Of the nine nuclear power reactors whose operating licenses expire by 2030, five are expected to restart after being shut down for a considerable period. This is because the Moon Jae-in administration, which pursued an anti-nuclear policy, missed the window to apply for "continued operation." Of the five reactors for which the timing of the continued operation application was postponed at that time, two have been shut down, and three are likely to be shut down. They can restart if they receive approval for continued operation from the Nuclear Safety and Security Commission, but under current law, if approval is not granted before the operating license expiration date, the reactors must be shut down.
◇ Five reactors could have applied for continued operation under the Moon Jae-in administration but were delayed
According to Korea Hydro & Nuclear Power Co. (KHNP) on the 14th, Kori Unit 2 (license expiration date in parentheses: Apr. 8, 2023), for which the Nuclear Safety and Security Commission decided the previous day to approve continued operation, as well as Kori Unit 3 (Sept. 28, 2024) and Kori Unit 4 (Aug. 6, 2025), could have applied for continued operation during the Moon Jae-in administration.
Under the standards before the Enforcement Decree of the Nuclear Safety Act was amended at the end of 2023, KHNP could apply for continued operation two to five years before the reactor's operating license expiration date. This means Kori Unit 2 could have applied between Apr. 8, 2018, and Apr. 8, 2021; Kori Unit 3 between Sept. 29, 2019, and Sept. 28, 2022; and Kori Unit 4 between Aug. 6, 2020, and Aug. 6, 2023.
However, KHNP submitted the safety assessment report for Kori Unit 2's continued operation in Apr. 2022. The application was filed just before President Moon Jae-in left office. For the safety assessment reports for Kori Units 3 and 4, KHNP did not submit them until Sept. 2022, after the Yoon Suk-yeol administration took office. An industry source said, "At the time, it was an unavoidable situation to watch the Moon Jae-in administration, which advocated phasing out nuclear power."
The safety assessment report for Hanbit Unit 1, which is likely to be shut down as its operating life runs until Dec. 22 this year, was also submitted only in June 2023, under the Yoon Suk-yeol administration. Hanbit Unit 2 (Sept. 11, 2026) and Wolsong Unit 2 (Nov. 1, 2026) also could have begun the extension process during the Moon Jae-in administration, but it did not happen. The safety assessment reports for Hanbit Unit 2 and Wolsong Unit 2 were submitted in Oct. 2023 and Apr. 2024, respectively.
◇ After early closure of Wolsong Unit 1 under the Moon Jae-in administration, even prior repairs were blocked… time needed before restart
The Moon Jae-in administration's anti-nuclear policy also affected the timing of the Nuclear Safety and Security Commission's deliberations. Following the controversy over the approval for continued operation and early closure of Wolsong Unit 1, related laws were revised to prohibit facility improvements before the operating license expiration date.
KHNP invested 700 billion won from Apr. 2009 to July 2011 to completely replace major equipment such as pressure tubes before the decision on continued operation of Wolsong Unit 1. Safety was reinforced to meet Nov. 20, 2012, when the design life was set to end.
However, Wolsong Unit 1 was finally closed in Dec. 2019 after KHNP decided in June 2018 to shut it down early. It had been scheduled to operate until Nov. 20, 2022, but the fallout of the Moon Jae-in administration's anti-nuclear policy had an impact. Subsequently, controversy erupted over the waste of taxpayers' money, and it became difficult to improve major equipment before approval for continued operation is granted.
Jung Beom-jin, a professor of nuclear engineering at Kyunghee University, said, "By preventing advance repairs after Wolsong Unit 1, the deliberation period at the commission has become longer, and even after approval for continued operation, it takes three months to restart." An industry source also said, "In the nuclear sector, continued operation is entirely natural," adding, "In the United States and Canada, maintenance work with continued operation in mind begins before the operating license expires."
◇ Reactor shutdowns cost more than 1 billion won a day in additional expense
The economic loss from reactor shutdowns is enormous. As Kori Unit 2 was halted for the continued operation review, electricity was mainly generated by importing liquefied natural gas (LNG), and since the unit cost of LNG power generation is higher, the additional expense was estimated at at least 1 billion won per day.
Kori Unit 2 has a generation capacity of 650 MW, with a daily output of 150,600 MWh (650 MW x 24 h). According to the Electric Power Statistics Information System, as of Sept., the generation cost per kWh is 166 won for LNG and 73 won for nuclear, with LNG being 93 won more expensive per kWh. Consequently, when Kori Unit 2 was shut down, about 1.138 billion won in additional expense had to be paid per day.
Given that Kori Units 3 and 4, which are currently halted for continued operation reviews, each have a capacity of 950 MW, using LNG generation instead of nuclear amounts to an additional 4.24 billion won per day. An industry source said, "The burden of higher electricity generation costs ultimately has no choice but to be passed on to the public."