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?☢️👩🏽🔬
Uranium, until technology is better, and invest in both but mostly in Uranium 10/1. But pulefuration is not always problem, i think, Sweden has uranium reactors but no nuclear weapons, not because they can't build nuclear weapons, but don't want it, or I reckon they can build one.... As a neighbor I wouldn't be concerned if Sweden built a thorium Reactors.
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)
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 agree, thorium MSRs are probably the fastest way for us to get off fossil fuels. I don't think Elina likes the thorium LFTR reactor design. I think we are seeing a sunken cost fallacy here, which is literally why research was stopped in the 70's on MSRs. The thorium abundance part failed to mention that we need something like 35 times less thorium than uranium to produce the same energy in heat. MSR reactors can also convert that energy into electricity more efficiently. So yeah to hell with uranium, we would never need to get it off the ocean floor. MSR reactors need more research done, they are superior in many ways to other reactor designs, its not just thorium reactors that need research done and need to be built. LFTRs combine the best of both.
Also a byproduct of U233 is a gamma emitter, U232, which would make a bomb easy to detect remotely with instruments. There are also methods to reduce proliferation risks that have been addressed before, for example running a design with “denatured” solution including U232
For your point 1, how do you account for the Protactinium, which was the stage that Elina specifically called out as the proliferation danger? That's what needs to be stored separately until decayed into U233, during which time weapons-grade nuclear material is increasingly available outside of the reactor, a situation not found at all in a typical uranium-based reactor.
@@theotherguy982 The decay from Pa to U233 only takes a week or so, thus there needs to be no "separate storage". It can be kept in dynamic salt solution. There will be no difference in the security measures between Th and U plants. all fissile material needs the same precautions. Who are you getting your information about "separate storage" from?
We don't need Thorium yet: _"Less than a kilometre from the western shore of the Bay of Fundy, the Point Lepreau Solid Radioactive Waste Management Facility temporarily houses about 160,000 spent fuel assemblies from New Brunswick’s only nuclear power reactor. Moltex Energy, a Saint John-based startup, proposes to recycle that radioactive waste into fresh fuel for a new 300-megawatt reactor called the Stable Salt Reactor-Wasteburner, or SSR-W."_
We need thorium to avoid going to war over Ukranium supplies. Look at how Russia already invaded Ukraine to take all their Ukranium. You won't see this in the mainstream media.....wake up peeps, we need you all full woke.......
Elina should be highlighting denatured molten salt reactor, too. That is a good use of Thorium. Mixing U238 with U233 to address concerns ... Reference Th232 -> U233.
@@mightym Hidrogen plane combustion? It is not that clean. It burns at higher temperatures and it creates much more nitrogen oxides. Might be an intermediary solution until we have completely clean transportation.
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.
Additionally, the disposal of thorium is a big part of why it's very hard to get rare earth mining approved in Western countries. Being able to turn a waste product into a product would go a long way toward opening new sources for the rare earth elements we need for expanding renewables. The irony is that using thorium could hasten the transition to renewables.
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!
Ofcourse they have downsides. But they have soooo many safety upsides it's insane. The biggest being that it does NOT use high pressure water in the reactor which is the biggest cause of disasters from the current designs. Because high pressure water flashes to steam and creates a hydrogen explosion. Hot gases goes UP into the atmosphere. LFTR's doesn't use any high pressure anything. If there is an accident where the molten salt for some reason would leak out of the reactor. The contamination is contained locally and the salt freezes to a solid salt. Making the contamination very easy to manage. They are also very much cheaper because they don't need a huge containment building around them because of the same reason. The designs I've seen also have a drain tank with a freeze plug. Fans using power from the reactor to blow cold air on a pipe to a drain tank. Freezing the salt to a solid state creating this plug. In case of a loss of power the fans stops cooling the pipe and the hot salt melts the solid salt in the pipe. Then it all drains to a draintank. This tank is prepared with a lot of surface area and neutron absorbing materials. Meaning the whole reaction stops and the salt freezes solid as it cools down.
@@YourFriendlyNuclearPhysicist Hey, how about liquid metal cooled fast neutron reactors? By using an eutectic mixture of tin and gallium that melts at 21C but boils at over 2000C we can make cores out of solid but thin thorium-uranium metal alloy disks stacked on rods and placed in a honeycomb shape. The volatile materials escape through the tiny spaces between the disks and bubble to the top while the rest mostly stay on the rods. Given a large enough core that can overcome via the square-cube law the neutron deficit due to escaping neutrons, it would actually be a viable way of producing power with minimal waste.
@@SonnyKnutson yeah, well, no. Creating hydrogen from water does not require steam or pressurized systems. Radiodissociation can happen at room temperatur. Molten solt reactors generate Tritium, an Hydrogen isotope, during STANDARD operation, which has to be dealt with. Some "salts", like UF6, are gases even at room temperature. They can be generated during standard operation, too. Unexpected contaminations like these have been found in filters of test reactors, and the engineers were "surprised", to say the least. You are not as proficiently informed as you think you are.
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.
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.
@hewdelfewijfe Your 'common misconception' was used for 2 years in Oakridge over 50 years ago. The reactor shut down every weekend when scientist went home. Shut down in hours not months like other reactors. Then restarted every Monday. The same cooling pipes used for the heat exchanger could be used to remove waste heat and even if they weren't the heat isn't so high that it's a problem. The reaction stops. The fuel solidifies. The heat dissipates. Nothing melts down. Too hot no fission. Too cold solidifies. It's completely self-regulating.
@hewdelfewijfe "When you scale that up to a commercial reactor, you're going to have much higher power densities, and then passive air cooling is not enough." A scaled up reactor would ALREADY have something other than passive air cooling. Are you really suggesting that it wouldn't also be used to cool the drain pan? "The drain plug is primarily about solving the problem of recriticality by moving the fuel to a new geometric configuration." It's not just the geometry. It gets the fuel away from the graphite moderator. My point still stands. If air cooling was enough to handle the decay heat on the Oakridge reactor then decay heat isn't a serious concern. REGARDLESS OF THE SIZE OF THE REACTOR! In fact one design incorporates storing the fuel until it decays to the proper element for burning then reintroducing it to the reactor. Molten Salt Reactors won't run at higher temperatures. The reaction is not sustainable at high temperatures. It's why they're inherently safe. Scale doesn't matter. In fact part of the problem with using them for power generation is their temperatures run so much lower that steam isn't the best choice for the power turbines. You're mixing the physics of the uranium chain with the thorium chain. Decay heat doesn't continue to build until it melts everything around it in the thorium chain. The higher the temp goes the less decay occurs. And without a moderator even at the proper temperature the reaction doesn't proceed.
@hewdelfewijfe Considering your arrogant response I figure I better simplify it even more for big brains like you. Molten Salt Thorium reactors are low temperature. It's the only way they work. Making them bigger doesn't change that. More 'power density' means higher temperatures. Higher temperatures means less or no reaction. Your entire premise is flawed.
@@tonyrmathisIt was not researched further because of it's inability to "easily" produce weapons grade waste . It is clear that research for domestic energy production was centered around military applications for enriched fuels. They actually said this in papers documents. I'm not making frivolous accusations. There were problems , but no resources were allocated to solving those problems . Money and manpower were allocated to solving the issues with Uranium reactors, because of military applications. This is why the USA and EU are so hell bent on stopping Iran's nuclear power plants.
Thanks Elina, I have subscribed, because of your unbiased and knowledgeable video. I worked for 35 years in the nuclear industry, NOT power generation but lots of work with isotopes. To me, it's not a case of 'teams' or 'winners', its about making the right choice and videos and input from people like yourself should give us the best option. Keep safe and keep up the good work.
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!
the thing is, modern reactors are already INCREDIBLY safe, of course being virtually impossible to catastrophically fail is better than incredibly safe. but given all the other problems, the safety ends up being not as interesting.
@@danilooliveira6580 No, not so "incredibly safe". High pressure water Uranium reactors will ALWAYS be inherently dangerous, prone to runaway meltdown and steam explosion. Three disastrous and long-lasting failures already across the world (plus two more in 1957). And then there is the easily retrieved Plutonium...far more dangerous than U233.
@@danilooliveira6580 Except for the cost. Current designs are safe because a lot is invested in construction. If new designs are safe by default then the cost of construction could be reduced. For example, MSRs operate at low pressure and can do without those costly containment buildings.
@@m4ktub1st No, MSR operates with extremely reactive coolant with high temperature which means it's the opposite of "safe by default" thus the safety measures are probably more expensive than PWR. MSR is only safe from total melt down. It has higher risk of other accident. Also, high gamma radiation means more embrittlement of core material = More frequent maintenance & shorter life span
Great explanation, Elina. There were a few things in there that has not been brought up and explained in other videos on the subject. I wasn't aware of Uranium 233 and how it is weapons grade. I do agree that finding a way to burn our old nuclear waste is a priority. Waste is a resource not yet exploited.
You haven't heard about U-233 being weapons grade because it isn't! No country has developed nuclear bombs based on U-233 for a reason. Impurities of U-232 as low as 50 ppm are enough to make it unusable for nuclear bombs and the impurity in a Thorium based reactor will always be much higher than that.
@@outerspaceisalieNo, they don't. What kind of material are you talking about? As I explained the U-233 itself isn't weapons grade due to the impurities and they produce neither U-235 nor Pu-239. 🙄
Mostly it's built in safety measures. One example I know of with a Gen 3 PWR design was using borated water in a "pool" at the bottom of the reactor vessel that due to density differences would stay in the "pool" while the regular water was traveling through the core. However, if the regular water started to boil off, the borated water would naturally move upward from the "pool" to cover the core and shutdown the reaction. Gen 3+ reactors typically require an act of sabotage, by removing the inherent safety systems, to cause a meltdown. Typically the worst accident you'll ever see with Gen 3+ reactor is a LOCA (loss of coolant accident) which on the scale of accidents is a 4 (TMI was a 5, Chernobyl and Fukushima were 7, the highest, Windscale was a 6). Accidents scale 1 to 4 are always contained within a small area whereas 5 can get into the environment and 6+ has environmental impact.
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
I think CANDU reactors are the way to go. They can run on unrefined uranium, thorium, or even spent fuel. They can refuel without shutting down. They also have been used for decades and are a known, safe design.
