South Korea's 'unstable' nuclear energy policy: From Lee through Moon to Yoon Governments


South Koreas nuclear energy policies have undergone significant changes over recent years, showing an unstable character depending on respective governments in power. This article explains the political factors behind these policy changes and the arguments made for and against nuclear energy in Korea; it also explores the competitive relationship between nuclear energy and renewable energy. While nuclear energy is unlikely to be phased out any time soon, the challenge for South Korea remains to create a distributed energy systems that increases local self-sufficiency in electricity supply and introduces distributed renewable energy-friendly markets.

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An anti-nuclear demonstration held in Busan, South Korea

1. Status and Policy Changes

When the first commercial reactor, Kori Unit 1, was connected to the grid in June 1977, South Korea became the 22nd country in the world that operated a nuclear power plant (NPP). Since then, the capacity of NPPs in the country has steadily increased, reaching a total installed capacity of 24,650 MW as of the end of January 2023.[1] Furthermore, as of the end of February 2023, three pressurized water reactors (1400 MW x 3) are under construction, scheduled for completion between 2023 and 2025, and a total of 25 reactors are in operation, ranking South Korea fifth in the world in terms of nuclear power capacity after the United States, France, China and Russia.[2] The share of nuclear energy in electricity generation was 27.4% as of 2021.[3] The Korea Electric Power Corporation (KEPCO), a public power generation company, monopolizes electricity production, transmission, distribution, and sales in the country. Korea Hydro & Nuclear Power Co. (KHNP), a subsidiary of KEPCO, operates the NPPs, which have been constructed according to the electricity supply and demand plan established by the Ministry of Trade, Industry and Energy.

South Korea's nuclear energy policy experienced important turning points under different governments over the last 15 years: the Lee Myung-Bak government (2008.2 ~ 2013.2), the Moon Jae-In government (2017. 5 ~ 2022. 5), and the Yoon Suk-Yeol government (2022. 5 ~ present).

In 2009, the Lee Myung-Bak administration established a plan to increase the share of nuclear energy to 59% by 2030, advocating low carbon green growth. In pursuit of this policy, and despite the Fukushima nuclear accident in March 2011, Samcheok and Yeongdeok were designated as new NPP sites in September 2012.

However, these new NPP sites were canceled by the Moon Jae-In government, which declared a nuclear phase-out policy. Thus, the Fukushima accident did not have a substantial impact on South Korea's nuclear energy policy until the Moon Jae-In government took office. President Moon announced that new NPPs would not be built, and the lifespan of the operating NPPs would not be extended after their designed lifespans expire.

Under President Moon, a decision about the construction of Shin-Kori Units 5 and 6 (now renamed as Saeul Units 3 and 4), about 30% completed at the time, was to be made through public deliberation. For this purpose, a citizen participation survey method was used for the first time on a national policy scale. A total of 500 citizen were selected through the following stages: First, in order to secure the representativeness of the sample, about 20,000 people were selected from across the country through random stratified sampling according to the ratio by region, gender, and age; second, about 5,000 among 20,000 people willing to participate in the public deliberation survey were chosen; finally, 500 people out of about 5,000 were selected through systemic sampling. This citizen group went through a pre-discussion process including learning from reference materials, e-learning courses, online Q&A sessions, television debates, regional round-table discussions, and video-watching sessions for discussions with future generations. A total of 471 citizens participated in the workshop held from October 13 to October 15, 2017, and through comprehensive discussions, the final decision was made[4]. As a result of the final survey of public deliberation, 59.5% of approximately 470 participating citizens was in favor of resuming construction, while 40.5% opposed it.[5] Accordingly, Shin-Kori Units 5 and 6 have been under construction as of the end of February 2023. In the case of the existing NPPs, they were supposed to shut down when their design lifespan is over, which was reflected in the 9th Basic Plan for Electricity Supply and Demand.

Furthermore, the Moon government shut down the two oldest NPPs (Kori Unit 1 and Wolseong Unit 1) in 2017 and 2019, respectively. A total of 7 NPPs (Hanbit Units 1~2, Kori Units 2~4, and Hanul Units 1~2) were supposed to shut down by 2030 according to the Moon government's nuclear energy policy.

However, the Yoon government overturned the previous government's ban on extension of the lifespan of the existing NPPs and the construction of new ones. It is unlikely that any of NPPs will be shut down by 2030. This was confirmed in the 10th Basic Plan for Electricity Supply and Demand published in January 2023. Figure 1 shows that the cumulative capacity of NPPs continued to increase according to the Yoon governments policy.

