Apr 04 2011

The Thorium Conspiracy

One of the defining attributes of scientific skepticism is so-called metacognition – we think about thinking. Psychologists have amassed a large body of evidence about how people think – the most common patterns that we tend to fall into. It’s unfortunate that this knowledge is not put to more frequent use.

Just one nugget of such metacognitive knowledge is the so-called fundamental attribution error – we tend to attribute other people’s behavior to internal factors while ignoring or downplaying external or situational factors. At the same time, we happily excuse our own behavior with situational factors. The textbook example is that if we see someone walking down the sidewalk and tripping, we will tend to think that they are clumsy. If we trip, then we blame the crack in the sidewalk.

This mental bias works on every hierarchical level, not just for an individual act by an individual person. In other words – we make the same mistake when thinking about the behavior of groups and organizations, and not just single acts but long term behavior. This attribution error also dovetails effectively with another cognitive bias, the tendency to see conspiracies, even where they do not exist. We tend to assume that organizations and even groups of disconnected people are behaving according to some deliberate internal plan, rather than just responding to situational factors. If we are not aware of those external factors, then we tend to leap to the conspiracy hypothesis as an explanation.

I believe this is often the case with those who try to explain the fact that we are not all driving electric cars as a conspiracy of the oil and car industries. I am not neglecting the legitimate internal factors here – industries primarily are driven by profit. But there are significant external factors that are often neglected by those arguing that it is all a conspiracy. Specifically – battery technology is just now getting to the point (with lithium-ion batteries) that electric cars can have a sufficient range to be used for commuting. Even then, the technology is very limiting. Batteries are expensive, they have a limited lifetime, and they are slow to charge. Hybrid technology makes them more viable, but then you are still burning a lot of gas for your mileage.

Previous battery technology was even worse, with ranges that are useful only for driving in a city, or for short commutes. While some people may have been happy with this, these limitations definitely restricted the utility of such cars, and therefore the potential market. It is not surprising that car companies, after exploring the technology in the 80s and again in the 90s, concluded that the market would not be great enough to warrant building an infrastructure to build, sell, and maintain these cars. You might disagree with their conclusions, but that doesn’t mean there is a dark hidden conspiracy here. There were external technological factors that were significant in their decisions, and often neglected or downplayed by the conspiracy theorists.

There is a less-well known conspiracy theory surrounding another technology – thorium nuclear reactors. This conspiracy has reared its head again after the Japan nuclear meltdowns following the tsunami. In a nutshell, thorium is a potential alternate nuclear fuel to uranium for building nuclear power plants. In most power plants, some energy source is used to heat water and create steam, and the steam is used to turn a turbine which is part of a generator that generates electricity. Whether the fuel is coal, natural gas, or uranium, the final process is the same.

Nuclear reactors are highly efficient because nuclear fission generates a great deal of heat with a small amount of fuel. They are technologically sophisticated, require great safety features, and have nuclear waste material to deal with, however. And uranium is a limited resource.

A thorium reactor would be very similar to a uranium reactor, except that the fission cycle would be different. Thorium has several advantages over uranium: it is very abundant in the earth’s crust (the US in particular has massive thorium deposits), it creates less radiation than uranium so it is easier to handle, and a thorium cycle would produce less radioactive waste material (although not no waste, as some sites claim). This all sounds great – so how come we don’t have thorium reactor power plants all over the place?

That’s the question. The attribution error leads us to think that there must be some nefarious motivation keeping this technology down. One frequent claim is that the uranium cycle can also be used to make fuel for nuclear weapons, but not the thorium cycle. While this can be viewed as an advantage, it may not be for a nuclear weapons power (like the US) who need weapons grade fissionable material for their nuclear weapons.

So this can be both an advantage or disadvantage. It seems to be primarily an advantage, however. The liquid flouride thorium reactor (LFTR) does have less potential for producing waste for use in weapons, and therefore are less of a risk for terrorist exploitation. Countries that need plutonium to make weapons can still manage to make it, even without nuclear reactors for power.

Why, then, do we not have thorium reactors? This is a hard question to answer – much more complex than the electric car question which has an obvious answer in the limits of battery technology. Here is a thorough recent report from the International Atomic Energy Agency. It’s pretty technical in places, and certainly outside my area of expertise. But from my reading (and consulting other summaries) it seems that thorium reactor technology has great promise, and many advantages. Just like electric cars, we will probably see thorium reactors in our future. But the reasons we don’t have them yet seem to be related to the fact that there are still many technological hurdles that have not yet been overcome. More research is needed in developing the fuel from thorium ore, and in designing the specific reactor cycle, and in handling the waste. We can’t just plug thorium pellets into a uranium reactors – and until all the little details are worked out, we can’t build a functioning reactor.

