Hello everyone, Do you support nuclear power? Should we build small nuclear power plants? If so, where should they be built? These topics have recently been hotly debated, But before you take a side, Do you really know what Terry Gou refers to As the 'Small Modular Reactor (SMR)'? Is it safe? Is it truly the future of nuclear power? In fact, some people have already successfully operated small nuclear power plants, And they are already connected to the grid for power generation. How did they do it? Creating scientific content is not easy, If you think the content of this episode is good, After watching, feel free to use the 'Super Thanks'. Your every encouragement Is the best support for us. Local revitalization is in full swing across Taiwan, The Youth Development Administration of the Ministry of Education To foster a sense of identity for young people with their hometown land Invest in local development, In cooperation with 25 learning-focused youth gathering spots in the 112th year, Offering 132 courses, Let young people understand how to participate in the community Through local courses and onsite practice. Establish a basic concept of local action and local revitalization, Develop action plans, Lead young people step by step from Dreamer to Actor. Welcome young people aged 15 to 35 who care about local affairs, Have dreams and ideas about community affairs, To join us. As nuclear power plants gradually retire, Taiwan is also gradually moving towards a nuclear-free homeland. Mr. Terry Gou's sudden proposal of 'one nuclear power plant per city and county' Has rekindled the heat of the nuclear energy debate. Although it seems radical, Some people think If it's the 'Small Modular Reactor (SMR)' mentioned by Mr. Gou, Maybe it's possible. But what exactly is this SMR? The only remaining Operating nuclear power plant in Taiwan is the Nuclear Power Plant 3. Nuclear Power Plant 3 has two units, Each unit's power generation is about 950MW. The protagonist this time, the small nuclear power plant, Its official name is Small Modular Reactor, SMR, Small Modular Reactor. The power generation is usually between 20-300MW, Which is much smaller than regular nuclear power plants. There are even smaller ones, Small enough to have a power output of only 1-20MW, These are known as MMR reactors. Hey, that's odd, Don't people usually want the power output to increase? Why are they getting smaller with development? Does this mean we need to build more nuclear power plants? Well, that's indeed the case. The characteristic of small nuclear power plants is their small power output, Because this creates three advantages: Safety, Low cost, And easy assembly. These three advantages actually address the biggest bottlenecks in nuclear power development today. Nuclear power generation has a history of 60 years, But to date, it only accounts for about 10% Of global power generation. The biggest issues Are none other than safety, High cost, And long construction time. Right, even disregarding safety, The lengthy construction time. And the expensive cost of electricity generation, Are one of the reasons that deter many power companies. According to energy research firm BNEF, That is, Bloomberg New Energy Finance's survey, From 2009 to 2021, The cost of constructing renewable energy sources like wind and solar power, Has decreased by 72% and 90% respectively in 12 years, This has already become the first choice in many regions when developing new energy. On the contrary, nuclear power has increased by 36%. If we compare the levelized cost of energy per unit of electricity, Nuclear energy is 4.5 times their cost. In addition, nuclear power plants take 5 to 10 years to build. Even though nuclear power is a low-carbon power generation method, People tend to choose the development of mature renewable energy. Aside from that, Even if nuclear engineers present data and theories, Emphasizing that the occurrence rate of nuclear accidents is very low, The case of the Fukushima power plant still lingers in people's minds. And rationality often falls short in the face of emotion. This doesn't need much explanation. However, despite this, As human power demands intensify, And the need to simultaneously achieve the common goal of net-zero emissions, There are still many countries, such as France and Finland. Recommissioning nuclear power plants or increasing the usage ratio of nuclear power. Why is that? Because nuclear energy has a significant advantage. That is, stable and continuous power generation. Renewable energies like solar and wind power, Are easily influenced by weather and time, affecting their power generation. In contrast, nuclear power is considered base load power. Its positioning is fundamentally different from wind and solar power. But we are like highly demanding customers, Wanting it to be good, fast, and cheap. In addition to stability