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Gov't again delays decision to restart Kori 2 nuclear reactor as country faces growing strain on power supply

Published: 23 Oct. 2025, 22:39

The photo shows the Kori Unit 2 reactor, center, and the Kori Unit 1 reactor, right, located in Busan. The government decided to decommission both in June after they spent eight years offline. [SONG BONG-GEUN]

The Lee Jae Myung administration again delayed the decision to restart the Kori Unit 2 nuclear reactor, postponing a key test of its nuclear energy policy as the country faces mounting strain on its power supply.

The Nuclear Safety and Security Commission (NSSC) met on Thursday to review the reactor's license extension, but it failed to reach a conclusion. This was the second time in less than a month the commission deferred its decision, having previously failed to finalize the issue at its Sept. 25 meeting.

The NSSC did, however, approve Kori 2’s accident management plan. The next review is scheduled for Nov. 13. This plan includes how the plant would respond to and mitigate the consequences of severe accidents, such as a reactor meltdown or major system failure.

Kori Unit 2 is the first of 10 reactors undergoing license renewal evaluations under the Lee administration. The review is also the first since 2015, when the government approved an extension for Wolsong Unit 1. The outcome was expected to signal how the administration will handle the country’s aging nuclear fleet.

The longer the delay, the shorter Kori 2's viable operation period becomes.

Current regulations set the extension term from the shutdown date, regardless of when approval is granted. Kori 2’s approved end date is April 2033.

Even if operations resume this month, the reactor could run for only around six years. Korea Hydro & Nuclear Power (KHNP), the operator, expects actual operations to begin sometime in the first half of next year after undergoing required maintenance.

Shorter operation periods reduce economic feasibility. The nuclear industry estimates that each day a reactor remains offline results in about 1 billion won ($690,000) in losses.

The United States reviews nuclear plant license renewals and typically sets terms of 20 years. During the Yoon Suk Yeol administration, Korea considered extending reactor licenses from 10 to 20 years, but the Lee administration has not taken up the discussion.

An aerial view shows Constellation's Clinton Clean Energy Center's single nuclear reactor power plant on July 25 in Clinton, Illinois. [AFP/YONHAP]

Concerns over power supply shortages are growing as a result.

Under the Moon Jae-in government, multiple reactors shut down in line with the nuclear phaseout policy. KHNP declined to apply for continued operation, despite this leading to fines.

Ten large reactors — including Kori Units 3-4, Hanbit Units 1-2, Hanul Units 1-2 and Wolsong Units 2-4 — face license expirations by 2029. Their combined capacity totals 8.45 gigawatts.

“Replacing that output with renewables would require more than twice the extra capacity called for in the 11th Basic Plan of Long-Term Electricity Supply and Demand,” an industry official said. “If we don’t implement continued operation, we won’t be able to respond to rising demand from AI and other factors.”

Globally, license renewals for reactors are on the rise. As of late last year, 258 of 285 reactors — or 91 percent — with expired licenses secured approvals for continued operation.

In the United States, 86 of 94 active reactors have been renewed. The trend also shows longer extension periods. Twenty-two U.S. reactors have applied for 80-year licenses, and eight have already received approval.

In contrast, Korea currently has no reactor operating beyond its original design life. Wolsong Unit 1, the only reactor that previously gained an extension, has since gone permanently offline.

The photo shows the Kori Unit 2 reactor in Busan. [SONG BONG-GEUN]

“The U.S Nuclear Regulatory Commission grants approval for nuclear power plants that have proven their safety to operate for up to 80 years,” said Jeong Yong-hoon, a professor of Nuclear and Quantum Engineering at the Korea Advanced Institute of Science and Technology (Kaist).

He added that Korea’s Kori Unit 2 is “no less safe than its American counterparts” and could easily operate for 80 to 100 years.”

Even if the Kori Unit 2 decision is finalized in the next meeting, the nuclear sector remains cautious. Many in the industry worry the government may postpone new reactor construction by leaning on existing units for longer.

“It takes too long to build a reactor to meet immediate demand,” President Lee said during a press conference on Sept. 11. “While construction becomes possible after safety and site issues are solved, the current outlook is low.”

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
BY KANG KWANG-WOO [[email protected]]