In this blog post, we will examine the potential of nuclear power generation, which offers both safety and economic efficiency.
Nuclear power generation has always been a controversial topic, and the Fukushima nuclear accident in Japan has made people around the world wary of nuclear power. Nuclear power generation is a method of generating electricity by using the heat generated from the fission of uranium to drive turbines. Northeast Asian countries such as South Korea, Japan, and China are among the most active regions in the construction and operation of nuclear power plants. Therefore, it is only natural that people in these countries are more interested in and fearful of nuclear power than in other countries. However, is South Korea’s energy production sufficient to immediately halt nuclear power generation? The answer is no. In other words, given that fossil fuels will be depleted in the not-too-distant future, we cannot immediately halt nuclear power generation for safety reasons alone. Despite safety concerns, nuclear power generation should not be discontinued unless alternative energy technologies that are superior to nuclear power in terms of price and supply are developed. Since the 1960s, South Korea has experienced rapid economic growth and improved living standards, which has led to a sharp increase in electricity consumption. Therefore, the expansion of nuclear power generation is essential to meet this demand for electricity.
Nuclear power plants generate about 30% of South Korea’s electricity, which is a significant amount. As we saw in 2011, when the shutdown of nuclear power plants led to a significant reduction in the amount of electricity available, we would face a serious power shortage if nuclear power plants were to be shut down. Currently, South Korea, which does not produce a single drop of oil, relies on imports from other countries for most of its energy sources, including oil, coal, and natural gas. South Korea’s economic growth is expected to continue, and energy consumption will continue to increase, deepening the country’s dependence on foreign countries. Today, energy is synonymous with national power. An energy crisis could strike at any time, and we must therefore prepare for such a crisis while striving to establish an energy self-sufficient system. The two oil crises of the 1970s alone demonstrate that energy self-sufficiency is central to national security. Although alternative energy technologies are being actively developed in South Korea and other advanced countries, it is difficult to put them into practical use as large-capacity energy sources, and fossil fuels cannot be used indefinitely due to their finite nature. Under these circumstances, nuclear power is currently the most promising eco-friendly technology for achieving energy independence. Nuclear power is currently the main source of electricity, accounting for approximately 36% of the total, and is expected to account for approximately 59% by 2030, playing a key role in the development of the national economy. In other words, nuclear power is no longer an energy source that needs to be considered as an option, but an essential energy source that determines the development of the country. Although there are opinions criticizing South Korea’s distorted electricity market, saying that it is necessary to move away from a nuclear-centered centralized energy supply and achieve regional energy independence, South Korea’s industry requires a steady supply of electricity, so energy sources such as solar, wind, and hydroelectric power plants, which are greatly affected by external conditions, are not suitable. Even if these alternative energy sources can be used to supply energy to local areas, nuclear energy will still be responsible for supplying the vast amount of energy needed by the capital region in the future.
Furthermore, nuclear energy requires advanced science and technology, which can be used to develop other cutting-edge technologies. With the exception of low-enriched uranium, which is imported as fuel for nuclear power plants, all other materials can be produced domestically, so achieving technological independence would have a huge ripple effect on other industries. Technologies related to nuclear power generation are also a key part of national strategy, and South Korea has now achieved independence in all areas of nuclear power plant technology, including construction and operation. If South Korea develops the fundamental technologies necessary to secure technological ownership with the aim of exporting nuclear power plants, it will become a tremendous national power. For example, North Korea’s military power derived from its nuclear technology has strengthened its national power, limiting access to the country. Since nuclear power generation is based on nuclear technology, South Korea will also be able to secure national power through advanced technology if it continues to research nuclear power generation.