and low carbon, We also want nuclear power to be safe and cheap to build. So, are small nuclear power plants, Really the perfect choice? The main feature of Small Modular Reactors (SMRs) is just one word, Small. As long as they're small, with reduced power, The reactor will not release too much heat at once. They can even eliminate the need for external cooling equipment. And rely on natural circulation for cooling. We all know, The Fukushima nuclear power plant accident occurred Primarily because the tsunami damaged the plant's Generators, which served as emergency power sources. After the backup battery power was exhausted. The cooling system thus completely failed. Eventually, the temperature inside the reactor could not be controlled and kept rising. High-temperature steam and the zirconium alloy in the fuel cladding Underwent a zirconium-steam reaction. This created a large amount of flammable hydrogen gas. The hydrogen then interacted with the oxygen in the air, Ultimately causing an explosion. If the reactor of an SMR Can eliminate dependence on external cooling systems And cool down by itself, It can largely avoid a zirconium-steam reaction, Hydrogen explosions, and core meltdown accidents. But on that note, How does an SMR achieve cooling without an external system? Let's take the American company NuScale as an example, Which is currently the most advanced in SMR development. In their 60 MW reactor, There are 37 fuel assemblies. The entire reactor is about 17.8 meters tall And about 3 meters in diameter. This size and modular design Allow the reactor to be transported by truck or train. As a result, it can be manufactured in the factory first, And then delivered and installed at a designated location. Factory manufacturing implies the possibility of mass production. Reducing the production cost of a single reactor. Do you think the power generation of one reactor is not enough? Just add another one. Besides being cheap, The advantage of SMR being small and safe Allows it to have multiple reactors in a power plant at the same time. Its flexibility is extremely high. NuScale encases the entire water circulation system within the reactor. Primary coolant Cycles up and down through thermal convection, a concept we learned in middle school. It doesn't require any pump at all, Reducing the risk during a power outage. The heat from the primary coolant Is then transferred to the secondary coolant, Turning the secondary coolant into steam, Which drives the turbine to generate electricity. If there were a real power outage incident, The reactor also has an emergency cooling system, Immersing the entire reactor directly in a large water tank. According to calculations, the water would completely evaporate after 30 days, And by this time, the power of the reactor Would have decreased to less than 4% of the original. The temperature could be stabilized just by circulating air. So, ... Yan Li, you make it sound so impressive, Where's the sauce? Oh, I mean, where's the reactor? The reality is, The power output of current SMRs has met and even exceeded standards, But they have not yet achieved their design objectives in terms of safety. It was originally predicted that the first SMR would be introduced in 2015 or 2016, Now this deadline Has been pushed back to 2028. As the development time lengthens, The costs are also continually rising, It seems that the 'cheap' goal of SMR is getting further away. Is the SMR route really unfeasible? Not necessarily, Because in China, The first onshore SMR has already been connected to the grid. In 2020, Russia activated the first Offshore small-scale nuclear power plant. But let's not talk about the offshore ones for now. At the end of 2021, in Shandong Province, China, The 'Shidao Bay High-Temperature Gas-Cooled Reactor Nuclear Power Plant Demonstration Project' Officially began generating power, Becoming the first small-scale nuclear power plant on land, With a power output of 200MW. Although the total volume of the power plant is not small, Given its power output, And its emphasis on safety design, It is indeed a genuine SMR. Let's first explain the term. The so-called High-Temperature Gas-Cooled Reactor, Refers to the material that acts as a coolant and heat exchanger flowing through the fuel rods, Which uses gas, such as helium. The biggest difference from pressurized water reactors that use water as a coolant Is that there's no need to worry about a zirconium-water reaction causing explosion risks. And it can withstand higher reaction temperatures, Thus resulting in better heat conversion efficiency. In addition, The design of the Shidao Bay nuclear power plant is quite interesting. It uses a spherical reactor. Inside a large reactor, shaped much like an hourglass, What we know as fuel rods Are made into fuel balls, each about 6.7 centimeters in diameter. 