9 Reasons to Like the New Nukes

Liquid (“Molten”) Fluoride Salt

I spent a number of years when I first learned about this just asking people, “Okay, tell me what’s wrong with this. Tell me why it’s not the greatest thing since sliced bread”. Because really, I wasn’t a nuclear engineer back then, I didn’t want to get involved if it wasn’t important. I wanted someone to come and say, “oh, we did this and this and this and it totally did not work out.” That would have been simple. I’d be like, okay, fine. But the fact that they didn’t say that, and they said that “this was a great idea. We really should have done it” — that stuck in my craw for a long time.

Turns out everything I learned, everything I studied, just made this look better and better. - Kirk Sorensen

The activist community LeadNow asked its backers to back a “clean energy” plan, but when you look at the plan summary it turns out to be a “strictly renewable energy” plan that excludes nuclear energy. Similarly, Iron & Earth is promoting “renewable” rather than “clean” energy. This is a recurring theme I’ve noticed from traditional environmentalists: they demand “renewable” energy instead of “clean” or “sustainable” energy, the implication being that nuclear energy is to be excluded.

“I think the objections to ‘nuclear power’ are actually objections to solid-fuel reactors.” - Mike Conley

Have you heard of Thorium? It’s an element in the earth’s crust four times more common than Uranium. And one small pellet of it contains a lifetime supply of energy.

It burns in reactors called Liquid Fueled Thorium Reactors (LFTRs), which is in the broader category of molten salt reactors (MSRs).

An LFTR power plant has never been built before. The world’s thorium is sitting in the ground, unused. There is no market for it.

Molten salt reactors (again, that’s MSRs for short) are an old idea, and very new: the U.S. never funded molten-salt research very highly, and cut off all remaining funding 40 years ago, in 1976. There are no reactors in existence today, but a new, young generation of scientists and engineers are trying to develop this technology once again. China is working on them much more aggressively than the U.S., and is on track to start their first reactor in 2020. So the R&D will take years, and reaching price-parity with coal will take several more years in the best-case scenario.

A Japanese concept, which is unlikely to be funded due to fears of Fukushima

But outside China, the speed of development depends partly on public support: public opposition could sink any nuclear project, and MSRs are especially vulnerable because they lack financial support from the established players in the nuclear industry. On the other hand, MSRs could be developed much faster if there were political will do so. If enough people let go of their knee-jerk reactions against anything “nuclear”, development could speed up quickly as leaders voice their support for R&D programs. That’s why, even before any MSRs exist, it’s a good idea to learn about them.

MSRs, and the subcategory of LFTRs, have the following advantages:

1. Very high safety: in a properly-designed reactor, total power loss or internal corrosion cannot cause a catastrophic outcome. The usual concept of ‘meltdown’ doesn’t even apply since the fuel is a liquid, and freezes (hardens at high temperature) after a total power loss! No human intervention is needed in an emergency, because the reactor uses “passive” safety: heat dissipation is assured by physics, not by pumps or control systems, and there is nothing in the reactor that can cause explosively high pressures. Even in case of terrorist attack, it contains radioactive gasses in only small quantities, so if a reactor were blown apart, environmental damage would be relatively low, and casualties from radioactivity might well be zero. This fact would make other targets more attractive to terrorists.
2. Economy of scale, if produced in a factory. In the long run, TCO (that’s Total Cost of Ownership) can be cheaper than for coal. Many of the costs of traditional reactors are mitigated by MSRs: their pressure vessel and containment buildings can be smaller and less expensive; they can use smaller turbines (because they run hotter); they do not need expensive fuel fabrication; and as everyone knows, assembly lines have cost advantages — advantages that the nuclear sector has never enjoyed before. Smaller reactors can be built in factories and transported on trucks; larger ones can be built in shipyards and transported on barges.
3. Extremely high fuel density: As Kirk Sorensen (a nuclear engineer and former NASA engineer) says, “You could hold a lifetime supply of thorium energy in the palm of your hand.” MSRs use so little fuel that all the fuel the reactor ever uses could be sealed inside the reactor when it leaves the factory.
4. Low toxic waste: under normal operation, they will produce less long-lived nuclear waste than traditional reactors. Most of the waste will be dangerous for a shorter time period than people worry about with traditional nuclear waste (roughly 300 rather than 3000 years).
5. Thorium, the fuel of LFTRs, is “virtually” renewable; perhaps a better word would be sustainable. It is hundreds of times more common in the Earth’s crust than the most popular nuclear fuel, Uranium 235; it could power human civilization for longer than the sun will last: 30 billion years (give or take) according to Alvin Weinberg. Right now, thorium is a “waste” product from mining rare earth minerals.
6. In contrast to large wind turbines, SMRs can be placed next to electricity consumers to save money on transmission lines, due to their small size and high safety level. However, politically speaking, this advantage won’t be realized until people eventually believe that they actually are safe.
7. Unlike wind and solar energy, nuclear energy produces substantial “waste” heat, which could be used for industrial processes. In fact, the heat could be used instead of producing electricity, which is more useful than most people realize. It would reduce cost (no turbines required), and more importantly, because electricity generation from heat is only 30–50% efficient, industrial customers could get twice as much energy “for free” if they have a way to consume the heat directly, 24/7.
8. Nuclear reactors are “always on”, so when the sun is not shining or the wind is not blowing, they do not require a backup fossil-fuel plant, or extra investment for energy storage. Since wind and solar do require backup energy sources, MSRs are one possible way to provide that backup energy, the others being fossil fuels, hydroelectric dams (which can only be built in certain places) and energy storage facilities (which are expensive today, though that may change.)
9. Fixing stifling regulations related to thorium could also make it easier to mine rare earths (used in a wide variety of electronics and modern technology). Rare earth mines are always “contaminated” with thorium, an issue which seems to have shut down rare earth mining in the U.S., as Congress has allowed China to grab the entire rare earths market rather than fix its own regulations. This allows China to not only restrict the world’s supply of rare earths, but to grow its own high-tech manufacturing sectors at the expense of manufacturing in the U.S. and worldwide. Thorium occurs naturally and is found throughout the planet; it is only slightly radioactive — safe enough to carry around in your pocket — and much less radioactive than certain materials encountered during oil & gas mining, like Radium-226 and Radon gas. The problem is, it is regulated the same way as much more radioactive uranium and plutonium. Miners avoid separating rare earths from thorium, because putting thorium back in the ground it came from is illegal. Not dangerous — just illegal.

MSRs do have a few disadvantages.

Obviously, since they’re new, the up-front R&D cost is higher and time-to-market is longer, which is a big reason they have not been built commercially before.

Possibly the biggest problem, though, is certification: the US NRC must invent new regulations to cover this new kind of reactor. They don’t make promises about what their regulations will be, when they will be ready, how long they will take to certify a reactor or how much it will cost. Dr. Per Peterson, UC Berkeley says: “we’ve not built small modular reactors, even light water, so we haven’t built that experience base on how the NRC might or should manage it. And this is one of the flaws that has impeded innovation in the nuclear energy technology area, which is that this is a first mover barrier. Because quite honestly, once the answer comes out as to how NRC will manage that sort of question, everybody knows what that answer is and everybody else can free ride on whoever it was that took the risk of building the first SMR station.”

“Anything that’s different, that’s never been done before, it seems like in the nuclear field, everybody wants to be number two.”

Other than that the main challenges seem to be about longevity. With no prior experience to guide them, it’s difficult to predict how reactor components might degrade, and how fast, in the long term, as radiation and chemical corrosion tends to damage reactor components over time. Lifespan is important because the reactor tends to cost more than its fuel, and if engineers can’t work out how to repair a reactor, much of it might have to be thrown away. Some nuclear startups are therefore trying to make reactor cores cheap enough to make a profit even if much of the core must be thrown away after a few years.

Whatever MSR design you look at, there’s still quite a bit of R&D left to do, and once reactors become available they might take a decade to become cheap enough to compete globally in the electricity market (initial buyers would be those needing an intense heat source, or serving remote locations, while initial sellers might use a design that is less-than-ideal but more economical). And, no matter how fantastic the technology itself might be, it will take time to soothe the common people’s knee-jerk reaction against anything nuclear.

However, climate change is not a challenge we should meet tepidly; let us not throw away possible solutions, and let’s not just assume solar and wind power will be cheap and plentiful enough to solve our climate change problem. Economics trumps morality: if it’s cheap, it will win in the market. Investing in more types of energy technology will boost the chances of soundly beating fossil fuels on price. Besides, in the long run, nuclear technology should (in theory) become cheaper than solar and coal, which in turn could improve quality of life for many people around the world — but only if the necessary initial investments happen.