Once-through fuel cycles are nuclear training wheels; for million year sustainability we need breeders (Th or U238) and reprocessing. Yes Candus can breed using thorium, but they need more frequent reprocessing compared to fast breeders or LWRs, which drives up cost. Liquid fuel makes reprocessing cheaper, so it's that or fast breeders (with or without LWRs).
Did she skip over the safety aspects of did I just miss it? Not being able to sustain run away chain reactions that lead to meltdowns is a major advantage in my opinion.
@tonyrmathis Yeah and having cesium rods that need to be in safe storage with no earthquakes for 1000s of years could be another advantage. Better to just completely ignore the benefits of disposing of such waste with breeder reactors (LFTR Thorium) in favor of going with what you know works. (Apologies to other readers that I emit sarcasm in response to untruthful stupidity). Tony and I got triggered.
@@wezleyjackson9918 I find there's two types of people who oppose thorium reactors. Those with a vested interest in other designs and members of the eco-cult who don't consider humans to be part of nature. One doesn't want change because it means less money and more work for them. The other that just hates people and wants fewer of them.
@@tonyrmathisYour right, she missed several major points about the advantages of LFTR. No mention of the higher thermodynamic efficiency from operating at 800 deg C for instance. No mention of ‘freeze plugs’. She did mention ‘negative coefficient’ of ‘operation’ - but failed to explain it. (Thorium reactors are passively safe - because if they start to overheat, the liquid expands, reducing the reaction rate, so it cools down by itself). That was tested out at oak-ridge, when it was left running for several days, without any active controls being used.
The thing with thorium reactors and uranium there will always be advantages and disadvantages. But honestly I agree we need something where the reactor deals with its own waste, I would also be open to the idea of fast breeder reactors.
Waste hansn't been an issue since the late 60s when dry casks were being utilized and not a sinlge leak has ever happened from a dry cask. Also you can bury them similar to how the planet handles its own versions of nuclear waste on site and it wouldn't be harmful or dangerous to anyone and you could easily do it for the life of the entire plant.
I have to be honest this was one of the better explained Videos on thorium reactors Most of us are Novices at how a thorium reactor would work with the pros and cons to go with it.
I think really what we should be focusing on in this technology is the molten salt aspect of it. The incredible efficiency largely comes from that aspect of the technology. Thorium is great for a lot of reasons and it is probably our preferred fuel but what's wonderful about molten salt is that we can make it much more efficient and separate out waste products very easily as well as building intrinsic safety in the geometry of the nuclear core through thermal expansion and the drainage basins.
I had heard of Thorium and molten salt in terms of reactors, but never so detailed and well explained. Thank you. Real Engineering just covered Helion's fusion reactor, I'd be curious to see your reaction to it.
@@Joe-by8jh ... I'm pretty sure the thorium reactor at Oakridge was connected to a thermal radiator because there was no generator connected to the heat exchanger. It pumped out a bunch of thermal energy that had to be dissipated. It isn't really like fusion where you need to pump in loads of electricity... Once the fission reaction is happening all you have to keep up to it is more thorium (except for running the pumps and other machinery I suppose). My biggest gripe about the Oakridge reactor was that uranium was mostly used in it to test the design.. A lot of thorium was turned into U233, but they were shut down for political (supposedly budgetary) reasons before they could use much of it. Something like 500t of the U233 is currently being destroyed because it was never allowed to be used (a significant effort is underway to save that U233). Also because of the way they were shut down, the reactor and equipment were never cleaned out before the fuel froze inside. They still have to clean that up somewhere I believe. The concept of the experimental thorium reactor requiring more power than it made isn't really a logical concept for fission power in general I don't think...? Unless you have statistics on how much power was required..? I think the thermal output at the radiator was about 7MW..
Thank you so much for making this! I really learned a lot from it, found considerations I didn't realize was there. I'm actually less optimistic about thorium now than I was before, mostly because some of the stories I heard was apparently wildly exhaggerated. Top notch Elina :)
Finally, a professional who actually knows about Thorium! That was a fantastic explanation. Also, great to see that some young people still do go into the sciences, very important for all of us. Keep up the good work!
An technical and well balanced look at reactors, or any energy source, is a rare thing as it seems as if there is a tug of war over the future energy market as it continues to grow. Thank you for this.
Excellent video! I was arguing with my nuclear engineering friend of mine (I'm an electrical engineer) over thorium reactors a few years ago. He was very much against adopting it on scale based on practicality.
My experience of doing the requirements analysis of the control system for a nuclear power station project has made me a fan of renewables. Basically the interaction between government & large private interests make megaprojects with large political & economic implications very traumatic.
Thank you for your unfiltered opinion on the subject that isn't poisoned by unbridled optimism. You clearly have a more informed background on the subject and the ability to reason about the benefits as opposed to the disadvantages. Thank you again.
As a former reactor operator trainee, the Department . of energy defunded our FFTF Project and I along with hundreds, all disciplines were laid off, your discussion was excellent, I preferred uranium
amazingly clear, concise and through presentation. logical analysis of pros and cons. Storage and proliferation are obviously of relevant concern.. thank you
So good to hear the other side of the coin on this matter! All I have heard previously was positive with no hint that there was any downsides to thorium at all.
Amazing video. I really love they way you take a subject and you break it down into parts and then start to explain each part. It is so helpful to understand the topic. Thank you can't wait for your next video ❤️
Honestly, molten salts seem to have so many applications over the last 20 years. Learning about Thorium reactors in a balanced, nuanced way is why I love this channel.
I think the main reason there is lots of talk about molten salt reactors and batteries is we now have materials that will not corrode as easily with different types of molten salts
@@HootMaRoot Yes, still more high temperature corrotion resistant materials would be needed but a lot of it already exists. Plastic composites that can take nearly 2000 degrees celcius.
@@HootMaRoot "As easily" are the key words. There is no known material that can handle molten salt. It's like liquid sandpaper. It will deteriorate anything eventually. The only answer is to build two power plants and constantly rotate one while the other is being rebuilt. Not worth it.
@@ipissed Why? Just make sure each lasts long enough to payback and more the investment, and have enough spare parts so they can be built fast enough. Done.
Great video and feels free from any agenda or politics as these topics often get loaded with. For my part I hope we continue research on Thorium reactors, but after hearing your pros and cons I am less sold on them then before.
Great video, but one mistake is to assume we would long-term store the liquid fuel as spent. All waste elements would be extracted from the fuel on a continuous basis, in a process that would probably be economically viable from just selling other trace elements being produced. A lot of very expensive isotopes for science and medicine would be more available this way (molybdenum-99 etc). The unwanted biproducts would be in oxide or fluoride form that after aging becomes for example metallic forms like Neodymium. With the electric car industry requiring staggering amounts of this rare earth metal this waste also becomes a business. (Neodymium-147 has a half-life of 10.9 days so not very much more aging than is done with cheese.) When it comes to proliferation the liquid uranium reactors would not be any better as the actual risk is in a reactor where different parts of the biproducts can easily be separated out during operation. As-is, non-liquid reactors are run to produce materials, and then the fuel rods are liquified and centrifuged in a separation and enrichment effort to produce the same materials. The liquification can be based on salt again, so pretty much the same.
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!
While a new regulatory and oversight scheme might be needed to secure the Protactinium as it decays to U-233 stored outside the core in some countries, I don't think that is any more a proliferation risk than the Plutonium in current waste streams, or indeed the U-235 already used in current fuels. Team Thorium!
Agree. The many many added safety benefits of LFTR's seems like a nobrainer to me. One of the biggest being that there is no high pressure water in the reactor that can spread into the atmosphere in case of a catastrophy. It simply leaks and goes solid without much contamination except some local.
Well I guess reporcessing and pulling out the Pu-239 from spent fuel is chemically a lot more challanging than just fluorinating your Pa-233 decay tank until the U-233 hexafluoride bubbles out which is about one more step away from being ready to make a bomb out of it. Now Iam normally the one who dismiss proliferation risks, as I think it's bizarre to imagine a bad actor with the resources and scientific background to covertly steal the material, build a bomb out of it (without any testing) and use before anyone notice, when going a much cheaper and frankly technicllly simpler route with bilogical warfare just makes a tons more sense even if said actor just wants to see the world burn, I thought it worth mentioning why the two things are different by their difficulty. Seperating is actually easier, building a bomb out of it when you can only remote handle because of U-232 contamination with hard gamma decay chains is not trivial matter at all. So as many thing it is actually nuanced, its true that separation is easier but does it make it more of a proliferation risk ? I don't think so.
The regulatory regime in many countries is designed solely to defend old school 1950s reactor designs, and the later minor (improvements on that design). Or rather, the regulatory regime is designed to defend the regulatory regime. The risk of weapons proliferation due to use, disposal, and potential abuse of thorium reactors is far less than the risks associated with use, disposal and abuse of medical grade nuclear products. The risks of failure are astronomically lower than light water and presurised reactors. And the thorium reactor design lifespan is substantially longer vastly reducing decommisioning costs. To make a comparison, the paperwork required to obtain a thorium reactor licence in mosy countries (those signed up to the present international regulatory regime) exceeds the amount of paperwork required by the entire global civil aviation regulatory regime to authorise use of a new aircraft. Not because the regime is pointless, but because the nuclear regime -unlike civil aviation- is based not on sound scientific and engineering premises, but because the nuclear regime is designed purely to reflect cold war premises, and 1950s high pressure reactor designs and not open to adaptation to accomodate newer technological developments or scientific advancement. Fusion reactors actually have a easier future simply because it steps arround the entire nuclear regulatory regime.
The U233 proliferation issue is one the Thorium fanbois never mention. Plus the more practical issue of high level waste. Thanks for raising it. Very succinct explanation. Thank you.
Very informative video, and good to see you address the proliferation risk! That is also my main concern, and it's often missing from the discussion. One model that seems safer and more useful is to use a combination of Thorium and depleted Uranium as fuel…
But neither thorium nor depleted uranium are fissile, so you need to transmute them into U-232 and plutonium in a breeder first. But because it's relatively simple to chemically separate those products from their precursors (when compared to uranium enrichment), it immediately creates a danger of proliferation of weapons-grade fissile material. I'm sorry, but that doesn't fit my definition of "safer". YMMV.
