In this blog post, we will examine the safety debates surrounding nuclear power that have arisen since the Fukushima accident, as well as South Korea’s energy security, nuclear power plant exports, and the potential for expanding renewable energy. We will also explore what role nuclear power can play in future electricity policy.
In the past, South Korea has repeatedly experienced power supply and demand instability, particularly during the summer months. In September 2011, in particular, a combination of higher-than-expected electricity demand and insufficient supply capacity led to large-scale rolling blackouts, and public concern over the power supply and demand situation persisted thereafter. At that time, securing sufficient power supply capacity was such a critical national priority that a large-scale energy-saving campaign was launched, urging the public to refrain from using air conditioners during the summer. However, the current electricity situation has changed significantly from that time. Power generation capacity has expanded substantially, electricity demand management and power market operations have advanced, and renewable energy facilities—including solar and wind power—have grown rapidly. At the same time, the importance of a stable power supply is increasing once again as new sources of electricity demand expand, such as data centers, the artificial intelligence industry, the semiconductor industry, electric vehicles, and industrial electrification. Responding to rising electricity demand goes beyond simply building more power plants. We must consider a variety of measures in tandem, including improving energy efficiency, demand management, expanding the transmission grid, energy storage systems, renewable energy, nuclear power, and LNG-fired generation. In South Korea’s current electricity policy, nuclear power is treated as a key pillar among these various power sources. In fact, nuclear power accounts for approximately 31% of the country’s total electricity generation, and the government’s long-term electricity supply and demand plan calls for the continued use of nuclear power alongside the expansion of renewable energy.
The first argument in favor of expanding or maintaining nuclear power generation at a certain level is energy security. Since South Korea imports a significant portion of its key energy resources, such as oil and natural gas, from abroad, it is heavily influenced by international energy prices and geopolitical conditions. Not only during past oil crises but also during the recent international energy crisis, it has been confirmed that high import dependence on specific fuels can place a considerable burden on the national economy and the electricity market. Since uranium must also be sourced from abroad, nuclear power cannot be considered fully energy-independent in the strictest sense. However, nuclear fuel has the advantage of producing a massive amount of energy with a smaller quantity compared to fossil fuels and is relatively easy to store for long periods. Furthermore, because the proportion of fuel costs in total power generation costs differs from that of fossil fuel-based power generation, nuclear power is relatively less sensitive to fluctuations in international fuel prices. South Korea has developed nuclear power into an industry by accumulating expertise in the design, construction, and operation of nuclear power plants. The APR1400, a flagship export-oriented nuclear reactor, has received certification under the European Utility Requirements and design certification from the U.S. Nuclear Regulatory Commission; four APR1400 reactors, led by South Korea, were constructed at the Barakah Nuclear Power Plant in the United Arab Emirates. Barakah Unit 1 began commercial operation in 2021, Unit 2 in 2022, and Unit 3 in 2023; the final Unit 4 also entered commercial operation in 2024, meaning all four units are currently in commercial operation. South Korea’s nuclear power plant export projects, which had previously remained at the contract stage, have now progressed to the actual construction and commercial operation phases. Therefore, nuclear power should not be viewed merely as a domestic power source but must also be examined from an industrial perspective, encompassing power plant design, construction, equipment, and operation and maintenance. However, rather than assuming that nuclear power exports automatically guarantee energy self-sufficiency or national economic growth, factors such as the fuel supply chain, construction costs, financial terms, safety regulations, and spent nuclear fuel management must be evaluated together.
The 2011 accident at the Fukushima Daiichi Nuclear Power Plant is a case that invariably comes up in arguments opposing nuclear power plant construction or calling for a reduction in reliance on nuclear power. This accident made it clear to the entire world that when a major accident occurs at a nuclear power plant, its impact is not confined to the plant itself but can lead to evacuations in surrounding areas, contamination management, long-term decommissioning efforts, and significant social costs. On the other hand, South Korea’s nuclear safety regulatory system has also been subject to ongoing international review. The International Atomic Energy Agency’s Integrated Regulatory Review Service (IRRS), conducted in South Korea immediately following the Fukushima accident, reviewed the country’s nuclear and radiation safety regulatory system against IAEA safety standards. While identifying several best practices in areas such as the regulatory framework and expertise, it also highlighted areas requiring improvement. Therefore, it is inappropriate to simply compare the number of country-specific recommendations from that review and conclude that the safety of South Korea’s nuclear power plants is superior to that of other countries. This is because the IRRS is not a system that ranks the likelihood of accidents at individual nuclear power plants by country, but rather a procedure that reviews regulatory frameworks and safety management systems against international safety standards and proposes improvements. What is important is to maintain the strengths identified through international reviews while continuously incorporating the recommendations and improvements suggested. Nuclear power plant safety is not guaranteed permanently by a single assessment; rather, it must be understood as an ongoing process that continuously incorporates factors such as facility aging, new information on natural disasters, technological changes, and accident experience.
