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.
Maik H says:
May 6, 2011 at 2:22 am
Sad but very true, I fear. In part I brought up this idea to point out that very fact, that there are reasonable, practical storage solutions, and that the problem is political.
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 …
In a world without terrorists that would be lovely. But for right now, I don’t want it in a “more accessible place”, thanks.
Posting for WattsUpWithThat has been a rare opportunity for me. It’s a chance for me to collaborate with a host of people that I’ve never met, such as yourself. This tossing back and forth of ideas, and building and refining concepts in concert, can be extremely productive. My thanks to you as well.
w.
Willis Eschenbach says:
May 6, 2011 at 3:05 pm
You need to pick your material carefully. You are correct that stainless is subject to what we boatbuilders call “crevice corrosion”, which occurs in anoxic conditions. However, crevice corrosion doesn’t occur much at temperatures below about 10°C, and the temperature at the bottom of the ocean is well below that.
But the radioactive material will probably be well above that. For long enough anyway.
I’ve been touting that idea to people who don’t have the power to do anything about it for years. My only difference is to drop them in the Cascadia subduction zone and let Gaia stuff them under the bed (sea).
Geoff Sherrington says:
May 6, 2011 at 2:55 am
Interesting, and all valid points. Works for me.
w.
Legatus says:
May 6, 2011 at 3:13 am
Possibly so. It never bothers me if I find out that an idea I came up with independently has been thought of or even patented before. I actually like it, because it’s independent support for my idea. In any case … consider it uncensored.
w.
SteveE says:
May 6, 2011 at 3:40 am
Yeah, you’re right. I forget about state sponsored terrorism. I’ve updated the head post, sink it and forget about it.
Z says:
May 6, 2011 at 2:43 pm
Never heard of that. That’s like throwing the Ring into Mount Doom … just goes on down.
w.
Even with no cables, they will be easy to locate and dig out. If you can’t spot them by their high energy gamma, you’ll spot the heat signature on the seafloor. All is needed is a little ROV with a, infrared camera, a digging shovel/water jet digger, a robotic arm, and a lifting device (gas generator (chemical) and lifting bag). Can probably be improvised from existing oil well equipment. If they do it in the Mariana trench, it’ll be trickier, yes, but not impossible. With the new crop of high performance, long range pocket submarine being designed, don’t count on your little dart remaining there for a long time.
If terrorism is your problem you need to keep an eye on the stuff. We have lots of GAFA in Australia. Some of it is already declared “contaminated” from British nuclear testing.
Dig a hole, put it in there. Shouldn’t be too hard to organise surveillance. There aren’t exactly lots of people around. When you find a use for it, you can easily go and get it.
Willis,
any scheme that does not include reprocessing is virtually pointless and wasteful.
1) reprocess the fuel to remove products of reaction and contaminants.
2) the balance of the material can be re used as new fuel.
3) any left over U238 can be used in reactors using the Canadian system which uses heavy water.
4) use the products of reaction (plutonium et al) to make bomb grade material.
5) the balance of the material is the prime candidate for your lawn dart scheme.
Harry the Hacker is right – the problem with a glass based product is that over a relatively short period of time it de-vitrifies, and the contents are easily leached into the surroundings. This has been a major problem with the French waste disposal program.
The Australian SYNROC product has the active radionuclides locked into silicate crystal lattices, which are extremely stable over the appropriate half-lives. SYNROC is basically inert for burial at sea, or on land such as in underground repositories.
Willis, the idea of deep ocean disposal has been around for literally decades. Honestly it doesn’t make much sense however. High level nuclear waste is easty to deal with technologically – it’s only a problem politically.
Plus, there really just isn’t very much of it by virtually any standard. For the USA, we’ve had roughly 20% of our electricity produced by nuclear power for many decades now, and have roughly 104 operating large commercial reactors. ALL of the spent fuel from the last 50+ years, if stacked together, would take up the space of one football field roughly 5 to 7 yards deep IIRC. Of course, that’s not how it would actually be stored, it would be spaced out more because of the waste heat issue, but that gives one the idea of the volume involved. All of that high level waste, plus all the high level waste from military uses, would easily fit into Yucca Mountain (which could also be expanded as needed). That spent fuel, if reprocessed, would be reduced in volume to about 1/100th the current amount.
Meanwhile, the duration it needs to be stored isn’t an issue either – its exceedingly easy to monitor and then if necessary repackage. Even so, the design requirements for Yucca were/are absurd – originally it was for safe storage without any handling/repackaging for 10,000 years!!! Think about that for a moment, that’s longer than the written history of man! I believe they extended that by quite a bit (maybe to 1 million years?). Anyhow, the design was required to be such that if we all suddenly dissappeared or magically lost all recollection of the site, OR space aliens landed on the planet, there was no way it would be accidently dug or drilled into without recognizing the radiation risk. No joke, space aliens must be protected from drilling into the site that is some 1200 ft. below grade.
