[0:00]This video is sponsored by Soylent, the complete nutritional food back by science. See the link in the description for a special discount for Arvin Ash viewers. In 1973, natural gas, oil, and coal made up 87% of the world's energy supply. By 2019, this number was down to 81%. This reduction is a direct result of the push towards green energy in the last few decades. You would think that this increase in green energy came from solar or wind power. But no, it has come largely from the adoption of nuclear power. Nuclear power went from 1% of our energy consumption to 5% in the same 1973 to 2019 period. But when many people think of nuclear, it conjures up images such as these from the Chernobyl disaster in 1986, when a nuclear power plant blew up in the Soviet Union. Or the explosion of the housing at the Fukushima nuclear plant in 2011 in Japan. Some in the general public also have an unfounded, but lingering fear that nuclear power plants could explode like an atomic bomb. This is an impossibility, but there is a real threat that an uncontrolled meltdown of the nuclear reactor could release harmful radiation in the atmosphere. There has also been a concern about waste products, which can be highly radioactive and would need to be stored for thousands of years before they're safe. But what if I told you that a technology exists which would not only make such scenarios and disasters obsolete, but the physics of which would make nuclear power plants essentially melt-down proof and produce far less harmful radioactive waste products. And to top it off, unlike some other pie in the sky technologies such as fusion, which always seems to be decades away from commercialization. The basic physics of this technology was proven to work over 50 years ago. Could this be the silver bullet that we've been looking for that saves us from climate change disaster? How does it work? What makes it so safe? And how is it different from conventional nuclear power plants that operate today? That's coming up. Right now.
[2:13]I'm going to show you how nuclear technology can safely and sustainably power our planet, but first, we need to power our bodies. And nuclear can't help us with that. This is where today's sponsor, Soylent can help. I often work 12 to 18 hours a day, I barely have time to eat, let alone prepare meals. Soylent is a godsend for people like me who are looking for healthy and nutritional meals that can be consumed without having to plan, prepare or take time. Soylent is a science-based meal replacement drink. The formulation is based on research and clinical trials. They've done the homework so that you don't have to. Now the science is great, but the bottom line for me is that if it doesn't taste good, I won't drink it. This tastes great. And in a survey of 40,000 people by Kanta Research, it beat out its competitors. Another big reason I prefer Soylent is because I'm lactose intolerant. My body can't take any milk products. Soylent is completely plant-based, so it doesn't wreak havoc in my stomach. My personal favorite is the Cafe Mocha flavor. It's got a really rich, dark coffee flavor, which I find irresistible. Soylent has a special offer right now for Arvin Ash viewers. The first 500 people to use this link and the code ARVIN30 will get 30% off their first subscription. I highly recommend it. I think you're going to be pleased. And now, back to nuclear. To really understand how a molten salt nuclear reactor works, it's important to take a step back and look at how a power plant works in general. Not just a nuclear power plant because the essential schematics is really the same. The only difference is where the power comes from to produce the heat. Any power plant has some fuel which causes some liquid to be heated. This liquid can be water but doesn't have to be. This hot liquid can be used to do one of two things. Either we convert it to hot water for use in some kind of industrial process, or we convert it to steam to drive a turbine to create electricity. Then the hot liquid is cooled down again so that it can be reused, that is, reheated to continue the cycle. In a coal fueled plant, the power generation comes from burning coal. Coal is generally a cheap source of fuel in many countries, but the big drawback, as you're probably aware of using coal, is not only the generation of greenhouse gases such as carbon dioxide, but also atmospheric pollutants like sulfur dioxide and nitrogen oxides, which are known to be harmful to humans. A nuclear power plant works in much the same way. But with the exception that the source of energy is from the nuclear process of fission. Fission, very simply put, is when in the core of the reactor, we split a heavy element like uranium into smaller elements like krypton and barium. If we look at the total mass of the products of the fission process and subtract that from the original mass of the uranium, which we started with, this mass difference is what is released as energy, as described by the mass-energy equivalence principle, E = mc^2. The mass difference is actually tiny, but the amount of energy released is huge because, as shown in this equation, the mass is multiplied by the speed of light squared, which is a huge number. This is essentially why nuclear power plants can generate an incredible amount of energy with very little fuel. To give you some numbers, 1 kilogram of coal produces around 8 kilowatt-hours of energy, whereas 1 kilogram of uranium 235 produces a whopping 24 million kilowatt-hours of energy. So why aren't these standard nuclear power plants everywhere? Well, there are several drawbacks. First, although they are relatively cheap to run, they are very expensive to build. This is largely because nuclear power plants are technically complex, requiring construction specialists and have to satisfy strict licensing, design and safety requirements. But of course, the elephant in the room is that the uranium fission technology used in current nuclear power plants produces highly radioactive and harmful byproducts, which requires storage for long periods of time. And in the case of the very