In this blog post, we will examine nuclear power—which accounts for a significant portion of South Korea’s electricity supply—from the perspectives of environmental impact, safety, economic viability, international examples, and energy security, and assess whether the country should continue to rely on nuclear power in the future.
A look at South Korea’s current electricity generation mix reveals that nuclear power has established itself as a key source, accounting for around 30% of total electricity generation. Recent official statistics also show that nuclear power has surpassed coal and natural gas to become the single largest source of electricity. Following the Fukushima nuclear accident, concerns about the safety of nuclear power have risen significantly worldwide, and in South Korea as well, arguments have been raised that the country should reduce its reliance on nuclear power and transition toward a nuclear-free future in the long term. However, today’s power system has become far more complex than in the past. The generation capacity of renewable energy sources, such as solar and wind power, is rapidly increasing, and advancements in energy storage systems, power grids, and demand response technologies mean that reducing nuclear power does not necessarily require making up the shortfall solely with fossil fuel-fired power generation. Nevertheless, considering the intermittency of renewable energy, the pace of transmission grid expansion, and the costs and construction time required for large-scale storage facilities, replacing nuclear power in the short term is also no simple matter. Therefore, the question of whether to continue nuclear power generation is not simply a matter of unconditionally excluding or selecting a specific energy source, but rather one that requires a comprehensive assessment of factors such as greenhouse gas reduction, stability of power supply, economic viability, and safety. With these points in mind, this article aims to examine the argument that South Korea needs to continue utilizing nuclear power generation at a certain level, focusing on three main aspects.
First, nuclear power has the advantage of being a low-carbon energy source with very low direct emissions of greenhouse gases and air pollutants, as it does not directly burn fossil fuels such as coal or natural gas during the power generation process. In contrast, thermal power generation using coal, oil, and natural gas can emit various pollutants—including carbon dioxide, nitrogen oxides, sulfur oxides, and fine particulate matter—during the fuel combustion process. The World Health Organization identifies power generation and industrial activities that use fossil fuels as one of the major sources of air pollution and assesses that air pollution imposes a massive global health burden. Hydropower also has the advantage of not directly burning fossil fuels during the power generation process; however, the construction of large-scale dams can significantly impact river flow, sediment transport, aquatic ecosystems, and the environment of surrounding areas. Nuclear power generates electricity by using heat from uranium fission to heat water, create steam, and drive turbines; therefore, it does not emit carbon dioxide during plant operation in the same way that fossil fuel-based power generation does. When considering the entire life cycle—including uranium mining and enrichment, nuclear power plant construction, decommissioning, and spent nuclear fuel management—it is not entirely free of greenhouse gas emissions; however, international assessments indicate that the life-cycle greenhouse gas emissions from nuclear power are significantly lower than those from coal or natural gas power generation. Nevertheless, it cannot be concluded that nuclear power has no environmental impact whatsoever. The environmental impact of uranium mining, the thermal effects resulting from the use of cooling water, and the long-term management and disposal of radioactive waste must all be taken into account. Therefore, it is more accurate to view the environmental benefits of nuclear power not as “having no impact on the environment,” but rather as a low-carbon power source capable of significantly reducing carbon emissions and air pollution compared to fossil fuel-based power generation.
