sunspot: I try to educate people about radioactive materials, how they work, their pros and cons, their biological risk and how to protect oneself from radiation. As a Health Physicist, I have a great deal of radiation knowledge. I see no delusional people in the postings above. You said radiation doesn’t cure cancer and you are technically correct. It doesn’t cure it, it kills it. My radiation oncologist brother would gladly explain this process in great detail and he might also tell you how many lives he has saved. I too can also give you a lot of details of the process. So far you have basically only ragged on the posters here. We like to discuss the science of things on this website. If you have specific examples of radiation risk that you would like to discuss, I might be game to discuss them with you. Generally I have found that there are some rabid, closed-minded anti-nuclear folks out there who are a waste of time to have a discussion with. Are you one of these? If not, I enjoy educating folks and would hope that you could bring something to the table that would educate me. Otherwise …
Brian H, I thought of subduction zones, too. Then I though, why wait? Just dig a shaft down to the core and toss the stuff in.
Should take a week or so. Perhaps less if we get two guys digging.
How does plutonium change in the environment?
All isotopes of plutonium undergo radioactive decay. As plutonium decays, it releases radiation and forms other radioactive isotopes. For example, Pu-238 emits an alpha particle and becomes uranium-234; Pu-239 emits an alpha particle and becomes uranium-235.
This process happens slowly since the half-lives of plutonium isotopes tend to be relatively long: Pu-238 has a half-life of 87.7 years; Pu-239 has a half-life is 24,100 years, and Pu-240 has a half-life of 6,560 years. The decay process continues until a stable, non-radioactive element is formed.
What does plutonium do once it gets into the body?
The stomach does not absorb plutonium very well, and most plutonium swallowed with food or water passes from the body through the feces. When inhaled, plutonium can remain in the lungs depending upon its particle size and how well the particular chemical form dissolves. The chemical forms that dissolve less easily may lodge in the lungs or move out with phlegm, and either be swallowed or spit out. But, the lungs may absorb chemical forms that dissolve more easily and pass them into the bloodstream.
Once in the bloodstream, plutonium moves throughout the body and into the bones, liver, or other body organs. Plutonium that reaches body organs generally stays in the body for decades and continues to expose the surrounding tissue to radiation.
How can plutonium affect people’s health?
External exposure to plutonium poses very little health risk, since plutonium isotopes emit alpha radiation, and almost no beta or gamma radiation. In contrast, internal exposure to plutonium is an extremely serious health hazard. It generally stays in the body for decades, exposing organs and tissues to radiation, and increasing the risk of cancer. Plutonium is also a toxic metal, and may cause damage to the kidneys.
If anybody has had the displeasure of watching someone die from medically induced radiation poisoning, then they would know that these genocidal chemicals let loose in our environment would be detrimental to all creatures on the planet.
It would be only a matter time before some of these invisible cancer bombs land, unnoticed on your own dinner plate/s !
Actually, you don’t need to bury this stuff. Bring Integral Fast Reactors on line; they can use this stuff for fuel. Look up Internet references to Argonne National Laboratory’s IFR project. The Clinton administration killed it when it needed only three years to complete its research and engineering schedule. Clinton also forbade anyone on the project to even talk about the IFR or its cancellation. It almost seems as if the environmentalists want to make sure that nuclear energy cannot be used, at least in the U.S., by deliberately forcing the accumulation of toxic waste at current operation reactor sites; the public and its safety be damned.
Ok, the first mistake that just about everyone makes when looking at spent nuclear fuel is to consider it “waste” because to waste it would really be the wasteful act.
The fuel can be recycled a number of times (up to ten or so) to extract all but about 5% of the energy out of it. Since the fuel is being used in fission this has an added benefit of fissioning many of the most toxic of the radioactive substances thus reducing the overall radioactive half life down from 10,000-100,000 to something a little more manageable around 300-500 years. After this recycling process has extracted all but the last dregs of the potential energy it then really is spent fuel with technology within today’s reach. However, it may be possible yet in the future to extract even that last 5% or a good portion of it should we find that prudent or economic.
There are other benefits too, three main benefits actually [1 – 3]:
Burying nuclear waste or tossing it away is not practical and goes against every standard of environmental stewardship. Extracting all the energy from it that we possibly can is much more prudent and more responsible.
As such “Modest Proposal for Nuclear Waste Disposal” is seriously flawed as the nuclear waste is NOT waste, it’s a resource that we are going to need to provide clean energy for our future. Only after all but the last bit of potential energy has been extracted from the nuclear fuel is it truly waste and by then it’s much safer to deal with with plans such as the “modest proposal” (but seriously don’t bury the stuff at sea).
What’s most amusing is that the Jonathan Swift connection was missed.
I especially liked the “Tuna-shaped” darts bit.