@@RexxSchneider Proliferation is a BAD argument !!! The countries with long history of operating nuclear reactors and even thouse countries which posess or produce its own nuclear weapons, how that "proliferation" mantra forbids them to design, build and succesifuly operate liquid salt thorium reactors on their own soil? You see - your many times expresed mantra is 100% debunked !!!
This is very interesting topic - Indian nuclear policy has been focused on Thorium since the beginning as we have the world's largest or second largest deposit. Furthermore, we were cutoff from all nuclear discussions for decades (Pakistan was allowed though despite being known nuclear proliferaters) so we had to develop our own way with things regarding Thorium reactors (Breeder reactors). We are focusing on becoming self-sufficient energy power with our own reserves in the next stage of our nuclear policy.
Thorium doesn't lend itself well to solid fuel systems due to the extreme gamma issues of the fuel rods and produces at least as much waste as uranium if used this way. Indian efforts have been mostly geared towards solid-fuelled operation and suffering accordingly The best way to proceed is to get a working molten salt system and THEN switch to fuelling on thorium. Keep an eye on Wuwei...
Kalimera Elina. Thanks for a great overview, and doing it in English. I'm super impressed that you did this in your second language. I'm sure I couldn't even understand this in the other languages I know.
I’m a long time viewer and supporter of Subine and only today discovered your channel. Loved your reaction to her video and look forward to viewing more of your content.
Love your videos, they are very helpfully. I have a test about partial physics, and your content helps me be motivated about the subject and helps to learn.
Nobody seems to have ever heard of the Canadian heavy water reactor CANDU, that's been around since the 70s. From what I can tell it's a unique design. Where I live, CANDU reactors provide 2/3rds of our electricity. They run on natural uranium with deuterium as the moderator, and can be refueled while running, with the fuel loaded horizontally instead of vertically. Control rods are suspended electromagnetically for passive shutdown with power failure.
I only recently started looking into nuclear, and CANDU was the first type that popped up while hunting for PHWR details. Seemed like there was a lot of development with some issues with politics and execution, and it was hard to tell whether their newer models just aren't being implemented due to past failures or whether other models are more attractive--or some combination of the two. To me, not knowing much about it, the designs sound pretty good for small-scale, potentially modular designs. Like some other commenters i'd definitely like to hear Elina's take on recent or not-so-recent developments for CANDU-6 derivatives and CANDU-9, and whether there is a future for the models despite what appears to be a lack of significant interest. The US hasn't seemed to have been a target market, and i'm wondering whether we just have better designs already that i haven't seen yet.
@@eboyce24 CANDU was developed b/c Canada was a tier 1 nuclear power that participated in the Manhattan Project, but didn't have the manufacturing base to build large single vessel designs, and wanted to be free of the enrichment requirement. Deuterium allows use of natural uranium, and the pressure tube design allowed easy manufacture of the bits. The downside of HW is more space is required btwn fuel bundles so the core is larger overall than an equivalent light water reactor. US and other powers were uninterested b/c they needed the enrichment capability anyway for weapons. However, another bonus is you can burn spent LW reactor fuel in a CANDU. S Korea has one of each and does exactly that.
Great video! Please do one on CANDU / heavy water realtors. They have a lot of hype around them like Thorium reactors. It would be nice to see an unbiased video on these too.
There have been tests for the use of thorium as a fertile fuel in HWRs that are using reprocessed LWR fuel. Speficically Pu-Th MOX , a Pu-Th-U MOX, or a sort of a «breeding blanket» similar to the ones utilized in fast breeders. India is the country most interested in developing this technology at the present. I personally like HWRs quite a bit. And its a much more proven technological basis than LFTR.
This was very interesting :) I did not know about the liquid salt state of the thorium in these reactors. Thank you so much for the great explaination of how this works :)
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.
LFTRs has graphite in its core to moderate speed of neutrons, so the graphite deforms under neutronic radiation and needs to be replaced once in a while, this increases the operational cost, however there are solutions to mitigate this cost. Another problem is leaks of tritium, also could be mitigated with some engineering. The Hastelloy N was invented in ORNL during MSRE and according to some reports I have read from MSRE the corrosion found was tiny or non-existing.
The problem with Hastelloy N is that it was never nuclear-certified. In the US that certification would take 20 years and a few billion dollars because the NRC hates nuclear. Instead, they are just replacing (refurbishing) the reactor vessel every 6-9 years as you said. From the numbers I've seen, this is still very economical.
Three countries have tried to use U-233 for bombs. The US, the USSR, and Pakistan. All three tried it and ran away from it, due to the severe problems of gamma ray raadiation and the life of a bomb's internals. None of them tried it a second time. That is as far from proliferation as you can get.
Great video. Really hoping that the CANDU SMR projects continue to be funded and eventually produce effective reactors. Widespread use of SMRs that also burn waste would be a huge benefit to reducing waste and fossil fuel use. Not sure if the SMR designs provide for any tritium extraction for fusion research but given the general design of SMRs I doubt it.
Why is everyone so worried about nuclear waste? After all, nuclear waste is literally a few square meters of space near the station. Unlike coal-fired power, which emits thousands and thousands of times more radioactive waste, among other things. When coal is burned, radioactive waste is also generated. Does anyone take this waste into account? No. In fact, when the pipeline to Germany was blown up, it was like dropping several atomic bombs. But no one cares at all.
As to the waste problem - the fact that its higly radioactive means that it has a short half life, which means that in the long run its less of a problem than conventional nuclear spent fuel which requires tens of thousands of years of storage instead of tens of years that the lftr waste would require to become safe. Problem with potential weaponization is pretty much nonexistent, because simply the fact that an element will exist in the fluid core, doesn't mean that you can physically separate it from the fluid to get any weapons grade resources. That's exactly why its the conventional nuclear reactors (special versions but still) that are used to manufacture weapons grade uranium and plutonium, and one of the reasosn why lftr research was dropped by the usa over 50 years ago - because it was impossible to practically extract anything valuable to the nuclear weapons program from lftr reactors.
First, the reactors used in France use Plutonium as a fuel source which is highly usable to make nuclear bombs. Second, the US DOE designed and implemented a Thorium reactor in the 1960's and the reactor was operated for over 5 years without an incident. The reason why the project was shut down was because DOD had decided that light water reactors were to be used to power submarines and other military platforms in the late 1960's and they didn't want this initiative to detract from the DOD decision.
Thank you for this balanced and honest analysis. Ther is a lot of talk going on and it is hard to determine what is true and what is wishful thinking. What i take away from your talk is that the process engineering is still incomplete and needs research and proliferation is a concern. I think these are challenges we can crack and the promise of safe and low cost energy is still there in LFTR. This should get more attention in the university community and politics should free up the way to develop this.
How can you call it balanced and honest when she intentionally misled the audience to believe that fissile Uranium235 is only 3 times less common than Thorium by using the numbers for the useless U238?
@@wollm1325 It doesn't matters, the uninformed people will understand 3:1 because that is what the scientist said in general. The people don't care for the details.
The idea of using what is currently considered waste as fuel in future reactors seems like a good one. I hope we can devise passively safer modular reactors that can do this.
Very underrated channel; thank you very much for this beautiful video; this should be shown in all secondary schools from grades 6 and up. Keep up the good work, loving the feeds.
I was afraid you were selling thorium and playing down its weaknesses, but you came through in the last half and brought up the realities that I knew must be. Very good, as always.
Team Thorium! Well done. I would love to see major DARPA emphasis placed on research and development. Any process that transforms 200,000 year half-life waste into 200 year half-life waste is moving in the right direction.👍
Ironically most of that "waste" isn't fuel rods but clothing and lab equipment or anything else that comes in contact during the refining and processing of uranium.
I love that Elina understands that the student, before understanding the answer, must understand the question. I'm pretty old, and just how the next generation gets energy is unimportant to me. I watch because I take pleasure in hearing complex issues described in plain language, but not reduced to child-friendly tokens.
Okay, on your video commenting on the "Nuclear Waste" video, I said I wanted a video on Thorium--and here it is, and as complete and thorough in answering all my Thorium questions! Very impressive! And thank you for educating us on these important, possibly emerging technologies.
Hello, thank you for this. Regarding storage of the molten salt waste materials, you mentioned that liquids are difficult to store long term. Wouldn’t they solidify once they are out of the reactor (they would be “salts”, not “molten” any more)?
FLIBE salt is solid at room temp. and actually dissolves only slowly in water. Not too bad, imo. Fresh out of the reactor, with no chemical repurification cycling, you would have radioactive self-heating. Enough to keep it molten for a month, maybe? I dunno that. There are usually two stages of conventional spent fuel storage. Fresh&hot, in a pool. Older&warm, in a sealed casket.
You can also remove the Flibe salt through vacuum distillation. In other words, you can theoretically separate the salt, the fuel, and various fission waste products in a process that is similar to what is used in the oil industry to separate various hydrocarbons, just at much higher temperatures and more corrosive conditions. Technically challenging but in theory possible.
Unlike the oxide based fuel in uranium reactors, many heavy metal fluorides will react with atmospheric moisture. This results in production of toxic HF as well as water soluble complexes which can leach out. So, 'dry' storage underground would not work well.
About the storage for the salts. You say they are liquid but they are not liquid in atmospheric temperatures. They melt at around 2-300 degrees. So they would be solid for storage. Like table salt :P
Hi Elina, can you discuss about high-temperature gas-cooled reactors like Japan's (red/pink) Hydrogen reactor that got activated last year and claims to produce energy and hydrogen in an environmentally sustainable way? Also any thoughts on the recent development about nuclear fusion announced by the Americans.
The recent development about nuclear fusion announced by the Americans majorly downplayed the fact that to charge the lasers required 300Mj. They focused their announcement on the measure that the 2Mj lasers produced 3Mj of output, and WOW ignition was achieved. That is very, very far from net energy gain. 2c
@@MonsterSound.Bradley Yeah Fusion announcements only ever count the energy difference in the last step, and leave out the 19 other steps along the way that cost them 99% of their energy.
You explained the pros and cons of using thorium very logically and clearly. Previously, I read materials that only sang praises of thorium. This video clears up my puzzlement over why thorium was not chosen over uranium when the nuclear energy was first started. Thanks very much.
Excellent presentation. You answered virtually all of my questions. I'm thinking, the thorium "deal breaker" is the high gamma ray emission of thorium waste. Shielding against gamma rays is extreamly difficult. Its like trying to eliminate light from a nightclub. Any tiny "leak" is like a gamma knife, and can go undetected for a time if it arrises newly. Its a huge challege for gamma ray source labs, and they are not dealing with the huge amounts of material the industry would need to ramp up to. Not impossible, but inconvenient and dangerous.
