In this blog post, I will examine the safety, economic viability, and environmental aspects of nuclear power, as well as energy security and the competitiveness of South Korea’s nuclear power exports, to consider how South Korea should utilize nuclear power.
The 2011 Great East Japan Earthquake led to the devastating accident at the Fukushima Daiichi Nuclear Power Plant. As a result, not only South Korea but the entire world was prompted to reconsider nuclear power. Looking at global trends in nuclear power since the accident, while some countries—such as Germany, which completed its phase-out by shutting down its last three reactors in April 2023—have moved away from nuclear power, others—including the United States and France—are pursuing the continued operation of existing plants and the construction of new ones, unwilling to give up the benefits that nuclear power offers. Amid this international climate, what stance should South Korea take regarding nuclear power?
According to the latest energy supply and demand statistics from the Ministry of Trade, Industry and Energy, nuclear power accounted for approximately 31.7% of South Korea’s total electricity generation in 2024, making it the largest source of power for the first time in 18 years. This underscores the vital role nuclear energy plays in South Korea’s electricity supply. While some people cite the nuclear accident in Japan to argue against the safety of nuclear power, South Korea’s nuclear power plants are equipped with various safety facilities and accident response systems tailored to the specific reactor types and design characteristics. Furthermore, the numerous advantages of nuclear energy hold significant importance given South Korea’s energy circumstances. In South Korea, which has heavily relied on fossil fuels—that emit greenhouse gases contributing to global warming and have limited reserves—nuclear power can serve as a low-carbon power source. Given its competitiveness in terms of fuel costs and generation expenses, nuclear energy can be a key factor in helping South Korea, a nation with scarce energy resources and high import dependence, prepare for energy supply instability and secure a stable power supply infrastructure.
Nuclear power, which is generated in a manner entirely different from thermal power, offers distinct advantages over thermal power generation. As mentioned earlier, thermal power generation using fossil fuels such as oil, coal, and natural gas has long served as a major source of electricity in South Korea. However, there are two significant physical challenges to the long-term use of this method. Carbon dioxide (CO₂), emitted during the combustion of fossil fuels, is a major greenhouse gas that exacerbates climate change; furthermore, because fossil fuels are finite resources, it is difficult to guarantee a stable supply over the long term. Nuclear power generation, which utilizes the fission of uranium, does not directly burn fossil fuels during the power generation process and can therefore significantly mitigate these issues associated with thermal power generation. In the fission process, a neutron collides with a uranium nucleus, splitting it into two and releasing energy; this triggers a chain reaction as the neutrons produced in this process react with other atomic nuclei. This process itself does not emit carbon dioxide in the same way as the combustion of fossil fuels. However, since nuclear power generation also produces a certain amount of greenhouse gases throughout its entire lifecycle—including uranium mining and enrichment, fuel fabrication, power plant construction and decommissioning, and waste management—it is more accurate to view it as a power source with low carbon emissions on a life-cycle basis rather than describing it as an “energy source that emits no greenhouse gases at all.” Furthermore, while uranium is a finite resource, just like oil or coal, it has the advantage of being usable for a stable, long-term energy supply, given its high energy density and the availability of various resource and fuel cycle technologies. Therefore, by actively utilizing nuclear power, South Korea can better address the greenhouse gas issues and energy supply instability stemming from fossil fuel-based electricity generation.
On the other hand, some argue that we should reduce reliance on nuclear power and use other low-carbon energy sources, citing the risks of nuclear accidents or radioactive material leaks caused by radioactive waste. If radioactive material were to leak into the environment, it could indeed cause harm to human health and the environment, as many people fear, and because long-term management is required depending on the type of radioactive material, it must be handled with great care. However, the safety of a nuclear power plant cannot be judged based solely on the type of reactor; it requires a comprehensive assessment that includes multiple layers of protection, the containment building, cooling systems, emergency power supplies, accident management systems, seismic design, and safety verification by regulatory agencies. In South Korea, the Nuclear Safety and Security Commission continuously monitors the safety of nuclear power plants and has established separate safety management and regulatory systems for the storage and disposal of spent nuclear fuel and radioactive waste. Therefore, while the risks of nuclear power should not be ignored, it is also inappropriate to conclude that all current nuclear power plants pose the same level of risk based solely on major accidents that occurred in the past.
