ORNL MSRW 2020 was held via Zoom due to COVID. I was able to record (almost) the whole stream on my laptop, and ORNL supplied server-side recordings for most of the talks. My ORNL MSRW 2020 Playlist continues to be a work-in-progress, even though 2020 has ended.
Democratic candidate Andrew Yang came out in support of Advanced Nuclear, specifically in support of Thorium Molten-Salt Reactors. Joe Biden was elected on a platform which includes nuclear power, the first Democratic platform to do so in 48 years.
As Andrew Yang began to face criticism for his support of "Thorium Reactors" I saw it follow a familiar pattern. The following prose was written by me in 2020, but the videos are a mix of (mostly) old and new. What follows is my 2020 defense of Yang, written just as he dropped out of the race.
Andrew Yang's policy on nuclear power (basically to "build Thorium Reactors") faced some misleading "fact-checks" created by strongly anti-nuclear organizations. Because any candidate taking a pro-nuclear stance can expect to receive failling grades on the environment from anti-nuclear organizations such as Greanpeace, it is worth inspecting what a 2020 "fact-check" looks like, when it comes to Thorium Molten-Salt Reactors. Because no matter what reactor is proposed, anti-nuclear organizations will employ the very same tactics.
Thorium is a mildly radioactive metal which can be turned into nuclear fuel inside a Thorium Reactor, and then fissioned to produce both energy and valuable isotopes.

This reactor would be different from today's reactors in almost every aspect. Different fuel. Different coolant. Different approach to safety. Different approach to fissile security. What goes into the reactor is different. What comes out is different.

This gives people a new perspective on nuclear. What people assumed was the only approach is no longer the case. We can start asking, what do we want from nuclear power? ...instead of take-it or leave-it.
Perhaps the starkest contrast with conventional reactors is how the Molten-Salt in a Thorium Molten-Salt Reactor helps us replace engineered-and-redundant safety systems with passive ones which always work. Passive safety systems based on the laws of physics, not robust and redundant equpiment.

Statistically, over the 60 years we've had civilian nuclear power, it has always been the safest form of energy production. By raising "safety" as a feature of Thorium Reactors, many supporters of nuclear power see Thorium as a solution to a problem which does not exist.

But I'd ask you to dive into the safety-case regardless. We've had 3 major nuclear accidents in those 60 years. In all 3, the conventional reactor choice of water as coolant played a role.
To summarize the downsides of using Water as a coolant:
  • Water boils into ineffectual-for-cooling steam at a mere 100°C. (TMI&Fuku.)
  • Steam reacts with fuel rod cladding into explosive gases: Hydrogen and Oxygen.
  • Steam occupies 1000x volume of water. Large pressure vessels are costly result.
  • Steam or Hydrogen explosions spread radioactive material. (TMI&Chern&Fuku.)
  • Thorium is insoluble in water, excluding any "Fluid Fuel Reactor" concepts fueled by Thorium.
To summarize the advantages of using Molten Salts as coolant:
  • Salts held together by ionic bonds. Broken bonds repair themselves.
  • Molten Salts can have a liquid range of over 1,000°C.
  • Thorium can be dissolved in salt, enabling a "Fluid Fuel Reactor" which can be designed to operate extremely efficiently when powered by Thorium.
We have less experience with Molten Salts than with water, but we do have experience.
The Molten-Salt Reactor Experiment was designed in 1961, was constructed and began operating by 1965, operated at full power in 1968 and completed operation in 1969. That's 50 years ago.
China began pursuing Thorium Molten-Salt Reactors in 2011.
China's SINAP are currently assembling a 2MW "TMSR-LF1" pilot plant from already constructed-and-shipped parts. Assembling it. Now.
The United States has once again begun funding Thorium Molten-Salt Reactor research, starting in 2016.
In the United States, over time, Molten-Salt Reactors have been taken more and more seriously. First solid-fuel versions which only use salt as coolant. Then, research into liquid-fuel variants (like the MSRE and like China's pilot plant) began receiving DOE funding as well.

Even Bill Gates who referred to liquid-fuel reactors as "hard" in 2010, now has TerraPower developing a liquid-fuel Molten-Salt Reactor.