It’s not just climate change, either. Ocean acidification is a potentially huge problem caused by the extra carbon in the atmosphere, and there are already signs that we’ve seriously harmed ocean ecosystems all over the world. It’s worth noting that eliminating carbon emissions is not enough by itself to reverse this problem, because the ocean “heals” very slowly. Because SM-MSRs are potentially the cheapest form of energy in the long run, they could be used to perform large-scale chemical processes. Perhaps this heat can be harnessed to sequester carbon dioxide and actively reverse problems like ocean acidification. This might not be feasible with wind or solar farms, because changing the chemistry of an entire ocean requires more power than they could produce economically. The point is, having a cheap and abundant source of energy provides flexibility. Scientists might find a way to solve the problem without massive amounts of energy — but if they don’t, it’ll be a good thing we have a new, cheap nuclear power source.

And the advantages keep going. For instance, consider point #4, that MSRs can produce less nuclear waste that a U-235-based reactor. If you look into this issue more deeply, you’ll learn that some of the nuclear “waste” produced by a U-235 reactor doesn’t have to be waste at all; in particular, some MSR designs can use plutonium “waste” as fuel, destroying most of it in the process.

But wait, it gets better. The small amount of leftover waste is toxic, yes — but if it is separated into its components, some of those are very valuable because they can only be produced by certain nuclear reactions. For instance, certain radioactive substances that are in short supply today can be used in cancer treatments, while others can be used in satellites and space probes — notably Pu-238, which was used to power deep space probes until NASA ran out of it (and Pu-238, it should be noted, is not an ingredient in nuclear weapons).

Plus, compared to conventional reactors, some MSRs designs will not need downtime for refueling; they’ll do load-following more quickly; and they can use air to cool outer surfaces rather than water, so they need not be placed near a body of water. They can even be used in space, and would be excellent power sources for lunar or Mars outposts. Having said that, waste heat from an MSR would be very useful for desalinating sea water to produce drinking water, so there is a good reason to place them near an ocean.

“If we could ever, competitively, at a cheap rate, get fresh water from saltwater that would be in the long-range interests of humanity [and] really dwarf any other scientific accomplishments.” - John F. Kennedy, April 12, 1961

For all these reasons, I would urge you not to oppose all nuclear energy, and I would urge governments to implement a clean-energy investment strategy that supports all clean energy technology, not just “strictly” renewable technology; and to implement reasonable regulations that don’t favor old technologies or block new ones. Although nuclear energy will be cheaper in the long run, it requires substantial funding up-front for research and prototyping, which is why a government research program would be very helpful.

We need to push past the knee-jerk anti-nuclear sentiment, and accelerate the R&D quickly enough to address climate change in a big way.

Once you learn something, you can’t pretend you didn’t learn it, you can’t pretend that you don’t know what a powerful thing this is, and you can choose to do that, but that’s not the moral choice to make. […] So the moral thing, the right thing to do is to just do what we’re doing…. which is in my opinion, sort of the bare minimum. - John Kutsch, Terrestrial Energy

Intrigued? Have a look at Thorium Remix, which explains the LFTR again, this time with pictures, diagrams and sound bites.

THORIUM REMIX

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Edit: A previous version of this article stated that LFTRs are proliferation-resistant. LFTRs produce and burn U-233 that is contaminated by U-232, which is makes it very unattractive for weapons, but a reader pointed out that, in the process of converting Thorium to U-233, an LFTR produces modest amounts of Pa-233, which, in a process that was left unstated, could apparently yield uncontaminated U-233. A nation wanting to build small nuclear weapons could modify a reactor to extract this Pa-233. Another company making a non-LFTR design claims high proliferation resistance, however.

Edit: A previous version of this article stated that HEU was needed to start a LFTR, but a lower enrichment level called HALEU is sufficient for all MSRs, and nuclear engineer David Leblanc says LEU alone will be enough (see section 6 of his article) for their reactor. LEU is much easier to procure.

Edit: A previous version of this article stated that MSRs produce 1% as much dangerously radioactive waste as a traditional enriched-uranium reactor, per unit of energy. This was a serious misinterpretation of the facts on my part, and I apologize.