There are differences between domestic nuclear power plants and those at Chernobyl and Fukushima in terms of reactor type, design, and safety equipment. The reactor involved in the Chernobyl accident was an RBMK-type reactor, while the reactors at the Fukushima Daiichi Nuclear Power Plant that were involved in the accident used boiling water reactors. In contrast, most nuclear power plants in South Korea use pressurized water reactors, and the Wolsong Nuclear Power Plant uses a pressurized heavy-water reactor. The principle of a pressurized water reactor can be understood as a method of heat transfer that separates the two cooling water systems. Heat generated by nuclear fission inside the reactor is transferred to the primary coolant, and the high-temperature, high-pressure primary coolant moves to the steam generator, where it transfers heat to the water in the secondary system. Since the primary and secondary coolants are physically separated, the primary coolant—which contains radioactive materials—does not flow directly into the steam turbine system during normal power generation. This system separation is one of the key safety features that reduces the risk of radioactive material leakage to the outside. However, this does not completely eliminate the possibility of radioactive material leakage in the event of an accident; actual safety depends on the performance of multiple layers of defense, including the containment building, emergency cooling systems, passive safety features, and accident management procedures. The APR1400, currently in operation in South Korea, is also a pressurized water reactor (PWR) that incorporates a design improved for safety and economic efficiency based on the experience gained from existing nuclear power plants. Therefore, when evaluating the safety of South Korean nuclear power plants, it is necessary to comprehensively examine the design, safety systems, operations, and regulatory framework of each plant, rather than making simple comparisons based solely on a specific reactor type.
In addition, radioactive waste generated by South Korea’s nuclear power industry requires strict management. Radioactive waste is not simply discarded; it is classified according to type and radioactivity level, undergoes appropriate processing and packaging, and is then managed at designated facilities. Low- and intermediate-level radioactive waste is disposed of at the Gyeongju Low- and Intermediate-Level Radioactive Waste Disposal Facility, while high-level radioactive waste, such as spent nuclear fuel, requires a separate storage and disposal system. In particular, because spent nuclear fuel generates significant heat and radioactivity, it is currently being safely managed in storage facilities on nuclear power plant sites, while systems and procedures are being developed to establish long-term interim storage and permanent disposal facilities. Therefore, portraying all radioactive waste as if it has already been permanently disposed of does not reflect the current situation, and the safe management of radioactive waste remains a critical challenge in nuclear policy moving forward. The Nuclear Safety and Security Commission is also establishing a safety regulatory framework to address new regulatory requirements related to spent nuclear fuel storage and disposal facilities, and environmental radiation monitoring is being conducted continuously both around nuclear power plants and nationwide. If we maintain this multi-layered safety management system and continue to advance storage and disposal technologies and systems to ensure the long-term safe management of radioactive waste, we will be able to systematically reduce the risks posed by radioactive waste.
Even in this context, where safety must be continuously managed, the fact that nuclear power remains highly competitive in terms of generation costs is one of the key reasons why it is difficult to easily abandon nuclear power. Nuclear power generation is characterized by the relatively low proportion of fuel in the power generation process, as a small amount of uranium fuel can yield a very large amount of energy. The energy generated by uranium fission has a very high energy density compared to the combustion of fossil fuels, and even a small amount of nuclear fuel can produce large-scale electricity over a long period. These characteristics help to relatively mitigate the impact of fluctuations in international energy prices or fuel prices on power generation costs. Of course, when evaluating the actual cost of nuclear power generation, one must consider not only fuel costs but also power plant construction costs, financing costs, operation and maintenance costs, ongoing operating costs, waste management costs, and decommissioning costs. Nevertheless, nuclear power offers economic advantages in that it can supply large-scale, stable electricity based on high capacity factor and a low proportion of fuel costs.