Also – the whole iodine bit in your article is a really poor choice. Any radioactive iodine is quite literally GONE and no longer radioactive after roughly 60 days from when the fuel was last in an operating reactor. Iodine is quite simply a non-issue.
I am very curious about your statement that land species have biological mechanisms to seek out iodine that ocean species don’t – that’s the first I’ve ever heard anything along those lines. Would you elaborate please?
Also note that our bodies do NOT ‘seek’ out radioactive isotopes of any sort. The problem is that for the majority of isotopes, our bodies can’t tell the difference between a radioactive isotope and one that isn’t. So wherever the body uses a non-radioactive isotope, if a radioactive version of that same isotope is presented, the body uses it just as it would the non-radioactive version.
That’s why we are all radioactive all the time as it is. That’s why sleeping next to your spouse every night gives you roughly the equivalent of a chest x-ray every year – from the naturally radioactive potassium that is in each of us. We all evolved in this environment (actually in far higher level radioactive environment for most of evolution), however, so it’s not a big deal – the body and every cell has repair mechanisms to cope with the damage. It only becomes an issue if we are exposed to very high levels/amounts of radiation, far greater than normal levels. But the point is that even then our bodies don’t seek out or accumulate radioisotopes specifically.
So – the issue becomes just what value deep sea disposal has over land sites such as Yucca Mountain that can be controlled, accessed if desired (for reprocessing or ‘mining’ other valuable materials) and so on …. and frankly I suspect that deep sea disposal just isn’t the best option when the issues of valuable materials in the ‘waste,’ total costs, etc. are all considered.
Again, however – the problem with high level waste isn’t a technical one at all – hasn’t been for decades. It is a political football, that has been played pretty disgustingly with taxpayers as usual getting the very very short end of the stick. Just look at Yucca for example – rate payers have already paid something like $7 to $13 billion to get it selected, then developed and licensed to the point that it was ready to finally be built – and a further ~$21+ billion or so sitting there already paid to actually build and operate it – only to have the Obama administration kill it for NO justifiable/real scientific or technical reason. (anyone wanting starter info on the $$ values I mention, see: http://www.world-nuclear-news.org/WR_Double_attack_on_US_nuclear_waste_fees_1003111.html)
Some commenters have made the point that low level radioactivity may be beneficial to health.
Back in the 1930s a number of European spa towns specifically advertised the radioactivity of their spa water as a selling point.
OK, thanks to Greenpiss and the rest, that’s not so fashionable today.
But the basic idea is still around and being worked on. And one of the most famous radioactive spas at Hofgastein in Austria is even now advertising a symposium to be held next year:-
http://www.nucmed-gastein.at/index.php?id=4
Rational Debate says:
May 6, 2011 at 10:02 pm
I know that. However, many people don’t believe it. I thought if I demonstrated a technologically simple way to put it out of the reach of most everyone, the political nature of the discussion might be highlighted. I think that I have been successful in that.
I’m perfectly happy with Yucca Mountain, and have been for years.
My point is more general. When a chemical or element necessary for life is rare in the environment, organisms develop a whole host of mechanisms to locate, identify, and strain it out of the environment for their use.
If a chemical or element is very common in the environment, on the other hand, organisms can get it as needed, and thus they do not need to develop exotic or specialized ways to obtain it. If it is extremely common, the organisms may need to develop mechanisms in the other direction, mechanisms to protect themselves from the element or chemical.
In other words, the responses and mechanisms that the organisms develop are dependent on the concentration of the desirable (or undesirable) substance in the environment.
The responses of salmon to the changes in sodium and chlorine concentrations, first in the fresh water they are born in, then in the oceanic environment, are instructive in this regard. In the first case they have developed mechanisms to collect and store the elements and prevent them from leaving their bodies.
In the ocean they have the opposite problem, the concentration is too high, and so they also have mechanisms to prevent the elements from entering their bodies and excreting them when then come in.
As I said, it’s a matter of concentrations. In the tropics water is common. In the desert, plants and animals develop special mechanisms and methods to extract water from the environment and store it in their bodies. Same principle.
Agreed.
Thanks for the thoughts,
w.
Willis,
A great idea! Another place to put nuclear waste is in very deep dry holes — where companies drill for oil, but don’t find any. Glassify the radioactive waste and wrap it in a stainless steel jacket.
Create an assemblage (say, 20 feet long) and lower it to the bottom. Add 20-50 feet of concrete. Lower another assemblage of glassified waste into it, followed by 20-50 feet of concrete. Do that for 1/2 mile, and then fill the rest of the hole with concrete. With nuclear waste 17,000-20,000 feet below the surface, it would take seismic activity equivalent to the Rocky Mountain Overthrust to bring it to the surface — a surface, it should be noted, where nothing had survived the enormous upheaval.
