Nuclear Physicist Explains - What are Thorium Reactors?

This is the most advanced video I’ve made so far, I tried my best to explain it as simple as I could. Let me know what you think! Are you guys team thorium or team uranium?☢️👩🏽‍🔬

The thing that I heard and sounded attractive to me, was the idea that Thorium is already being mined in great quantity but is considered tailings to other mining processes. Specifically, rare earth element mining supposedly produces a lot of Thorium waste, so that would have the advantage of creating a use for something we are currently "throwing away" right now. I am no expert, so what I have heard may be typical internet FUD, but if it is true, it does add to the benefits of Thorium.

Finally, a proper explanation that isn't just hype. You made it quite clear and understandable. Thank you very much

I’ve heard a lot about the advantages of thorium. This was a well balanced and unbiased presentation of the pros and cons.

Great video Elina! I've been reading about thorium as a fuel source for years, but you gave a thorough explanation of the process. I always thought the waste produced was minimal ( compared to LWR) and could be recycled.

Chapters: 0:32 - What is a Thorium Reactor 1:43 - How is a Thorium Reactor different from Uranium Reactor 3:06 - Fuel Abundance (amount of uranium and thorium in Earth crust vs oceans) 4:36 - Safety (Proliferation & temperature) 7:28 - Economics (enrichment vs amount used in a reactor, fuel manufacturing costs, and refueling operations) 10:45 - Efficiency (higher efficiency, but neutron speed issues) 12:35 - Waste (no trans-uranic wastes, lower radioactivity, short-term toxicity, solid vs liquid waste, chemical problems) 14:52 - Proliferation (hard to steal, U-233 proliferation) 18:49 - Current Status (little experience with running or dealing with waste)

No one else I've ever watched talking about thorium has ever explained the proliferation issues with it. Thank you that was fantastic

Thank you for the clear explanation of the issues involved in the consideration of thorium reactors for nuclear energy production. I have never heard such a comprehensive explanation and found it quite enlightening.

My favorite little feature of the LFTR prototype was possibly its simplest aspect - if there is any kind of power loss or need to shut down, the cooling mechanism keeping the drain outlet solid stops, the plug melts, and the reactor empties itself into the storage / reheater tank where the liquid salt freezes until you are ready to start it up again.

Elina, I've been studying LFTR reactors for over 15 years and I think you've made a good video here, but wanted to add some points: 1. (Abundance), everything you said is correct, however, thorium is also available as 6%+ concentrations in Monazite sands, which are the sands used for extraction of rare-earths (the materials we use for high technology and renewables today). The thorium is currently considered waste, and due to being (mildly) radioactive, is considered a disposal hazard. When thorium reactors take off properly, the fuel will basically be free - the waste from our rare earth mining. One other point, when considering land extraction, thorium is more abundant across many countries compared to uranium. This means you don't need to have access to the ocean or to be one of the "lucky" countries that have or don't have uranium. Thorium is basically everywhere, but especially in the rare-earths (particularly the "heavy" rare earths). Keep in mind also we have a LOT of U238 (depleted uranium) lying around, so this is another great source of non-fissile, ie FERTILE fuel for reactors, just like Th232 is a fertile fuel. 2. (Safety), As you know, reactors in general are very safe, you need only compare deaths/TWh the "deathprint". You also mentioned about the fuel from a LFTR potentially freezing in the reactor during power loss. This is unlikely due to an additional automatic safety feature known as the freeze or salt plug. In the bottom of the tank there is a pipe that leads to another tank which is designed to radiate as much heat as possible and can be a storage tank. A fan blowing on the salt plug keeps it solid. If power is lost, the fan loses power and the salt will melt due to losing its cooling, and the reactor salt drains into the tank below it. Note this is all done without human or computer intervention. 3. (Economics), all very well done in your video. I'd add that if you assume 6% thorium (in monazite sand) and you assume you can extract and consume all of that thorium in a LFTR, then a soda can of sand has the energy equivalence of 40,000 gal of gasoline. Google Monazite sand (and thorium) as well as the energy density of thorium and gasoline to check my math. To me, this means thorium (and LFTRs) make oil obsolete or archaic. Liquid fuels could easily be made from the reactor heat. 4. (Efficiency), again all well done. I'd point out that the U233 would make an excellent start-up material for more reactors. Once you have a proper LFTR running, you can extract some of the fuel as startup for other reactors. U233 also becomes Ac225 from natural decay, and this is a cancer treatment called "MATT - Medical Actinium Theraputic Treatment". Also the U233 can eventually become Pu238 which is used to power RTGs for space exploration. You need a special reactor for making RTG fuel, as standard reactors with U238 contaminate it with too much Pu239 and other heavier isotopes. 5. (Waste), the fission of U233 creates a similar mix of isotopes to U235 (and Pu239) fission, with some ratios changed a bit. These fission products decay comparatively quickly (you are correct about the hundreds of years figure). Once you have isolated the fission products then you have a more concentrated (but less volume) of waste and much of this waste can be recycled, which is not easily true for the solid fuel reactors of today. Since the fuel is a liquid you can chemically pull out the elements of interest, and many of these isotopes are valuable. There is no reason to assume that alternatives to water ponds would be required to house the waste of a LFTR as the same fission products are made. However, there will likely need to be some interm cooling for the first day or week after the hottest (thermally and radioactive) materials are extracted. They will rapidly solidify however, or could be reacted with other elements to make solids of the element of interest for storage in the spent fuel pool. 6. (Proliferation) The U233-based bomb does work, but it still is difficult to deal with. The U232 produced along with the U233 is highly radioactive and thus easy to detect. It would also cause havoc with the bomb makers as well as any electronics. Finally, one could make this argument about a lot of reactors. Used improperly, they can be used to breed materials into bomb materials. However, it is easier to enrich U235 than it is to go through the diversion of fuel from reactors.

