How Molten Salt Reactors Could Revive Nuclear Power

The first 500 people to use this link and code ARVIN30 will get 30% off their first subscription with Soylent: bit.ly/3S3KnYB Many thanks to Soylent for sponsoring this video. Support us by clicking the link above,. Quick story about their name: Soylent was actually named after the food in the 1966 science fiction novel "Make Room! Make Room!" and later 1973 film Soylent Green. While the food in the book is made from soy and lentils (hence the name), the food in the movie is made from humans. Soylent actually in 2022 (the year the film takes place), released a SoylentGreen snack bar in a mystery flavor as a humorous nod to the film.

Isn't it a bit eery that a food company is named Soylent?

First: As a nuclear power plant engineer who is very interested in new nuclear power plants I would like to complement you on being I believe the 1st YouTuber to talk about the very real corrosion issue with MSR's. People often wonder why there was never a 2nd MSR test reactor after Oak Ridge. It was because there was no known super-alloy of the day that could withstand the corrosive effects of the daughter products and chemicals generated by their reactions in the mixed molten salt stream that occurred at the Oak Ridge test MSR. The good news is that a number of countries have been doing research into new "exotic" super-alloys that should better withstand the corrosion (to the best of my knowledge - no one has found an "immune" super-alloy at this time). Also, that the concept of chemical separation of the problem daughter products and resultant chemicals has been developed and limited testing of the concept has been done without actually using real MSR molten salts and daughter/chemical byproducts. So the theory is that if you use a much better super-alloy than what was used in Oak Ridge and can filter enough of the daughter products and chemical reactants that you can minimize the corrosion rate to one that would allow construction of a 40+ year operating life reactor and molten salt stream piping and equipment. As you pointed out this is only a theory and has not yet been adequately demonstrated. China built and started up a 2 MWthermal test reactor in I believe August 2023 to test their best guess of the right exotic super-alloy and an adequate filtering system. This test reactor is about 1/4 the size of the 1960's Oak Ridge Reactor. If it works (which is an unknown and failure is a real possibility) they plan on building another test reactor 10-15 size larger to see how it scales up. If that works then a small power plant (likely in the 40 - 60 MWe range). Then if that works they can design a power plant likely in the 200-400 MWe range. Etc. Each step is likely to require a minimum of 5 years of successful run time before finalizing the next larger size plant design and starting construction. Reliable MSR power plants are likely several decades away. Note that the history of nuclear plant development worldwide shows that scaling up from test or small reactors often does not go very well. Lots of plants the next size larger did not work well - or needed major modifications. No one at this point knows enough about the performance of any fuel in a MSR to do anything but take a very large gamble on building a power plant sized reactor (and we know that well as the USA built 4 commercial thorium fueled nuclear power plants in the 1960's - 1970's and all 4 were both a technical and a commercial economic failure: I will post separately on that history). Second: Liquid salts are not the only material that expand and self control a nuclear reacton in a reactor. Light water BWR's and PWR's do the same (I'm not sure of heavy water reactor designs); and in the case of PWRs (which I have worked extensively in) once the reactor is in the power range they pull out the control rods more and just let the water temperature self moderate the reaction rate. So nothing new here. Third: I hate to pop your bubble about Copenhagen Atomics, and about 15 other such companies in both the MSR and SMR market. I consider them an investment scam company (they exist to get investor money to fund jobs for a decade or more). They are not serious at all about building a real nuclear reactor and their designs and timetable are laughable to anyone with real experience in the nuclear industry. They don't even have a clue on which super-alloy will be needed to make the concept work yet (ordinary 304 SS is corrosion resistant to the pure lithium salt with unreacted nuclear fuel in it - the problems start once the nuclear reaction starts). Companies that are serious are working with a nuclear regulator for eventual licensing of the reactor. This typically takes several years and multi-millions of dollars in a "pre-License" review process (and all western nations have such a process or will tell you to use a design licensed by other western countries). The best example right now is I suggest that you look up the Canadian Nuclear Safety Commission website, page down to "New Reactor Facility Projects" link, then use the link under "Current pre-licensing vendor design reviews" heading not quite half way down the page. There are two links near the top of the page for "Current" and "Completed" and a list of project at the bottom of the page. When this process is completed the vendor knows what will be needed in a license application for a reactor design. It typically takes several years to review a license application once submitted if it has all the required information and the regulator agrees things are properly designed and proper procedures and staffing will exist. The mass production possibility is a myth. Airbus and Boeing build over 100 of the same model airplane each year, and they are largely hand assembled. Yes a number of parts are mass produced; but its cost prohibitive at that production rate to build a plant that could automate the assembly much more than it is currently. You would likely need to have orders on the order of 250 near identical MSR plants per year for at least 5 years to justify building a plant for mass production (and that plant will take years to build). Just not happening - no one needs that many new power plants (even at 50 MWe each) for that amount of time. Also, nuclear plant is highly site specific due to earthquake and natural disaster requirements. One location may need very light reinforcement and provisions for a natural disaster. The next site may need 10 times as much. The sites with low risk do not want to pay for 10 times the reinforcement materials. Building nuclear plants requires a assembly of lots of parts; and having it in an appropriate safety structure. Also, nuclear construction codes exist due to lives lost and major nuclear plant issues. No short-cutting those and only about the top 25% of workers adjust to working like that (it's a completely different approach than normal construction). They also want to be paid for their expertise. This myth also assumes that your design is well proven. It took the light water PWR about 50 years of operating history and lots of failures along the way to know how to build a well proven design (the current AP-1000). It will likely take a similar amount of time and failures to get MSR reactor plants that are really well proven after the designs are proven in test reactors. Who is going to buy more than a few units until the design is shown to work well for decades? Low production numbers means no special factory and highly skilled and paid workers custom building most everything. Have a great day,