Another energy source that South Korea currently relies on is fossil fuels, which not only cause serious environmental problems but also have limited reserves. The lifespan of fossil fuels (oil and coal) is only about 60 years, which is a problem that cannot be overlooked. However, uranium, the raw material for nuclear power generation, is currently distributed evenly throughout the world. Furthermore, since it is imported from politically and economically stable developed countries, it is not greatly affected by global energy situations. On the other hand, oil is concentrated in the Middle East, where political crises are constant, so in the event of an emergency, supply could be interrupted or prices could skyrocket, leading to a third or fourth oil crisis. Oil is also difficult to transport and store due to its large volume. In this respect, uranium can generate enormous amounts of energy from a small amount of fuel, and its small size makes it easy to transport and store. For example, it is said that 1.5 million tons of oil are needed to operate a 1 million kW power plant for one year. However, only 30 tons of uranium are needed for the same amount of power. This is extremely efficient, and once uranium is loaded into a nuclear power plant, it does not need to be replaced for 12 to 18 months, which is very convenient and also means that the same amount of fuel can be stored. In this way, nuclear power generation has many advantages over fossil fuel power generation. Some argue that nuclear power is not cheap, but when comparing the cost of nuclear power with that of coal and oil-fired power generation, last year’s cost per kWh was $0.0182 for nuclear power, of which fuel costs accounted for $0.0030. Coal-fired power generation was $0.0239 (fuel cost $0.0138), and oil-fired power generation was $0.0253 (fuel cost $0.0149). Solar power also has a production cost that is about 15 times higher than nuclear power, and wind and hydroelectric power generate very little electricity compared to the land area required for their installation. Considering these ratios, nuclear power has the lowest power generation cost, and nuclear power plants have the added benefit of fuel storage, as they operate with three years’ worth of nuclear fuel in their reactors. However, nuclear power generation is somewhat more expensive to construct than other methods such as thermal power generation. However, in the long term, uranium, which is used as fuel for more than 40 years of operation, is significantly cheaper than oil and natural gas, so the unit price of electricity is lower. In addition, fuel costs usually account for more than 50% of the cost of generating electricity from oil, coal, and natural gas, so when fuel prices rise, it has a significant impact on the cost of generating electricity. However, uranium is not only inexpensive, but fuel costs account for only about 10% of the cost of generating electricity, so even if the price of uranium rises, it does not have a significant impact on the cost of generating electricity. In other words, it can maintain consistent economic efficiency.
The biggest reason for opposition to nuclear power is safety. However, the Fukushima nuclear accident, which is still a subject of controversy, can be considered a special case caused by a natural disaster. Nevertheless, the issue of radioactive material leaking into the environment and harming human health is the most controversial point and the biggest challenge that nuclear power must overcome. Nuclear power has various safety measures in place to address this issue. First, strict quality control and generous safety designs are adopted. The designs allow for sufficient margin so that each piece of equipment can withstand the forces and temperatures to which it is subjected during operation, and high-performance, high-quality materials are selected and thoroughly quality controlled. In addition, the facilities are built to withstand natural phenomena such as earthquakes and typhoons. For example, the concrete used in the dome structure of power plants, which are subject to high internal pressure, is reinforced with pre-stressed concrete to ensure that the concrete is tightly bound with steel bars. This enables the structure to withstand internal pressure. The second is the introduction of an interlock system. This system prevents nuclear power plants from continuing to operate in the event of human error or malfunction. It works in the same way as a door that will not open unless the first door is completely closed. The third is a safety feature called “fail safe.” This is a device that automatically ensures safety in the event of a machine failure. For example, if it is safer to stop the machine in the event of a failure, the machine will stop on its own. This is similar to a valve that automatically closes when a pipe breaks because it is safer to do so. A nuclear reactor constantly monitors its own pressure, temperature, output, and other conditions, and if there is even the slightest deviation from normal conditions, it automatically detects it and restores itself to its original state. If restoration is not possible, the reactor stops. In addition, multiple cooling systems are in place in case of an emergency. For safety reasons, nuclear reactors are equipped with two or more independent devices that perform the same function. This is the concept of multiple safety protection. The nuclear power generation system is designed to ensure safety from various angles by anticipating various types of errors.