Cumulative Capacity of NPPs in South Korea
Figure 1: Cumulative Capacity of NPPs in South Korea

Source: The author, based on nuclear power capacity data of KHNP and the Basic Plans for Electricity Supply and Demand.

Furthermore, the Yoon government took measures to promptly resume the construction of new NPPs. Under the Moon Jae-in administration, Shin-Kori Units 5 and 6 had been regarded as the last new NPPs to be connected to the power grid; the construction of Shin-Hanul Units 3 and 4, which were planned after Shin-Kori Units 5 and 6, was not promoted. However, the Moon administration did not cancel the approval of the construction plan for Shin-Hanul Units 3 and 4 on the grounds that compensation issues were not legally stipulated. Along with the inauguration of the Yoon government, which promotes the nuclear energy expansion policy, measures have been taken to promptly implement the construction of Shin-Hanul Units 3 and 4.

Why the reversal of the nuclear phase-out?

The Moon government's nuclear phase-out policy was easily overturned by the Yoon government in just five years because this policy was never enacted law through a revision of the Atomic Energy Act. This was partly due to weak consensus on the nuclear phase-out policy within the then ruling Democratic Party, which led some assembly members to express their support for the development of small modular rectors (SMRs) including the possibility of resuming construction of Shin-Hanul Units 3 and 4. Even President Moon emphasized cooperation with the United States in pioneering the overseas NPP market during the Partnering for Green Growth and the Global Goals 2030 (P4G)[6] Summit in Seoul in June 2021.[7] Lee Jae-Myung, Democratic Party presidential candidate during the 2022 campaign, also pledged to consider resuming construction of Shin-Hanul Units 3 and 4.[8] Thus the limits of the Moon governments nuclear phase-out policy were revealed, as it supported the export of NPPs and the development of SMRs.

2. Advocacy for Nuclear Power in South Korea and the Competitive Relationship between Nuclear Power and Renewable Energy

In South Korea, the construction of NPPs has been promoted as a source of domestic and cheap energy to support rapid economic growth, the heavy and chemical industry and export-led economic development. Since Korea relies on foreign sources for more than 98% of its energy, nuclear energy has been advocated as a major energy source to ensure a stable energy supply. This argument still dominates the discourse on nuclear energy in the country.

In response to the global financial crisis in 2008 and international pressure to reduce greenhouse gas (GHG) emissions, the Lee Myung-Bak administration advocated nuclear energy as a low-carbon technology. The government promoted the export industrialization of the nuclear power industry and signed the first NPP export contract with the UAE, making nuclear energy a pillar of green growth. This policy stance is being followed by the Yoon Suk-Yeol government, which announced a support plan for the nuclear power industry to 'restore the domestic nuclear power industry ecosystem facing lack of work' due to the Moon Jae-In government's nuclear phase-out policy and to 'strengthen future competitiveness' of the nuclear power industry.[9] To this end, the government plans to expedite the procedure for resuming the construction of Shin-Hanul Units 3 and 4 as soon as possible.

Over time, the emphasis of the governments advocacy logic has shifted away from energy security to GHG reduction, and more recently to industrial policy.

When the Lee Myung-Bak administration took office in 2008, South Korea set its first GHG reduction target. The Lee administration planned to expand both nuclear power and renewable energy under the banner of low carbon green growth. However, while the share of nuclear energy was planned to be increased to 59% by 2030, the share of renewable energy supply was planned to be increased from the 1% level at that time to only 12% by 2030. Thus, the emphasis was placed on nuclear power rather than renewable energy.[10] As a result, Korea's share of renewable energy in electricity generation is 6.0% in 2021[11], remaining the lowest in all OECD countries and far behind the OECD average of 17%. In the National Determined Contribution (NDC) finalized by Moon administration in 2021, the target for renewable electricity generation was 30.2% by 2030. However, it decreased by about 10% to 21.6% in the 10th Plan established by the Yoon government, while the share of nuclear power increased from 23.9% by 2030 in the NDC to 32.4% in the 10th Plan. Additionally, as the renewable energy target was lowered, the renewable energy supply mandatory supply ratio, which was raised in 2021 to achieve the 2030 target of 30%, was also lowered, from 25% to 15% in 2026.[12]

The expansion of renewable energy is one of the essential policies in responding to the climate crisis. Therefore, lowering the renewable energy target Korea recently received a very poor evaluation in the 2023 Climate Change Performance Index.[13] With the current ruling party, the People Power Party, or its predecessor, in power (2008~2016, 2022~present), conservative parties were active in expanding nuclear power and passive in increasing renewable energy. In contrast. The Democratic Party (2017~2021) took a more active policy to gradually move away from nuclear power and expand renewable energy.