Major nuclear accidents, including the Fukushima disaster, serve as important examples illustrating the risks of nuclear power generation; therefore, it would be unwise to dismiss them simply as extremely rare occurrences. The Fukushima accident resulted from a massive earthquake and tsunami that simultaneously cut off the plant’s power and cooling systems, leading to severe core damage and the release of radioactive materials; it subsequently brought about significant changes to nuclear safety regulations and emergency response systems worldwide. The Chernobyl accident also demonstrates that the damage caused by a nuclear accident can persist for a long time. In particular, nuclear power has the characteristic that, even if the frequency of accidents is low, the scope of damage and the recovery period can be extremely extensive when a major accident occurs. Therefore, the safety of nuclear power should not be evaluated based solely on the probability of an accident occurring; both the likelihood of an accident and the scale of damage in the event of an accident must be considered together. However, when comparing the risks of different energy sources, it is also inappropriate to examine nuclear accidents in isolation. The combustion of fossil fuels, such as coal and oil, continuously emits various air pollutants, including fine particulate matter, and this pollution is linked to a wide range of health problems, including respiratory and cardiovascular diseases. The World Health Organization estimates that outdoor air pollution alone causes millions of premature deaths worldwide each year, and the power generation sector is identified as one of the major sources of these emissions. Ultimately, rather than simply concluding that “nuclear power is dangerous and thermal power is safe” or, conversely, that “nuclear power is safe and thermal power is dangerous,” we must compare the different forms of risk inherent in each energy source. Nuclear power must manage the long-term risks of major accidents and radioactive waste, while fossil fuel power generation carries the risk of continuously emitting greenhouse gases and air pollutants. Therefore, if nuclear power is to continue, it must be operated under the premise of strengthened safety standards, independent regulation, continuous facility improvements, and emergency response systems.
Even when economic factors are taken into account, completely replacing nuclear power with other means in the short term is no simple matter. Nuclear power requires enormous initial costs and a long construction period to build power plants, and costs for safety upgrades, decommissioning, and spent nuclear fuel management must also be considered; therefore, it is difficult to conclude that it is the cheapest source of power in all situations. Recently, as the costs of solar and wind power have dropped significantly, assessments of the economic viability of new power generation facilities have also changed considerably from the past. However, nuclear power plants that are already built and operating stably have the advantage of fuel costs accounting for a relatively small portion of total generation costs and the ability to produce large-scale electricity over the long term. In contrast, while the construction costs of coal- and natural gas-fired power plants may be relatively low, they require the continuous purchase of fuel and are highly susceptible to fluctuations in international fuel prices and geopolitical conditions. In particular, if international prices for natural gas and oil spike, generation costs can rise rapidly. Although nuclear power is not a means of complete energy self-sufficiency because uranium must be imported from abroad, nuclear fuel has a high energy density, allowing for long-term power generation with relatively small amounts of fuel and making it easy to stockpile a certain quantity. For this reason, the International Energy Agency also assesses that nuclear power can play a role not only in reducing carbon emissions but also in lowering dependence on fossil fuel imports and strengthening energy security. Ultimately, the economic viability of nuclear power should not be judged solely by the unit cost of electricity generation; rather, it requires a comprehensive comparison of the construction and financing costs of new nuclear power plants, the costs of extending the operating life of existing plants, fuel price volatility, the costs of the power grid and storage facilities, as well as waste management and decommissioning costs.
When examining international examples, it is also necessary to distinguish between past and present trends. In the past, some argued—citing examples from countries such as Germany and Japan—that the world was collectively shifting from a “nuclear phase-out” to a “pro-nuclear” stance; however, current policies vary significantly from country to country. Following the Fukushima accident, Germany accelerated its existing nuclear phase-out plan and ultimately shut down its last nuclear power plant, ceasing commercial nuclear power generation. Rather than restarting nuclear power plants, Germany is transforming its power system by focusing on expanding renewable energy, strengthening the power grid, and trading electricity with neighboring countries. Therefore, the past claim that Germany reverted to a pro-nuclear policy due to the practical limitations of phasing out nuclear power does not align with current realities. In contrast, while Japan suspended operations at most of its nuclear power plants following the Fukushima accident, it has since been gradually restarting those plants that have passed strengthened safety regulations. Recently, a number of reactors have been brought back online, and the Japanese government maintains a policy of utilizing nuclear power—alongside the expansion of renewable energy—as a power source to ensure energy security and achieve carbon neutrality. Even on a global scale, policies regarding nuclear power do not move in a single direction. While some countries are pursuing a phased phase-out of nuclear power, others, such as France, are extending the lifespans of existing plants and pushing for new construction; the United States and several European countries are also reviewing or pursuing the use of existing nuclear power plants or the development of new reactors and small modular reactors. At the same time, renewable energy generation—centered on solar and wind power—is also increasing very rapidly. Therefore, rather than concluding that expanding or phasing out nuclear power is necessarily correct based on the example of a single country, it is more reasonable to examine each country’s power grid structure, resource availability, industrial structure, electricity demand, climate conditions, and energy security together.
