The debate surrounding the necessity and safety of nuclear power is still raging. Nuclear power is essential for energy independence and economic efficiency, but safety is a major challenge.
Nuclear power is as controversial as ever, and the Fukushima nuclear power plant disaster in Japan has made people around the world wary of nuclear power. Nuclear power is the fission of uranium to generate massive amounts of heat, which is then used to drive turbines to generate electricity. Northeast Asian countries such as South Korea, Japan, and China are among the most active regions in building and operating nuclear power plants, so it’s no wonder that there is more public interest and fear than in other countries. But can South Korea really afford to shut down nuclear power anytime soon? The answer is no. If we face the fact that fossil energy is going to run out in the not-too-distant future, we can’t shut down nuclear power for safety reasons alone. Despite the safety concerns, nuclear power generation should not be discontinued unless alternative energy generation technologies are developed that are superior in price and supply to nuclear power. South Korea’s electricity consumption has increased dramatically since the 1960s due to rapid economic growth and rising living standards, so expanding nuclear power generation is essential to meet this demand.
Nuclear power generates about 30% of South Korea’s electricity, which is not a small amount. As we saw in 2011, when a nuclear power plant shut down and the amount of standby power was significantly reduced, we would be in a serious power shortage. Korea is currently oil-free and relies on foreign imports for most of its energy sources, including oil, coal, and natural gas. As Korea’s economic growth continues, its energy consumption will continue to increase, making us more and more dependent on foreign sources. Today, energy is national power. An energy crisis can strike at any time, so we must prepare for it and work to build energy independence. We only need to look at the two oil waves in the 70s to realize that energy independence is the key to national security. Although alternative energy technology is being actively developed in Korea and other developed countries, it is difficult to commercialize it as a large-scale energy source, and fossil energy cannot be used indefinitely due to its finite nature. Under these circumstances, nuclear power is currently the most promising eco-friendly technology for energy independence. It is the main source of electricity generation, which currently accounts for about 36% and will account for about 59% by 2030, and it is playing a supporting role in the development of the national economy. In other words, nuclear power generation is no longer a choice, but an essential energy source that determines the development of the country. Although there are those who criticize South Korea’s distorted power market, saying that the country needs to move away from a centralized supply of nuclear energy and toward regional energy independence, the country’s industries require steady power, making solar, wind, and hydroelectric power plants, which are highly dependent on external conditions, unsuitable. Even if these alternative energies are able to provide local energy, the vast amount of energy that will be needed to power the metropolitan area in the future will be nuclear energy.
Nuclear energy also requires a high level of science and technology, which makes it a cutting-edge technology. Since all but the import of low-enriched uranium, the fuel used in nuclear power plants, can be domestically produced, it is a quasi-domestic energy that will have a significant ripple effect on other industries if it achieves technological independence. The technologies related to nuclear power generation are also a key part of Korea’s national strategy, and the country has reached the stage where it is now self-reliant in both nuclear power plant technology as well as construction and operation. It would be a tremendous national strength to develop the source technology to secure technology ownership with the goal of exporting nuclear power plants. In the case of North Korea, for example, the military power of nuclear technology has made the country so powerful that access to it is restricted. Nuclear power plants are powered by nuclear technology, so if South Korea continues to research nuclear technology through nuclear power plants, it will be able to secure its national power through advanced technology.
Fossil energy, another energy source that South Korea currently relies on, has serious environmental problems, but it also has finite fossil fuel reserves. The lifespan of fossil fuels (oil, coal, etc.) is only about 60 years, so this is a problem that cannot be overlooked. However, uranium, the raw material for nuclear power, is currently found in large deposits around the world. Moreover, its sources are located in politically and economically stable industrialized nations, so it’s not affected much by the world’s energy situation. Oil, on the other hand, is concentrated in the Middle East, where political crises are prevalent, which can lead to supply disruptions or price spikes in the event of a third or fourth oil shock, and its bulk makes it difficult to transport and stockpile. In contrast, uranium can produce a lot of energy from a small amount of fuel, and its small volume makes it easy to transport and store. For example, it takes 1.5 million tons of oil to run a 1 million kW power plant for a year. But with uranium, you only need 30 tons, a fraction of that amount. This is very efficient, and once the reactor is loaded with uranium, it doesn’t need to be refueled for 12 to 18 months, which is very convenient and creates a fuel reserve. In many ways, nuclear power has advantages over fossil energy generation. There is also the argument that nuclear power is not cheap, but if you compare the cost of nuclear versus coal and oil-fired power generation, the cost per kilowatt hour last year was $0.0182 for nuclear power and $0.0030 for dual fuel. Coal-fired power is $0.0239 ($0.0138 fuel cost) and oil-fired power is $0.0253 ($0.0149 fuel cost). Solar is also about 15 times more expensive to produce than nuclear, and wind, hydro, and other energy sources produce very little electricity relative to the amount of land they are sited on. Based on these ratios, nuclear power is the cheapest to generate, and nuclear power plants have a three-year supply of nuclear fuel in their reactors, so they have a fuel reserve. However, nuclear power is somewhat more expensive to build than other methods, such as thermal power. However, in the long run, the cost per unit of electricity sold is low because uranium, the fuel used during the 40+ years of operation, is much cheaper than oil or natural gas. In addition, the fuel cost of oil, coal, and natural gas usually accounts for more than 50% of the cost of electricity generation, so any increase in fuel prices will have a significant impact on the cost of electricity generation. However, uranium is not only cheap, but the fuel cost is only about 10%, so even if the price of uranium increases, the cost of power generation will not be affected much, which means that it can maintain a steady economic performance.
