Skip to content

Thorium Nuclear: The Race We Started and Are Now Losing

2011 February 16
by Colin Lissandrello

While China’s GDP is still only roughly one third of the US’, China is gaining fast, with Deutsche Bank predicting that it will surpass the US by the early 2020s.  So, if China were to embark on a research and development project with the aim of patenting and manufacturing a design for the next generation of nuclear power, one that would revolutionize the cost, availability, and safety with which nuclear energy is produced, we should be rushing to compete, right?

We aren’t.

On January 25, at its annual Chinese Academy of Sciences conference, The People’s Republic of China announced such a project. Its vision is to have a marketable thorium Molten-Salt Reactor (MSR)—a form of liquid-fuel reactor—within 20 years.

There would be many advantages to transitioning from today’s solid-fuel, uranium reactors to largely thorium-driven, liquid-fuel reactors. One metric ton of thorium yields 200 times more energy than one metric ton of uranium, and 3.5 million times more energy than one metric ton of coal. It can burn the plutonium residue left by uranium reactors, providing a means by which to eliminate our current stores of radioactive waste. It would leave behind very little waste of its own, which would only require storage for a few hundred years, rather than the few hundred thousand years required for the waste of today’s reactors. Making weapons from the byproducts would be nearly impossible. Because the reactors would be built at atmospheric pressure, they would be much smaller, safer and cheaper.  But not only would the reactors be cheaper: the amount of fuel required to produce one gigawatt of electricity in a thorium reactor would cost an estimated 1/6000th of what we pay today for one gigawatt worth of fuel in our uranium reactors.

Perhaps the centerpiece to these advantages is that thorium is far, far more common than uranium, and the US is sitting on top of roughly 15% of the world’s massive supply, second only to Australia. So thorium nuclear appears to be a very long-term solution to our energy demands (potentially for tens of thousands of years). Investment should be a no-brainer. There’s no need to put all our eggs in one basket, but leaving it empty would be negligent. After all, it’s quite the basket.

Alvin Weinberg

US physicists first hatched the idea of thorium nuclear after the Manhattan Project in the late 1940s, and hundreds of tests were performed from the ‘50s through the early ‘70s at the Oak Ridge National Lab, under then-director Alvin Weinberg. These tests demonstrated thorium’s superiority to uranium, a large reason being its production of more neutrons per collision, contributing to its significantly higher potency, efficiency and cleanliness. Weinberg’s team also worked on liquid-fuel reactors, and completed a functional thorium MSR reactor in ’65. Weinberg continued to champion thorium nuclear going forward, but to no avail: higher-ups wanted the plutonium leftovers from uranium reactors to make atomic bombs, and uranium reactors were already the industry standard. In 1973, Weinberg was finally given the boot, the US nuclear industry signed contracts to build a record 41 (uranium) nuclear reactors, and the research on thorium nuclear came to a close.

So why didn’t we pick up where we left off as soon as the proliferation of nuclear bombs was no longer on our to-do list? To be fair, there is one hang-up with thorium MSR reactors: once the reaction starts, it keeps going, potentially indefinitely. The design would have to be virtually immune to corrosion from hot, radioactive salt. Once this issue is overcome, however, the reactors would be practically harmless, assuming no outside interference. And to be clear, this is not seen as a potential roadblock, so there really is no good reason we aren’t already funding an R&D team. Funding research on a thorium MSR reactor is not a long-shot, but rather a long time comin’. Sure, MSR reactors are not the only viable approach to a fourth-generation nuclear reactor, but they appear to be the best option for thorium.


Some die-hard green proponents among you might be thinking, “That’s nice that it’s cleaner than today’s reactors, but I don’t like the idea of storing radioactive nuclear waste for hundreds of years. Plus, safer is great, but there’s still a chance of something going wrong. Let’s put all our resources into developing truly clean, safe technologies like solar and wind.”

While I would love to see this happen, we nevertheless need a cost-efficient, completely reliable baseline output for our electricity grid. Solar thermal farms in southwestern deserts and wind farms along coasts might be cost-efficient sources of energy, but they’re not reliable enough. Sure, we could employ a variety of renewables to mitigate lulls in the production of any given one, but to actually run this nation on them we would need to overcompensate for our demand by a huge margin, and then have a massive system of energy storage. Not only would the energy storage be an enormous investment, but also the cost-efficiency of the systems would be relatively poor, due to diminishing returns. If the U.S. were not in economic competition with other nations, this might be feasible, but for now we must accept that such a future is not realistic. And that’s the hopeful answer, coming from one who would love to see as green a future as possible: thorium nuclear could potentially be so cost-efficient that, even in ideal conditions, renewables would not be able to compete, and would thus remain at the fringes of our energy supply. Not quite ideal, but far better than the fossil fuels and nuclear reactors of today.