Go tell the Chinese who claim to have a Gen4 commercial grade research Thorium LFTR reactor running safely. Just because the USA and entrenched Uranium/Plutonium industry turned their back on Thorium LFTRs and development has only gone ahead by India and China, doesn't mean we can conclude this technology cannot be safer than traditional Uranium/Plutonium nuclear.
Thank you, that was a pretty good explanation and summary of the state of art. I always wondered about the Thorium hype, and was a little suspicious it might not be as rosy as sometimes depicted. Your presentation confirms my reservations. The aspect of proliferation of weapons grade fuel might indeed remain the biggest obstacle for wide commercial use, compared to the technical issues which probably will be solved sooner or later.
Unfortunate reality: It's easier to sell a molten salt reactor to the public because of the very high passive safety, and honestly public perception is BY FAR the largest barrier to nuclear research...so might as well embrace that
What a good explanation. Well done for being impartial and mentioning some of the negative aspects and challenges of Thorium as well as the good, many other posts claim it is almost non-polluting, whereas you give details on how toxic it is likely to be.
As I watch this, I have not yet seen the "Oppenheimer" film, but its release encouraged me to read "The Making of the Atomic Bomb". It is a great read (though long!) almost in cases like a novel, yet all well documented. Thank you for the content that you produce, it makes physics attainable for folks like me, two years in high school decades back, and one for non-science majors in college.
Richard Rhodes' book "The Making of the Atomic Bomb" may not be the primary source material for "Oppenheimer" (which I saw on opening weekend), but it is a fascinating and very accessible piece of historical science writing which I recommend to everyone wanting to read about the history of nuclear physics and the bomb up through the end of WW II. I've read it twice now. A short read about the atomic bomb survivors' stories which came out shortly after WW II by an accomplished journalist is John Hershey's "Hiroshima". I'm about to read the weighty piece of deep research book more directly focused on J. Robert Oppenheimer, "American Prometheus" by Kai Bird and Martin J. Sherwin, which is the text that Oppenheimer was written based on, and I'm very much looking forward to that.
Man's history is the inhumane conduct against his fellow man. I had not heard about the capability to weaponize the material. It had been my hope to lessen the danger from nuclear reactors. I appreciate the information.
The most comprehensive "essay" that I heard so far, on Thorium reactor, to date. With all negative points, Thorium reactor is safer compared to the Uranium ones, even the mining of which is - hazardous. Lot of work is awaiting to be done on Thorium reactor still, which isn't as straight forward a s a U235 reactor. Problems abound & need to be tackled one at a time. What is needed is effort with a lot of patience. Thus, the development of Thorium reactor is a lengthy process, with many unknowns. The narrator (a nuclear scientist herself) explained all that, patiently & with knowledge.
Thanks for the video! I'd be interested in a part 2 with more detail like dollar cost comparisons, radiation field strengths, half lives, and the interesting materials science questions.
To quote someone: The Moltex Static Salt design does away with almost every hazard from traditional nuclear power. Its sheer simplicity and intrinsic safety should dramatically reduce costs. It’s also scaleable by building more reactors on the same site. It is naturally load following and and cannot over heat. Excessive temperature stops the nuclear reaction long before it becomes dangerous. It could be disconnected from load at full power and nothing nasty would happen. It has boron shut-down rods but they are not needed as an emergency tool. There is no water or steam in the core so no pressure and considerably less corrosion than we get in PWR cores. We should be moving heaven and earth to build these things. Instead we have an out of control nuclear regulator that completely stalled progress. Moltex is now getting the job done in Canada.
There are many options for managing oxidation in MSR reactors that are being tested. Removing oxygen is just one simple option. India is well along the way to building dozens of fast breeder reactors. India has very large deposits of Thorium. China has a prototype MSR reactor operational using a significant amount of US research and technology. China has a significant stockpile of Thorium as a by product of rare earth mining. MSR reactors offer a great method of burning up weapons grade material and waste which can greatly reduce proliferation risks.
Hi Elina, In the future I would like you to explain the type of reactor on Thorium and U238 which are BOTH found in abundance in combination with a small particle accelerator( already in existence) in order to produce fission between the two of them. Thank you for your lovely and cheerful explanation! All the best to you! Professionals like you will be in high demand in the near "interesting future that awaits us
I am a former nuclear engineer who worked on the redesign of the Diablo Canyon units 1 and 2 and they achieved criticality in 1983-1984. The plants are still operational in 2024. I like that you created this video. Here are my thoughts on a new video that can be created 1. You must SLOW DOWN your presentation. The audience may not understand nuclear physics. So you must spend more time on the basic physics of the Th-232 transmutation, compare and contrast with Uranium fission. Just another 3-4 minutes should work 2. Take the time to explain how the LTFR is constructed. How it is contained in a pressure vessel. How the corrosion problem is solved etc. 3. Explain the heat exchange that generates pressurised steam that is transported to the turbine generator where electricity is produced. How the primary heat exchange is happening inside the containment building. Unless you explain these things end to end, your audience cannot relate to how the entire thorium fuel cycle works to produce electricity without proliferation. I will be happy to work with you on this. If interested, reply to this message and we can then discuss next steps.
This was a very clear explanation, however, I am a qualified nuclear reactor operator, so that gives me a head start. The process of turning Thorium into Uranium is similar to Commercial Reactors, where Uranium is converted into Plutonium. In both the reaction produces a more fissile fuel. If I remember correctly, it is called Resonance Absorbtion (or Adsorbtion, I never remember the difference). This process extends the life of a Uranium Fuel Cell. Over the course of 40 years or so the fuel cells will be taken out, stored, and reinstalled in a different location in the core. Resonance Absorbtion typically needs fast neutrons as opposed to slow neutrons and so the production of Plutonium is reasonably financial arrangement. The fuel does not need to be processed to use the Plutonium. But if the salt is sodium, that is a very bad thing. As you mentioned, Sodium and Water don't get along very well. So, since you need to transfer the heat from the Salt to the Water in a heat exchanger there is the possibility of a leak in the heat exchanger. In a commercial Reactor the leak would be detected by electronic means, a detector. A leak from a Salt reactor would be much different. I am not sure you are for or against. Personally, I think creating trash that is radioactive for any length of time is a mistake. Perhaps I am wrong about Thorium; it has been a while since I got to play with a reactor. Feel free to let me know, be nice though.
It would be better for mankind if we went back to the modest lifestyle of the good old Hebrews: to wine, bread and salt, music, oxes and sheep - and be happier with less waste of atomic energy and reactive ressources. Our comfortable, energy wasting lifestyle is hard to renounce on for most post modern materialists. A little rest risk life is always willing to offer.
LFTRs don't necessarily need water for power generation. They can also use "flash" gases (CO2, N, etc.,) in a modified hot gas turbine. The heat exchanger super heats the gas, the gas expands with force moving a turbine, and once the gas has left the turbine it's collected, cooled down, and put back into the loop.
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?☢️👩🏽🔬
Team what has been shown to work on scale, at this point I am more in favor of Uranium.
How about team accelerator driven sub-critical reactors? 😁😁
Team Both and also Team Fusion
Thorium for sure! But Uranium is still needed to start the reaction I think? ^^
Uranium, until technology is better, and invest in both but mostly in Uranium 10/1.
But pulefuration is not always problem, i think, Sweden has uranium reactors but no nuclear weapons, not because they can't build nuclear weapons, but don't want it, or I reckon they can build one....
As a neighbor I wouldn't be concerned if Sweden built a thorium Reactors.
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)
Thank you for the time stamps and short notes. It is really helpful!
Where are Thorium reactors ... nowhere to be found. Why ... Thorium is not fissible.
@@marcwinkler Tell me you didn't watch the video without saying you didn't watch the video
@@marcwinkler There is a test one being built in China.
@@paulsmith3921 Let them do the research, good luck!
this is the most condensed, professional and credible video I have seen on the subject. Congratulations
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 agree, thorium MSRs are probably the fastest way for us to get off fossil fuels. I don't think Elina likes the thorium LFTR reactor design. I think we are seeing a sunken cost fallacy here, which is literally why research was stopped in the 70's on MSRs. The thorium abundance part failed to mention that we need something like 35 times less thorium than uranium to produce the same energy in heat. MSR reactors can also convert that energy into electricity more efficiently. So yeah to hell with uranium, we would never need to get it off the ocean floor. MSR reactors need more research done, they are superior in many ways to other reactor designs, its not just thorium reactors that need research done and need to be built. LFTRs combine the best of both.
Also a byproduct of U233 is a gamma emitter, U232, which would make a bomb easy to detect remotely with instruments. There are also methods to reduce proliferation risks that have been addressed before, for example running a design with “denatured” solution including U232
@Robert Weekes you sour milk the milk, so it doesn't taste so good... No one wants to have that around..
For your point 1, how do you account for the Protactinium, which was the stage that Elina specifically called out as the proliferation danger? That's what needs to be stored separately until decayed into U233, during which time weapons-grade nuclear material is increasingly available outside of the reactor, a situation not found at all in a typical uranium-based reactor.
@@theotherguy982 The decay from Pa to U233 only takes a week or so, thus there needs to be no "separate storage". It can be kept in dynamic salt solution. There will be no difference in the security measures between Th and U plants. all fissile material needs the same precautions. Who are you getting your information about "separate storage" from?
We don't need Thorium yet:
_"Less than a kilometre from the western shore of the Bay of Fundy, the Point Lepreau Solid Radioactive Waste Management Facility temporarily houses about 160,000 spent fuel assemblies from New Brunswick’s only nuclear power reactor. Moltex Energy, a Saint John-based startup, proposes to recycle that radioactive waste into fresh fuel for a new 300-megawatt reactor called the Stable Salt Reactor-Wasteburner, or SSR-W."_
We need thorium to avoid going to war over Ukranium supplies. Look at how Russia already invaded Ukraine to take all their Ukranium. You won't see this in the mainstream media.....wake up peeps, we need you all full woke.......
No one else I've ever watched talking about thorium has ever explained the proliferation issues with it. Thank you that was fantastic
Elina should be highlighting denatured molten salt reactor, too. That is a good use of Thorium. Mixing U238 with U233 to address concerns ... Reference Th232 -> U233.