0:01 As he was taking the bottles out of the box, I was wondering -- will there be a green bottle? Yes!!! Soylent Green!!!

What's interesting is that nearly all the negatives of solid fuel reactors have been solved by the Canadian CANDU reactors many decades ago. I'm disappointed the Canadian design wasn't even mentioned. Edit: except for the cost

Kirk Sorensen was on this case for decades now. Good to see this finally hitting mainstream.

For those of use who watched Soylent Green...how could they name their product that! :face-orange-biting-nails:

A big drawback of coal is how much radiation it releases because of the radioactive elements in the coal you are burning 🔥

Thank you! Thank you so much for covering this! You did a great video and covered all of the important points. Here’s a couple of additional things: 1) You should see if you could tour Flibe Energy and interview Kirk Sorensen if possible. Flibe has several important additional uses for lithium-fluoride thorium molten salt reactors (LFTR) that involve using the radioactive byproducts for medical purposes and the heat for desalination and recycling. Also, Plutonium 238 is a byproduct and this is very rare and very useful for radioisotope batteries. 2) Another important benefit of LFTRs is since they don’t use water for cooling, they don’t need to be near large bodies of water. 3) There are other important political reasons why the world stuck with water-based reactors. 4) The low pressure and no water make them perfect for space-, moon-, and Mars-based power generation.

Your collection of videos on YouTube are the greatest of all the YouTube science channels! Even you older ones are relevant, thank you for years of teaching me more about how the world works

SOYLENT GREEN IS PEOPLE!!!!!