rare accidents, it can cause an environmental disaster. So this technology faces much public resistance because of its perceived safety issues. Real or not, this perception has been shaped over many decades from highly publicized nuclear accidents, the most recent of which are Chernobyl in 1986 and Fukushima in 2011. But there's a different type of nuclear technology using molten salt and thorium, which can eliminate many of the problems that commercial nuclear plants of today are riddled with. To understand how molten salt nuclear reactors can be so much better than current reactor designs, let's compare how traditional nuclear power plants work and contrast that with a molten salt reactor design. In the core of a traditional reactor, where the energy is created, solid nuclear fuel is placed in a series of rods. The fission reactions take place here. The fuel traditionally is uranium 238 with a tiny amount of uranium 235, only about 3 to 4%. This is the fissile part. It's important to understand that U238, which makes up about 96 to 97% of the material in the rods, is not fissionable. Only the uranium 235 can be split in a fission reaction to make energy. So under a small fraction of the fuel gets used in the process. This leads to one of the problems with this type of nuclear fuel. Even though we can get a lot of energy from this tiny fraction, it is still quite wasteful. But the bigger problem with so much U238 is that although it does not split, it transmutes to highly radioactive isotopes, such as plutonium 239. This is a highly toxic waste product that needs to be stored for thousands of years before it decays to safer and more stable elements. This is the core of the nuclear waste problem, which many in the general public object to. The speed of the reaction, that is, the rate at which energy is produced in the reactor, is regulated by control rods. These control rods contain neutron-absorbing materials such as cadmium or boron, which reduce the number of neutrons available to split the U235. The control rods can control or stop the reaction. If we didn't have this, the fuel rods could get overheated and cause a meltdown. You should also understand that when the U235 splits, the neutrons produced in this reaction are usually too fast and quickly dissipate. This makes them unavailable for the fission process. So a moderator is used to slow down the neutrons so that they are more likely to cause fission in the fuel. These moderators are typically water, heavy water or graphite. Heavy water is where the hydrogen atoms in the water molecule are replaced by deuterium that have one extra neutrons in their nuclei. And that brings us to the last central component of the reactor, the cooling. This is done by transferring or harvesting the heat produced in the fission process. Without this process, the heat produced in the reactor would have nowhere to go. This could risk a meltdown. Failure of this aspect is what happened in highly publicized nuclear accidents at Chernobyl, Fukushima and Three Mile Island. Traditional nuclear reactors typically use the same moderating regular water or heavy water to transfer the heat away from the core. Using regular water is cheap and simple. Heavy water is more expensive, but it absorbs fewer neutrons keeping more of them available for the fission process, so that's why it's used. If using ordinary water as the coolant, it can be either directly connected or connected via second loop to a generator to make electricity. The water is then cooled down and reused as the coolant in the reactor, similar to the way the coolant in your car is reused after being cooled in the radiator. This is how most commercial reactors work, roughly speaking. There are lots of different designs and there are some differences in features, but what I discussed so far applies to most nuclear reactors in use today. Now let's contrast this with how molten salt reactors work. Keep in mind that as of January 2024, these types of reactors are in various stages of development and have not been commercialized yet. There are two main differences. First, instead of solid fuels, the fuel is dissolved in molten salt, which is in liquid form. The second difference is that instead of water as the coolant, they use a second molten salt as the coolant. These have several advantages as well as some disadvantages. First, these salts are not table salts, like sodium chloride you have at home, but more complex salts made in labs. There is no standard formula for the salt, and each producer may have their own specification. The type of salt used by Copenhagen Atomics, one of the premier molten salt reactor research and manufacturing facilities, which I had the pleasure of visiting recently, use for example, fluoride lithium-based salts. The main requirement for the salt is that it must contain some fissile fuel dissolved in it, which can drive the nuclear process. This fissile material can be the same U235 mixture used in most traditional power plants, but it can also be something like thorium or plutonium. The latter could come from nuclear waste produced by traditional reactors. Uranium and thorium are mined, and there is enough on earth to keep reactors running for hundreds of years. The big picture I want to paint for you is that in such reactors, the fissile material, such as uranium, is not part of the salt, which is in liquid form. This can allow it to move and circulate. This is very different from traditional designs where the uranium is a solid and stays stagnant in the control rods. It just sits in the core and can't go anywhere. Why is it better to have a design where the nuclear fuel can circulate? There are several reasons related to both operational efficiency and safety. First, because it's molten, it operates at much higher temperatures and can carry a lot more heat than water. To give you an idea, the maximum temperature of the molten salt in the reactor is about 700° Celsius. Whereas the operating temperature of water under very high pressure is only about 300° Celsius. The molten salt does not operate under high pressure, which is another