Nuclear Physicist Explains - What are SMRs? Small Modular Reactors

[@YourFriendlyNuclearPhysicist]

Now you know what SMRs are! They’re actually part of my research at the moment. Their biggest drawback would be their cost which is on the high side for now but they have potential to change the game if mass produced. Thanks for watching let me know what else you’d like me to explain below! ☢️👩🏽‍🔬

[@Wawyed]

Thank you for the video. I was wondering if you could make a video about Fusion Reactors, how they work, what are the difficulties with them and wether you think they are the future of Nuclear Energy. Thanks again!

[@paulmobleyscience]

@Elina Charatsidou Being that we see factory built "modular" things, what about recalls? How will the quality control work on this assembly line?

[@paulmobleyscience]

Burying them underground only gives them that much more opportunity to leak into the biota. The safety fail safe systems are not failsafe as the Nuscale design left the moderator in the condenser. You only ever show the small benefits in a 9 minute video but I never see one single negative thing about any of all this Elina. Why don't you tell them both sides of the coin Elina?

[@RMSTitanicWSL]

Not sure there's enough demand for energy to mass-produce reactors--but that also depends on your definition of "mass produce". For most automobiles, 10,000 cars of one model per year is a small number to produce. Pens are produced by the millions. Same for plastic bottles and hundreds of other consumer items. For railroad locomotives and aircraft, 500 units of one type made per year, such as an SD40-2 or a Boeing 737, qualifies it as being "mass produced". These sound like disposable reactors, build them, plant them where they need to be, and 25 years later, bring the replacement out, swap them, and take the old one off to be buried. Come to think of it, they sound more like large battery packs that make energy from nuclear power, and perhaps they should be designed to be just that. Ideally, they'd be made so they could easily be transported by heavy-duty railcars or even heavy-haul trucks with ease. This means your "dream" maximum design weight is about 20,000 kg, your ideal maximum design weight would be 40,000 kg, and you definitely would want to get the maximum design weight below 60,000 kg. Dimension-wise, your "dream" maximum shipping dimensions for are 3 m wide, 3 m tall, and 16 m long. If you're somehow able to pull this off, most trains and large lorries (called tractor-trailers in the US and Canada) across the globe will be able to safely move them along the major rail and road routes of the world without exceeding the loading gauge of those roads. I don't think that will be practical or safe, since reactors have various requirements, such as shielding, but that would be your dream goal. Here, your ideal shipping dimensions will be 5 m wide, 5 m tall, and 25 m long, this will still allow quite a bit of flexibility in transport, especially if you can keep the weight down. Likely more realistic are shipping dimensions of 8 m wide, 8 m tall, and 40 m long, and this is as likely large as they can be to make inland transportation as an intact, preassembled unit more than a pipe dream--this is probably achievable as many nuclear submarines have a 10 m by 10 m cross section. Note that they can be shipped on their side if designed for that, then turned upright with cranes at the final location. You'll also want to take care to have a minimum number of external protrusions that might snag on things during transport. Burying them in pools might make them relatively safe from most natural disasters, but earthquakes and landslides would still be problems. I think there will be huge problems with making certain they are sited safely so there aren't any repeats of Fukushima. Care must also be taken that the pools don't get drained by sinkhole formation, quakes, or other events, or some provision must be made that it won't be a safety issue should some weird catastrophe drain the pool it is mounted in. Overall, this is a concept whose time is overdue, provided those issues can be addressed.

[@philshorten3221]

Thank you! 2 things... The physical amount of material in the core, which being smaller is perhaps not quite as "big" of a worry in terms of containment in the event of a catastrophic accident. Part of what made chernobyl so bad was the enormous size of the reactor and sheer volume of fuel. Also SMRs can be placed closer to heavy industry etc so you don't need a sprawling grid distributing power across the entire country!

[@Fs0n1ine]

Would be great to have a follow-up video that compares the 4 SMR types (thermal, fast, gas-cooled, molten salt-cooled) and shows their similarities, differences on costs, safety, fuels used, etc.

[@davidrubinstein9722]

I think it would be great if you made a video explaining to people how the new reactor designed are designed to be more "fail safe" by physics rather than by safety systems. In other words, when things happen to the new reactors, that would be catastrophic to the older ones, the reactions stops by itself, not by mechanical intervention.

[@paulmobleyscience]

Nuscales failsafe left the failsafe in the condenser and wasn't failsafe like Nuscale advertised it. You people don't really think they are failsafe do you?

[@aljohnson3717]

@@paulmobleyscience 😂

[@OnYourMarkgitsitGooo]

Curious question: Can this be weaponized at all? My only concern is that nuclear technology would be very dangerous in the wrong hands. Would this be an exception? What if some nefarious organization gets a hold of these and somehow builds a nuclear warhead out of this?

[@maasl3873]

​@paulcataluna9796 You can build a military nuclear facility without having any civil nuclear power plants because there are different means to produce enough material for a nuclear bomb. North Korea doesn't have a civil power plant but it has nuclear weapons. Having a wealthy society keeps countries from starting wars and having hostile regimes and dictatorships. We could end povert, hunger and the global warming with cheap smr, the heat of the smr can be used for desalination, high-temperature electrolysis or process heat for the industry, and with CO2 capture nuclear can run CO2-negative because it's the only source of energy producing less than 5 gramms CO2 per kilowatthour, so it can remove more CO2 than it produces. Sorry for my bad English, I hope the message got through it nevertheless.

[@Peter-b5b6k]

@@paulmobleyscience The molten salt reactors are failsafe by physics. Even if blown up by a bomb the molten salt will just solidify and encapsulate the radioactive materials.

[@Rorschach1024]

There is a former coal fired power plant in Wyoming that was being shut down. The coal fired boiler was removed, SMR's are being installed and will use the existing steam turbines to continue generating electricity. This is the best use of SMR's, replacing coal fired boilers in existing plants.

[@Mark-zk7uj]

what's the status of this?

[@tfolsenuclear]

Great video as always! As a nuclear engineer and project manager, I feel SMRs are the way of the future for new build reactors, mainly because of scaleability, cost, and build time. In the US, planning was beginning on Vogtle 3 and 4 (AP1000) back in 2006, and fuel loading just commenced this year with operation starting on Unit 3 next year. 17 years and $30 Billion. That is a lot of time and money. SMRs would be much faster!