Furthermore, when determining whether the Fukushima accident could be repeated in the same form in South Korea, it is necessary to examine specific factors such as reactor type, plant-specific design, site conditions, and emergency power configurations. The core cause of the Fukushima accident was the prolonged loss of cooling capabilities following a massive earthquake and tsunami, which led to the loss of off-site power and the flooding of emergency diesel generators and electrical equipment. Failure to adequately remove the decay heat generated by the reactor resulted in fuel damage, and the hydrogen produced during this process accumulated in the reactor building, leading to an explosion. Since South Korean nuclear power plants vary in design depending on the plant and reactor type, they cannot be considered structurally identical to the Fukushima plant in Japan. Furthermore, since the Fukushima accident, efforts to reinforce safety systems and implement accident management measures to prepare for extreme natural disasters and prolonged power outages have been continuously pursued. However, these differences do not mean that the possibility of a severe accident has been completely eliminated. In nuclear safety, it is crucial to consider the possibility of multiple hazards—such as earthquakes, tsunamis, typhoons, fires, flooding, and power loss—occurring simultaneously and to establish a multi-layered defense system. The fundamental principle of nuclear power plant safety is to design various safety systems—including reactor cooling, emergency power supply, hydrogen management, containment structures, radiation protection, and emergency response systems—to function in stages, ensuring that even if one system fails, another can compensate for it. In particular, since the Fukushima accident, the importance of accident management that accounts for extreme situations exceeding design criteria has grown even more significant. South Korea’s nuclear safety regulations are also being continuously improved, taking into account the safety standards of the International Atomic Energy Agency (IAEA) and international reviews. Ultimately, nuclear power plant safety is not an issue that can be judged based on a single piece of equipment or past evaluation results alone; rather, it requires a comprehensive examination of design, operation, the independence of regulatory agencies, emergency response, management of aging facilities, and safety culture.
Proponents of phasing out nuclear power often cite Germany as a model, suggesting a plan to gradually phase out nuclear power while expanding renewable energy sources such as wind and solar power. Following the Fukushima accident, Germany strengthened its policy to shut down nuclear power plants and ultimately completed its nuclear phase-out by halting operations at its last three reactors. However, the current German electricity market can no longer be explained simply by the old model of “exporting surplus solar power cheaply during the day and importing nuclear power from France at a high cost at night.” Germany continuously trades electricity with neighboring countries within Europe’s integrated power grid, and electricity is imported or exported based on generation levels, demand, and market prices at any given time. According to the German Federal Network Agency, the share of renewable energy in Germany’s electricity production has recently surpassed half, and wind power has become one of the most important sources of generation. At the same time, Germany is participating in the European electricity market by importing and exporting significant amounts of electricity. The Federal Network Agency explains that electricity imports do not necessarily indicate a shortage of domestic generation capacity but can also result from an economic choice to utilize cheaper electricity available on the European market. A major limitation of solar and wind power is that their output fluctuates depending on sunlight and wind conditions. However, unlike in the past, today’s advancements in large-scale battery energy storage systems, pumped-storage hydropower, cross-border transmission grids, demand response, and grid control technologies have diversified the means available to address this variability. That said, storage and grid integration issues have not been completely resolved. As the share of renewable energy increases, investment in transmission grid expansion, storage facilities, and flexibility resources is also necessary. From a land-use perspective, while nuclear power has the advantage of requiring relatively little land to secure the same installed capacity, the actual land use for solar and wind power varies significantly depending on the generation method, installation location, and equipment utilization rate; therefore, it is difficult to compare the efficiency of these energy sources based solely on a simple area ratio. This is because there are also methods that share space with other uses, such as offshore wind power or solar panels installed on the roofs of buildings and industrial facilities. Conversely, while nuclear power has the advantage of high capacity factor and the ability to stably produce large-scale electricity, issues such as construction time, initial investment costs, radioactive waste management, and decommissioning costs must also be taken into account. Therefore, rather than viewing nuclear power and renewable energy as power sources where one completely replaces the other, it is necessary to comprehensively compare their respective characteristics, costs, grid stability, and carbon emission reduction effects.
Nuclear power has long been used as a major power source due to its high energy density and stable power generation, and it is once again gaining attention as issues of carbon neutrality and energy security have come to the fore. However, the choices made by countries around the world are not unified in a single direction. While some countries, such as Germany, have shut down all their nuclear power plants, others—including China—continue to build new ones, and still others are extending the lifespans of existing plants or developing new reactor technologies. South Korea, too, is pursuing an electricity policy that takes into account nuclear power, renewable energy, LNG, energy storage systems, and transmission grids, rather than completely ruling out nuclear power or relying solely on it. The government’s long-term power supply and demand plan incorporates the utilization of existing nuclear power plants, new large-scale nuclear power plants, and small modular reactors (SMRs), while also including the expansion of renewable energy and the enhancement of energy storage systems. Under this long-term plan, nuclear power generation capacity is set to increase in the future. The extent to which South Korea will utilize nuclear power is not a matter that can be determined solely by generation costs or output. Alongside the advantages of energy security, carbon emission reduction, industrial competitiveness, and grid stability, challenges such as the risk of major accidents, the disposal of spent nuclear fuel and high-level radioactive waste, the management of aging nuclear power plants, and the construction time and costs of new plants must also be considered. Renewable energy also has the advantages of not requiring fuel and reducing carbon emissions, but issues such as intermittency, the expansion of transmission grids, securing storage facilities, site selection, and public acceptance must be addressed. Ultimately, the choice South Korea faces in the wake of the Fukushima accident is not a simple binary choice between “nuclear power or renewable energy,” but rather how to harmonize multiple objectives: safety, economic viability, energy security, and carbon neutrality. Nuclear power currently accounts for a significant portion of South Korea’s electricity supply and is expected to remain a key power source for the foreseeable future; however, its role and scale must be continuously reassessed in light of the expansion of renewable energy, investments in the power grid, advancements in storage technology, and changes in electricity demand.