Great content, very clear and concise and exhaustive for a difficult topic, best thorium reactor video i have seen.

I love your easy explanation to a complicated subject. As a Refrigeration Mechanic I may have enjoyed more advanced learning in Physics. Great work! Calgary, Canada

Good video: I'm team Thorium! 1) I think the proliferation issue is overplayed: we have the same issues (if not worse) when it comes to Uranium. Nuclear fuels and processes will always need security. The U233 stage of thorium cycle does not need a specific place for storage: it will be in a dynamic salt solution and will not need to be separated out and cooled off. 2) Availability: only if we use up all available Thorium then we will need to develop (really expensive) undersea mining of Uranium! But the existing Thorium in India, China and in the tailings of rare earth mining will last for kiloyears even if all energy production is diverted to Thorium plants. This is not a significant problem 3) Tech difficulties: if 10% of fusion research funding were diverted to Thorium tech solutions (corrosion issues and pumps, mainly) then there would be working reactors by the end of 2023 (not 2050 as the projected date for anything useful to come out of ITER!). 4) Storage of waste: ditto re technical issues. The slightly larger front end costs of Thorium waste are heavily outweighed by the long term issues of conventional storage of the Uranium cycle (and these do not disappear even with reuse of Uranium waste as a fuel in a MSR). 5) In conclusion, Thorium needs to be front and centre right now, not kept on the shelf in case Uranium doesn't work out..Many thanks for a great run-down!

I learned so much about Thorium reactors! I’ve heard about them before, but people acted like they had no downsides. I really appreciate all the work you put into making this video!

Amazing, I love it ! Thank you for the perfect sum of MSR and Thorium explanation. Will look for new episodes :hand-pink-waving:

Very clear summary and explanation of the pros, cons, and trade-offs. Many thanks! I have not looked into thorium reactors much before. Excellent introduction.

I've always liked everything I've heard about thorium reactors (admittedly, mostly due to the safety advantages of molten salt designed compared to our more common PWR designs), but you pointed out concerns I've not heard discussed before. Thank you!

Excellent video! My late father-in-law worked on the molten salt reactor experiment during his career at ORNL. He'd have loved your explanation.

Thank you for explaining this in a very understandable and hype-free format that focuses on what we currently actually know and also what the drawbacks are.

Well done, Understandable balanced and placed in correct perspective. The way you put the important things shows a deep knowledge, the only suggestion is, you may talk a little slower, for me not a problem but the amount of useful information cramped in a short period of time, makes it less accessible and you may lose interested listeners. So as a lecture : GOOD material, as info , far to much above common for not already well informed scholars. As a document: Pure GOLD, no nonsense or influencer like behavior As a grandfather I would be very proud of you!