Furthermore, when considering the issue of reducing the share of nuclear power or replacing it with other power sources, one cannot ignore South Korea’s energy supply structure. South Korea relies on foreign sources for most of its energy needs, and recent statistics show that the country’s dependence on imported energy far exceeds 90 percent. In particular, nearly all of its petroleum is imported, and the Middle East continues to account for a very high proportion of crude oil imports, making the country highly vulnerable to international political developments and maritime shipping conditions. It has already been confirmed on numerous occasions that international crises—such as the Russia-Ukraine war and tensions in the Middle East—can cause oil and natural gas prices to fluctuate sharply. Of course, since the uranium used in nuclear power generation must also be sourced from abroad, nuclear power does not in itself guarantee energy self-sufficiency. However, nuclear fuel has a much higher energy density than fossil fuels, allowing for long-term power generation with relatively small quantities, and it offers certain advantages in terms of fuel procurement and stockpiling. Surrounded by the sea on three sides and lacking a direct land-based power grid connection to neighboring countries in the north, South Korea faces structural limitations that make it difficult to freely import or export large amounts of electricity from neighboring countries as needed, unlike European nations. For this reason, it is crucial to ensure the stability of an independent power grid by appropriately combining various resources—including not only stable baseload power but also solar and wind power, energy storage systems, transmission grids, demand response, and gas-fired power generation. Although the share of renewable energy in power generation continues to rise and advancements in storage and grid technologies have opened up more diverse alternatives than in the past, replacing existing nuclear power on a large scale in the short term would require significant investment in facilities and the power grid, given the current scale of electricity consumption and industrial structure. This characteristic is one of the reasons why it is difficult to simply rule out the role of nuclear power when discussing South Korea’s energy policy.
Since the Fukushima nuclear accident, public perception of nuclear power has been marked by strong concerns regarding safety. These concerns are entirely understandable given the nature of nuclear power—including the damage caused by major accidents and the long-term management of radioactive waste—and they are issues that must never be taken lightly if nuclear power is to continue. At the same time, considering the current energy landscape, nuclear power offers several advantages: its lifecycle greenhouse gas emissions are significantly lower than those of fossil fuels; it can reliably supply large-scale electricity; and fluctuations in fuel prices have a relatively minor impact on overall generation costs. On the other hand, renewable energy is growing rapidly and playing an increasingly important role in greenhouse gas reduction and the energy transition, so there is no need to view nuclear power and renewable energy as mutually exclusive sources of electricity. In countries like South Korea, which have a high dependence on energy imports and are not directly connected to the power grids of other nations, combining various low-carbon power sources—rather than relying excessively on any single source—can be a practical approach that balances both the stability of the power supply and carbon reduction. Therefore, if nuclear power is to continue to be utilized, the focus should not simply be on increasing the number of nuclear power plants. Instead, safety technologies and regulations to reduce the likelihood of major accidents must be continuously strengthened; the extension of operating life for aging plants must be strictly reviewed; and systems and technologies capable of safely managing spent nuclear fuel and high-level radioactive waste over the long term must be established. At the same time, it is necessary to simultaneously promote the expansion of renewable energy, the reinforcement of the power grid, the expansion of energy storage systems, and the management of electricity demand. Ultimately, the challenge ahead lies not in a dichotomous choice between unconditionally expanding or unconditionally phasing out nuclear power, but rather in comprehensively evaluating safety, environmental impact, economic viability, and energy security to determine the appropriate role nuclear power should play within South Korea’s power system—and, in the process, continuously reducing the risks of accidents and the challenges posed by radioactive waste.