Old hat.
This very idea was researched extensively in the 1980s by Rip Anderson, the same person who gave us WIPP. He assembled an international team, identified a 39000 square mile location centered at 32N164W to be used for this purpose, did all the required analysis even to the point of drawings for a double hulled transfer ship and disposal canister, deemed this approach to be orders of magnitude better than Yucca Mountain, and had the concurrence of the International Atomic Energy Agency but could not find the 200 million dollars necessary for a 20 year test of concept. Apparently the DOE much preferred to spend the 20 billion dollars required to develop Yucca Mountain for this purpose and we can now see where that got them.
More information on nuclear waste disposal is available at http://dirigoenergy.org/spent-nuclear-fuel.
Willis writes that “I’m perfectly happy with Yucca Mountain, and have been for years.”
I’m NOT happy with Yucca Mountain… but only because it’s unbelievable overkill in terms of the actual safety issues. And because we’ve already spent more money on it than would have been needed to pay for a more rational storage scheme — and that’s before construction even begins.
The nuclear utilities have already paid in several times the total amount of money needed to vitrify and store all the high-level waste they’ve ever created or will create with the currently operating plants. (Um… that’s a US-only statement, of course.) The paid-in money not yet spent would be more than enough to (a) license the entire design of the European reprocessing and vitrification plant (IP, plans, everything), (b) build our own copy of it, (c) operate it long enough to reprocess all the current spent fuel, (d) vitrify the leftover waste, and (e) either stick the small billets in dry storage (as in France) or produce big billets that can just be buried anywhere.
Of course that won’t happen. Quite aside from public fears, the US Govt runs on cash accounting, so the expense of steps (a)-(e) above would be considered to be a current expense that increases the deficit rather than spending funds pre-paid by the operators of the nuclear plants (which would be a far more accurate description). Those funds weren’t “revenue” in the first place — they were a legally mandated pre-payment for services that have yet to be rendered by the Government. ::face-palm::
Xenophon
There have been proposed various different ways for getting rid of nuclear waste:
-Putting it into depleted mines, in dry rock formations, which are separated from the biosphere by thick layers of water resistant sediments. This method is used for billions of tons of toxic wastes world wide. Many types of toxic waste stay dangerous for ever, so this method should be suitable for nuclear waste, as it stays dangerous for only a limited time. Furthermore, all the nuclear waste, that remains more radioactive than natural radiation of the standard environment, for longer than 800 years, is stored as chemically stable oxides. Non of these actinide-oxides are water-soluble.
-Putting the nuclear waste into clay lined pits in a dry desert and covering it with several dozen feet of sand or dirt. There are already many theoretical uses for most of the nuclear waste, so this might become a valuable resource in the future.
-reducing the amount of toxic waste by separating the water-soluble parts and solving them in large areas of the deep sea. Storing the non-water soluble parts in conventional toxic waste dumps. This has two safety features:
First, the oceans contain literally quintillions of tons of nuclear isotopes, so diluted nuclear waste can not significantly increase the natural radioactivity of the seawater. Second, The deep sea currents don’t reach the surface within thousands of years, so the the soluble waste would have become LESS radioactive than the pure seawater by the time it reaches the surface.
-Putting nuclear waste, including plutonium and other actinides, into barrels and placing them into a continental basin of Antarctica. The heat of the plutonium lets the barrels melt their way all the way down to the ground of the basin. The water freezes again in some distance behind the barrels, as soon the heat conductivity and area of ice is large enough.
Can nuclear waste be dropped into an active volcano and sucked down into the volcano and burned up/melted?
The major problem with the waste is the plutonium.
A thorium reactor is the holy grail in nuclear power. As it turns out, a thorium reactor can also “eat” the plutonium waste.
http://www.patentstorm.us/patents/6442226/description.html
India and maybe Russia have an operating thorium reactor. China has announced they are pursuing them. The US? We’re funding windmills. (and the US has the second largest thorium reserves in the world.)
For those not familiar with a thorium reactor, here are a few links:
Thorium: Is It the Better Nuclear Fuel? It may turn out to be a quantum leap in the search for economy and safety.
http://cavendishscience.org/bks/nuc/thrupdat.htm
Cleaner Nuclear Power?
http://www.thoriumpower.com/files/MIT_Cleaner_Nuclear_Power.pdf
Accelerator-driven Nuclear Energy
http://www.world-nuclear.org/info/inf35.html
New age nuclear
http://www.cosmosmagazine.com/node/348/
The Thorium Reactor and possible tie to THOR is on the 4h page.
Reintroducing Thorium
A largely forgotten natural resource holds vast nuclear power potential
http://pubs.acs.org/cen/science/87/8746sci2.html
Is thorium the answer to our energy crisis?