But Thorium-specific Molten-Salt Reactors were the very last to receive funding. Even as the 1965 MSRE had been built as a stepping-stone towards a (more complex) Thorium Molten-Salt Reactor.
Just as safety isn't seen as a "problem" by the nuclear industry (because the current fleet is statistically safe) some of the Thorium Molten-Salt Reactor's features are also seen as solving problems which aren't really problems.

To-date, civilian nuclear waste has sat in cooling pools and dry-cask storage. It harms no-one, but there it is. Those spent fuel rods contain Uranium, Plutonium and Fission Products. Many people find this to be troubling.

In contrast, a Thorium Molten-Salt Reactor can be designed to produce nothing more than Fission Products. Thorium goes in. Fission Products come out. Per unit of power, an incredibly small volume of waste compared to today's reactors. Also, valuable. Because for all the valuable materials trapped in today's spent fuel rods, they're trapped with Plutonium which many people would prefer remains trapped in those spent fuel rods.
What could we be doing with our spent fuel rods, our "Nuclear Waste?"
We could keep spent fuel rods in Dry Cask storage. Already, many nuclear power plants feature a collection of dry casks near the reactor. They sit there, doing nothing. But they do present a barrier to remediating retired power plants. (Assuming a new reactor can't simply be built right next to the retired one, making the very same site suitable for continued housing of the dry casks.)

We could move spend fuel into a geological repository. California prohibits the construction of new nuclear power until the question of spent fuel has been addressed. So this is one way to deal with political challenges facing nuclear power, deal with non-fuel-rod nuclear waste (such as radioactive hardware like pipes), and deal with the actual spent fuel rods themselves. Yucca Mountain storage is opposed by Nancy Pelosi (and Nevada voters), so the only way to remove the political risk from this approach is to pursue multiple geological storage sites in parallel.

Or, we could, if we so wanted... recycle the spent fuel rods. In fact, spent fuel pellets are mostly (93%) un-fissioned uranium. This neither dangerous, nor valuable, nor fuel for a Thorium Reactor. It simply constitutes the bulk tonnage of what is nuclear waste, making the problem seem bigger than it really is. The useful stuff, and the hazerdous stuff, is diluted by the uranium. Without unfissioned uranium, we'd have a waste story that looks more like France.
France's decision to build a nuclear fleet was made in 1974, and by 1990 they succeeded in decarbonizing their electricity supply (as well as transitioning most household heating from fossil-fuel to electricity). Would you like to address Global Warming? This is how you address Global Warming... with 1980s technology.
So what could we do with 2020 technology based upon the long-neglected Thorium Molten-Salt Reactor concept? Reprocess our fuel, without the hassle of reprocessing.

The reason France's nuclear waste takes up so little space, is because they chemically reprocess their fuel. Their spent fuel (just like ours) consisted of spent fuel rods... solids. To reprocesses they dissolve the solid fuel into liquid form, and then separate the materials. Most of what can be fissioned goes back into the reactors.

In the French version of this, enormous amounts of transport and infrastructure are involved. France (just like us) uses a fuel form-factor not well suited for recycling. In fact, any solid-fuel nuclear power plant is ill-suited for recycling. That is why Oak Ridge National Lab built the Molten Salt Reactor Experiment: to validate the concept of dissolving nuclear fuel into a liquid, so we could finally add online chemistry to our nuclear toolbox.
It is the development of such chemical tools, for a Molten-Salt environment, which makes the Thorium Molten-Salt Reactor unique. The Thorium Molten-Salt Reactor, to run exclusively on Thorium fuel, absolutely depends on the development of online chemistry tools. That was the concept behind ORNL-4528 in 1968, and it wasn't until 2016 that those challenges finally started to receive funding.
Andrew Yang proposed (in 2020) that with $50 Billion in federal funding we would see such reactors brought online by 2027. This was challenged as unlikely, although such best-case projections have already been made by both let's tackle-the-chemistry-now Flibe Energy and less-effecient-plants-for-Indonesia ThorCon Power.

Yang's 2027 date served as an indicator how serious he was about seeing Thorium Reactors through. Any further into the future, and he would be trusting his successor to continue funding development. Any further into the future, and he would be communicating "this will be someone else's problem to ultimately solve." Andrew Yang seemed to be indicating he would monitor progress, and help ensure bureaucratic delays were minimized.