In the current technological and political situation of South Korea, nuclear power and renewable energy are also in competition with each other. With expanding nuclear power, providing a constant supply of electricity 24 hours a day, there is high possibility that the output of solar or wind power will be limited, unless a storage facility is available to store electricity generated from solar or wind power. This is because the power gird in Korea is not connected to other countries like in Europe and nuclear power, due to difficulties of load adjusting, cannot easily control output in a situation of electricity oversupply. In fact, Jeju Island, which in terms of the power grid can be considered a mini-model for the entire Korean territory, has a high share of renewable energy generation at 16.2% (2020), and recently restrictions on wind and solar power output have increased in the event of electricity oversupply.[14] Furthermore, if large NPPs are constructed under limit budget constraints, political and economic support for other low-carbon technologies will inevitably be reduced.[15] The conflicting energy policy directions and electricity supply plans of the Moon and Yoon governments highlight this issue well.

3. Unresolved Spent Nuclear Fuel Storage Issues

Although more than 40 years have passed since the commercial operation of NPPs began, spent nuclear fuels (SNFs) generated from NPPs have been temporarily stored at the NPP sites without any interim storage of SNFs or a permanent nuclear waste disposal site. At Wolseong NPP, where four heavy water reactors are in operation, there is a dry storage facility for SNFs called MACSTOR (Modular Air-cooled Canister Storage), and the SNFs discharged from the remaining 22 light water reactors have been stored in the cooling water tank of the NPPs. As the cooling water tanks approach saturation, public deliberations on SNFs were held twice: the first from October 2013 to June 2015 and the second from May 2019 to January 2021. However, the basic plan for high-level nuclear waste that was established after the first public deliberation collapsed without being implemented due to opposition from residents of the NPP areas and anti-nuclear environmental groups. After the second public deliberation, a special bill on the management of high-level nuclear waste is being discussed in the National Assembly as of the end of February 2023.

A key issue is the construction of a temporary or short-term dry storage facility of SNFs at the NPP sites to store SNFs until an interim storage or permanent disposal sites are determined and built. However, the residents of the NPP areas strongly oppose the construction of such a facility, fearing that the site will become a permanent disposal site if the final disposal site or interim storage cannot be secured.[16] Recently, KHNP has been promoting the construction of a dry storage facility on the Kori site due to the dismantling of Kori Unit 1 and saturation of the wet storage facility for SNFs in Kori Unit 2.[17] However, due to opposition from anti-nuclear groups, the related briefing session hosted by the city of Busan was canceled.[18]

An anti-nuclear demonstration held in Busan, South Korea
Opposing the lifespan extension of nuclear power plants and nuclear waste disposal facilities and demanding the shutdown of the nuclear power plants in an anti-nuclear demonstration held in Busan on the 12th anniversary of the Fukushima nuclear accident.

4. Public Opinion on Nuclear Energy

Due to the rise in energy prices caused by the recent Ukraine-Russia war and the inauguration of the government that advocates for nuclear energy, public opinion on nuclear energy in Korea has changed over the past five years.

In a survey on the future path of nuclear energy conducted during the public deliberation of Shin-Kori Units 5 and 6 in 2017, 53.2% said that nuclear energy should be reduced in the future, 35.5% opted for maintaining the status quo, and only 9.7% were in favour of expansion of nuclear energy.[19] In a poll conducted in 2018, 84.6% and 72%, respectively, were in favor of reducing nuclear and coal power plants and increasing renewable energy and natural gas power plants. However, in a survey conducted by the Korean Nuclear Society in August of the same year, during the height of the heat wave, 71.6% answered in favor of using nuclear power as a means of generating electricity, but when asked the preferred electricity supply sources, 44.9% answered for PV (photovoltaic) and 29.9% for nuclear power.[20]

A survey commissioned by the Korean Nuclear Society in 2021[21] shows that public opinion has changed. 72.1% supported nuclear energy, far higher than the 24.2% against it, and 35.9% answered that nuclear power generation should be increased from the current 25~30%, while 34.0% wanted to maintain the status quo and 28.1% favored reducing the nuclear share. When asked to choose two main future power sources, solar energy was the highest at 33.8%, followed by nuclear power at 30.6%. For the NPPs whose lifespan is about to expire, 78.9% of the respondents said that a decision on whether or not to extend the operation should be made after evaluating safety and economic feasibility, which was overwhelmingly higher than the 18.5% who said that they should be permanently shut down without lifespan extension. In a 2022 opinion poll about the direction of energy policy, when asked about their evaluation of the Moon Jae-In government's nuclear phase-out policy, such as banning the construction of new NPPs and the lifespan extension of existing ones, 37.8% responded that they like the policy (25.0% very good, 12.8% good), while 54.0% said it was undesirable (42.2% very wrong, 11.8% wrong).[22] In the same year, in KHNP's survey, 69.2% said nuclear energy for power generation was necessary.[23] In summary, recent public opinion polls show that support for nuclear power outweighs opposition to it.