[@St3v3NWL]

Highly depends on the availability/price and capacity of renewables like solar/wind and possibly hydrogen fuel.

[@danadurnfordkevinblanchdebunk]

@@St3v3NWL Nope, renewables with storage are more expensive than even old school nuclear.

[@St3v3NWL]

@@danadurnfordkevinblanchdebunk Right now, maybe. Who knows what will happen in the next decade.

[@danadurnfordkevinblanchdebunk]

@@St3v3NWL It's already very clear where we are headed in the next decade by looking at Germany and California, two regions which are committing themselves to renewables. Without nuclear we are going to have exorbitant electricity rates, energy rationing, and massive rolling blackouts.

[@paulmobleyscience]

@Elina Charatsidou Why won't this next response post on youtube? Would their third party company they hired for fact checking know any of this? Hello sir, as a nuclear engineer could I ask your opinion on the difference between naturally occurring H3 Tritum thats extremely rare on Earth and only found in trace amounts in the atmosphere and H3O Tritiated water from H2O neutron capturing from our global water cooled nuclear reactor fleet at tens of thousands of TBq every site every year that is taken up in plantlife where it either replaces hydrogen in the plant or binds directly to the Carbon in the plant to form Organically Bound Tritium which bonds for a longer period than that of Naturally occuring H3 tritium from the sun at a biological Half-life of 12-30 days inside our bodies that causes double DNA strandbreaks, Micronucleus formations, cell necrosis or aptosis, chromosal aberrations and various other phenomena thus negatively affecting human health? Do you think the standards must be reset now knowing this newer research?

[@philplasma]

Great video Elina. The government of Canada (where I live) announced somewhat recently that they would invest in Canadian companies making SMRs. Hopefully we'll see some soon here, to especially go in the provinces that are still burning fossil fuels for electricity generation. SMR would also be great near power hungry industry like steel or cement. And finally, for drought stricken places that are not too distant from a sea or ocean, SMRs could be used for desalination.

[@konradcomrade4845]

add Paper Industry.

[@davetupling2678]

Hi Phil, I've read a lot over the years regarding MSRs, one of its abilities is to work in area's away from large amounts of cooling water this is due to the high working temperature, fan forced cooling would be more than adequate, at 75 I'm hoping I'm still around to see them in action.

[@clarkkent9080]

The NuScale SMR project (the ONLY SMR project in the U.S.) was to come online starting in 2029 and was supposed to replace electricity from coal plants that are closing. Instead, NuScale and the Utah utilities announced Wednesday (11/ 8/23) they're terminating the project after a decade of working on it. The cancellation comes amid supply chain problems, high interest rates and a failure to obtain the desired tax credits.

[@HuntingTarg]

That's sad and a little bit pathetic. A decade of sunk cost and man-hours yields no results. I don't fault them, I fault 'political weather.'

[@paulmobleyscience]

@HuntingTarg Incorrect, it was always a scam. Let's not forget the moderator was left in the condenser and the fail safe didn't work...or did we forget?

[@clarkkent9080]

@@HuntingTarg Do you have ANY basis for blaming it on political weather??? NuScale was given $2 billion in taxpayer money for the project, $400 million for the NRC review and help with the design and free government land on which to build. Do you want the taxpayer to pay everything and just turn it over to the investor firm when complete?

[@deadwingdomain]

And that is it. It's not about the technology. It's about the money they can make. Incentives drive every successful technology. An nuclear was never a good idea. Just a marketable idea. An now we have things like Fukushima.

[@jmj7543]

It's not a scam but it's better to be straightforward with the problems because we can all see there are many understandable challenges. 1. Russia-Ukraine war. 2. High interest rates. 3. Covid-19. 4. Political lobbying especially in the US where it's located --> (Yes they got funded by the government but it's not a money issue as much as it is political because if it wasn't politically hard every tech company would fund it themselves). The magnificent 7 alone have increased their cash amounts about TEN TIMES. There's a reason why everyone used to invest in renewable green energy but after realizing that it is super expensive it's better to wait for the approval of new reactors by NRC.

[@GeoffryGifari]

huh the passive deactivation seems to exclude/minimally involves electronics. fascinating

[@HuntingTarg]

It's a design feature called _inherent stability;_ basically enough has been learned from both operational data and computer simulations that operating conditions can be anticipated and planned for during the design phase. I still find it astounding.

[@deadwingdomain]

Until it fails to work!

[@WhatWeDoChannel]

We have already broken ground for one in OntarioCanada and have plans to build a couple more. We need the clean power for the electrification process that is under way now!

[@aaroncosier735]

Really? My understanding is that there is only an MOU in place. No registered design, no committed finance. Odd that Canada isn't backing it's very own CANDU, favouring a fundamentally less efficient SMR concept. Very strange.

[@WhatWeDoChannel]

@@aaroncosier735 well, we are refurbishing the CANDU reactors at the Pickering power station to get another 30 years out of them, and we already did the ones at Point Elgin. I think the relative simplicity of installing SMRs makes them an attractive option for the powers that be. There is a big EV transition under way in Ontario, so they need more power relatively quickly in order to supply projected power requirements.

[@aaroncosier735]

@@WhatWeDoChannel Refurbishing is not quite the same as new build. I agree that doing so gets a little more back out of sunk costs. The *claimed* simplicity of SMRs is so far just advertising. Small reactors are not attractive: they are less efficient and projected to cost twice as much per unit of energy produced. The only selling point is the perceived modularity, which is still a pipe dream. None of the existing SMR concepts has gotten past the drawing board. They will require demonstrators to confirm the basic concepts, and those will not be "modular". Then further rounds to get to a hand-built prototype of the future modular design, then a factory to make them. Don't expect to see SMRs for many years. EVs may increase demand, yes, but they also have a huge storage capacity. They will enable the use and storage of more variable renewables. Rather than increase demand for nuclear, I think EV storage will increase the usability for renewables, which are available *now* rather than SMRs which could yet be decades away.

[@mariagavriilidou7525]

Amazing video as always and your way of explaining things is really amazing. I know nothing about nuclear physics and after your videos I always feel that I learned something new. ❤️❤️

[@YourFriendlyNuclearPhysicist]

☢️👩🏽‍🔬🧡

[@GeoffryGifari]

love the animations and illustrations here!