Research is ongoing – India, in particular seems to be aggressively researching thorium reactors. But research takes time.

I have also seen claims that thorium reactors (at least in the past) were not as cost-effective as uranium reactors. If true, we may have to wait for uranium fuel to become scarce before thorium reactors become economically attractive. Until someone completely designs, builds, and operates a thorium reactors, there will continue to be a lot of speculation on many of these details.


I don’t know exactly why we have uranium reactors instead of thorium reactors, and there seems to be a lot of opinions out there. But I do think the answer is mostly to be found in the external factors – the details of the technology and required research. This is a promising technology, and I hope it ultimately fulfills its promise. But we are not quite there yet.

The thorium question does also appear to be another example of people jumping to the internal conspiracy answer, and ignoring the external situational factors. Those types of answers just seem more appealing to many people, while saying something like, “it just takes time to work out the technology” seems very unsatisfying. But a good skeptic should rise above their inherited cognitive tendencies.

23 responses so far

23 Responses to “The Thorium Conspiracy”

  1. streddyon 04 Apr 2011 at 8:59 am

    Hi Steve,

    Another great post. I think you didn’t cover off as much as the history of plutonium that you might of. If we go back we find the only reason nuclear energy was made was to make nuclear weapons, nuclear power was just a spin off.

    So this premises our argument with a huge amount of R&D, time , money and egos all spent on uranium. Why would governments around spend another 15-20 years researching the thorium fuel cycle just to get a plant that does produce pluntonium.

    Thorium hopefully won’t turn out to be the next cold fusion. It shows some real promise and its public attention in the last 5 years is gaining great momentum.

  2. CWon 04 Apr 2011 at 9:21 am

    I attended a townhall at the University of Michigan where nuclear energy was discussed with some scientists. I asked about thorium and a couple of points that were emphasized is that the same thing happening at Fukushima could happen at a thorium plant (in terms of the sequence of events that led to the consequences occurring now).

    But the point regarding the supply of thorium…, while thorium is abundant in Earth, it’s not accumulated in the quantities like uranium. So it’s not as economical to extract because the quantities of thorium are more sparse. However, the benefit of this is likely to be less environmental impact.

    The professor said the transition to thorium would likely come at a point uranium mining becomes more costly. Another professor who works on technology for space exploration, said that thorium might be come an option for commercial/government space programs (and possibly, military) before it’s used in commercial power plants.

  3. Steven Novellaon 04 Apr 2011 at 9:34 am

    CW – It seems plausible that the uranium cycle was given a significant leg up due to the nuclear weapons research programs. Without this leg up, developing thorium technology (especially in the wake of uranium technology) may not be cost-effective.

    This makes historical contingency a significant external factor. This is different than saying that the thorium technology is not being pursued because it lacks weaponization potential.

  4. streddyon 04 Apr 2011 at 9:36 am

    That’s actually an incorrect statement. A thorium reactor type called LFTR (liquid fluoride) as Steve mentioned can’t melt down as it’s already “melted”. Any loss or power or the flip of a swith LFTR just cools down not heats up like a traditional uraninin reactors.

    Generally what you’ll find with most nuclear scientists is that they simply aren’t very aware of thorium.

  5. adam22on 04 Apr 2011 at 11:04 am

    Well done. I hadn’t had any conspiracies about nuclear reactors, though I used to have some about the auto industry and such. I hadn’t held them anymore, but it’s nice to look back and see how they might have developed. Thanks!

  6. Datan0deon 04 Apr 2011 at 12:12 pm

    C’mon, Steve. We all know that we aren’t driving around in electric cars because of the Stonecutters! 😉


    (Oh, and great post by the way. I’d heard that thorium reactors are promising, but wasn’t aware that the technology isn’t fully worked out yet.)