In a post I did below I mentioned that I would post the history of Thorium fueled power plants. The USA built 4 of them. This is an edited version of a post I did elsewhere. Thorium as a potentially viable fuel was identified in the 1950's by many countries. First though is that thorium is not fissile (you cannot get a nuclear reaction using thorium). A thorium reactor actually runs on U233 in the end - and its U233 that is recoverable from them. In the presence of a properly controlled nuclear reaction thorium 232 absorbs a neutron and becomes protactinium233. The protactinium233 then decays to U233 (which takes about 2 months to get usable quantities of U233). As such all thorium reactors must be seeded with U233, U235, or plutonium239 (the common fissile materials) to supply fuel for the first 4+ months of operation. I’m not going to list and discuss all the existing test reactors that had thorium loaded into them or the thorium specific test reactors that were built. Suffice to say that thorium was tested in both existing test reactors and specific built thorium designed test reactors by multiple countries. Also in all kinds of designs since the 1950’s: Light Water, Heavy Water, High Temp Hot Gas (HTGR) and of course the Oak Ridge Molten Salt Reactor (MSR). The recent several decades have focused on HTGR pebble bed designs and of course China just built and started up in August 2023 a new thorium based MSR to determine if we technically have solved the molten salt corrosion issues well enough to proceed with further development. I am including the Shippingport thorium core load 3 (1977-1982) as a test reactor. Shippingport was a naval aircraft carrier PWR that became the 1st demonstration and test reactor for commercial power: 60MWe output, Online 1958 (1st nuclear electrical power generation from a plant built with its primary purpose to generate electricity). This thorium core proved that a thorium core could self-generate surplus U233 for recovery by reprocessing. Shippingport was shut down in 1982 at the end of this test. To date only the USA felt that they had thorium fuel designs based on test reactors that worked well enough to design commercial power plants from, which did not work out as explained below. In retrospect they can be viewed as very large and vastly costly test reactors. The USA had also spent the equivalent of $Billions in today’s money to build a stockpile of U233 to seed thorium reactors and for atomic bomb tests in the 1960's (the U233 bomb worked well). Note that they are now looking to spend $billions to dispose of that U233 stock as the containers are degrading and disposal is cheaper than repackaging the U233 stock into new containers which does not count long term cost of storage that follows – and eventual use or disposal in the future. Also, there is no real foreseen use at this time for that U233 to justify the cost of preserving it. 1st attempt was Indian Point Unit 1 – light water thorium fueled 275MWe PWR power plant. Online in 1962. The thorium fuel performed so badly that they changed to uranium fuel in 1965 and the plant spent the rest of its life as a uranium reactor that operated well. Unit 1 was shut down in 1974 due to changes in regulations from when it was built as the emergency core cooing system that was acceptable in 1962 was no longer acceptable in 1974, and initial plant design made retrofit of an acceptable system uneconomical (nuclear power plants tend to have lots of rooms with very substantial reinforced concrete walls – there may be almost no room to install something different). 2nd attempt (approved for construction at essentially the same time as Indian Point Unit 1) was Elk River – a light water thorium fueled 22 MWe BWR (Online in 1964, Shut down 3 ½ years later in 1968 due to major design and construction issues which led to cracks in the reactor vessel and main piping resulting in significant reactor water leakage. I have found comments that says the reactor and power plant did not operate as expected; but, no evidence if this was a fuel issue or other issues. More interesting is that this was presented as a prototype for a “Small Modular Reactor” for rural America (SMR’s as the reactor assembly and boiler was built in a plant and shipped to site by a railcar), which could be done anywhere as the key SMR concept of small nuclear reactors would be economical due to mass production was presented at an international conference in 1955. However, 17 power plant reactors which would be considered SMR size today were built in the USA from the 1950’s into the 1970’s. Not one of them is operating today – where a number of large central station nuclear power plants built at the same time are still operating. Other than the cracks and reactor water leaks the biggest lesson learned was that small nuclear units like this would never be cost competitive with larger nuclear units as they need more materials and cost much more to build on a MWhr generated basis; and also cost much more to operate and maintain on a MWhr generated basis than a larger plant due to staffing requirements. Note that a 12MWe uranium power plant in Piqua, Ohio which ran from 1963-1966 was closed with the same conclusion. 3rd attempt was Peach Bottom Unit 1 - a thorium fueled HTGR reactor (as that seemed to be the most applicable technology other than light water based on test reactors). I believe it was about 60MWe output. Online in 1967, shutdown in 1974. There were severe problems with the thorium fuel and it was quickly changed to U235 fuel. There were massive other plant design problems (scaling up from a test reactor size rarely goes smooth). A total commercial and technical flop. 4th attempt (based on lessons learned from Peach Bottom) was Fort St Vrain - a 330MWe output thorium fueled HTGR. Online in 1979, shutdown in 1989 due to several issues in the plant design that affected operation and required excessive and expensive maintenance and only produced 15% of the power it should have if it could run well enough to base load at 100% output which is how most US Nuclear Reactors are loaded. I had a coworker who had worked at Fort St Vrain and he told me that in the end it was also converted to Uranium fuel. I have been unable to verify that with limited internet searches (multiple sources report that Peach Bottom Unit 1 was quickly converted to Uranium). Fort St Vrain was again both a major technical and economic flop. Bottom line is that there has been extensive research into thorium-based reactors by multiple countries from the 1950’s to current time, and the USA even built 4 commercial power plants using BWR, PWR, and HTGR designs. No country to date has made a test reactor or power plant work well enough to design a future power plant at this point – especially when they look at the USA’s attempts at building thorium fueled power plants by substantial scaling up of test reactors. The world history of initial nuclear power plant designs, and even 2nd generation designs, in many countries show lots of failures as what seems to work so well on paper often does not work in practice (or is too expensive to maintain). Research continues and just because thorium did not work well and was not economical in the past does not mean that it won’t work well or be economical in the future. It’s just going to take a lot of money and time. If it was easy, it would have already been done. There are also a lot of investor scam companies out there claiming that they have the solution, when no one really knows what the solutions are yet. These companies often talk of building plants on a fast timetable but have never even started a "pre-licensing" review of their design which is normally needed to get to the point to be able to submit a reactor design for licensing (figure several years for pre-license review, and then several more years for licensing once a license application is submitted). Just how many reactors does anyone think they are going to build that are not approved by the nuclear regulators? But, they generate good paying jobs for people for a decade or more by telling by telling investors and lots of people that the solution is obvious and simple.