[@atariplayer3686]

Awesome explanations Elina 🤓👏

[@MustrumRidiekel]

Would love to hear your opinion on ITER

[@lautarovalenzuela4962]

Great video! In Argentina we are disignig the CAREM reactor, its also a SMR. Check it out

[@greigmartin9148]

Thanks for that, Elina, clear, precise and easy to understand for us engineers who want a better understanding of the nuclear energy sector. 👍

[@HYDRONORTHWESTTECHNOLOGI-jf1yf]

Yes, this is an excellent professional Physicist presentation, thank you for the absolutely educational discussion, please. My question as a layman on the above subject is how can this SMR be Hybridised to be applicable with Solar power Supply System with a battery Storage systems, especially in areas with more than 12 hour of solar radiation?

[@HuntingTarg]

That's more of a grid design issue than a reactor system design one, but essentially yes - it would just take a mini-substation with a set of high-power switching inverters. What I want to know is why would you want a yuge solar farm along with an SMR; integrating solar into housing, commercial, and parking structures is fine. SMRs should mean that taking up acres of land with solar should be unnecessary.

[@christoffkapp]

What is a IBR-2 high-flux pulsed reactor?

[@keeganplayz1875]

Here in the United States, specifically in my state, There is a nuclear power company called NuScale. They actually focus on building and designing these SMRs, which is pretty good for someone like me who wants to get a degree in Nuclear engineering so I can work locally.

[@MrLaizard]

The only SMR propotype currently being built in America is located in Argentina, the CAREM (Central Argentina de Elementos Modulares)

[@wentaolyu3472]

Great info on SMRs! Would like to see more potential drawbacks and risk assessment as well.

[@clarkkent9080]

Biggest drawback is there is not and never has been economies of small scale. New nuclear is already the most expensive method to produce power and downsizing will only make it even less cost effective

[@kevinmerrell9952]

Great video! Thanks!

[@YourFriendlyNuclearPhysicist]

Glad you liked it!☢️👩🏽‍🔬

[@sytsemichielsen8224]

Can you make a video about nuclear fusion reactors and if they are te future of nuclear energy?

[@andreas5287]

Hey Elina thanks for another good explanation! Would love to hear about the pros and cons of liquid salt and gas for cooling and extracting energy 🙂

[@YourFriendlyNuclearPhysicist]

Coming up in the future! Thanks for the suggestion and support ☢️👩🏽‍🔬

[@paulmobleyscience]

@@YourFriendlyNuclearPhysicist Great! Make sure to please at least mention the Tellurium embrittlement issue for a split second for molten salts or Hallam Nuclear site in Nebraska with lead Bismuth. Thank you Elina

[@diegoboldini901]

What do lo think about Argentina's CAREM SRM? The first prototype is being built in the Atucha 's power plant where two PHWR are operating. Thanks!

[@enemyofthestatewearein7945]

Although it may be technically possible, IMO output flexibility is not really a useful feature of SMR. Since most costs for any NPP are in construction, reducing the output at any time just increases the cost per unit of electricity produced. I think that all Nuclear is most useful as a baseload source, because it can reduce the amount of (expensive) backup capacity that is needed for variable renewable sources. Many studies show that for a low carbon electricity system, including some nuclear in the energy mix greatly reduces the total electricity system cost, even if the nuclear electricity is itself expensive. The key feature of SMR as you highlighted, is the possibility to reduce build costs through mass production.

[@Matt-go6wo]

At 6:42 Elina mentions a 25 year refuel cycle for the SMR. What reactor design is this? I thought the designs such as the AP300 were up to a 4 year cycle.

[@HuntingTarg]

I do think 25 is overly optimistic. The understanding I had from Real Engineering was 10-15 years before refueling

[@kayakMike1000]

I don't really care much for SMRs, as they run at really high pressure. I think Alvin Wienberg said he couldn't guarantee the safety of water cooled reactors over a certain power output because they can explode from pressure build up if cooling fails... He was really dedicated to safety... Do you think the SMRs are safe?

[@paulmobleyscience]

Agreed

[@HuntingTarg]

I think they can be 'saf - _er_ ' than the legacy gen 2 and 3 reactors atill in ooerstion around the world - which is still saying something from the perspective of operating hours per injury. A steam explosion inside a secondary containment vessel isn't cause for alarm - certainly not hazmat and national security personnel. California's MTBE scandal caused A LOT more damage to public health and the environment. Inherent stability design can - and in my unqualified opinion ought to - take such considerations into account and have power limits like you mentioned fixed into its design parameters. Most people don't really want guarantees, they want (principled) confidence.

[@RobKMusic]

Thank you Elina. I'd never even heard of a SMR.

[@YourFriendlyNuclearPhysicist]

☢️👩🏽‍🔬

[@jailsontorres5176]

It is really Good explanation..

[@Photogaltn]

Would love to see an update to this video!

[@91plm]

great content! keep this up!

[@kr3942]

Great video ! Thank you so much for your dedication to make this topic accessible for everyone. Real pleasure fo have met you in person last week ;)

[@YourFriendlyNuclearPhysicist]

Thank you so much for the support and I’m glad you enjoyed the video 👩🏽‍🔬☢️

[@JessWLStuart]

Thanks for explaining this so well! :D

[@spidrespidre]

Rather than the title SMR being applied to a reactor below a certain size, it's perhaps more fair to say that the term should apply to any reactor that can be mass produced in a factory or maybe a shipyard. I'm making this alternative distinction because the S-PRISM, VBER-300, IRIS, Rolls-Royce SMR and TMSR-500 designs are all greater than 300MWe. Keep up the great work

[@HuntingTarg]

One of the limitations on designs being fabricated and assembled in a factory is transportation. You can't just plan a roadtrip for an assembly massing over 100 tons and 15-20 meters in length. Also, most nuclear countries have strict regulations on how much fissile material can be shipped in one load, how much can arrive at a given destination at once or in a timeframe, and how much can remain undispositioned on site in a specified timeframe. So the limitations on the physical size of SMRs aren't just due to engineering, but also logistics and process control.

[@capoman1]

So what medium do these gen 4 fast reactors use? I saw Candu can use U238 and uses heavy water. I've heard that gen 4 require liquid medium like liquid lead or molten medium.