  7. locutusbrgon 04 Apr 2011 at 1:05 pm

    You have also failed to touch on the psychological aspect of popular culture’s fear of Nuclear power.
    There have been no new facilities built in the US in the last twenty years at all. No new site proposed since the 1970’s. Primarily oil was cheap and people are fearful of nuclear power. Development of nuclear power needs three things(in the US). Money, technical knowledge, and political will. Three mile island, and Chernobyl disasters sapped any political stock it had left. Private business can develop new batteries without government direct involvement. Developing new fission systems independent of government involvement is impossible. Lets face it, if we had adopted the French mindset 30 years ago we would have new, modern, safer reactors now without thorium. It is a hard sell, to overcome the collective social mindset of the anti-nuclear movement ,supported by the china syndrome movie, followed by three mile island, and then Chernobyl.
    It is my opinion that this is a major factor in stagnation in both new fission and fusion development. If you follow any skeptical blogs recently about the Japan reactors you will see how irrational people are about nuclear power.

  8. sonicon 04 Apr 2011 at 2:49 pm

    I was playing cards with my lobbyist friend the other night.
    His take on conspiracies–
    “If you don’t believe in conspiracies, you aren’t participating.”
    My take is that the more government is involved in an industry (like the nuclear power industry) the more likely it has been effected by one or more ‘deals’ that won’t make the light of day. It seems it is not unusual for an elected official to vote for something that he doesn’t want so that someone else will vote for something he does. Apparently often what is wanted has to do with money going into some specific pocket. (This is often called taking care of one’s constituency.)
    Apparently this situation has gotten worse in my state in proportion to the size of the state’s budget.
    I don’t know what this has to do with thorium vs. uranium specifically, but it seems it might be an important part of any analysis of the situation as it is an area of extreme government regulation and control.

  9. SilverLiningWallpaperon 04 Apr 2011 at 2:56 pm

    You might want to watch, Who Killed The Electric Car?

  10. larchon 04 Apr 2011 at 2:57 pm

    On a recent podcast from Dr Kiki’s Science Hour, there was an interview with a nuclear scientist discussing the development of Thorium as a reactor fuel. One analogy he used echoes CW’s comment. He said that using uranium was like building a fire in a forest with a certain amount of wood from dry fallen trees while thorium was akin to using the green underbrush which is abundant but is harder to ignite.

  11. Fred Cunninghamon 04 Apr 2011 at 3:08 pm

    There was an excellent article in the July-August 2010 issue of American Scientist (Sigma Xi) on thorium reactors. I’ll try to bring you a copy at the NECSS. One factor that is claimed for the solid uranium design was Rickover chose it for the Nautilus, also it is difficult to use thorium for producing bombs as separating U233 from U232 is not easy. The potential waste reduction is tremendous, the nasty actinides are reduced by a factor of ten thousand, the volume and the number of years of storage are reduced by several orders of magnitude. I think that the main reason we are not further in development is that our huge collection of scientific geniuses that we have in Congress have not funded just about every proposal to develop thorium reactors.

  12. SimonWon 04 Apr 2011 at 3:34 pm

    Integral Fast Reactor anyone, can burn Thorium if needed, can be a breeder if needed, as a liquid metal reactor it can probably be engineered to self cool in the event of pump failure, and instead of melt down it melts off. There is the slight issue of liquid sodium as a coolant and waste reprocessing, but on the plus side it can be used to transmute some other high level waste into something more manageable reducing the need for long term geologic storage.

    As a species we’ve been remarkably stupid by failing to invest in the peaceful developments of Fission and Fusion technologies. Fear and stupidity trump conspiracy here I suspect, how else can one describe the years of wrangling over where to build the next Fusion reactor.

    I’m not sure the term “efficient” used by Steve is quite right, most Nuclear reactors are inefficient, if by efficiency you mean the proportion of available fuel converted to useful energy. Of course being a nuclear reactor means even inefficient reactors produce a lot of power for a small amount of fuel compared to chemical reactions. Perhaps time for another SGU guest on the future fission reactors.

  13. bachfiendon 04 Apr 2011 at 5:27 pm

    I second the suggestion of having a fission expert as an interviewee on SGU.

    Efficiency of power plants is the deciding factor. Coal powered plants apparently convert about 30-50% of the energy of coal into useful energy, the rest goes into waste heat.

    Most nuclear power plants are even worse, managing to convert only 1% of the available energy into useful energy, a lot of the remaining energy remaining in the residual radioactivity of the waste which has to be stored for hundreds of thousands of years.

    The 4th generation nuclear reactor (is that the same as the integral fast reactor SimonW?) promised to be much more efficient generating a smaller amount of waste needing to be safely stored for only hundreds of years (doable today) was killed off by Clinton/Gore in the ’90s.