good safety feature because there is no chance of pressure vessel failure. Furthermore, because the fuel salt is being pumped into the reactor to keep it circulating, if anything goes wrong, for example, if the pump stops working, the fuel will simply drain out via gravity into the bottom holding tanks. This would happen without any human intervention and is a big safety feature. This is almost like an on-off switch, which essentially just turns the reactor off in case of failure. The heat from the reaction cannot overwhelm the cooling apparatus. Molten salt also happens to have a chemical property which makes it safer. When molten salt becomes too hot, it naturally expands. That is, the distance between its molecules increases. This reduces the nuclear chain reactions because the distance between the fissile atoms increases. So the likelihood of neutron nuclei collisions decreases and the chain reaction slows down all by itself. If the salt gets too hot, this is like a built-in thermodynamic safety valve. So in case of trouble, the salt can be just allowed to overheat and the chain reactions will be reduced by itself. This makes the idea of runaway overheating or meltdown virtually obsolete. Now, there is an additional major operational benefit. In conventional reactors, the fuel is solid. When the fuel runs out, they have to be shut down so that the fuel rods can be replaced. This can be costly. But in molten salt reactor, since the fuel is circulating, the reactor does not have to be shut down to be refueled. It can be refueled on the go, that is, while it is still in operation. And by the same method, scrubbers can be installed which can take undesirable fission byproducts like xenon gas out of the fuel while it's still running. Finally, because the core by virtue of using molten salt is very hot, 500+ degrees Celsius, it has a much better thermal efficiency. You can thus make more heat from a smaller core. So the reactor is not only unpressurized, but it also has a smaller footprint, so it costs less to build for a given energy output. The reactor designed by Copenhagen Atomics are so efficient and small, in fact, that the whole thing can fit in a 40 ft container and be produced on an assembly line, drastically reducing manufacturing costs. So, if molten salt reactors are so great, why are they not everywhere? This is a good question and the answer is fairly simple. Molten salts are traditionally highly corrosive. Corrosion is what we commonly know as rust on iron, but more things than just iron can rust and that in general is what corrosion is. Chemically, it's when the metal container housing the molten salt reacts with oxygen. If you want to see corrosion in action, just put a piece of iron in salt water and see how it begins to rust. A similar problem can occur with molten salt reactors if the corrosion problem is not addressed, leaks could occur. So anything touching the salt must either be replaced very often or be made of high temperature, non-corrosive materials, which are very expensive. The way Copenhagen Atomics has addressed this problem is by keeping the salt ultra clean. That is, they have found a way to eliminate essentially all the moisture and air from the process so that it does not corrode. Salt cannot corrode anything if there's no moisture or oxygen available. Another drawback with molten salt reactors is that they have not been commercially proven. This is something that research and manufacturing companies like Copenhagen Atomics are working very hard to do. But before they're proven, there's always going to be some doubt about their feasibility. Now, I want to address perhaps the biggest reason for the public's objection to nuclear reactors. The nuclear waste issue. Molten salt reactors would not help much to solve the issue of significant radioactive waste. If we use the same uranium fuel source as today's conventional reactors, that is, the issue of what to do with the radioactive plutonium 239 would still be a problem. However, if we use thorium instead of uranium in these reactors, there would be a lot less radioactive waste, and the severity of the radioactivity would be much more manageable. Thorium fission byproducts have much lower half-lives on the order of several decades. Instead of thousands of years for uranium 235 before they can be safely handled. Thorium produces not only a lot less radioactive waste, but it also much more abundant than uranium. If you want to know more about thorium, I have a dedicated video about it right here. In a nutshell, the reason it does not produce as much radioactivity is because there is a lot less plutonium 239 produced in the fission process when thorium is split versus uranium 235. As far as safety is concerned, the worst case scenario for molten salt reactors would probably be if the molten salt with the radioactive material leaked somehow. While this would release some radioactivity, the salt would become solid as it cools and contain the radioactive fuel, so it would be possible to clean it up pretty effectively. And thanks to physics and the built-in safety features of molten salt reactors, we would never see disasters such as Chernobyl or Fukushima again because they can physically not happen. The bottom line is that we have a technology available today that can provide abundant green energy for the foreseeable future, with no shortage of the fuel. Little to no greenhouse gas emissions and manageable radioactive waste. There's a huge upside and the drawbacks are few. In my opinion, this is good for mankind and we should at least consider it, if not embrace it. I'd like to thank Copenhagen Atomics for their generosity and letting me tour their facilities to learn firsthand how molten salt reactors work. I'll have a dedicated video about Copenhagen Atomics, including interviews with their leader soon. Now, as you might imagine, there's a lot more details that I could have gotten into, but I hope this video provides a good summary for you. What do you think? Should we embrace nuclear or not? Let me know in the comments. I'll see you in the next video, my friend.