[@GeoffryGifari]

what about maintenance? are SMRs cheaper to maintain/require less repair/don't need as many high-skilled workers to maintain?

[@aaroncosier735]

Those are the assumptions. It might not work out that way. At least one proposal is that the reactors be single-use, and the depleted reactor becomes a sort of decay storage enclosure. Not sure how that works out in the event of faults or gross failure. Not sure how confident we can be that an already corroded reactor vessel is somehow a good or dependable containment, either onsite or in transport. How long will it last? What is the deadline for repackaging?

[@jaydub8085]

I came to learn what small is. Thank you.

[@hollismccray3297]

Very good video! I would be interested to know what you think about the dual-fluid reactor concept. It sounds very promising from a layman's perspective.

[@jeffriechel]

How does the efficiency of smr’s comparison to gen 3 reactors? I thought they were less efficient than some renewables.

[@JetDom767]

Stupid question but can the SMR be integrated into the current control rooms to reduce the building costs associated with constructing control rooms? Fantastic explanation I had some knowledge around SMRs but you really aided my knowledge. Suggestion for a video would be could you watch The China Syndrome starring Jack Lemmon and Jane Fonda?

[@daniellarson3068]

The only stupid question is the one that isn't asked. Changing existing nuclear control rooms would require a lot of analysis. Since the inception of nuclear power there has been a lot of rules applied to their control. Wiring must be carefully separated. Nuke plant have separate safety trains that must be largely redundant. They usually have all the wiring pass through a cable spreading room. These are often rather full already. There are fire requirements for all wiring. (Appendix R). Everything must be seismically analyzed for earthquakes. My gut feel is that it would be easier to have a separate "greenfield" structure rather than trying to tie it in with a decades old plant ("brownfield.) Operators in the existing control room (Senior Reactor Operators) require a lot of training. If these operators were also expected to handle a new totally different system, it could be asking much. Critical parts of nuclear plants are statistically analyzed for failures. (Probabalistic Risk Assessment). Will the use of the existing control room introduce new failure modes or increase the risk of existing failure modes? Big analysis there. There is also the matter of when. These places can make a million dollars a day. Are they to be shut down while the new equipment is tied into the control room? Tying new equipment to an existing plant can mean all sorts of local plant equipment that may need to be taken down while the new installation takes place. In addition, the existing equipment may need modifications to allow the installation of the new equipment. These places can be rather full so existing piping and cables may (will) need rerouting. All affected equipment must then be tested. Everything has to be documented to ensure the health and safety of the public. The NRC will have it no other way. All that documentation is extremely expensive. This is my viewpoint from nearly 20 years ago when I worked at a nuke. It's probably even more complex now as the security concerns have grown greatly after 9/11/2001.

[@HuntingTarg]

​@@daniellarson3068 The only proper way would be to convert an entire plant during a refuel/retrofit. That's a hard sell when many countries are being pressured to simply decommission in the face of 'the green new deal.' Individual installations in remotely located and remotely monitored situations seems more viable to me.

[@daniellarson3068]

@@HuntingTargYes - Gutting and rewiring control room would take a great quantity of time. Building new would most likely be more cost effective. The problems I discussed above and many others would be simplified.

[@efran216]

@Elina Charatsidou I'm not sure if this asking too much, but is there a rough cost savings breakdown for curently built reaactor and SMR's? Also, in your opinion are Thorium reactors viable? No matter the answer, could we get a video on this subject.

[@MrBrew4321]

I think some of the SMR proposals have included thorium. Thorium is just a fuel that's harder to burn. Making the engine smaller doesn't better the possibility of using that fuel. You just have to mix it with high level nuclear waste which is in my opinion killing two birds with one stone.

[@efran216]

@@MrBrew4321 Thanks. I'll have to try and find more information on that.

[@PMA65537]

Economics depends on a lot more than just the reactor type. The number built, their power output, lifetime, future interest rates and energy prices are all factors and some of these are not known in advance.

[@vclealj]

Can you make a video about the CANDU Reactor?

[@Johnchuk3]

what about shipping?

[@whozaskin3639]

Decentralized power is a good thing!

[@HuntingTarg]

In computing and politics as well as energy...😊

[@deadwingdomain]

​@@HuntingTarg another politics joke... 🤨

[@deadwingdomain]

Tell that to Texas. Who will be on the National grid after their incompetence lead to deaths.

[@jdlessl]

Slays me that it's taken almost 70 years for these to start being developed. So many useful applications. In the event of a natural disaster that damages the local grid, you can truck in a bunch of these to provide limited power. Critical infrastructure like hospitals could have one to serve as their own generator in case of black/brown-outs; would simply supply to the grid the rest of the time. What about shipping vessels and cruise liners? A big electric car/semi charging center could wind up needing many megawatts of power; SMRs let you produce it on-site rather than beefing up the entire grid capacity between it and the nearest power plant. What about the facilities that these plug into? Any standardized, boilerplate designs for those?

[@robbebrecx2136]

I believe if we implement a certain SMR and mass produce it to place them in our industry hubs it will be more profitible then renewebels. Make a video about the potential recycling of our old nuclear waste and reducing the half life?

[@YourFriendlyNuclearPhysicist]

Thanks great suggestion !☢️👩🏽‍🔬

[@patrickdegenaar9495]

How does a fast breeder process prevent proliferation?? Surely fast neutrons + U238 => Pu239, which is a fissile material which can be chemically separated to make bombs (ignoring the Pu240 problem).

[@HuntingTarg]

It requires either enriched U-235, which is expensive and dangerous, or it requires additional alternative fuels which reduce the fast neutron flux and so make the reactor less efficient. It is also possible (generally speaking, IDK how feasible it is for SMRs) to design a hybrid fast-thermal design where Pu-239 (I think this is right) absorbs thermal neutrons as the reactor goes through its fuel cycle and so has secondary reactivity.

[@GeoffryGifari]

Topic ideas! (you don't have to do this immediately... just suggesting): betavoltaics and its applications, glow of cherenkov radiation

[@thearisen7301]

Need a follow up on Micro Reactors and Coal plant to Nuclear plant conversion along with maybe explaining Liquid Metal, Gas & Molten Salt reactors. I would add that the US has started on Terrapower's Natrium reactor in Wyoming with the energy company that'll be operating it just starting the process for 5 more, so 6 total.