Finally, a proper explanation that isn't just hype.
You made it quite clear and understandable.
Thank you very much
+1 on that. I've seen a few clips about this, but clearly they did not understand the process and implications.
@@mightym Hidrogen plane combustion? It is not that clean. It burns at higher temperatures and it creates much more nitrogen oxides. Might be an intermediary solution until we have completely clean transportation.
@@mightym That is very simple. You do not use pure oxygen, but you use air. Air is about 80% nitrogen.
@@mightym Where do you get the energy to split water? Hydrogen is an energy storage technology. Nuclear fission is an energy generation technology.
@@mightym Maybe you're looking for a free energy scheme?
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.
This is true Google is great.
Additionally, the disposal of thorium is a big part of why it's very hard to get rare earth mining approved in Western countries. Being able to turn a waste product into a product would go a long way toward opening new sources for the rare earth elements we need for expanding renewables. The irony is that using thorium could hasten the transition to renewables.
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!
Thank you so much I’m so glad you found it informative ☢️👩🏽🔬
Ofcourse they have downsides. But they have soooo many safety upsides it's insane. The biggest being that it does NOT use high pressure water in the reactor which is the biggest cause of disasters from the current designs. Because high pressure water flashes to steam and creates a hydrogen explosion. Hot gases goes UP into the atmosphere.
LFTR's doesn't use any high pressure anything. If there is an accident where the molten salt for some reason would leak out of the reactor. The contamination is contained locally and the salt freezes to a solid salt. Making the contamination very easy to manage. They are also very much cheaper because they don't need a huge containment building around them because of the same reason.
The designs I've seen also have a drain tank with a freeze plug. Fans using power from the reactor to blow cold air on a pipe to a drain tank. Freezing the salt to a solid state creating this plug. In case of a loss of power the fans stops cooling the pipe and the hot salt melts the solid salt in the pipe. Then it all drains to a draintank. This tank is prepared with a lot of surface area and neutron absorbing materials. Meaning the whole reaction stops and the salt freezes solid as it cools down.
@@SonnyKnutson hey dude there's a video above your comment you may want to watch.
@@YourFriendlyNuclearPhysicist
Hey, how about liquid metal cooled fast neutron reactors?
By using an eutectic mixture of tin and gallium that melts at 21C but boils at over 2000C we can make cores out of solid but thin thorium-uranium metal alloy disks stacked on rods and placed in a honeycomb shape. The volatile materials escape through the tiny spaces between the disks and bubble to the top while the rest mostly stay on the rods.
Given a large enough core that can overcome via the square-cube law the neutron deficit due to escaping neutrons, it would actually be a viable way of producing power with minimal waste.
@@SonnyKnutson yeah, well, no. Creating hydrogen from water does not require steam or pressurized systems. Radiodissociation can happen at room temperatur. Molten solt reactors generate Tritium, an Hydrogen isotope, during STANDARD operation, which has to be dealt with. Some "salts", like UF6, are gases even at room temperature. They can be generated during standard operation, too. Unexpected contaminations like these have been found in filters of test reactors, and the engineers were "surprised", to say the least. You are not as proficiently informed as you think you are.
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.
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.
Easily done as well, just make the tank a donut shaped reservoir
@hewdelfewijfe
Your 'common misconception' was used for 2 years in Oakridge over 50 years ago. The reactor shut down every weekend when scientist went home. Shut down in hours not months like other reactors. Then restarted every Monday. The same cooling pipes used for the heat exchanger could be used to remove waste heat and even if they weren't the heat isn't so high that it's a problem. The reaction stops. The fuel solidifies. The heat dissipates. Nothing melts down. Too hot no fission. Too cold solidifies. It's completely self-regulating.
@hewdelfewijfe
"When you scale that up to a commercial reactor, you're going to have much higher power densities, and then passive air cooling is not enough."
A scaled up reactor would ALREADY have something other than passive air cooling. Are you really suggesting that it wouldn't also be used to cool the drain pan?
"The drain plug is primarily about solving the problem of recriticality by moving the fuel to a new geometric configuration."
It's not just the geometry. It gets the fuel away from the graphite moderator.
My point still stands. If air cooling was enough to handle the decay heat on the Oakridge reactor then decay heat isn't a serious concern. REGARDLESS OF THE SIZE OF THE REACTOR! In fact one design incorporates storing the fuel until it decays to the proper element for burning then reintroducing it to the reactor.
Molten Salt Reactors won't run at higher temperatures. The reaction is not sustainable at high temperatures. It's why they're inherently safe. Scale doesn't matter. In fact part of the problem with using them for power generation is their temperatures run so much lower that steam isn't the best choice for the power turbines.
You're mixing the physics of the uranium chain with the thorium chain. Decay heat doesn't continue to build until it melts everything around it in the thorium chain. The higher the temp goes the less decay occurs. And without a moderator even at the proper temperature the reaction doesn't proceed.
@hewdelfewijfe
Considering your arrogant response I figure I better simplify it even more for big brains like you.
Molten Salt Thorium reactors are low temperature. It's the only way they work. Making them bigger doesn't change that. More 'power density' means higher temperatures. Higher temperatures means less or no reaction. Your entire premise is flawed.
@@tonyrmathisIt was not researched further because of it's inability to "easily" produce weapons grade waste .
It is clear that research for domestic energy production was centered around military applications for enriched fuels.
They actually said this in papers documents. I'm not making frivolous accusations.
There were problems , but no resources were allocated to solving those problems . Money and manpower were allocated to solving the issues with Uranium reactors, because of military applications. This is why the USA and EU are so hell bent on stopping Iran's nuclear power plants.
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.
This scientist is highly capable and a delight from which to learn. Thanks so much for this excellent work!
She knows and understands what she is talking about. A rare phenomenon these days. 🍷🌁
no, it's all biased BS.
Thanks Elina, I have subscribed, because of your unbiased and knowledgeable video. I worked for 35 years in the nuclear industry, NOT power generation but lots of work with isotopes. To me, it's not a case of 'teams' or 'winners', its about making the right choice and videos and input from people like yourself should give us the best option. Keep safe and keep up the good work.
unbiased 😂😂😂😂😂😂 russia sits on the most of the nuclear fuel market do you astroturfing trolls think we are all stupid???
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!
the thing is, modern reactors are already INCREDIBLY safe, of course being virtually impossible to catastrophically fail is better than incredibly safe. but given all the other problems, the safety ends up being not as interesting.
@@danilooliveira6580 No, not so "incredibly safe". High pressure water Uranium reactors will ALWAYS be inherently dangerous, prone to runaway meltdown and steam explosion.
Three disastrous and long-lasting failures already across the world (plus two more in 1957). And then there is the easily retrieved Plutonium...far more dangerous than U233.
@@danilooliveira6580 Except for the cost. Current designs are safe because a lot is invested in construction. If new designs are safe by default then the cost of construction could be reduced. For example, MSRs operate at low pressure and can do without those costly containment buildings.
@@m4ktub1st No, MSR operates with extremely reactive coolant with high temperature which means it's the opposite of "safe by default" thus the safety measures are probably more expensive than PWR. MSR is only safe from total melt down. It has higher risk of other accident.
Also, high gamma radiation means more embrittlement of core material = More frequent maintenance & shorter life span
@@dongleseon8785 Thank you. I was indeed assuming most of the cost was to protect from a total melt down, the most catastrophic scenario.
Great explanation, Elina. There were a few things in there that has not been brought up and explained in other videos on the subject. I wasn't aware of Uranium 233 and how it is weapons grade. I do agree that finding a way to burn our old nuclear waste is a priority. Waste is a resource not yet exploited.
Burning waste can be done most easily in an MSR, because it’s much easier to do chemistry with liquids than solids 🧪
There are already some ways to burn waste, but it has so many downsides and is so expensive that we dont really do it.
You haven't heard about U-233 being weapons grade because it isn't! No country has developed nuclear bombs based on U-233 for a reason. Impurities of U-232 as low as 50 ppm are enough to make it unusable for nuclear bombs and the impurity in a Thorium based reactor will always be much higher than that.
@@ObiWahn68 but u-233 reactors do produce weapons grade material. 😂
@@outerspaceisalieNo, they don't. What kind of material are you talking about? As I explained the U-233 itself isn't weapons grade due to the impurities and they produce neither U-235 nor Pu-239. 🙄
Can you do a video explaining the difference between generation 1, 2, 3, and generation 4 reactors? Excellent videos I have watched every single one!
Mostly it's built in safety measures.
One example I know of with a Gen 3 PWR design was using borated water in a "pool" at the bottom of the reactor vessel that due to density differences would stay in the "pool" while the regular water was traveling through the core. However, if the regular water started to boil off, the borated water would naturally move upward from the "pool" to cover the core and shutdown the reaction.
Gen 3+ reactors typically require an act of sabotage, by removing the inherent safety systems, to cause a meltdown. Typically the worst accident you'll ever see with Gen 3+ reactor is a LOCA (loss of coolant accident) which on the scale of accidents is a 4 (TMI was a 5, Chernobyl and Fukushima were 7, the highest, Windscale was a 6). Accidents scale 1 to 4 are always contained within a small area whereas 5 can get into the environment and 6+ has environmental impact.
@@csdn4483 Also, Gen 4 contain large improvements in efficiency: from Gen 3/3+ ~33%; Gen 4 ~50% efficient.
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
I’m with Eugene Wigner and Alvin Weinberg on this one… Go Thorium MSR!
I think CANDU reactors are the way to go. They can run on unrefined uranium, thorium, or even spent fuel. They can refuel without shutting down. They also have been used for decades and are a known, safe design.
Once-through fuel cycles are nuclear training wheels; for million year sustainability we need breeders (Th or U238) and reprocessing.
Yes Candus can breed using thorium, but they need more frequent reprocessing compared to fast breeders or LWRs, which drives up cost. Liquid fuel makes reprocessing cheaper, so it's that or fast breeders (with or without LWRs).
I’ve heard a lot about the advantages of thorium. This was a well balanced and unbiased presentation of the pros and cons.
Did she skip over the safety aspects of did I just miss it? Not being able to sustain run away chain reactions that lead to meltdowns is a major advantage in my opinion.
