South Korea's nuclear-first energy policy to face setback with Yoon's impeachment

South Korea's years-long, nuclear-focused energy policy may lose some steam with the departure of impeached President Yoon Suk-yeol, who implemented a nuclear-first energy policy, sharply reversing his predecessor's nuclear phaseout.

Yoon, who was inaugurated in May 2022 with a pledge to revive the nuclear power sector, was removed from office on April 4, immediately after the Constitutional Court upheld the National Assembly's impeachment of him.

In a unanimous ruling earlier in the day, the court found that Yoon committed a grave violation of the Constitution by imposing martial law aimed at cracking down on the opposition, which criticized his high-handed governance style and a series of scandals that also involved his wife.

Yoon has been stripped of his presidential powers since Dec. 14, when the National Assembly approved an impeachment motion for his Dec. 3 declaration of martial law. Since then, the country's prime minister has been serving as the acting president.

Snap election

Under the Constitution, a snap presidential election will be held within 60 days, meaning the country could be without a head of state for an additional two months.

According to recent public surveys, Lee Jae-myung, chairman of the main opposition Democratic Party, is the most favored candidate for the next presidency, well ahead of any candidates from Yoon's ruling conservative People Power Party.

If Lee wins the election, likely in late May or early June, he is expected to adjust Yoon's nuclear-first power mix policy by boosting the role of renewable sources backed by LNG, driven by strong support from anti-nuclear civic groups and environmentalists for the Democratic Party.

The opposition party has long focused its power mix policy on renewable sources supported by LNG, while reducing the role of nuclear power plants due to concerns about nuclear safety and the disposal of nuclear waste.

"There could be some adjustments to the nuclear-focused power mix policy in the event of a ruling by the Democratic Party, but the party is unlikely to return to a nuclear phaseout due to mounting power demand, particularly with the rise of the AI era," said Chung Dong-wook, energy system engineering professor at Chung-Ang University in Seoul.

Nuclear-focused policy

Since taking office, Yoon has prioritized increasing nuclear power use to meet South Korea's growing energy demand and help manufacturers reduce costs, reviving long-delayed projects to build more nuclear reactors, which has reduced LNG demand.

Under Yoon's nuclear-focused power mix policy, the utilization rate of nuclear reactors reached 83.8% in 2024 and 81.8% in 2023, compared with 74.5% in 2021, 70.6% in 2019 and 65.9% in 2018, according to state-owned nuclear power operator Korea Hydro & Nuclear Power.

Yoon's road map for power supply calls for nuclear energy's share in the power mix to rise to 31.8% in 2030 and further to 35.6% in 2038, from 31.4% in 2024.

To meet the goal of nuclear power supply, the country plans to build three additional nuclear reactors by 2038, with a combined capacity of 4.4 GW, marking the first such initiative in nearly a decade.

LNG was to suffer

On the contrary, the portion of LNG in the power mix is expected to drop to 11.1% in 2038, compared with 25.1% in 2030 and 28.2% in 2024.

Meanwhile, the role of coal, blamed for air pollution, will also fall to 10.3% in 2038, from 17.4% in 2030 and 32.9% in 2024.

Renewable sources will account for 32.9% of South Korea's electricity production in 2038, compared with 21.6% in 2030 and 6.9% in 2024.

With Yoon's sudden removal, his politically disputed project to explore crude oil and natural gas fields off the country's southeast coast is also expected to suffer a major setback.

Oil and gas discovery

In a press briefing in June 2024, Yoon announced that South Korea had discovered a massive oil and natural gas reserve in Block 6-1 off the southeast coast, saying that it could hold up to 14 billion barrels of oil equivalent -- an amount that could meet the country's gas demand for 29 years and oil demand for four years.

However, the Ministry of Trade, Industry and Energy acknowledged in February that its key exploratory drilling had failed to find economically viable reserves, sparking criticism that the project was politically motivated to address Yoon's declining approval rating.

Local energy companies have also expressed concerns about the lack of coordinated efforts with the government to address trade and tariff pressures from US President Donald Trump, due to the protracted political leadership void.

South Korea's LNG importers are still awaiting the government's stance on the US call for their participation in the Alaska LNG project, which is considered costly and risky.