27,000 of these fuel balls Fill the reactor like sand in an hourglass. Uranium fuel is wrapped in the center of the spherical structure, While graphite, which acts as a neutron moderator, is on the outside. High-temperature helium gas, which acts as a coolant, Passes between the balls. Taking away heat, The fuel balls can be removed from below And refilled from the top. So why is this design considered safe? We know that the main actor involved in the chain reaction is uranium-235. And over 90% of the fuel composition is uranium-238, Which seldom participates in the reaction. In a high temperature environment, The neutron capture ability of uranium-238 greatly increases, Stealing the neutrons that uranium-235 needs, Thus stopping the chain reaction. Compared to traditional reactors, High-temperature gas-cooled reactors can react with less uranium-235, Meaning there can be more uranium-238 in the fuel rods. Which can absorb excess neutrons when the temperature spikes. Plus, high-temperature gas-cooled reactors are inherently able to withstand high temperatures, So if there really is a loss of power, The temperature of the entire reactor, Would stabilize around 1600℃. Of course, in reality, High-temperature gas-cooled reactors also have control rod designs, The situation I just mentioned only applies in the most extreme cases, When all power or mechanical assistance is lost, Only then would it be a consideration. Whether high-temperature gas-cooled reactors can be successful, Will take much time to observe. For instance, whether graphite-encased fuel balls are prone to friction and rupture, Is something that needs further attention. Besides China, Many countries are also developing various forms of SMR, Some even working on Micro Modular Reactors (MMR) with power ratings below 20 MW. For example, the MARVEL reactor being constructed By the Idaho National Laboratory in the United States, Is one such project. And the nuclear energy company Radiant, founded by Doug Bernauer, a former SpaceX employee, They are creating a container-sized MMR that can be easily transported. They hope it can replace high-polluting diesel emergency generators used during community power outages. Whether it's small or micro nuclear power plants, Aside from technology that still needs to be developed, Whether costs can be lowered is also an important indicator. Of course, there's another significant issue, That of nuclear waste, waiting to be solved. According to research estimates by Argonne National Laboratory of the US Department of Energy, The nuclear waste generated per unit of energy by the NuScale reactor is 1.1 times that of traditional nuclear power plants. And due to the design of the spherical encapsulation in pebble bed reactors, the volume of nuclear waste also increases. That is, while nuclear power plants have become safer with miniaturization, the amount of nuclear waste produced has not reduced. The disposal of this nuclear waste is a problem that nuclear power plants worldwide have to face. Specific measures and research. Everyone can review our video on this topic. In this episode, we analyzed the advantages and bottlenecks of small nuclear power plants. Just like when we introduced other energy sources in the past, we hope you can see that we are not endorsing any political figures. We believe this is what scientific literacy is about. Want to discuss whether or not to build a small nuclear power plant? Well, at least we should first know what it is, right? Speaking of which, the High Temperature Gas-cooled Reactor we introduced today, is classified as one of the members of the fourth-generation reactors. Other members of the fourth-generation reactors, include the traveling wave reactor we mentioned in the last episode, which was invested in by Bill Gates. What is the traveling wave reactor that Bill Gates invested in? Can it really recycle nuclear waste and solve the nuclear waste problem for good? If you are interested, you are welcome to join our membership, or support us through Super Thanks and other ways, to help us produce content on this topic. We appreciate your support. Of course, if you're willing to share this episode, it's a great encouragement. Lastly, we would like to ask you all, if the Small Modular Reactor (SMR) technology truly matures, would you want one installed in your community? Do you think, since it's truly safe and low-carbon, why not have it? Or do you feel, we should solve the problem of disposing nuclear waste first, then talk about it? Or do you believe, that no matter what, nuclear power plants with the risk of radiation pollution, shouldn't be in my backyard? Or perhaps you think, we should wait for nuclear fusion, or other fourth-generation nuclear reactors? Alright, that's it for this episode. If you liked it, feel free to hit Super Thanks to support us. 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