Perhaps the most decisive factor as to whether Thorium Reactors can be build during a single President's time in office, is how quickly the first $10 million (million, not billion!) are allocated. That is because much of the chemistry research is...
  • Inexpensive. Ridiculously inexpensive.
  • Not involving Plutonium or Enriched Uranium (is why so inexpensive).
  • Possible to run in parallel (same time), not in series (one after the other).
  • Of immense future value beyond development of Thorium Reactors.
The seemingly overlooked aspect of Yang's plan to fund Thorium Molten-Salt Reactors, was that the $50 Billion was to be shared with Fusion Power research as well. Molten-Salts are the technical overlap. Salt pumps, monitoring of salt chemsirty, salt purification, salt heat exchangers, and power conversion systems to turn hot salt into electricity... this R&D budget for advanced atomic power solutions (Thorium and Fusion) doesn't just move us forward on the most exciting concepts. There's a world of Molten-Salt approaches (which are closer to commercializaton) which also benifit.

Thorium Molten-Salt Reactors by 2027? Quite possibly... if experiments exploring some online chemistry approaches show success. But, a President making Molten-Salt research a national priority is a prerequesite for any 2027 Thorium goal. Regardless how easy/hard some challenges prove to be, by pursuing Thorium Molten-Salt Reactor research, 2027 will see very exciting, passively safe, high temperature and carbon-free energy solutions.
At UCB, Dr. Per Peterson and Kirk Sorensen discuss the use of FLiBe Molten-Salt in Molten-Salt Reactors. They focus on Dr. Per Peterson's favored approach: Solid-Fuel with Molten-Salt coolant. Insead of solid fuel rods, this approach uses "pebbles" (2-inch spheres) as fuel. The pebbles float in the Molten-Salt, the salt being twice as heavy as water.

UCB's Compact Integral Effects Test (CIET) was constructed to simulate FLiBe Molten-Salt's heat transfer properties, by using Dowtherm (at lower and easier temperatures) and scaling time.

The choice of solid (pebble) fuel was made so to avoid the need for online chemical processing. The trade-off is fuel effeciency, an inability (or impracticality) of using Thorium as fuel, and also a spent-fuel scenario nearly identical to today's reactors.
Despite the creation of spent-fuel pebbles, the solid-fuel molten-salt approach still gets us...
  • Beyond water coolant, H2O which dissociates into explosive gasses.
  • Coolant (salt) that chemically traps radioactive isotopes should any escape the fuel.
  • High temperature process heat for creating carbon-neutral fuels, and replacing all large-scale combustion-for-heat applications.
  • Advanced Reactor designed for low-cost factory construction and assembly.
  • Ultra low-carbon nuclear power. Far lower than today's low-carbon nuclear.
Solid-fuel molten-salt research helps (liquid-fuel) Thorium Reactors. Thorium Reactor research helps solid-fuel Molten-Salt Reactor development. They are all Molten-Salt Reactors. Yang's $50 Billion is well targetted to a long underfunded area of basic research.
Fusion power is hard. In fact, to say we want to "replicate our Sun in a bottle" is to vastly understate the problem.

The Sun is hot, but not so hot we can't create 15,000,000°C here on Earth. What we can not replicate is The Sun's 250,000,000,000 Earth-atmospheres of pressue. And if we could extactly replicate "The Sun in a bottle", keep in mind our Sun emits enough radiation to heat Earth only because it is large enough for 1,300,000 Earths to fit inside. The actual energy density of our entire Sun is 1/400,000th of the 1965 Molten-Salt Reactor Experiment. The Sun is powerful because it is large, not because of its energy density.

Should we ever be capable of a net-positive sustained energy production from a Fusion Reactor, then we'll need to fuel it (by creating Tritium), and we'll need to protect the vessel from neutron radiation. FLiBe Molten-Salt offers a solution to both looming challenges.

Both the Thorium Reactor and a Fusion Reactor make use of a "breeder blanket". This is a surrounding layer of FLiBe Molten-Salt used to absorb the neutron radiation and turn some of the salt content into fuel.

Thorium Reactors do this by dissolving Thorium in the blanket salt. Thorium, once struck by a neutron, evolves into Uranium-233. On-line chemistry moves U-233 from the blanket salt into the core salt, refueling the core so that nuclear fission can be sustained.

Fusion Reactors do this by using FLiBe salt with identical chemical properties, but a different isotope of Lithium. This Li-6 isotope neede for Fusion Reactors is more likely to be struck by neutrons than the Li-7 in Thorium Reactors. It is the Li-6 (and Beryllium) in the Fusion-salt-blanket which create Tritium (fuel for Fusion) when struck by neutrons.