The biggest argument against nuclear power is safety, but even the controversial Fukushima accident is a special case of a natural disaster. However, the issue of radioactive material escaping to the outside world and harming humans is the most controversial and the biggest challenge for nuclear power. Nuclear power has a number of safety measures in place to prevent this. The first is strict quality control and generous safety design. The design of each device is relaxed to ensure that it can withstand the forces and temperatures applied to it during operation, and materials are selected with high performance and high quality, and quality control is thorough. In addition, they are built strongly to withstand natural phenomena such as earthquakes and typhoons. For example, the concrete in the dome structure of the power plant, which is subject to high pressure, is pre-stressed and reinforced with steel bars. This allows the structure to withstand the pressure. The second is the introduction of an interlock system. Thanks to this system, the nuclear power plant has the ability to defend itself against any human error or malfunction in the event that it occurs. It is like a door that is not allowed to open until the first door is completely closed. The third is a safety feature called Fail Safe. This is a device that automatically ensures that the machine is safe if it fails. For example, if it is safer for the machine to stop in the event of a malfunction, it will stop itself. It’s like a valve that will shut itself off if it’s safe to do so because of a broken pipe. The reactor monitors its own pressure, temperature, power output, etc. all the time, and if it deviates from the normal state even slightly, it detects it and automatically restores it. If it does not restore it, it will shut down. In addition, there are many cooling systems in place just in case. In a nuclear reactor, there are two or more independent facilities with the same function for important safety protection. This is the concept of multiple safety protection. The system of nuclear power generation is designed to support safety from various angles, assuming various faults.
However, as with any machine, no matter how perfectly a nuclear power plant is designed, constructed, and operated, the possibility of failure or accident cannot be completely excluded. Therefore, it is very important to thoroughly prevent the spread of damage in the event of an accident. To this end, nuclear power plants have a number of safety measures in place. First, the slightest abnormality is detected immediately. If there is a leak in a pipe, even if it is very minor, automatic monitoring systems are installed to detect it immediately so that appropriate countermeasures can be taken early. Second, the reactor is equipped with an automatic emergency shutdown in case of any abnormalities. If there is an abnormality in the temperature or pressure within the reactor, the reactor will be automatically shut down as soon as it is realized. The devices involved are highly reliable and high-performance. In addition, there are at least two devices that perform the same function, so that if one fails, the other can fulfill its function.
The Chernobyl accident, like Fukushima, was not a natural disaster, but a man-made disaster. Therefore, in order to prepare for a situation where radiation leaks despite the various safeguards mentioned above, South Korea analyzed the Chernobyl and Fukushima nuclear accidents and came up with appropriate safety measures. First of all, Korea’s nuclear power plants use pressurized water reactors, which are different from Chernobyl. Pressurized light water reactors are designed to reduce reactivity (nuclear fission) as the core temperature rises. Even if the core temperature is abnormally high, the reactor will return to its normal state immediately because the reactivity (fission) will decrease by itself. In other words, the pressurized light water reactor adopted by the Korean nuclear power plant is much safer than Chernobyl. In addition, after the Fukushima nuclear disaster, the emergency procedures were revised to allow for a more aggressive response in the early stages of an accident. In preparation for a natural disaster such as a tsunami, the safety of nuclear power plants has been enhanced by reinforcing coastal barriers, installing water barriers, reinforcing emergency cooling systems, and installing additional emergency power sources and mobile emergency power sources.
Even in the event of an unforeseen accident, today’s nuclear power plants are designed to emit no radiation. This is the multi-protection method, which is the core of the concept of defense in depth. The concept of multiple protection refers to the installation of multiple layers of barriers to prevent radioactive materials from leaking out of the plant. Nuclear power plants operating in Korea are composed of the first barrier, which traps radioactive materials generated by nuclear fission in compressed, sintered, and molded uranium oxide metal; the second barrier, which seals trace amounts of gaseous components that escape the first barrier in alloy metal pipes; and the third barrier, which prevents radioactive materials from leaking out of the reactor vessel and pipes made of thick steel when the second barrier fails and radioactivity leaks out. In addition, there is a fourth barrier, which is a thick steel plate installed on the inner wall of the reactor containment building to keep radioactive materials contained within the reactor containment building in case of an emergency, and finally a fifth barrier, which is a 120 cm thick reinforced reinforced concrete outer wall of the reactor containment building to prevent radioactive materials from leaking into the outside environment. The safety of this structure has been proven in the TMI nuclear accident in the United States and the Chernobyl nuclear accident in the former Soviet Union. In the case of Chernobyl, radioactive material leaked out of the plant and harmed the public, while in the case of TMI, the barrier system kept the radioactive material contained within the reactor containment vessel and did not harm the external environment.
As a result of the two nuclear accidents, Korea’s nuclear power generation has made great strides in learning from the causes of the accidents and developing earthquake-resistant designs that are sufficiently prepared for earthquakes with a magnitude of 6.5 or less. Moreover, Korea is not only recognized for its safety, but also for its efficiency and affordability. The utilization rate of Korea’s standard nuclear reactors in use today is 99.3%, far above the global average (79.4%), reflecting the country’s world-class operational performance and construction experience. Moreover, considering the fact that Korea relies on nuclear energy for 30% of its energy supply, stopping the development of nuclear power plants would cause great inconvenience to citizens’ lives. Therefore, the development of nuclear power plants should continue.