[@minhduongnguyen3671]

I have a question so will it take longer to refuel smr than gen 3 reactors? And can we put some human safety protocol for some reason the passive protocol doesn't work and jus to be sure for safety?

[@kokofan50]

Most SMRs have either online fueling or a set amount of fuel for their intended life span. It’s going to take the laws of physics to fail for passive systems to fail.

[@minhduongnguyen3671]

@@kokofan50 wait online fueling? How does that work? And they have a lifespan, like after 25 years they will be gone?

[@kokofan50]

@@minhduongnguyen3671 All molten salt reactors remove the salt from the core and pump it in a heat exchanger. Some also want to remove various isotopes to sell for radiation therapy for cancer, to fuel RTGs, and other stuff. After the processing they just a bit of uranium salt to make for the difference.

[@HuntingTarg]

In some countries (the US I know for sure) there are regulations about having 'eyes-on' security personnel at all times. It adds to cost, but national security concerns of late have shot up regarding domestic threats, and right now energy prices will support the increased cost, even if it is just remote monitoring.

[@barryon8706]

If you're looking for other subjects to talk on, perhaps accelerator-driven reactors? Or thermal vs. fast reactors and their advantages and disadvantages?

[@YourFriendlyNuclearPhysicist]

Thanks great suggestions ☢️👩🏽‍🔬

[@frankchan4272]

Can you please remind me what post fission byproducts are produced by fissioning U-238? U-235 is iodine, cesium, strontium, xenon and barium I don’t remember U-238 as thought it was more stable than U-238.

[@davidnewland2556]

if they end up being as built units meaning every one is different, that could mean repairs could be a bit pricey and operations could be expensive there's going to have to be a learning curve, regarding efficient operation..

[@jandorniak6473]

I liked the video, but you did not separate which features come from them being small or modular, and which features (like negative temperature coefficient) come from simply being a different type of reactor. KGHM - Polish nationally owned copper mining and refining conglomerate - has signed an intention letter to convert coal power plants to nuclear using SMRs. I tried to read up on it, but resources are scarce, could you make a video explaining why the Japanese HTTR is so safe? Or maybe it's gas reactors in general?

[@vicentesloboda]

Nice one. Would you make a video about Thorium reactors? Will they ever be a thing?

[@texasblueboy1508]

I would think, the old coal fired power plants would be great sites for these SMR's plants. A lot of the infrastructure is already there.

[@Rorschach1024]

That is precisely what is being done right now in wyoming.

[@pauliusnarkevicius9959]

Does small elements could be created from Nuclear (Atomic) Power, i.e. for powering regular Flying Planes and Ships?

[@HuntingTarg]

No; there is something called a buckling ratio, which relates the outer surface area of the reactor volume to the spatial volume of neutron flux within the reactor. When the reactor size gets smaller, the buckling ratio increases, and because of design physics makes it harder for a single unit to sustain power output. Besides other problems like power-to-weight ratio, reactor vessels can't be both small and light enough while generating enough electricity to power things like planes or cars. Or as Issac Arthur put it in his video on fission and fusion energy, "But no really, the Thorium-powered car is so much 🐃💩."

[@jakobcarlsen6968]

How long time does it take for the radiation in the waste in a reactor to come down to the level of natural Uranium you dig up from the earth?

[@YourFriendlyNuclearPhysicist]

With the current reactors that we use this fuel implanted (UO2) when taken out of the reactor will need approx 100.000y to reach background radiation levels

[@jakobcarlsen6968]

@@YourFriendlyNuclearPhysicist As I understand there is high level waste and low level waste. Is all the spent fuel from inside the reactor high level waste? And how does Thorium decay? I am Norwegian and here the talk about nuclear, specially Thorium breeder reactors, is getting more attention.

[@PMA65537]

There is a graph in this video. kzbin.info/www/bejne/gZ_bnKaBoq-UbLc

[@electrochipvoidsoul1219]

What do the different generations of reactors mean?

[@HuntingTarg]

They represent different design principles and practices - understanding them takes an understanding of the particulars of different ways of generating capturable energy from fuel.

[@jrpeet]

Really helpful

[@bartoszlataa245]

Hi Elina, this is Bartek (you can call me Bart) I have a few questions for you that are bugging me I have to admit that I don't know much about nuclear physics (I'm very interested in it) 1. Does gamma radiation occur (radiate) in its harmful form on people from inside the reactor during its operation. I ask because I have heard that this type of radiation can pass through thick concrete walls and I have also read (in books on nuclear blast) that it can go through tank armor? 2. A friend of mine once told me that after the explosion of the hydrogen bomb (he probably meant the 50 megaton Car bombe) the troops attacking that would occupy this area could move there without any obstacles because such a (hydrogen) bomb is relatively clean and does not generate radioactive fallout. Is it true ?

[@HuntingTarg]

You can learn about Gamma radiation from cosmology as well as from nuclear physics. Gamma radiation is high-energy, highly penetrating photon radiation that can only be reduced by dense materials that have atomic nuclei close together: Lead, Iron, and Tungsten tend to work well for this, and contribute to a reactor vessel's weight. The 'H-bomb' is a variant of nuclear weapon that produces very little fallout, because it uses a 2-stage fission-> fusion process. Modern "Thermonuclear" weapons use a 3-stage fission->fusion->fission process which increases yield many times, but also creates more radioactive byproducts, aka fallout.

[@TheRealSnakePlisken]

Great idea. So where are all of these SMRs? And I heard they cost much more than other reactors. Production problems, too. Hhmmm.

[@chrisfox7393]

Keep it up Elina, gen 4 reactors need to be part of the decarbonisation mix. Too much fear about nuclear technology out there atm without much rationality. I’m a chemical engineer that has recently started a business with the intent to decarbonise the light industrial sector in Australia. Our modelling shows that renewables are great for somewhere up to 70% but beyond that you need either solid base load power (ie SMR) or a huge amount of storage (and whilst everyone’s gripe these days is that nuclear is too expensive, I would challenge that the amount of storage required is also eye wateringly expensive). Long and the short is we can’t throw all our eggs in one basket all tech available is required. We have dug ourselves into a deep hole and we know don’t have the luxury of being choosy as to how we climb out……….