Many objections raised to The Thorium Reactor: Creation of Tritium, expensive Hastelloy-N vessel material, and the need for online chemistry... those challenges could have been raised against Fusion Reactors. On the other hand, they're also the low-hanging-fruit of atomic R&D... if we want the very best Nuclear Reactors, and we want Fusion Power, then let's solve our looming challenges in parallel. Starting now.
The following video featuring Dr. Charles Forsberg does not mention Thorium Reactors, instead focusing on solid-fuel Molten-Salt Reactors. It does however, give us an insightful look into the overlapping technologies involved.
Despite Yang's foresight in targetting Thorium Molten-Salt Reactors, organizations opposed to nuclear power have crafted some significant articles challenging his plan. Let's take a look at the claims Andrew Yang has made about Thorium Reactors.
Thorium Reactor claims made by Andrew Yang:
  1. Thorium reactors would be more economical than traditional uranium reactors, particularly because thorium is more abundant than uranium, has more energy potential than uranium, and doesn’t have to be enriched.
  2. Thorium reactors will be safer than current reactors.
  3. Waste from thorium reactors would be easier to deal with than waste from today’s uranium reactors.
  4. Thorium would be more proliferation-resistant than current reactors—you can’t make nuclear weapons out of it.
  5. Building new nuclear reactors will likely be necessary if the United States wants to achieve net-zero emissions by 2049.
Before Andrew Yang mentioned Thorium Reactors, the counter-argument made (to the media and to legislators) was that "Thorium Reactors have been tried already, and showed no advantage over Uranium." Indeed, Shippingport Atomic Power Station used Thorium in its 1977-1982 fuel load. However, the intent was not to prove Thorium's commercial viability as a fuel. It was simply to confirm that Thorium could be bred into Uraium-233... which it did... within difficult to reprocess solid fuel rods.
Solid-fuel Shippingport was nothing remotely similar to the liquid-fuel Thorium Molten-Salt Reactor envissioned by Oak Ridge National Lab, "ORNL-4528".
As Andrew Yang faced "fact checks" on his Thorium Reactor claims, a less outrageous but similar dismissal took place.

Just as Shippingport bears no resemblance to any Thorium Reactor we would pursue today, there's still room for interpretation when Yang specifies "Thorium Molten-Salt Reactor." Based upon Yang's claims of what a Thorium Reactor can do, it is clear he refers to the following: a Thermal-spectrum, dual-fluid, Thorium Molten-Salt Reactor with online chemistry.

Political candidates should not need to be so precise. Not in sounde bites on stage. Not in policy pages to be read by voters. Such details make Nuclear Power choices seem overwhelming to the general public, because there are 1,000 distinct combinations of reactor sub-categories.
For example, one choice: Fast-spectrum or thermal-spectrum? In 2015, an OECD NEA study looked at Thorium in fast-spectrum (instead of thermal-spectrum) reactors, and before the report was even released to the public testimony was given citing the report to a United States Energy Committee in which Thorium Reactors were dismissed as "not having any advantage." (As Thorium does not, in fast-spectrum reactors. The advantage is in thermal-spectrum.)
THE Thorium Reactor, the one people actually think about when tossing casual terms likes "Thorium Reactor" around, has remained the same since 2009. It was in 2009 when WIRED's story on Thorium (and a series of Google Tech Talks) introduced the public to "LFTR" (the Liquid Fluoride Thorium Reactor) based on the dual-fluid "ORNL-4528" design.
That's The Thorium Reactor, 2-fluid, clearly stated in 2009. (There is an error, however, concerning the drain-tank's frequency of use.)
The Bulletin of Atomic Scientists is an organization which claims to be open-minded about nuclear power, yet consistently opposes it. Their "fact-check" on Andrew Yang is the top Google result for YANG + THORIUM.

The Bulletin cites Nicholas R. Brown, who cites a DOE 2014 Nuclear Fuel Cycle Study. The study looks at a thermal-spectrum, single-fluid, Thorium Molten-Salt Reactor with online chemistry... "ORNL-4541". That's not the reactor promoted by advocates since 2009.

This distinction matters, and it matters to some of the Thorium Reactor claims Andrew Yang is making.