  14. daedalus2uon 04 Apr 2011 at 5:52 pm

    I think the main reason light water uranium fueled reactors have been adopted was because that is what was developed for nuclear submarines. It is largely historical contingency which then vested a great deal of power and incentive in companies with light water uranium reactor expertise. Non-light water reactors have to be larger because it takes more moderator to slow the neutrons down. In a submarine you want a small reactor, which is why you want to use an easily fissionable fuel. You could use U233 in light water reactors but making it and recovering it from thorium breeders would be costly.

    Canada which did not develop nuclear submarines developed the CANDU reactor which uses natural uranium (not enriched) and uses heavy water as a moderator, so the reactor has to be larger. Larger reactors also mean a larger containment building which drives up the initial cost. Fuel is not that big a part of the cost of nuclear power, so being able to use cheaper natural uranium isn’t that big of an advantage.

    Light water uranium reactors require uranium enrichment, but there was lots of enrichment capacity built to produce weapons grade uranium. Nuclear submarines use highly enriched uranium as fuel and so can go 20+ years without refueling.

    Different reactor cycles require reprocessing of spent fuel. I think that reprocessing of fuel has been untenable for political reasons, mostly due to the terrible history of fuel reprocessing (which was done for weapons production) and the terrible handling of radioactive waste, most of which was generated during weapons production, and mostly because it was cheaper to be sloppy. At the time, there were lots of atmospheric tests putting lots of fission products in the atmosphere, so leaking fission products from reprocessing was no big deal.

    Usual practice is to keep the thorium and uranium separated in the reactor. One of the ways they do that is make the beads of UO2 and ThO2 different sizes and simply screen them during reprocessing. When the thorium is recycled, you can get pretty pure U233 which can be used to make nuclear weapons. If there wasn’t a lot of U235 in natural uranium, nuclear power (and nuclear weapons) would be made from thorium.

    It takes so long to build and license nuclear power plants that one of the largest costs is interest during construction.

    “Efficient” isn’t the right term. The correct term is “profitable”. What actions are most profitable depend a lot on historical contingencies.

  15. CivilUnreston 04 Apr 2011 at 8:23 pm


    I think you’re comparing apples and oranges with nuclear fission versus coal efficiency.

    Since coal burning breaks only chemical bonds, it’s efficiency in releasing energy can’t even come close to fission power, which breaks nuclei.

  16. CivilUnreston 04 Apr 2011 at 8:27 pm


    I have a conflict of interest here (since I bought stock in this company), but Lightbridge Technologies claims to have invented a thorium-impregnated fuel pellet that works in modern light-water reactors AND has some (but not all) of the benefits of a pure thorium reactor.

    They currently have contracts with the Indian government and the Russian Federation.


    If these guys ever take off and I become a billionaire, I won’t forget all you little people.

  17. eiskrystalon 05 Apr 2011 at 4:08 am

    -As a species we’ve been remarkably stupid by failing to invest in the peaceful developments of Fission and Fusion technologies. Fear and stupidity trump conspiracy here I suspect, how else can one describe the years of wrangling over where to build the next Fusion reactor.-

    I don’t know, why don’t you ask the japanese…

  18. bachfiendon 05 Apr 2011 at 5:00 am


    No, I’m not comparing apples and oranges. You’ve missed the point. Nuclear fission is inherently less efficient than burning coal because it results in radioactive waste, which still contains a lot of energy as it decays (as shown in Japan with the spent fuel rods attaining extremely high temperatures when the coolant water was lost). All the energy in coal is released but some is wasted in heating the environment.

    Making the nuclear reactors more efficient would entail generating less radioactive waste.

  19. streddyon 05 Apr 2011 at 7:56 am


    Wasn’t that one of the points of the post? Thorium is far more efficient than uranium. In the uranium fuel cycle you can only burn 5% of the usable fuel before discarding the rest. In a LFTR reactor all the thorium fuel is consumed in the process.

    As has been pointed out in other media the world will stray away from nuclear technology now and that will actually be worse for the environment as nuclear is the only green alternative to burning coal and oil for baseload power.

  20. SquirrelEliteon 05 Apr 2011 at 9:44 am

    I suggest Rod Adams of the Atomic Show podcast as a possible guest on SGU.

    Here is a link to one of his shows which discusses thorium reactors.