[@network_king]

Could things like SMRs be used for things like large cargo ships, submarines, perhaps large aircraft? Also what about htings like large factories steel mill, data centers that use a lot of power could they setup their own power plant basically?

[@kokofan50]

The naval reactors that have been used for decades are SMRs. Although, naval reactors have some problems that aren’t suitable for civilian ship. Yes, a SMR would be good for a steel mill. People even want to directly use the heat to do things like desalinate seawater.

[@midnike8783]

The Russians use such reactors in their nuclear icebreakers and mini-nuclear power plants.

[@HuntingTarg]

​@@kokofan50military propulsion reactors aren't exactly SMRs; they don't use all the same design principles. They're designed for high, actively controllable output, and consequently don't have inherent stability, and are made with startup/shutdown procedures so they don't need to be monitored when the ship is not deployed or ready for duty.

[@edokamichael1218]

This is amazing. What is the difference between a Small Modular Reactor & Floating Nuclear Power plant.

[@paulanderson7796]

Very little.

[@wernermuller3522]

Die US-Firma NuScale hat Aufgeben beim SMR und das Projekt eingestellt, 11-2023. Wieder mal dumm gelaufen für die Atomkraftwerke. Der SMR war ohnehin nur Schwachsinn im Quadrat.

[@SuiLagadema]

I have a question, if I may: Are nuclear submarine reactors considered SMRs?

[@paulmobleyscience]

@Ex Lagadema Yes which means they are actually Gen 2 reactors and nothing new. The TRISO pebble fuel surrounded by multiple layers of Carbon with 2 different types to the Thorium decay chain where its U233 for the fissle fuel and not Th232. Or MSR tech with the Tellurium Segregation of the Hasteloy-N issue which makes them much more expensive to the IMSR replaceable core every 4-7 years for the graphite expansion/contraction issue. These designs, fuels and coolants are nothing new and only the attempt of the industry to keep from slipping past 9% globally for our energy needs. They are putting lipstick on a pig and trying to pass it off as the next new hot thing. If you need more I have it all backed up.

[@midnike8783]

Not really, submarine reactors usually use high enrichment uranium. They cannot be used in civilian facilities because of nuclear nonproliferation restrictions. The exception is the Russian reactors for their nuclear-powered icebreakers, which run on "energy-grade" enriched uranium. They use them for their mini-nuclear power plants. One is already in service, four more are under construction.

[@HuntingTarg]

​@@midnike8783 That's interesting, if they are really building more nuclear icebreakers; the two the USSR built for clearing the port of Arkhangelsk and the White Sea were decommissioned years ago. 'Bout time.

[@HuntingTarg]

@paulmobleyscience is pooh-poohing good tech all over this channel. The real answer is, yes and no. Yes in that military naval propulsion reactor designs are made to be reproducible so that the same vessel design has the same reactor design throughout the class. No in that they are not fabricated completely in a factory and then shipped somewhere; in naval construction the reactor vessel is first installed, then fueled when the fuel elements are put in place. National security laws & policies dictate that the fuel be handled separately. Propulsion reactors also must vary power output on demand and so do not have inherent stability in their design.

[@andreycham4797]

Who are your sources ? Academik Lomonosov is up and running since December 2019

[@Conditional_Finality]

Can you elaborate how the nuclear waste are going to be managed? As SMR are mass produced means there will be more of them ,which means more nuclear waste. How are we going to manage increased nuclear waste.

[@placidp2443]

This is my kind of ASMR videos 😙👌

[@alecdoig507]

What are the small reactors that the navy's use in submerines and ships like are they like smrs, thank you for all you do it makes it easier to understand

[@HuntingTarg]

No, they are highly enriched PWRs, HWRs, or molten salt designs. They are not designed the same way SMRs are, because they need high-range, on-demand variable power output.

[@cameronmale83]

"Economic costs on the high side" is a massive understatement.

[@Deinorius]

The one thing I missed in this video are the possible downsides to SMRs, if they even take into effect those studies saying the possible cuts in cost are diminished by security and what all. I know of the possible advantages enough as should a lot of viewers too. The possible hurdles are the things that are more important to know of to get over them and proceed.

[@NuclearSavety]

When you look at nice glossy advertisement material for an SMR, with nice CGI plant site views, always ask, where is the 100m high stack, where goes the nuclear ventilation of the controlled area, where go the radioactive gases of the coolant purification, where is the cooling tower for the waste heat, where is the tritium discharged? ... And then ask, would the electricity not be cheaper when i build the SMR larger? Then i still need only one plant crew, only one building, only one turbine ...

[@Deinorius]

@@NuclearSavety First the first part, yes exactly! For the latter part, no! Why shouldn't it be possible to use more SMRs in one plant? You are more flexible, it's still easier to manufacture and so on.

[@NuclearSavety]

@@Deinorius 2 SMR need 2 containments. One twice-as-large SMR needs one containment which costs 30% more .... economy of scale ... And 2 SMR have twice as many valves, twice as many pipes, twice as many valves, basically twice as many points of failure, twice as much maintainence efforts ...

[@arpudli8962]

Smr can be located closer to cities or factories that uses most of our electricity, so I thought that pays off for loosing energy from bigger plants due to distance or?! Is it that expensive to have extra control room? Is it not possible to have remote control rooms for multiple smr? I thought it's much faster and cheaper to build an smr than a regular nuclear plant?! Is it not true? More pipes more valves more issues but if one fails an other one can replace it. Meanwhile if something fails in a big powerplant than it's all goes to hell or?!

[@sanjaypande3406]

Super. India is also entering in SMR now. By the way, use Red nail paint in next video. TC.

[@eyalkarni3290]

Hi Elina, you didn't mention (or I missed) how much energy a single smr produces (vs regular core)?

[@dillianmitchell1096]

Wow I could listen to you talk all day about smrs. You mentioned decommission is 25 years. Is it possible to build one that last for hundreds of years?

[@clarkkent9080]

Absolutely, just like you can keep a car running for 100 years. But parts become scarce after just a few years and just like a car, the cost to maintain makes anything more than 25 years no longer cost effective.