But whether DOE choose to evaluate single-fluid or dual-fluid Thorium Reactors, The Bulletin fails to clarify Nicholas R. Brown's following statement, which they close with:

"Thorium-uranium fuel cycles provide no inherent benefits
relative to uranium-plutonium fuel cycles,
so the new reactors need not be thorium-powered."

They were evaluating "ORNL-4541" the single-fluid design with inferior online chemistry. It leaves Protactinium in the waste stream, making their Thorium Reactor a producer of something more than just Fission Products. This putt their particular choice of Thorium Reactor high in the ballpark of... other Advanced Reactors which vastly outperform the existing fleet.
The dual-fluid Thorium Molten-Salt reactor (based on ORNL-4528 optimzed for actinide recycling) is not found in this evaluation. It would have appeared near the far right side of this chart.

EG26 (Evaluation Group 26) is of ORNL-4541, a Less Effecient Single-Fluid Thermal-Spectrum Thorium Molten-Salt Reactor.
Activity_HN refers to the radioactivity of "Other Heavy Metal Elements". Protactinium is not split-out in the graph, and so the presence of Pa-231 would fall under this category. ORNL-4541, the single-fluid design, was not optimized for actinide recycling.
The fuel-cycle evaluation looked at the wrong Thorium Reactor. It performs OK-ish, but... wrong reactor.

Similarly, the Bulletin-cited 2012 "Proliferation and Theft" paper did not look at online reprocessing in Molten-Salt Reactors at all...

"For the purpose of this study,
the reactor design is assumed to be that of
the Advanced Heavy Water Reactor
proposed by India."

...they looked at THOREX reprocessing of solid fuel rods, with U-233 exiting reactors and being transported to reprocessing facilities.

The Bulletin's "fact-check" is one of less efficient, and less secure technologies.
Again, Thorium Reactor claims made by Andrew Yang:
  1. Thorium reactors would be more economical than traditional uranium reactors, particularly because thorium is more abundant than uranium, has more energy potential than uranium, and doesn’t have to be enriched.
  2. Thorium reactors will be safer than current reactors.
  3. Waste from thorium reactors would be easier to deal with than waste from today’s uranium reactors.
  4. Thorium would be more proliferation-resistant than current reactors—you can’t make nuclear weapons out of it.
  5. Building new nuclear reactors will likely be necessary if the United States wants to achieve net-zero emissions by 2049.
1. Cost. Andrew Yang has claimed an economic advantage for Thorium Reactors.

Yang's citing of Thorium's abundance, and energy potential without needing enrichment are not the biggest opportunities to reduce the cost of nuclear power, but they are all helpful in lowering the cost nuclear power.

Solid-fuel-rod assembly bundles are valued at over $100 Million dollars apiece. A reactor may simultaniously hold dozens of assemblies (each one containing about 200 fuel rods). However, conventional reactors will extract power from a given fuel-rod assembly bundle over 6 years period, so these seemingly large fuel expenses are amortized, and end up having a tiny impact on the per-kWh cost of nuclear.

Because Uranium fuel costs are low, The Bulletin categorizes this claim as "false." But that doesn't mean Thorium Reactors won't have cost advantages over today's reactors.

By harnessing Thorium's full "energy potential", that is, fissioning all our fuel into Fission Products (instead of today's U+Pu+FP "spent fuel"), we immediately call into question 10% of Nuclear's overall cost per-kWh.

That is not where anyone is looking to the bigest cost savings... every "Advanced Reactor" concept being pursued is looking to smaller sized components as a means of reducing cost. On-site construction is expensive and prone to complications. Factory construction (thanks to reduced size) lends itself to economies of volume production and learning curves.

While it is merely the SMR (Small Modular Reactor) aspect of Thorium Reactors which promises the biggest cost reduction, there are a number of overall economic advantages (and some disadvantages) brought to the table by an extremely effecient Thorium Reactor. That is because an advanced online chemical processing tools are required, and "Seed Fissile" is also required.

The "Seed Fissile" could be Enriched Uranium (a cost), Uranium-233 (only enough has been created for the pilot plant), or it could be Plutonium converted into U-233. Plutonium from decomissioned weapons or spent fuel rods could be a source of revenue. As a Thorium Reactor produces power, U-233 remains in the power plant, acting as a "Nuclear Catalyst" converting Thorium into energy. Once a Thorium Reactor is seeded with U-233, only Thorium fuel is required to sustain operation.