@tonyrmathis Yeah and having cesium rods that need to be in safe storage with no earthquakes for 1000s of years could be another advantage. Better to just completely ignore the benefits of disposing of such waste with breeder reactors (LFTR Thorium) in favor of going with what you know works. (Apologies to other readers that I emit sarcasm in response to untruthful stupidity). Tony and I got triggered.
@@wezleyjackson9918
I find there's two types of people who oppose thorium reactors. Those with a vested interest in other designs and members of the eco-cult who don't consider humans to be part of nature.
One doesn't want change because it means less money and more work for them. The other that just hates people and wants fewer of them.
Kind of - though she did miss a few major points - and failed to properly mention the LFTR’s advantages.
See my other note about 7 points missed.
@@tonyrmathisYour right, she missed several major points about the advantages of LFTR. No mention of the higher thermodynamic efficiency from operating at 800 deg C for instance. No mention of ‘freeze plugs’.
She did mention ‘negative coefficient’ of ‘operation’ - but failed to explain it.
(Thorium reactors are passively safe - because if they start to overheat, the liquid expands, reducing the reaction rate, so it cools down by itself). That was tested out at oak-ridge, when it was left running for several days, without any active controls being used.
The thing with thorium reactors and uranium there will always be advantages and disadvantages. But honestly I agree we need something where the reactor deals with its own waste, I would also be open to the idea of fast breeder reactors.
google 6 150 000 results for history of past experiences like superphenix tricky staff
Waste hansn't been an issue since the late 60s when dry casks were being utilized and not a sinlge leak has ever happened from a dry cask. Also you can bury them similar to how the planet handles its own versions of nuclear waste on site and it wouldn't be harmful or dangerous to anyone and you could easily do it for the life of the entire plant.
I have to be honest this was one of the better explained Videos on thorium reactors Most of us are Novices at how a thorium reactor would work with the pros and cons to go with it.
I think really what we should be focusing on in this technology is the molten salt aspect of it. The incredible efficiency largely comes from that aspect of the technology. Thorium is great for a lot of reasons and it is probably our preferred fuel but what's wonderful about molten salt is that we can make it much more efficient and separate out waste products very easily as well as building intrinsic safety in the geometry of the nuclear core through thermal expansion and the drainage basins.
I had heard of Thorium and molten salt in terms of reactors, but never so detailed and well explained. Thank you. Real Engineering just covered Helion's fusion reactor, I'd be curious to see your reaction to it.
:)
Yes- saw the Helion news too. Looks interesting
I may suggest this video, which treats the matter in an even more in-depth way: ruclips.net/video/H6mhw-CNxaE/видео.html
@@Joe-by8jh Did you mean fusion reactor? Your comment makes no sense either way.
@@Joe-by8jh ... I'm pretty sure the thorium reactor at Oakridge was connected to a thermal radiator because there was no generator connected to the heat exchanger. It pumped out a bunch of thermal energy that had to be dissipated. It isn't really like fusion where you need to pump in loads of electricity... Once the fission reaction is happening all you have to keep up to it is more thorium (except for running the pumps and other machinery I suppose). My biggest gripe about the Oakridge reactor was that uranium was mostly used in it to test the design.. A lot of thorium was turned into U233, but they were shut down for political (supposedly budgetary) reasons before they could use much of it. Something like 500t of the U233 is currently being destroyed because it was never allowed to be used (a significant effort is underway to save that U233). Also because of the way they were shut down, the reactor and equipment were never cleaned out before the fuel froze inside. They still have to clean that up somewhere I believe.
The concept of the experimental thorium reactor requiring more power than it made isn't really a logical concept for fission power in general I don't think...? Unless you have statistics on how much power was required..? I think the thermal output at the radiator was about 7MW..
Thank you so much for making this! I really learned a lot from it, found considerations I didn't realize was there. I'm actually less optimistic about thorium now than I was before, mostly because some of the stories I heard was apparently wildly exhaggerated. Top notch Elina :)
Finally, a professional who actually knows about Thorium! That was a fantastic explanation. Also, great to see that some young people still do go into the sciences, very important for all of us. Keep up the good work!
An technical and well balanced look at reactors, or any energy source, is a rare thing as it seems as if there is a tug of war over the future energy market as it continues to grow. Thank you for this.
I think you would get a balanced view from any nuclear scientist.
@@langdalepaul ... just like we got a balanced view about the COVID "vax" from any doctor ? Hah !! 😂
Excellent video! I was arguing with my nuclear engineering friend of mine (I'm an electrical engineer) over thorium reactors a few years ago. He was very much against adopting it on scale based on practicality.
Thank you I’m so glad you liked it 👩🏽🔬☢️
Other than her, he had actually a grasp to reality and not just so flashy promotions from a bunch of tech scammer's😏
My experience of doing the requirements analysis of the control system for a nuclear power station project has made me a fan of renewables.
Basically the interaction between government & large private interests make megaprojects with large political & economic implications very traumatic.
@@RobBCactive 🤣🏆
Thank you for your unfiltered opinion on the subject that isn't poisoned by unbridled optimism. You clearly have a more informed background on the subject and the ability to reason about the benefits as opposed to the disadvantages. Thank you again.
As a former reactor operator trainee, the Department . of energy defunded our FFTF Project and I along with hundreds, all disciplines were laid off, your discussion was excellent, I preferred uranium
amazingly clear, concise and through presentation. logical analysis of pros and cons. Storage and proliferation are obviously of relevant concern.. thank you
So good to hear the other side of the coin on this matter! All I have heard previously was positive with no hint that there was any downsides to thorium at all.
This is the best video I've seen of the pros and cons of thorium reactors. Thank you!!
Thank you so much I’m glad you appreciate it 👩🏽🔬☢️
Amazing video. I really love they way you take a subject and you break it down into parts and then start to explain each part. It is so helpful to understand the topic. Thank you can't wait for your next video ❤️
A very good thorough description of the Th process! Tanks for the effort!
Great and clear video, thanks for the explanation! I'm just starting to learn about Thorium and this definitely got me to start in the right track
Honestly, molten salts seem to have so many applications over the last 20 years.
Learning about Thorium reactors in a balanced, nuanced way is why I love this channel.
I think the main reason there is lots of talk about molten salt reactors and batteries is we now have materials that will not corrode as easily with different types of molten salts
@@HootMaRoot Yes, still more high temperature corrotion resistant materials would be needed but a lot of it already exists. Plastic composites that can take nearly 2000 degrees celcius.
@@HootMaRoot I think a good section of the video should have been devoted to materials now available that can make lftr a reality.
@@HootMaRoot "As easily" are the key words. There is no known material that can handle molten salt. It's like liquid sandpaper. It will deteriorate anything eventually. The only answer is to build two power plants and constantly rotate one while the other is being rebuilt. Not worth it.
@@ipissed
Why? Just make sure each lasts long enough to payback and more the investment, and have enough spare parts so they can be built fast enough.
Done.
Great video and feels free from any agenda or politics as these topics often get loaded with. For my part I hope we continue research on Thorium reactors, but after hearing your pros and cons I am less sold on them then before.
Great video, but one mistake is to assume we would long-term store the liquid fuel as spent.
All waste elements would be extracted from the fuel on a continuous basis, in a process that would probably be economically viable from just selling other trace elements being produced. A lot of very expensive isotopes for science and medicine would be more available this way (molybdenum-99 etc). The unwanted biproducts would be in oxide or fluoride form that after aging becomes for example metallic forms like Neodymium. With the electric car industry requiring staggering amounts of this rare earth metal this waste also becomes a business. (Neodymium-147 has a half-life of 10.9 days so not very much more aging than is done with cheese.)
When it comes to proliferation the liquid uranium reactors would not be any better as the actual risk is in a reactor where different parts of the biproducts can easily be separated out during operation. As-is, non-liquid reactors are run to produce materials, and then the fuel rods are liquified and centrifuged in a separation and enrichment effort to produce the same materials. The liquification can be based on salt again, so pretty much the same.
amazing video, really appreciate the plain language explanation
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!
While a new regulatory and oversight scheme might be needed to secure the Protactinium as it decays to U-233 stored outside the core in some countries, I don't think that is any more a proliferation risk than the Plutonium in current waste streams, or indeed the U-235 already used in current fuels. Team Thorium!
Agree. The many many added safety benefits of LFTR's seems like a nobrainer to me. One of the biggest being that there is no high pressure water in the reactor that can spread into the atmosphere in case of a catastrophy. It simply leaks and goes solid without much contamination except some local.
Well I guess reporcessing and pulling out the Pu-239 from spent fuel is chemically a lot more challanging than just fluorinating your Pa-233 decay tank until the U-233 hexafluoride bubbles out which is about one more step away from being ready to make a bomb out of it. Now Iam normally the one who dismiss proliferation risks, as I think it's bizarre to imagine a bad actor with the resources and scientific background to covertly steal the material, build a bomb out of it (without any testing) and use before anyone notice, when going a much cheaper and frankly technicllly simpler route with bilogical warfare just makes a tons more sense even if said actor just wants to see the world burn, I thought it worth mentioning why the two things are different by their difficulty.
Seperating is actually easier, building a bomb out of it when you can only remote handle because of U-232 contamination with hard gamma decay chains is not trivial matter at all. So as many thing it is actually nuanced, its true that separation is easier but does it make it more of a proliferation risk ? I don't think so.
the sub critical design is good, and if the pump shutoff, the reactor just cools down, eventually, passive safety is a win.
The regulatory regime in many countries is designed solely to defend old school 1950s reactor designs, and the later minor (improvements on that design). Or rather, the regulatory regime is designed to defend the regulatory regime.
The risk of weapons proliferation due to use, disposal, and potential abuse of thorium reactors is far less than the risks associated with use, disposal and abuse of medical grade nuclear products. The risks of failure are astronomically lower than light water and presurised reactors. And the thorium reactor design lifespan is substantially longer vastly reducing decommisioning costs.
To make a comparison, the paperwork required to obtain a thorium reactor licence in mosy countries (those signed up to the present international regulatory regime) exceeds the amount of paperwork required by the entire global civil aviation regulatory regime to authorise use of a new aircraft. Not because the regime is pointless, but because the nuclear regime -unlike civil aviation- is based not on sound scientific and engineering premises, but because the nuclear regime is designed purely to reflect cold war premises, and 1950s high pressure reactor designs and not open to adaptation to accomodate newer technological developments or scientific advancement.