[@GeoffryGifari]

hmmm if the parts of SMR are factory-made and delivered world-wide, i imagine the safety of shipping radioisitopes needs extra precautions

[@striveforgreatness2251]

I'm no Scientist. However, I think the can be used to build Nuclear weapons fast by rouge nations that acquires one. That's why I don't like them. What do you think?

[@tayljim]

What about disposal at the end of its 25 year lifetime?

[@maxnewberryhtc]

Do they produce the same amount of waste per MW as larger reactors?

[@missano3856]

More but I'm the case of fast reactors that waste has a far lower level of transuranics. "what about the waste" isn't a huge technical challenge so much as an anti-nuclear talking point.

[@botrys583]

You should push for SMR's everywhere, build next to existing coal/gas fired power stations and connect to the existing infrastructure and slowly decommission the old coal/gas units. As many as possible, running at 90%, so that any down time of one can be covered by all the others

[@paulmobleyscience]

All these Nuclear Physicists and Engineers in here can't answer my basic simple scientific questions with respect as I challenge the science and not the people? I am challenging both the science and all people to answer these very fundamental questions while you all sing Kumbaya, holding hands and singing about energy density because it is the only single pro Nuclear has going for it while I point out the very long list of cons by the science and more importantly the people? These are questions not statements and should be answered as such. My title is an Engineer so let's not attack or promote the title as Elinas guidelines suggest, let's question the science here. I'll be waiting for any takers....thank you all

[@nikolatasev4948]

Great video. But when it talks about how cheap they will be, it was always mentioned in absolute terms. From what I read, for generation capacity and perhaps electricity unit generated, the first generation will be comparable, if not more expensive, than traditional plants.

[@mayurdahiwale5907]

Great explainer as always. Although i'd want to know what 'Non-proliferation' means... Very kind if someone clarifies

[@kokofan50]

It means not expanding the people who have nuclear weapons

[@fabiocavaleri]

The total life span of the smr is 25 years, which is olso the standard operational life of a modern freight ship, maybe some civilian transport application could be possible

[@mrdan2898]

Hmmm, this sounds similar to the Ussr RTG's but on a larger scale. What would happen if it's water bath would drain away!?

[@paulanderson7796]

If the water drains away the reactor will shut down. Water is a moderator - slows down fast moving free neutrons to increase the chances for capture or fission of other U236 nuclei. It's a self sustaining failsafe arrangement.

[@HuntingTarg]

SMRs and RTGs are fundamentally different. Look at NASA's MMRTG (Multi-Mission RadioThermoelectric Generator). It generates electricity by capturing the heat of isotope decay, not through neutron-induced fission, so it's not a reactor in that sense, it's more like a radioactive decay battery. NERVA, which was actually tested in a concept prototype, never flew, but was an actual reactor that used reaction heat to superheat thrust mass. The power supply for the Voyager, Mariner, Viking, Galileo, and Cassini space probes, among others, were RTGs because they can generate power constantly without regard for environmental factors such as sunlight intensity, external temperature, or craft orientation.

[@JustJamesDean]

Would SMR be similar to reactors in submarines?

[@paulanderson7796]

Very much so. I'd host a SMR in my own yard.

[@clarkkent9080]

Military reactors do not have the safety features of a commercial unit. Their ultimate heat sink in the event of an accident is the oceans. They are shutdown when the vessel is in port for this reason

[@HuntingTarg]

​​@@clarkkent9080 So in one way of speaking, similar but not the same. Even discounting an accident, there is no need to burn through highly enriched fuel when shore power is available, crew wants to go on liberty or leave, and operation requires circulating cooling water around the dock to which the boat is moored, putting wear on the pier and operating hours on the cooling system.

[@clarkkent9080]

@@HuntingTarg Shutting down a reactor, commercial or Navy unit does NOT stop decay heat of the radioactive fission products. While the heat load is low, it still requires an operating cooling system and reactor operations staff to man the controls. The Navy reactors are shutdown in port because submarines do not have all the safety systems of a commercial unit and rely on the ocean as the ultimate heat sink in an accident. Some nations will not even allow them to dock in their ports because of the risk of an accident

[@Cyber_Samurai]

Can SMR Recycle Nuclear Waste?

[@shutup2751]

the greatest nuclear physicist ever

[@paulmobleyscience]

She's pretty and why it's mostly men here and you all are hitting on her, stop it

[@shutup2751]

​@@paulmobleyscience sarcasm not your strong point ? take a joke

[@paulmobleyscience]

@@shutup2751 Actually sarcasm is my second language and very fluent in it. Tell me then why the Inverse square law, Talbots law, Lamberts Cosine law and the calculus and trigonometric calculations used in the Bulletin of the Bureau of Standards volume 3 does not apply to extended sources of radiation here on the surface of this planet and explain why that matters in the real world please and thank you sir.

[@shutup2751]

@@paulmobleyscience i am not reading all that mumbo jumbo

[@paulmobleyscience]

@@shutup2751 Wait I thought you knew the language of sarcasm.....You do understand even the pretty Elina can't even answer this and I know that you can't either before I asked it so you must speak a different dialect...my apologies

[@CDMS_pt]

Is there any news about fusion ??

[@davidthecustodian]

I'm no scientist, but I'm sure I heard about physicists working on an SMR in Oregon State University as well. Of course, this might be self-promotion on their part, but I heard them say their SMR is "the safest ever built."

[@allenbarrow4904]

This video is great tor explain the needs of using SMRs but what about mass produce which type in terms of safety, security, cost, etc...???? What scares governments and regulaters is someone creating either a " dirty bomb " or China Sydrome scenario. Which type of SMRs is safer to use and more power producing?? I think for rural and mountain areas, Uranium 238 type should be used and if a terrorist act is successful, the contamination is limited. But cities and densely population areas, Thorium reactors are suitable to use

[@toyrssvigs8220]

Good informative video. Where are you from mam?

[@ralfbaechle]

Great video and also very ondensed and to the point, something I'm so missing in many youtube videos. May I suggest a bit of a nerdier followup video with the nerdy details such as details on the type of fuel, safty systems etc.? I'm mildly amused by the term "small" being used for something of 300 MW.