Arguments that we should abandon nuclear power—which is competitive in terms of generation costs—and replace it entirely with renewable energy sources such as solar and wind must take South Korea’s current energy situation fully into account. Renewable energy is growing rapidly through technological advancements and the expansion of infrastructure, and in 2024, the share of renewable energy in South Korea’s total power generation exceeded 10% for the first time. However, because solar and wind power generation fluctuates depending on weather and time of day, scaling up these sources on a large scale requires simultaneous advancements in grid reinforcement, energy storage systems, reserve power, and grid operation technologies. Furthermore, considering the country’s land area, electricity demand, and industrial structure, it would be difficult to fully replace the current level of nuclear power generation with renewable energy in the short term. Therefore, rather than viewing nuclear power and renewable energy as mutually exclusive options, it is necessary to explore ways to leverage the strengths of each to simultaneously achieve a stable power supply and carbon reduction. In particular, while Germany—which previously pursued a policy of phasing out nuclear power—shut down its last three nuclear reactors in April 2023, this does not mean that other countries must necessarily follow the same energy policy. Since South Korea has a different industrial structure and energy supply conditions than Germany, it is important to establish an energy mix suited to South Korea’s reality.
South Korea can strengthen its energy security through nuclear power while simultaneously enhancing its national competitiveness. As emphasized earlier, South Korea’s electricity production has relied heavily on fossil fuels, and a significant portion of its major energy resources—such as oil, natural gas, and coal—are imported from abroad. This high dependence on imported energy increases the likelihood that the South Korean economy will be affected by sharp spikes in international oil and gas prices, political changes in major oil-producing countries, and instability in global supply chains. A prime example of this is the oil crisis of the 1970s. As oil prices skyrocketed in the wake of wars and political conflicts in the Middle East, the global economy suffered a major shock, and countries with high dependence on imported energy resources were inevitably hit the hardest. In this regard, nuclear power generation using uranium offers significant advantages. Although uranium is also a resource that must be imported, nuclear power provides distinct energy security benefits compared to oil and natural gas, as it can generate electricity for long periods with a small amount of fuel and allows for the stockpiling of fuel for several years. Furthermore, South Korea has accumulated a high level of technical expertise in the design, construction, operation, and maintenance of nuclear reactors, and has successfully exported its nuclear technology overseas, beginning with the award of the Barakah Nuclear Power Plant contract in the United Arab Emirates (UAE) in 2009. Since then, the country has continued to expand its competitiveness in the global nuclear power market, as evidenced by Korea Hydro & Nuclear Power being selected as the preferred bidder for the new nuclear power plant project in the Czech Republic. In other words, nuclear power generation and its underlying technology can be seen as both a means to alleviate South Korea’s high dependence on energy imports and an opportunity to enhance the country’s technological competitiveness in the international community.
Today, due to the nuclear accidents that occurred at Chernobyl and Fukushima, many people have concerns about the safety of nuclear power generation and even advocate for the closure of nuclear power plants. However, considering the significance of nuclear power in South Korea’s current situation, maintaining and utilizing nuclear power—with safety as a prerequisite—and expanding it as needed could be a reasonable option. First, the safety concerns raised by opponents of nuclear power must not be taken lightly; strict management at the national level and independent safety verification are necessary regarding radioactive waste management, responses to nuclear accidents, and the continued operation of aging reactors. South Korea’s nuclear power plants operate using various reactor types, including pressurized water reactors, and must undergo continuous safety verification by regulatory agencies based on the design characteristics and safety equipment of each reactor. Given South Korea’s electricity supply structure, which has relied heavily on expensive fossil fuel-based power generation that emits greenhouse gases, nuclear power—which provides a stable supply of large-scale electricity while keeping carbon emissions low—can be an important option both economically and environmentally. Furthermore, by strengthening energy security through nuclear power and continuously advancing South Korea’s nuclear technology for export, the country can not only reduce its dependence on other nations for energy but also further develop into a nation with competitive nuclear technology and industrial capabilities. However, to achieve these goals, it is essential not only to emphasize the economic viability and technological capabilities of nuclear power but also to secure public trust in safety and make concerted efforts to resolve the issue of radioactive waste management in the long term.