However, as with all machines, even if a nuclear power plant is designed, constructed, and operated with the utmost care, the possibility of malfunction or accident cannot be completely eliminated. Therefore, it is extremely important to thoroughly prevent the spread of damage in the event of an accident. To this end, nuclear power plants are equipped with various safety measures. First, even the slightest abnormality can be detected immediately. Automatic monitoring devices are installed to detect even the slightest leak in the pipes, enabling early and appropriate response measures to be taken. Second, the reactor is designed to automatically shut down in the event of an abnormality. If an abnormality in the temperature or pressure inside the reactor is detected, the reactor automatically shuts down. Highly reliable, high-performance devices are used for this purpose. In addition, two or more devices with the same function are installed so that if one fails, the other can perform the same function.
The Chernobyl accident, which was caused by human error rather than a natural disaster like Fukushima, should not be ignored. Therefore, despite the various safety measures mentioned above, in order to prepare for situations where radiation leaks occur, South Korea analyzed the Chernobyl and Fukushima nuclear accidents from various angles and sought appropriate safety measures. First, South Korean nuclear power plants use pressurized water reactors, which are different from those used in Chernobyl. Pressurized water reactors are designed so that when the temperature of the reactor core rises, the reaction (nuclear fission) decreases. Even if the core temperature rises abnormally, the reaction (nuclear fission) decreases automatically, allowing the reactor to return to normal immediately. In other words, the pressurized water reactors adopted by South Korean nuclear power plants are considerably safer than those used in Chernobyl. In addition, emergency procedures were revised in response to the Fukushima nuclear accident to enable a decisive response in the early stages of an accident. To prepare for natural disasters such as tsunamis, the safety of nuclear power plants has been enhanced by reinforcing coastal barriers, installing water intake barriers (barriers), reinforcing emergency cooling systems, and installing additional emergency power supplies and mobile emergency power supplies.
Even if an unexpected accident occurs, the current nuclear power plants are designed to prevent the release of radiation. This is a multiple defense system, which is the core of the defense-in-depth concept. The concept of multiple defense refers to the installation of multiple layers of protective barriers to prevent radioactive materials from escaping outside the power plant. Nuclear power plants operating in Korea have a first defense wall that traps radioactive materials generated by nuclear fission in compressed and molded uranium oxide metal, a second defense wall that seals any trace amounts of gas that escape the first defense wall in an alloy metal pipe, and a third barrier made of thick steel reactor vessels and pipes that prevent radioactive materials from escaping to the outside in the event of a problem with the second barrier. In addition, in preparation for emergencies, a fourth barrier consisting of thick steel plates installed on the inner walls of the reactor containment building to seal radioactive materials inside the reactor containment building, and a fifth barrier consisting of reinforced concrete walls 120 cm thick on the outer walls of the reactor containment building to prevent radioactive materials from escaping to the outside environment, for a total of five barriers. 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 Chernobyl accident, radioactive material leaked outside the power plant and caused damage to the general public, but in the TMI accident, the protective wall system prevented radioactive material from escaping from the reactor containment vessel and causing damage to the external environment.
Through these two nuclear accidents, South Korea’s nuclear power industry has made significant progress, such as implementing earthquake-resistant designs to ensure sufficient preparedness for earthquakes of magnitude 6.5 or less, and as a result, it has secured sufficient safety. Furthermore, South Korea is demonstrating its true value not only in terms of safety but also in terms of efficiency and economic feasibility. The Korean standard nuclear power plants currently in use in South Korea have the world’s best operating record and construction experience, and their utilization rate, which indicates the plant’s operating capacity, is 99.3%, far exceeding the global average (79.4%). Furthermore, considering that South Korea relies on nuclear energy for 30% of its total energy supply, discontinuing nuclear power plant development would cause significant inconvenience to citizens’ lives. Therefore, nuclear power plant development must continue.
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