[@YourFriendlyNuclearPhysicist]

That’s a great suggestion I’ll definitely expand on the different types of SMRs and gen 4 reactors in the future. Thanks for the support ☢️👩🏽‍🔬

[@markjmaxwell9819]

In all honesty when I first started to hear about small modular reactors the first thing that came to my mind was a reactor based on a nuclear submarine reactor. Since submarine reactors are built in a factory and are a closed loop system designed for a 25 year plus lifetime which are extremely safe it made sense. The concept of a nuclear submarine reactor seemed to be extremely logical to me as the basis for an SMR and I would imagine the design could be scaled up or down if needed. I don't think Australia needs nuclear reactors of any type besides the one we already have or it's replacement. But I am not anti-nuclear I just see nuclear power as an easy path to go down and not necessary for my country including overpriced nuclear submarines. The basic principle of how a nuclear reactor works is common knowledge. I have worked with steam generators and boilers and heat exchangers and associated equipment for a couple of years but the finer points of how big a control rod to use with what type of fissionable material versus the best material to slow the fission process is not my forte. It's how the reactor is designed and the ancillary systems after the reactor that make the difference. Some of the advantages of a closed loop system are less variables such as outside water supply issue's and threatening weather conditions. Much better tolerances and better materials are available with a factory built SMR compared to current designs for site built reactors I would imagine the first reactor would be expensive but subsequent rector's would be considerably cheaper. No surprise the Chinese have just about finished the first operational SMR and it will cost them much more than originally budgeted for. It seems the countries that had adopted nuclear power early on have become a little bit obsessed with anything nuclear especially the promise of a working fusion power plant... 😎

[@paulanderson7796]

@grahambennett8151The biggest threat in that scenario is loss of utility power. That is all.

[@joserobertodossantossoares4254]

Parabéns

[@nickpass]

Another great video! Super informative and easy to understand.

[@javiaveleon1]

Finally you make a smr video🙃

[@YourFriendlyNuclearPhysicist]

Here it is! Hope you enjoyed it!☢️👩🏽‍🔬

[@diogovalada1522]

Hi Elina, I have a few questions: 1) For now, it seems to me that SMRs should only be used in the context of a big power plant. Isn't it terrible for oversight if now big companies in energy intensive areas start using their own reactors in their backyard? It seems better for agencies such as the IAEA to only have a few sites to inspect. It also seems easier to implement a restricted site, where only authorized personnel can enter. 2) You mentioned maybe good aspects of SMRs, such as lesser refueling frequency, advanced fuels, flexibility, etc. Are they really a distinct advantage of SMRs? Isn't it something that usual bigger reactors can also be configured to do? Plus, as you said, some of them actually have higher refueling frequencies, which does raise the proliferation issue. 3) Regarding waste, you mentioned that SMRs can use advanced fuels which produce less waste, etc. On the other hand, I've also seen articles such as this one news.stanford.edu/2022/05/30/small-modular-reactors-produce-high-levels-nuclear-waste/ talking about higher level waste, due to their design and bigger neutron activation of the reactor structure itself. How do you balance this out? 4) You mentioned that SMRs attempt solve some of the standardization and certification problems. But again, is this really a revolutionary characteristic of SMRs? Because "normal" reactors can also be standardized and built with modular parts themselves (take the new Korean APR+ reactors for example aris.iaea.org/PDF/APR.pdf , with estimated construction times of 3 years) 5) Are they really safer? Big reactors can also have passive safety systems and so on. A lot of the points you mentioned feel like they are not specifically a unique feature of SMRs, but also features that bigger reactors can employ. What are really the unique advantages of SMRs (that normal reactors can really not have)? Disclaimer: I'm a physicist, not a nuclear physicist.

[@camresearch5120]

Fluid dynamics. Large pipes are more efficient. SMR reactors are being sold as Silicon valley style glossy brochured paper investment schemes, based on flawed (manipulated) simulations. Most of the site costs with a fraction of the total output. Efficiency of scale, large reactors aren't just by chance. We have had small reactors for decades SL1 was an early example....

[@larry-z9m]

@@camresearch5120 SL-1 was a real problem.

[@olafschermann1592]

The one operational swimming SMR located in east russia, isn’t that just a conventional reactor of the same type used on ships? Therefore the safety features are poor, especially when the reactor is located far from “helping” infrastructure like alternative powerplants providing electricity for cooling in case of an accident.

[@JAGMOHANYadav.-mo9or]

Perfect

[@misanthropichumanist4782]

Two things: 1. Isn't heat engine efficiency positively correlated with device scale? That is, wouldn't smaller reactors be somewhat less efficient than larger versions wrt electricity production? 2. How do SMR "passive safety features," work/what are they? If SMRs are scaled down versions of conventional commercial reactors (i.e. water-cooled thermal reactors running on either enriched uranium or reprocessed waste,) then I'd expect them to require active safety measures. Primarily, active cooling. Is this not the case? Regardless, I'd definitely appreciate elaboration on SMR designs in this regard. Thanks for your time!

[@kokofan50]

1) you’re right, but the other benefit more than make up for minor loses in efficiency. 2) it depends on the type of reactor. Molten salt reactors drain the fuel salt into a drain tank that disperses the heat, so the salt solidifies stopping the reaction. The helium in helium cooled reactors have such a high heat capacity that they’ll stay cool until the pile has cooled. The NuScale design uses a water bath to act as a heat sink. There’s a Rolls Royce design that uses the containment vessel as a heat sink. Also, smaller reactors are able to disperse heat better. That’s why they’re less efficient

[@misanthropichumanist4782]

@@kokofan50 Re 2: 🤦‍♂️ I forgot about the square cube law. Oops. Anyway, thank you for the explanation!

[@aaroncosier735]

Thermally, compensations may be made. However, the surface-area to volume ratio also impacts the neutron economy: how many neutrons leave the system as opposed to hitting fissile nuclei. Small reactors lose more neutrons, so sustaining a reaction requires that the source of neutrons (fissile material) be used up at a higher rate. Overall this results in less efficient fuel use and more waste per unit of energy generated. Some say this is not the limiting factor, but it doesn't help. Virtually no spent fuel waste has been disposed, so we have no idea how much this adds to the overall costs. Some estimates run very high, so halving efficiency (doubling waste costs) could be a serious matter. Some proponents think not. we will have to see. We will not know for sure until we see major nuclear nations actually dispose of a substantial fraction of spent fuel. Till then it's just hopeful guesses.