0:00 Soylent Green is both the name of a 1973 science fiction film and of a wafer-like food product in the film. The film is a police procedural set in the future, based on the 1966 novel Make Room! Make Room! The food is a processed protein ration made of human beings and distributed to an unsuspecting populace.

Beyond less waste, it can be used to burn the waste produced by traditional uranium fired reactors. I first heard of thorium molten salt reactors like 15 years ago. It's nice to see someone is finally working on their construction.

The problem with commercialisation of molten salt reactors is the wear issue, not only is the molten salt extremely corrosive and reactive it also mechanically etches it's vessels and pipes as it circulates. This was one of the primary reasons it was initialy shelved until further advances in materials sciences brought about the ability to negate or at least resist those effects long enough to be viable. I like the tech and it is pretty safe as an automated installtion, I would indeed like to see further development on this and other thorium cycle small reactors.

I can't thank you enough for producing content like this. Your videos are genuinely so informative and educational. I've passed this video along to multiple people I know that could benefit from watching this (the anti-nuclear energy types). I am excited to see your interview with Copenhagen Atomics!

The idea of shipping container sized nuclear reactors might be a more important innovation than either molten salt or thorium. If the reactors can be transported efficiently, then their manufacturing and maintenance can all happen at a central facility. The on site construction, then, becomes much easier to regulate. Also, for powering cargo ships and freight trains, a shipping container sized nuclear boiler would be really handy. That might even be the first market ready application. An efficient nuclear powered freight delivery system could be the backbone of green transportation infrastructure. I can imagine a high speed trans siberia nuclear train that goes 200 mph and only needs refuelling every other decade! The potential of nuclear makes the transition seem that much more attainable.

Soylent Green is my favorite, it reminds me of my grandparents 😊

What a superbly informative video! I'm an engineer of 40 years and I learned a lot. One thing; The turbine you show is I believe, a gas turbine rather than a steam turbine. Not that it does anything to detract from brilliance of the video, but you clearly value accuracy. Thank you for this lesson. I'm a believer and I subscribed.

As well as the gaseous pollutants, coal also produces arsenic as a byproduct; it also releases more radioactive waste, albeit low level, than a nuclear reactor.