Nuclear waste is not waste.
It is not trash.
In my life I have seen newspapers go from trash to cardboard.
I have seen aluminum cans become new aluminum cans.
I have seen used glass bottles become new glass bottles.
1) We need better mechanisms for isotopic separation. Chemically we can separate out elements, but isotopes require other techniques. Laser ionization? Centrifuges? Possibilities abound, but they will have to pay off.
2) We need more brain power put behind the use of isotopes. For the most part, daughter particles are neutron-heavy and thus good neutron sources. But what can they be used for? Examples abound: sheet metal mills where the thickness of the metal is gauged by a radioactive source, for instance.
3) Fire is dangerous. But we use fire in all sorts of ways. Just because a physical phenomenon like radioactivity can cause harm, we should not cease using the phenomenon for that reason. [Unless you are dead set against GM crops]
4) Posters are in the main correct: the problem is political, not scientific. So long as people are not properly educated, scare-mongers will run wild.
5) It is my understanding that the radio isotopes used in nuclear medicine are now in short supply. Can these be found in general nuclear “waste”?
For the most part, we are still pretty dumb about the whole issue.
Mathman;
Don’t be too sanguine about the glass and paper. I gather that in most jurisdictions the only recycling efforts that break even, all costs and offsets considered, are those of metals. And some places, not even that; some have been hidden-camera-filmed mixing the “recycled” blue-box contents directly back into the landfill waste stream.
“Things aren’t always what they seem; Skim milk masquerades as cream.” –G&S
Mathman;
For an interesting techy alternative, check out the plasma torch pilot at plascoenergygroup.com .
mathman:
the last time i saw neucleonic water level indicators for boiler waterlevels was in 1973. i have not followed their use since them but the fact that they are not on every boiler and water heater in the western world would indicate that there is some industrial reason that they are not used.
measuring material thickness in sheets is more easily done with a roller and laser setup. the sheet moves over the roller (at whatever speed you want it to) and two lasers are focused on it in converging lines. when the images are a true circle the thickness is what you want. if the figure 8 is oversized then the material is to thin and if the image is undersized the material is to thick. accuracy with standard equipment is .0005″.
this system has been in use since about 1985 in the machine tool industry.
C
Willis Eschenbach says:
May 6, 2011 at 3:18 pm
[…]
“I’m sorry for my lack of clarity. The problem is terrorism. I have no desire to see some vitrified waste mixed in with a truckload of ANFO …”
Okay, I see. I’m afraid I still have to disagree, though. When it comes to mixing ANFO with things that are extremely hard to procure, I guess that there is a wide range of biological or chemical options that I’d be more afraid of. So I’d go back to my flat counter of “Dangerous compared to what?”.
I have to admit that I’ve not looked into the lore of dirty bombs in any great detail, but even without going into things like the dispersabilty of radionuclides encased in a glass matrix, there is one crucial and readily apparent characteristic of radioactive materials that other nasty stuff doesn’t share: it’s radioactive (well, duh) and thus easily detectable even in miniscule amounts, amounts that are orders of magnitude from posing an actual health risk. Therefore, a dirty bomb would be extremely hard to hide during construction and delivery to its target site, and decontamination after a successful attack would be comparatively easy to do. The biggest effect would be a potential panic, and that would be a short-term effect and would only work once. Well, it would probably work a couple of times more in nutjob countries like my own (Germany), but even we would eventually look around and notice that we’re still alive and well.
My hunch (and I’d be happy if you could dismantle that hunch – I’m here to learn, after all) is that, assuming that a terrorist group has the means to park a truckload of ANFO in some inner city, we maybe should have the desire that they are dumb enough to try and put something on top that will increase their logistic headaches a hundredfold while not causing a lot of harm in and by itself.
This is a bit similar to my fervent and probably misplaced hope that a terrorist group smart enough to manage another hijack of a big civilian aircraft could simultaneously be dumb enough to crash that aircraft into the strongest walls they can find (i.e. a nuclear reactor) instead of, say, a busy city centre, a sports stadium or a chemical plant.
The latest joint US and Japan survey shows extremely high levels of nuclear radioactive contamination, with radiation levels higher than Chernobyl evacuation limits, now span over 800 kilometers in Japan.
Meanwhile US Media outlets continue to ignore the situation and run stories that the situation is under control.
http://blog.alexanderhiggins.com/2011/05/13/radiation-levels-higher-chernobyl-evacuation-limits-span-800-km-japan-22734/
Aside from the fact that your link is to an advertising site, and is hence spam, it’s not “800 km.” span, which suggest radius. It’s 800 sq. km., which is about 32 x 25 km equivalent, or 20 x 15 miles. A significant little patch, but hardly a “Chernobyl”.