The recent results of public opinion polls favorable to nuclear energy seem to be related to the rise in gas heating costs and electricity price due to the Russia-Ukraine war. KEPCO announced it would increase electricity price by 9.5% from January 2023, reflecting factors such as fuel price hikes, such as LNG in 2022.[24] In December 2022, the share of nuclear energy in electricity supply increased to 29.6%, and regarding this, KEPCO explained that it increased the operation of NPPs with high economic feasibility to minimize the increase in electricity price as energy prices such as coal and gas soared. The unit cost of nuclear power generation is KRW 52 (ca. USD 0.04) per kWh as of 2022, which is far lower than other power generation sources such as bituminous coal (KRW 157, ca. USD 0.12), anthracite coal (KRW 202, ca. USD 0.15), and LNG (KRW 240, ca. USD 0.18).[25]

5. Prospects for Nuclear Power in Distributed Energy Systems

The prospects for nuclear power in South Korea can be seen not only in the context of the recent political changes in the country's nuclear power policy but also the government's vision of a distributed energy system in the long term.

The political and social debate surrounding nuclear power in South Korea has not been as strong as in European countries, where the anti-nuclear movement was strong in the 1970s and 1980s. From the mid-1980s until the introduction of the policy of separating low-level and high-level radioactive waste disposal sites in 2005, the government's attempts to select radioactive waste disposal sites were met with strong resistance from local residents, but this resistance was not linked to opposition to the construction of NPPs. Originally, in South Korea, NPPs were built by state-owned enterprises in accordance with the government's electricity supply plan, as mentioned above. Their construction was not subject to political debate between political parties. When the Lee Myung-Bak government announced its nuclear expansion policy in 2008 (increasing the share of nuclear power generation to 59% by 2030), environmental groups and minor progressive parties opposed it, but there was no debate between mainstream parties. Even under the Park Geun-Hye administration (2013. 2 ~ 2017. 4) that came to power after the Fukushima nuclear disaster in Japan, the construction of nuclear power plants was in accordance with the existing electricity supply plan. This policy inertia began to break down under President Moon Jae-In, who called for nuclear phase-out and energy transition. The Moon government decided through public debate the construction of Shin-Kori Units 5 and 6, and subsequently announced that it would not build new NPPs and would not extend their lifespan.

The Moon administration's nuclear phase-out policy was heavily criticized by the conservative party and conservative media. The currently-ruling conservative party, People Power Party, has made clear its opposition to the Moon governments nuclear policy, and the conservative media also criticized the policy, defending the claims of the nuclear industry and nuclear scientists. The Democratic Party, the ruling party of the Moon government, did not actively respond to the criticism from the conservative party. As mentioned earlier, the party had not taken any legislative measures to ban the construction of new NPPs and to prohibit the extension of their lifespans. Furthermore, the members of the Democratic Party, and even President Moon, made statements that contradicted their nuclear phase-out policy, i.e., they advocated for the development of small nuclear reactors (SMRs) and the export of NPPs.

When People Power Party came to power in 2022, it is again promoting the construction of new NPPs. However, it is unlikely that NPPs will continue to be built, as South Korea is one of the countries with the highest nuclear power density in the world. The country has continued to build NPPs on the four sites (Uljin, Kori, Wolsong, Yeonggwang) decided upon in the 1970s. Shin-Kori Units 3 ~ 6 are also located right next to the existing Kori site, albeit under a new name of Saeul Units 1 ~ 4. The designated new sites (Samcheok and Yeongdeok) in the wake of the nuclear energy expansion policy by Lee Myung-Bak administration have been met with strong opposition from local residents. In a situation where it is difficult to secure new NPP sites due to issues of public acceptance, the construction of new NPPs that increase the density of existing sites will eventually reach its limits. This is why the current government is actively promoting the policy of extending the lifespan of NPPs a way to secure additional nuclear capacity without building new plants.