Fusion reactors actually have a easier future simply because it steps arround the entire nuclear regulatory regime.
@@johnwaldmann5222 Couldn't have said any better.
One of the best scientific "LECTURES" I've ever heard on the internet. Thanks from EGYPT
it is a BS presentation.
The U233 proliferation issue is one the Thorium fanbois never mention. Plus the more practical issue of high level waste. Thanks for raising it. Very succinct explanation. Thank you.
Very informative video, and good to see you address the proliferation risk! That is also my main concern, and it's often missing from the discussion. One model that seems safer and more useful is to use a combination of Thorium and depleted Uranium as fuel…
But neither thorium nor depleted uranium are fissile, so you need to transmute them into U-232 and plutonium in a breeder first. But because it's relatively simple to chemically separate those products from their precursors (when compared to uranium enrichment), it immediately creates a danger of proliferation of weapons-grade fissile material. I'm sorry, but that doesn't fit my definition of "safer". YMMV.
@@RexxSchneider Proliferation is a BAD argument !!! The countries with long history of operating nuclear reactors and even thouse countries which posess or produce its own nuclear weapons, how that "proliferation" mantra forbids them to design, build and succesifuly operate liquid salt thorium reactors on their own soil? You see - your many times expresed mantra is 100% debunked !!!
This is very interesting topic - Indian nuclear policy has been focused on Thorium since the beginning as we have the world's largest or second largest deposit. Furthermore, we were cutoff from all nuclear discussions for decades (Pakistan was allowed though despite being known nuclear proliferaters) so we had to develop our own way with things regarding Thorium reactors (Breeder reactors). We are focusing on becoming self-sufficient energy power with our own reserves in the next stage of our nuclear policy.
It is an impressive feat, it's also a testament to the CANDU reactor to be able to run on it as well.
Thorium doesn't lend itself well to solid fuel systems due to the extreme gamma issues of the fuel rods and produces at least as much waste as uranium if used this way. Indian efforts have been mostly geared towards solid-fuelled operation and suffering accordingly
The best way to proceed is to get a working molten salt system and THEN switch to fuelling on thorium. Keep an eye on Wuwei...
This is more in-depth than reaction videos, I love it. Would You consider expend this into a series on Generation IV Nuclear Reactors?
Kalimera Elina. Thanks for a great overview, and doing it in English. I'm super impressed that you did this in your second language. I'm sure I couldn't even understand this in the other languages I know.
I’m a long time viewer and supporter of Subine and only today discovered your channel. Loved your reaction to her video and look forward to viewing more of your content.
Love your videos, they are very helpfully. I have a test about partial physics, and your content helps me be motivated about the subject and helps to learn.
Nobody seems to have ever heard of the Canadian heavy water reactor CANDU, that's been around since the 70s. From what I can tell it's a unique design. Where I live, CANDU reactors provide 2/3rds of our electricity. They run on natural uranium with deuterium as the moderator, and can be refueled while running, with the fuel loaded horizontally instead of vertically. Control rods are suspended electromagnetically for passive shutdown with power failure.
I only recently started looking into nuclear, and CANDU was the first type that popped up while hunting for PHWR details. Seemed like there was a lot of development with some issues with politics and execution, and it was hard to tell whether their newer models just aren't being implemented due to past failures or whether other models are more attractive--or some combination of the two.
To me, not knowing much about it, the designs sound pretty good for small-scale, potentially modular designs. Like some other commenters i'd definitely like to hear Elina's take on recent or not-so-recent developments for CANDU-6 derivatives and CANDU-9, and whether there is a future for the models despite what appears to be a lack of significant interest. The US hasn't seemed to have been a target market, and i'm wondering whether we just have better designs already that i haven't seen yet.
@@eboyce24 CANDU was developed b/c Canada was a tier 1 nuclear power that participated in the Manhattan Project, but didn't have the manufacturing base to build large single vessel designs, and wanted to be free of the enrichment requirement. Deuterium allows use of natural uranium, and the pressure tube design allowed easy manufacture of the bits. The downside of HW is more space is required btwn fuel bundles so the core is larger overall than an equivalent light water reactor. US and other powers were uninterested b/c they needed the enrichment capability anyway for weapons. However, another bonus is you can burn spent LW reactor fuel in a CANDU. S Korea has one of each and does exactly that.
Great video!
Please do one on CANDU / heavy water realtors.
They have a lot of hype around them like Thorium reactors. It would be nice to see an unbiased video on these too.
There have been tests for the use of thorium as a fertile fuel in HWRs that are using reprocessed LWR fuel. Speficically Pu-Th MOX , a Pu-Th-U MOX, or a sort of a «breeding blanket» similar to the ones utilized in fast breeders. India is the country most interested in developing this technology at the present. I personally like HWRs quite a bit. And its a much more proven technological basis than LFTR.
This was very interesting :) I did not know about the liquid salt state of the thorium in these reactors. Thank you so much for the great explaination of how this works :)
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.
LFTRs has graphite in its core to moderate speed of neutrons, so the graphite deforms under neutronic radiation and needs to be replaced once in a while, this increases the operational cost, however there are solutions to mitigate this cost. Another problem is leaks of tritium, also could be mitigated with some engineering. The Hastelloy N was invented in ORNL during MSRE and according to some reports I have read from MSRE the corrosion found was tiny or non-existing.
The problem with Hastelloy N is that it was never nuclear-certified. In the US that certification would take 20 years and a few billion dollars because the NRC hates nuclear. Instead, they are just replacing (refurbishing) the reactor vessel every 6-9 years as you said. From the numbers I've seen, this is still very economical.
Three countries have tried to use U-233 for bombs. The US, the USSR, and Pakistan. All three tried it and ran away from it, due to the severe problems of gamma ray raadiation and the life of a bomb's internals. None of them tried it a second time. That is as far from proliferation as you can get.
Great video. Really hoping that the CANDU SMR projects continue to be funded and eventually produce effective reactors. Widespread use of SMRs that also burn waste would be a huge benefit to reducing waste and fossil fuel use. Not sure if the SMR designs provide for any tritium extraction for fusion research but given the general design of SMRs I doubt it.
Why is everyone so worried about nuclear waste? After all, nuclear waste is literally a few square meters of space near the station. Unlike coal-fired power, which emits thousands and thousands of times more radioactive waste, among other things. When coal is burned, radioactive waste is also generated. Does anyone take this waste into account? No. In fact, when the pipeline to Germany was blown up, it was like dropping several atomic bombs. But no one cares at all.
As to the waste problem - the fact that its higly radioactive means that it has a short half life, which means that in the long run its less of a problem than conventional nuclear spent fuel which requires tens of thousands of years of storage instead of tens of years that the lftr waste would require to become safe.
Problem with potential weaponization is pretty much nonexistent, because simply the fact that an element will exist in the fluid core, doesn't mean that you can physically separate it from the fluid to get any weapons grade resources.
That's exactly why its the conventional nuclear reactors (special versions but still) that are used to manufacture weapons grade uranium and plutonium, and one of the reasosn why lftr research was dropped by the usa over 50 years ago - because it was impossible to practically extract anything valuable to the nuclear weapons program from lftr reactors.
The presenter is highly & divinely intelligent, may God create more of this type of people, her voice and countenance is also angelic... Bravo Elina!
First, the reactors used in France use Plutonium as a fuel source which is highly usable to make nuclear bombs. Second, the US DOE designed and implemented a Thorium reactor in the 1960's and the reactor was operated for over 5 years without an incident. The reason why the project was shut down was because DOD had decided that light water reactors were to be used to power submarines and other military platforms in the late 1960's and they didn't want this initiative to detract from the DOD decision.
Gov interference
Molten salt as a heat exchange is a pretty cool idea, even without a nuclear heat source. I feel like I'm in the early days of the steam engine.
Early days of steam engine while the rest of the world is far ahead.
Thank you for this balanced and honest analysis. Ther is a lot of talk going on and it is hard to determine what is true and what is wishful thinking. What i take away from your talk is that the process engineering is still incomplete and needs research and proliferation is a concern.
I think these are challenges we can crack and the promise of safe and low cost energy is still there in LFTR. This should get more attention in the university community and politics should free up the way to develop this.
Indeed 👩🏽🔬☢️ thanks for your comment
How can you call it balanced and honest when she intentionally misled the audience to believe that fissile Uranium235 is only 3 times less common than Thorium by using the numbers for the useless U238?
@@axl1002 it was shown in the graph.
@@wollm1325 It doesn't matters, the uninformed people will understand 3:1 because that is what the scientist said in general. The people don't care for the details.
The idea of using what is currently considered waste as fuel in future reactors seems like a good one. I hope we can devise passively safer modular reactors that can do this.
Very underrated channel; thank you very much for this beautiful video; this should be shown in all secondary schools from grades 6 and up. Keep up the good work, loving the feeds.
Amazing, I love it ! Thank you for the perfect sum of MSR and Thorium explanation. Will look for new episodes
I was afraid you were selling thorium and playing down its weaknesses, but you came through in the last half and brought up the realities that I knew must be. Very good, as always.
Can you do a similar video with Copenhagen Atomics including their response to your comments on proliferation?
Team Thorium! Well done. I would love to see major DARPA emphasis placed on research and development. Any process that transforms 200,000 year half-life waste into 200 year half-life waste is moving in the right direction.👍
Ironically most of that "waste" isn't fuel rods but clothing and lab equipment or anything else that comes in contact during the refining and processing of uranium.
I love that Elina understands that the student, before understanding the answer, must understand the question. I'm pretty old, and just how the next generation gets energy is unimportant to me. I watch because I take pleasure in hearing complex issues described in plain language, but not reduced to child-friendly tokens.
Okay, on your video commenting on the "Nuclear Waste" video, I said I wanted a video on Thorium--and here it is, and as complete and thorough in answering all my Thorium questions! Very impressive! And thank you for educating us on these important, possibly emerging technologies.
Hello, thank you for this. Regarding storage of the molten salt waste materials, you mentioned that liquids are difficult to store long term. Wouldn’t they solidify once they are out of the reactor (they would be “salts”, not “molten” any more)?
I think the fluorine-salt compound itself is a liquid, even at room temperature. MAYBE? xD
FLIBE salt is solid at room temp. and actually dissolves only slowly in water. Not too bad, imo. Fresh out of the reactor, with no chemical repurification cycling, you would have radioactive self-heating. Enough to keep it molten for a month, maybe? I dunno that. There are usually two stages of conventional spent fuel storage. Fresh&hot, in a pool. Older&warm, in a sealed casket.