  21. Karl Withakayon 05 Apr 2011 at 12:49 pm

    “Thorium is far more efficient than uranium. In the uranium fuel cycle you can only burn 5% of the usable fuel before discarding the rest. In a LFTR reactor all the thorium fuel is consumed in the process.”

    I think to some degree, we are confusing reactor designs with fuel sources.

    In certain respects, Thorium/U-233 isn’t inherently that much cleaner than U-238/Pu-239 or U-235.

    Part of it depends on what type of waste we are discussing, short term vs long term waste.

    Some of it is also a matter of reactor design. The are molten fluoride salt reactor and other gen IV reactor designs that utilize Uranium 235 & U-238/Pu-239 more efficiently (from a waste perspective) than existing designs.

    Fission daughter products are dirty, regardless of whether they are from the fission of U-233 (as in a Thorium reactor), U-235, or Pu-239. The high activity, short term waste profiles are similar for Thorium, Uranium 235, and Pu 239. Short term fission daughter products are what are the main sources of heat and radiation trouble in Japan right now.

    What many of these modern Gen IV designs do to reduce waste, especially longer lived waste, is burn up and limit the minor actinides and transuranics. Thorium is a bit better for controlling actinide build up (and long term radioactive waste) then “regular” Uranium & Plutonium partly because of the lower starting mass of the atoms and the lower neutron capture cross section of U-233.

    However, there is a significant problem with Thorium. In a Thorium reactor, Thorium 232 breeds U-233, which is the fissile fuel that the reactor burns, but some U-232 is also produced by (n,2n) reactions. U-232 has very active, hard gamma emitters in its decay chain, which makes it a significant handling/shielding problem.

    Pa-233 buildup is also somewhat problematic in a Thorium design.

    Why don’t we have Thorium reactors today? Here are a few key reasons:

    1 We haven’t really been building a lot of new reactors of any design, let alone advanced, new (Gen IV) designs lately. The motivation for investment in new technologies isn’t especially great. How much money would you invest in new design research if you knew the opportunities to apply the benefits of that research were fairly limited?

    2 Since fuel cost is a minor component in the (short term) cost of nuclear power production, the short term financial motivations for using Thorium over establish Uranium are minimal at best. There’s enough Uranium & Plutonium to last a while that the greater abundance of Thorium won’t come into play for quite a while, especially if we reprocess retired warheads. The potential financial benefits for Thorium are mostly long term related to medium and low level waste management.

    “…as a species we’re just really bad at understanding costs that come later on. Instead, we assign a disproportionate amount of importance to what’s immediate and tangible.”

    -Barbara Kiviat of Time.com writing about credit cards but applicable to far more.

  22. CivilUnreston 06 Apr 2011 at 3:34 pm


    I still think it isn’t a valid comparison. The “energy available” for a nuclear reaction (E=mc^2) is orders of magnitude larger than for a chemical reaction (burning coal).

    I will concede, however, that while burnt coal can almost certainly not be burnt again, spent nuclear fuel has a lot of kick left in it. Luckily, Integral Fast Reactors and other new designs can extract up to 95% of the energy content of their fuels.

  23. messyjessyon 14 Apr 2011 at 6:46 pm

    I just registered so I could comment on this post. I’m going to come right out and admit that I haven’t read all of the comments on this because I’m at work and trying to tear myself away from the internet before I waste too much time… I’m sorry if I’m repeating information.

    Anyway, both my boyfriend and I are currently PhD students at Purdue University and his specialty is in nuclear engineering. I’ll ask him some more about this tonight, but my understanding of this issue is that the current infrastructure of our nuclear industry just wouldn’t support a thorium based fuel stream. Right now the expense of changing the way the entire industry works, from mining fuel, processing it, changing the reactor designs and building new, fuel reprocessing, etc, etc, etc, just can’t be justified. But as Steve mentions, nations with less developed nuclear power industries, such as India, are making significant inroads in thorium- based power research because the cost/ benefit ratio is far greater. Unfortunately, it will be an increasingly uphill battle to incorporate new nuclear technologies into this country’s nuclear industry due to very unfavorable public perception towards nuclear technologies, especially after Japan’s recent accident.

    If there is anyone in the area of Purdue, or even Chicago or Indianapolis, a group that I am part of called Purdue Student Pugwash is actually hosting a lecture event about this very topic. It will be held on April 20 on campus and will feature my BF’s research professor. I don’t know if cross-posting is cool here, but you can google the group name to find our site. If anyone has questions about the event, or something I can ask the BF about, I’ll be watching the comments.

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