Nuclear energy is a necessary ingredient in our transition away from fossil fuels, and thorium appears to be the way to go. It would be most unfortunate if we started this race ten years from now, lost it, and found ourselves adding the next generation of nuclear reactors to our list of Chinese import dependencies while scurrying to finish our own design. I would prefer taking steps to reduce our roughly $900 billion debt to an eventual superpower over hastening the end of our economic dominance.

5 Responses
  1. February 16, 2011

    Great article.
    Thorium is a great alternative and you’re right that even though going fully renewable would be better it’s not possible without a good base unless we can somehow find away to control the weather haha.


  2. Jason Weinman permalink
    May 3, 2011

    My understanding of Thorium Nuclear power is that it is more expensive than current nuclear alternatives. It certainly can’t be much safer, because current nuclear is more or less completely safe (as demonstrated by the fact that no one was killed as a result of the Fukushima disaster, even though Fukushima is horribly out dated, and had no passive fail-safes, and no one was exposed to particularly high radiation either). Modern reactors, the so called “Gen III+” reactors are smaller, cheaper, and orders of magnitude less prone to catastrophic failure like Fukushima, yet, I hesitate to say they’re safer because, again, Fukushima appears to have been totally safe. Also, so called nuclear waste from current reactors is also totally safe in its ultimate glassified form, and there is much less of it than equivalent waste from coal power. It also has a number of industrial and military uses, although, for no reason, federal laws prevent it from being used for those purposes, and other companies have to expend energy to produce what we refer to as nuclear waste for commercial purposes. Nuclear technology doesn’t need to be developed, it needs to be implemented, and the reason it isn’t is because of governmental mismanagement.

  3. Colin permalink
    May 3, 2011

    Jason, I’d be interested in sources for why you believe Thorium MSR reactors would be more expensive than our modern Plutonium ones. Smaller reactors, less maintenance, more efficient fuel, cheaper fuel, far less storage capacity required for waste… I can understand how adding research and development into the equation changes things, but only in the short term.

    As for Fukushima, I disagree that it was “totally safe.” It increased the radioactivity in the surrounding water a great deal, and that was before TEPCO started dumping millions of gallons of highly radioactive water. That said, I agree that it was horribly outdated and is an unrepresentative example of modern Plutonium reactors. And, I agree that modern Plutonium reactors are extremely safe. So, you’re right: “much safer” may have been a stretch. But here’s why I said it:

    1) Storage. 100’s of thousands of years vs. hundreds of years. We can say they’ll be safe, but maybe gigantic alien dragonoids invade 170,000 years from now and have super acid breath. We just don’t know.

    2) The guts. We’re talking about touchy, pressurized solid fuel rods vs. atmospheric fuel in liquid. The latter (Thorium MSR) can expand naturally to self-correct. Sure, you can make solid fuel extremely safe, but why not start out with a safer heart of the system?

    If these make it even marginally safer in today’s environment, and could potentially make a difference in the aforementioned alien invasion, and we’re talking about a far cheaper option, why not go for it?

    [Agreed that current nuclear is safer than coal.]

  4. May 6, 2011

    I don’t know about thorium MSR reactors. Perhaps these will be a better and cheaper alternative after all. I was referring to Thorium High Temperature Reactors, which already exist, such as this one in Germany

    You’re right that there was a lot of radiation released at Fukushima, but not enough to have a meaningful impact to people off site (nothing like the amounts that would even remotely increase cancer risk, for instance).

    But none of that is my point. If Gen IV reactors (, such as those being developed in the US, which promise many of the same benefits as MSR, provide a better alternative to present nuclear options, that would be great. Even if the next stage in nuclear power is developed by the Chinese, this could still only benefit the whole world, including the US, even if it does decreases our technology gap. Progress is not zero sum.

    What I’m really getting at though, is that the only reasonable policy in the meantime is to build the nuclear reactors that are already available. They may not be as good as future developments, but they are already better than all of the existing alternatives. If better alternatives like MSR and Gen IV are possible (and I’m sure they are), then private investment will lead to their eventual emergence. But in the meantime, insofar as the government insists on using central planning for our energy policy, the harmful/wasteful impact from fossil fuels and other energy sources can be more immediately addressed.

    In other news, I have started a blog, which is semi-political, here:

  5. Colin permalink
    May 6, 2011

    I agree that, in the meantime, we should be building more nuclear reactors and phasing out coal plants ASAP (while continuing to build and research renewables). However, I think it’s in our best interest to stay ahead of the technology curve, even if China beating us to Thorium MSR would benefit the whole world. With that in mind, I don’t think we should wait for private enterprise to kick in. I believe that we should jumpstart an initiative by funding research.

Comments are closed.