It could power the planet for thousands of years, the reactors would never blow up and the waste is relatively clean. So is thorium the nuclear fuel of the future?
http://www.independent.co.uk/news/science/is-thorium-the-answer-to-our-energy-crisis-428279.html
A Nuclear Reactor in Every Home
http://www.acceleratingfuture.com/michael/blog/2006/10/a-nuclear-reactor-in-every-home/
“Thorium-based nuclear energy” Interview with Professor Egil Lillest
http://www.divainternational.ch/spip.php?article161
Plan for Nuclear Reactor Without Nuclear Waste
http://www.nytimes.com/1995/05/16/news/16iht-atomen.ttt.html?pagewanted=1
Thorium: Is It the Better Nuclear Fuel?
It may turn out to be a quantum leap in the search for economy and safety.
http://cavendishscience.org/bks/nuc/thrupdat.htm
Will we run out of uranium?
http://metalsplace.com/news/articles/32845/will-we-run-out-of-uranium/
Thorium based fuel options for the generation of electricity: Developments in the 1990s
IAEA-TECDOC-1155
International Atomic Enerergy Agency
http://www.iaea.org/inisnkm/nkm/aws/fnss/fulltext/31030535.pdf
The Significant Thorium Deposits of the United States
http://energy.cr.usgs.gov/other/uranium/u2009/Van%20Gosen%20abstract.pdf
Thorium Energy Inc.: An economic overview of a pioneering company
http://www.resourceinvestor.com/News/2009/3/Pages/Thorium-Energy-Inc—An-economic-overview-of-a.aspx
S. 3680: Thorium Energy Independence and Security Act of 2008
http://www.govtrack.us/congress/bill.xpd?bill=s110-3680
Thorium reactor
http://everything2.com/title/thorium+reactor
Thorium
http://www.world-nuclear.org/info/inf62.html
Thorium Energy Alliance
http://www.thoriumenergyalliance.com/
Indian Research Reactors
http://www.barc.ernet.in/rcaindia/4_6.html
China Takes Lead in Race for Clean Nuclear Power
http://www.wired.com/wiredscience/2011/02/china-thorium-power/
China announces thorium reactor energy program, Obama still dwelling on “Sputnik moments”
http://wattsupwiththat.com/2011/01/30/china-announces-thorium-reactor-energy-program-obama-still-dwelling-on-sputnik-moments/
Here’s a good way to dispose of nuclear waste: use coal instead.
Vitrify the waste. Then grind up the glass. Mix the ground glass with concrete to dilute it even further and then dump the concrete mixture into one of the many caverns created by the underground nuclear tests at the Nevada Test Site. Most of these caverns are still “hot” and will require security and monitoring for the indeterminate future. This method will preclude any recovery of these high-level wastes without a huge industrial-size concentration process. We should have no cause for concern regarding future illicit use of these materials.
willis:
did you ever hear the saying “you gotta want what you got and got what you want.”
well you can have your cake and eat it.
some years ago some of the lads were irritated at various individuals that had killed a lot of americans.
rumor was that these individuals had a habit of hiding in caves and in deeeeep holes in the ground.
well the lads were eating lunch together one day and came up with a solution. they took some surplus army 8″ gunbarrels that were bent (army has lots of them) and cut them off about 15′ long. then they welded a hardened steel pointed insert into one end of the resulting tube (about a 4″ wall thickness) and attached a tail piece with a “smart bomb guidance system to the other end.
they tested a few by dropping them from airplanes and with high speed rocket sleds and were encouraged by their results.
then they packed a few with explosive and sent them off to iraq. worked quite well. only took 4 weeks from lunch to practical application.
and so W your idea has merit. i would advise dropping from an aircraft at at least 30,000 feet. the free drop accelleration would add a considerable amount of energy to your effect and the greenies currently don’t have aircraft that can interfere with the project.
besides the aircraft that are muscular enough to carry these things can also cause extreme heartburn to interfering aircraft. and if they can’t do it they have smallboy friends that can.
C
hang town bob:
i don’t think that the caverns you refer to exist. there’s a youtube file that shows an aircraft flying over that area and it is a huge series of pot holes. this would indicate collapsed caverns.
also the design of the acess to the small room that the explosion took place in was designed so that the explosion would close the corridor before the blast products could “get around the corner” and escape.
exceedingly nice try but probably no cigar.
C
I believe there are a number of US patents going as far back as 1979 that propose disposing nuclear waste in tectonic subduction zones where the radioactivity may have millions of years to decay before that waste might return to the surface. Once subducted down to the asthenosphere one might expect the long-lived heavy-element isotopes to gravitate downward.
Perhaps nuclear power generation facilities should all be sited in hardened, dry underground facilities that would prevent dispersal of radioactive isotopes in the event of worst-case natural or ‘man-made’ disasters.