Economic advantages of an advanced-chemistry Thorium powered system:
The Bulltin ranked this economic-advantage claim as "false". But The Bulletin has also noted elsewhere Small Modular Reactors are a way of "reducing capital costs" thanks to factory construction. Because Yang instead cited the cost of Uranium (Uranium fuel bundles sell for a mere $100 Million apiece) the to-be factory constructed Thorium Reactors can't be cost effective?

Thorium Reactors will reduce the cost of nuclear power, by being factory assembled, by avoiding Uranium solid-fuel assemblies, and by not producing anything remotely resembling conventional nuclear waste.
2. Safety. Andrew Yang has cited safety as an advantage of Thorium Reactors.

Andrew Yang has been the first to point out how very safe conventional reactors are. However, some of that safety is based on training and a strong regulatory environment. The use of water in large Pressurized Water Reactors presents challenges that add complexity when addressed. Dr. Alvin Weinberg was fired from his directorship position of Oak Ridge National Laboratory for raising this concern when advocating for the safety benifits of Molten-Salt Reactors over Pressurized Water Reactors for the civilian fleet.
The Bulletin's dismissal of Andrew Yang's safety claims as "misleading" rest on the fact most of a Thorium Reactor's safety comes from Molten-Salt and not from the Thorium Fuel Cycle. However, there are some other Advanced Reactor concepts which have less safe characteristics when compared to The Thorium Reactor.

Andrew Yang has noted that Thorium is Fertile, Not Fissile. The Thorium Reactor only contains enough Fissile to perpetuate operation, with online chemistry being responsible for continually adding more into the reactor's core salt as needed.

The starkest contrast to this is Chernobyl, with a fuel load of 192 tonnes, 2% Low-Enriched Uranium. Solid fuel reactors can't add fuel a bit at a time, so they are overloaded and use control-rods to compenstate for this "too much fuel" state.

Fast-spectrum reactors, an Advanced Reactor concept serving as the only fuel-effecient alternative to Thorium Reactors, are all extremely overloaded with fuel, in the sense that they are unmoderated. An introduction of moderator, as unlikely as that may be, is a safety concern which adds complexity to address. Just as use of pressurized water adds complexity to conventional reactors.
Every feature of a Thorium Reactor (except for its online chemistry being particularly adept at harvesting valuable materials) can also be found picking-and-choosing from other Advanced Reactors. But only the Thorium Fuel Cycle allows both effecient use of fuel, and also the avoidance of a civilian fleet where fission is unmoderated.

Consider an extreme example of why-thermal-spectrum: All U.S. Navy nuclear submarines use Thermal-Spectrum Reactors. If they used Fast-Spectrum Reactors then much more fissile would be required. That additional fissile becomes surplus fissile if moderator is introduced. Water (and seawater) are moderators. The U.S. Navy (wisely) choose to stick with thermal-spectrum reactors.

In the future, we might see Molten-Salt Reactors (even Thorium Molten-Salt Reactors) powering the world's fleet of cargo ships, completely eliminating 2.4% of global GHG emissions. Those reactors, floating on top of an Ocean of moderator, are unlikely to be fast-spectrum.
Can both effecient use of fuel, and also Molten-Salt be used without the Thorium Fuel Cycle? Yes. But The Bulletin dismisses those reactors. Ed Lyman, the acting director at The Bulletin, has testified:

Liquid metal-cooled fast reactors, high-temperature gas-cooled reactors, and molten salt reactors all introduce new safety and or/security issues relative to light-water reactors that may ultimately outweigh any improvements they may provide for uranium utilization or waste management.

Of course, The Bulletin sees ineffecient conventional reactors as a threat too... there is no existing reactor, or Advanced Reactor concept, or pursuit of Fusion Power... which satisfies The Bulletin.
The Bulletin called Yang's safety claim "True but misleading", because the biggest safety advances are found in the choice of Molten-Salt rather than the choice of Thorium fuel cycle. However, Yang is citing a very valid safety advantage.

The Bulletin (in their dismissal) cite Uranium-Plutonium Molten-Salt Reactors as being just as safe. So either The Bulletin is willing to generate conventional-reactor levels of nuclear waste (reactor using a moderator), or The Bulletin is claiming a fast-spectrum (unmoderated) Molten-Salt Reactor's inherent safety is acceptable? Which is it?