You are correct, she got that wrong.
You can also remove the Flibe salt through vacuum distillation. In other words, you can theoretically separate the salt, the fuel, and various fission waste products in a process that is similar to what is used in the oil industry to separate various hydrocarbons, just at much higher temperatures and more corrosive conditions. Technically challenging but in theory possible.
Unlike the oxide based fuel in uranium reactors, many heavy metal fluorides will react with atmospheric moisture. This results in production of toxic HF as well as water soluble complexes which can leach out. So, 'dry' storage underground would not work well.
About the storage for the salts. You say they are liquid but they are not liquid in atmospheric temperatures. They melt at around 2-300 degrees. So they would be solid for storage. Like table salt :P
Yep, she got that part wrong.
Salt dissolves readily in crust waters.
@@dalethomasdewitt Not that form of salt.
Hi Elina, can you discuss about high-temperature gas-cooled reactors like Japan's (red/pink) Hydrogen reactor that got activated last year and claims to produce energy and hydrogen in an environmentally sustainable way? Also any thoughts on the recent development about nuclear fusion announced by the Americans.
This please 🖤
The recent development about nuclear fusion announced by the Americans majorly downplayed the fact that to charge the lasers required 300Mj. They focused their announcement on the measure that the 2Mj lasers produced 3Mj of output, and WOW ignition was achieved. That is very, very far from net energy gain. 2c
@@MonsterSound.Bradley Yeah Fusion announcements only ever count the energy difference in the last step, and leave out the 19 other steps along the way that cost them 99% of their energy.
Συγχαρητήρια Ελίνα. An excellent explanation, keep the videos coming.
You explained the pros and cons of using thorium very logically and clearly.
Previously, I read materials that only sang praises of thorium.
This video clears up my puzzlement over why thorium was not chosen over uranium when the nuclear energy was first started.
Thanks very much.
Excellent presentation. You answered virtually all of my questions. I'm thinking, the thorium "deal breaker" is the high gamma ray emission of thorium waste. Shielding against gamma rays is extreamly difficult. Its like trying to eliminate light from a nightclub. Any tiny "leak" is like a gamma knife, and can go undetected for a time if it arrises newly. Its a huge challege for gamma ray source labs, and they are not dealing with the huge amounts of material the industry would need to ramp up to. Not impossible, but inconvenient and dangerous.
Go tell the Chinese who claim to have a Gen4 commercial grade research Thorium LFTR reactor running safely. Just because the USA and entrenched Uranium/Plutonium industry turned their back on Thorium LFTRs and development has only gone ahead by India and China, doesn't mean we can conclude this technology cannot be safer than traditional Uranium/Plutonium nuclear.
Thank you, that was a pretty good explanation and summary of the state of art. I always wondered about the Thorium hype, and was a little suspicious it might not be as rosy as sometimes depicted. Your presentation confirms my reservations. The aspect of proliferation of weapons grade fuel might indeed remain the biggest obstacle for wide commercial use, compared to the technical issues which probably will be solved sooner or later.
Unfortunate reality:
It's easier to sell a molten salt reactor to the public because of the very high passive safety, and honestly public perception is BY FAR the largest barrier to nuclear research...so might as well embrace that
What a good explanation. Well done for being impartial and mentioning some of the negative aspects and challenges of Thorium as well as the good, many other posts claim it is almost non-polluting, whereas you give details on how toxic it is likely to be.
Great to hear someone who knows what one is talking about. Very well done!
Finally, a proper girlfriend candidate
ruclips.net/video/ykz9Pe6nFyY/видео.htmlsi=T95lKoiZs4c5ghZa
As I watch this, I have not yet seen the "Oppenheimer" film, but its release encouraged me to read "The Making of the Atomic Bomb". It is a great read (though long!) almost in cases like a novel, yet all well documented. Thank you for the content that you produce, it makes physics attainable for folks like me, two years in high school decades back, and one for non-science majors in college.
Richard Rhodes' book "The Making of the Atomic Bomb" may not be the primary source material for "Oppenheimer" (which I saw on opening weekend), but it is a fascinating and very accessible piece of historical science writing which I recommend to everyone wanting to read about the history of nuclear physics and the bomb up through the end of WW II. I've read it twice now. A short read about the atomic bomb survivors' stories which came out shortly after WW II by an accomplished journalist is John Hershey's "Hiroshima". I'm about to read the weighty piece of deep research book more directly focused on J. Robert Oppenheimer, "American Prometheus" by Kai Bird and Martin J. Sherwin, which is the text that Oppenheimer was written based on, and I'm very much looking forward to that.
Man's history is the inhumane conduct against his fellow man. I had not heard about the capability to weaponize the material. It had been my hope to lessen the danger from nuclear reactors. I appreciate the information.
The most comprehensive "essay" that I heard so far, on Thorium reactor, to date.
With all negative points, Thorium reactor is safer compared to the Uranium ones, even the mining of which is - hazardous. Lot of work is awaiting to be done on Thorium reactor still, which isn't as straight forward a s a U235 reactor. Problems abound & need to be tackled one at a time. What is needed is effort with a lot of patience. Thus, the development of Thorium reactor is a lengthy process, with many unknowns. The narrator (a nuclear scientist herself) explained all that, patiently & with knowledge.
Thanks for the video!
I'd be interested in a part 2 with more detail like dollar cost comparisons, radiation field strengths, half lives, and the interesting materials science questions.
For answers about the economics, chemistry, half lives and materials, do a Google search for ThorCon Power and also Gordian Knot Book by Jack Devanney
Very good presentation! The best I've heard so far over the last several years.
To quote someone: The Moltex Static Salt design does away with almost every hazard from traditional nuclear power. Its sheer simplicity and intrinsic safety should dramatically reduce costs. It’s also scaleable by building more reactors on the same site. It is naturally load following and and cannot over heat. Excessive temperature stops the nuclear reaction long before it becomes dangerous. It could be disconnected from load at full power and nothing nasty would happen. It has boron shut-down rods but they are not needed as an emergency tool.
There is no water or steam in the core so no pressure and considerably less corrosion than we get in PWR cores.
We should be moving heaven and earth to build these things. Instead we have an out of control nuclear regulator that completely stalled progress. Moltex is now getting the job done in Canada.
There are many options for managing oxidation in MSR reactors that are being tested. Removing oxygen is just one simple option. India is well along the way to building dozens of fast breeder reactors. India has very large deposits of Thorium. China has a prototype MSR reactor operational using a significant amount of US research and technology. China has a significant stockpile of Thorium as a by product of rare earth mining. MSR reactors offer a great method of burning up weapons grade material and waste which can greatly reduce proliferation risks.
Best balanced explanation of thorium reactors. Its hard to find an honest presentation on this matter.
Great explanation of the complete fuel cycle. Thanks for making this video.
Hi Elina,
In the future I would like you to explain the type of reactor on Thorium and U238 which are BOTH found in abundance in combination with a small particle accelerator( already in existence) in order to produce fission between the two of them.
Thank you for your lovely and cheerful explanation! All the best to you! Professionals like you will be in high demand in the near "interesting future that awaits us
Great video thanx Elina! First time I actually have a reasonable understanding of the issues at stake in Thorium tech.
Ed Pheil describes the best sounding design for burning existing nuclear waste and generating heat and electricity.
19:10 The 1960 Oak Ridge Experiment didn't use thorium. It used U235 and they mentioned that it COULD use thorium.
Great, informative presentation. I understand a lot more about thorium reactors. Thanks!
I am a former nuclear engineer who worked on the redesign of the Diablo Canyon units 1 and 2 and they achieved criticality in 1983-1984. The plants are still operational in 2024. I like that you created this video. Here are my thoughts on a new video that can be created
1. You must SLOW DOWN your presentation. The audience may not understand nuclear physics. So you must spend more time on the basic physics of the Th-232 transmutation, compare and contrast with Uranium fission. Just another 3-4 minutes should work
2. Take the time to explain how the LTFR is constructed. How it is contained in a pressure vessel. How the corrosion problem is solved etc.
3. Explain the heat exchange that generates pressurised steam that is transported to the turbine generator where electricity is produced. How the primary heat exchange is happening inside the containment building.
Unless you explain these things end to end, your audience cannot relate to how the entire thorium fuel cycle works to produce electricity without proliferation. I will be happy to work with you on this. If interested, reply to this message and we can then discuss next steps.
This was a very clear explanation, however, I am a qualified nuclear reactor operator, so that gives me a head start.
The process of turning Thorium into Uranium is similar to Commercial Reactors, where Uranium is converted into Plutonium. In both the reaction produces a more fissile fuel. If I remember correctly, it is called Resonance Absorbtion (or Adsorbtion, I never remember the difference). This process extends the life of a Uranium Fuel Cell.
Over the course of 40 years or so the fuel cells will be taken out, stored, and reinstalled in a different location in the core. Resonance Absorbtion typically needs fast neutrons as opposed to slow neutrons and so the production of Plutonium is reasonably financial arrangement. The fuel does not need to be processed to use the Plutonium.
But if the salt is sodium, that is a very bad thing. As you mentioned, Sodium and Water don't get along very well. So, since you need to transfer the heat from the Salt to the Water in a heat exchanger there is the possibility of a leak in the heat exchanger. In a commercial Reactor the leak would be detected by electronic means, a detector. A leak from a Salt reactor would be much different.
I am not sure you are for or against. Personally, I think creating trash that is radioactive for any length of time is a mistake.
Perhaps I am wrong about Thorium; it has been a while since I got to play with a reactor. Feel free to let me know, be nice though.
It would be better for mankind if we went back to the modest lifestyle of the good old Hebrews: to wine, bread and salt, music, oxes and sheep - and be happier with less waste of atomic energy and reactive ressources. Our comfortable, energy wasting lifestyle is hard to renounce on for most post modern materialists. A little rest risk life is always willing to offer.
LFTRs don't necessarily need water for power generation. They can also use "flash" gases (CO2, N, etc.,) in a modified hot gas turbine. The heat exchanger super heats the gas, the gas expands with force moving a turbine, and once the gas has left the turbine it's collected, cooled down, and put back into the loop.
Fantastic interview Jesse, super entertaining and insightful