The table below shows the 2030 targets for the share of electricity generation by energy source in the 9th Basic Plan for Electricity Supply and Demand of 2020, the NDC of 2021, and the 10th Basic Plan for Electricity Supply and Demand finalized in January 2023.

Targets for the share of electricity production by energy sources in 2030
Table 1 Targets for the share of electricity production by energy sources in 2030

The changes in 2030 targets for nuclear energy, coal and renewables are significant. Compared to the 9th Plan, the share of coal in the 10th Plan has decreased by about 10%, while nuclear has increased by 7.4%, and renewables are at a similar level. Compared to the NDC targets, the share of renewables fell by 8.6% in the 10th Plan. It implies that the reduced share of coal power was filled by renewables under the Moon administration, while it was filled by nuclear energy under the current Yoon administration. For reference, South Korea's GHG emissions are still high, although they have been decreasing slightly in recent years (see Figure 2). As of 2020, about 86% of GHG emissions come from fuel combustion. About 39% of fuel combustion emissions come from electricity and heat production.[26]

South Korea’s Greenhouse Gas Emissions (1990-2020)
Figure 2: South Korea’s Greenhouse Gas Emissions (1990-2020)

Source: Greenhouse Gas Emissions data from Greenhouse Gas Inventory & Research Centre.

Whether nuclear or renewable energy sources contribute more to reducing carbon emissions depends on the government's GHG reduction targets and its will to implement them. South Korea first set a 2020 GHG target in 2009 when the Lee Myung-Bak administration declared low-carbon green growth. The Lee administration's main policy was to expand nuclear power. The GHG goal was a 30% reduction from business as usual (BAU) by 2020, with the emissions target of 543 million tons in 2020. However, as seen in Figure 2, emissions in 2020 were 656 million tons, failing to meet the initial target. The Yoon administration is also trying to reduce carbon emissions by expanding nuclear power. However nuclear power is not suitable for the long-term energy transition vision, which is to build a distributed energy system. Building a distributed energy system is no longer a normative energy transition vision, but a technical call.

Given renewable energy volatility expanding renewable energy, first and foremost on a technical level, requires a more long-term plan to ensure grid stability. South Korea's share of electricity production from renewables is low at 6~7%, but already by April 2023, measures will be taken to forcibly limit the output of PV, citing excess supply over demand. This is because PV facilities are concentrated in the southwestern part of the country, but a power grid that connects to the capital city has not been established.[27]

The current centralized power supply system based on large-scale power plants such as fossil fuel and nuclear power is facing limitations due to social acceptability issues surrounding high-voltage transmission networks, radioactive waste disposal sites and new NPP sites, and the growing imbalance of electricity supply and demand by region. In 2021, the government responded to these issues and established measures to build distributed energy system to achieve net zero carbon emission by 2050. Distributed energy system is a concept that produces electricity on a small to medium scale in areas close to where energy is consumed, and includes renewable energy, cogeneration, self-generation, energy storage (ESS), and demand resources. The National Assembly is currently discussing a related bill.

The establishment of distributed energy systems, which enables to increase local self-sufficiency in electricity supply and introduce distributed energy-friendly markets, will bring about a paradigm shift in the current electricity supply system, which is dominated by the centralized power supply system and KEPCO's monopoly on electricity transmission, distribution, and sales.[28] In a distributed energy system, the role of nuclear power may also be reduced in the long term. Furthermore, the issue of SNF storage is likely to remain a significant obstacle to the expansion of nuclear power in the absence of solution to the nuclear waste disposal. Overall, the nuclear energy expansion policy will be an unstable strategy on the way to carbon neutrality. 


[6] The P4G is a cooperative body, in which governments of 12 countries (South Korea, the Netherlands, Denmark, Mexico, Vietnam, Ethiopia, Chile, Kenya, Colombia, Bangladesh, Indonesia, and South Africa), international organizations/councils, private companies, and civil society participate, promoting public-private cooperation in key areas related to the green economy and accelerating the achievement of Sustainable Development Goals (SDGs) and the implementation of the Paris Agreement (

[15] Watson, Jim. 2009. “8.2. Setting future priorities” in 『Energy for the Future』 edited by I. Scrase and G. MacKerron. Sigrid Stagl (in Korean translation)

[21] Embrain Public. 2021.09. 『2021년 원자력발전에 대한 인식조사 결과보고서(2021 Awareness Survey on Nuclear Power Generation』

[26] National Greenhouse Gas Inventory (1990-2020) from Greenhouse Gas Inventory & Research Center, Ministry of Environment (