Unmoderated Molten-Salt Reactors will one day enter the public conversation, because they allow the effecient use of Uranium in the same way a moderated reactor can do with Thorium. The only problem is... such a Uranium reactor is unmoderated. The point... the safety point, of using Thorium instead of Uranium is to avoid a civilian fleet consisting of unmoderated reactors.
3. Waste. Andrew Yang cites Thorium Reactor waste as an advantage over other reactors.

Because all the Thorium is converted into fissile and then fissioned, Thorium Reactors produce only Fission Products. Segregated Fission Products.
Conventional reactors trap Fission Products, Plutonium, and (mostly) unfissioned Uranium together in solid spent fuel rods.

The Bulletin ignores immense value is trapped in conventional spent fuel, which can move materials from "waste" to "revenue" if only the form-factor would allow it.

The Bulletin only focuses on radioactivity of spent fuel (not the utility of the form-factor). And when looking at only-radioactivity, the evaluation of ORNL-4541 instead of ORNL-4528 shows Protactinium as waste. That is not The Thorium Reactor with 2-fluid design, and advanced online chemical processing.

Also, note that The Bulletin opposes more effecient reactors, and recycling nuclear waste.
4. Proliferation. Andrew Yang claims Thorium Reactors would be more proliferation resistant than current reactors.

In theory, a warhead could be made from Uranium-233. To-date one has not. Thorium, when struck with a neutron, becomes Uranium-233. U-233 can be found inside an operating Thorium Reactor, sustaining its operation. That is secured fissile.

In practice, Plutonium-239 has been used to create nuclear weapons. Uranium-238, when struck with a neutron, can absorb the neutron (instead of fissioning) to become Plutonium-239. Pu-239 can be found in spent fuel rods, and in nuclear warheads.

In practice, Uranium-235 has been used to create nuclear weapons. Uranium, when isotopically seperated into U-235 and U-238 (with centerfuges or gaseous diffusion or any other means) then... that's it. U-235 is weapons-grade material. Uranium can be found in the Earth's crust, and in seawater.

Of the 3 options listed above, enriching Uranium to weapons grade does not require a reactor of any sort. For a proliferation concerns, this sets the bar rather low.

But, ignoring Uranium, and... Iran's (attacked by Stuxnet) enrichment operation as a how-to example...
Does a Thorium Reactor present a lower or higher proliferation risk than Plutonium created by conventional reactors?

Despite Plutonium being in every spent fuel rod from a conventional reactor, Plutonium proliferation concerns are really quite overblown by anti-nuclear organizations.
This is because spent fuel rods contain not just Pu-239 (weapons material), Pu-238 (desired by NASA) but Pu-240 as well. Pu-240 is a contaminant, making the Pu useless for weapons, and useless for NASA. The only use for spent-fuel Plutonium is to be fissioned into energy in a fast-spectrum reactor. (This fissioning could also create U-233 for the seeing of Thorium Reactors if the fast-spectrum reactor was designed appropriately.)

So does U-233 (needed to seed a Thorium Reactor) present a proliferation concern?

Once inside a Thorium Reactor, no. It is required for the reactor's operation, and coexists with extremely radioactive materials. Thermal-spectrum Thorium Reactors do not produce surplus U-233 the same way conventional reactors produce surplus Plutonium. As U-233 is created, it is also being destroyed in equal amounts by being fissioned into energy.

Also, because fuel is kept in a liquid state inside the Thorium Reactor, it is possible to use online, real-time monitoring tools to maintain an inventory of the salt's contents. This is unique to Molten-Salt Reactors when compared to any solid-fuel Advanced Reactor, or conventional reactors.
Because theft of U-233 from a Thorium Reactor would cause power production to halt, and because reactor's salt chemistry can be continually monitored, any proliferation evaluation focused on fuel recycling must take into account a lack of surplus U-233. An operating Thorium Reactor does not realistically post a proliferation threat.
The single shipment of Seed Fissile to the not-yet-operating Thorium Reactor, if it was only U-233, could be considered a proliferation concern. However, just as the Plutonium in spent fuel rods from conventional reactors are contaminated with Pu-240, any U-233 could be similarly contaminated with trace amounts of U-232. The needs of a reactor are far less demanding than the needs of a warheard.
In 2016, The United States began funding reseach programs specific to The Thorium Reactor. In 2019, one such funded project is an Oak Ridge National Lab review of proliferation countermeasures to be used by The Thorium Reactor. This is a review likely to take into account liquid-fuel specific technologies (such as online real-time monitoring).
The Bulletin declares Andrew Yang's proliferation-resistant view of Thorium as "false".

However, the fact remains that Thorium can not be enriched into weapons grade material, while Uranium can, and has been repeatedly. That is not a hypothetical concern like never-created-a-weapon-from U-233.
5. Required. Andrew Yang claims Nuclear Power is required to achieve net-zero emissions by 2049.

The Bulletin finds this statement to be "True". Because it is true.

Dr. James Hansen, "The Godfather of Global Warming" has noted the challenge of intermittent energy sources, and how they've been impeding Germany's attempt to decarbonize.
Dr. James Hansen, like Andrew Yang, calls for the development of Thorium Molten-Salt Reactors in this Rolling Stone interview. Andrew Yang has never said where he first heard about Thorium Reactors. Maybe it was from "The Godfather of Global Warming" himself.
Andrew Yang's statements regarding Thorium Reactors are true.

To make them untrue requires looking at the wrong Thorium Reactor, requires comparisons against other Advanced Reactors (while not clearly stating so, leaving the reader to assume today's conventional reactors are being compared), or requires ignoring new proliferation countermeasures only made possible by liquid-fuel and real-time online monitoring.
The Bulletin, by discrediting Yang's Thorium Reactor proposal and the forward-looking Molten-Salt research which would accompany it, serves to delay the following technologies:
  • Thorium (liquid fuel) Molten-Salt Reactors
  • Recycling of spent nuclear fuel / nuclear waste
  • Solid-fuel Uranium Molten-Salt Reactors
  • Liquid-fuel Uranium Molten-Salt Reactors
  • Fusion Power
  • Solar Power Towers
  • Molten-Salt (thermal) energy storage systems
  • Dispersed cancer treatment via alpha targetted therapies
Solving Global Warming does not depend on convincing fellow Americans that Global Warming is real. It depends on the development of energy technology which can outperform coal and natrual gas while remaining reliable. Some politicians claim that renewables alone can meet our nation's energy needs.

If renewables can do so, and batteries are so cheap, and the only thing holding us back is political will... then why does Germany remain high-carbon (brown) in this 2019 timelapse of electricity related GHG emissions?
As United States transitions to a Biden Presidency, featuring the first Democratic Party Platform to support Nuclear Power in 48 years, it is essential that past mistakes are not repeated in 2021.
Andrew Yang's proposed $50 Billion in advanced-atomic R&D funding are not needed to see a Thorium Reactor (or many other Advanced Reactor designs) come to market. Without intelligently targetted funding, we won't likely see them by 2027, but we will see them.
We will see them unless The United States, once again, abruptly pivots away from in-development nuclear technologies.
This happened in 1971, when President Nixon narrowed down breeder research from Fast-Spectrum Uranium-Plutonium and also Thermal-Spectrum Thorium-U233, to only Fast-Spectrum Uranium-Plutonium. (This is why we do not already have Thorium Reactors.)
This happened in 1977, when President Carter indefinitely banned the reprocessing of nuclear fuel, making fast-spectrum reactors only more effecient than conventional reactors, and not a means of recycling nuclear waste. (It was allowed again by President Regan, lifting the ban in 1981.) President Carter's preferred energy solution was coal.
This happened in 1994, when Congress under President Clinton cancelled fast-spectrum Clinch River 3 years before completion.
The value Andrew Yang brought to the energy discussion is the very same point raised at the end of "Pandora's Box", a 6 hour miniseries created by the BBC in 1992. The statement made by historian Joseph Morone (at 43m25s) is exactly 2.5 minutes long. (Deep link.)
Andrew Yang pointed out, not only is nuclear power required, and is nuclear power safe... nuclear power is what we demand of it.
That recognition is all it takes for America (and the world) to have a bright, clean future of affordable energy.
This is a rather detailed video I made concerning The Thorium Reactor. I've deep-linked past the pre-credit sequence, and into the opening titles... many people otherwise mistake the opening credits for the end credits.
To support my educational and communication efforts, pledge $1/year. Thanks, -Gord
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