Nuclear safety commission approves continued operation of Kori units 3 and 4

The Nuclear Safety and Security Commission approved continued operation of Kori nuclear power plant units 3 and 4 at a meeting on the 27th. The units will enter restart procedures after unit 3 shut down on September 28, 2024, upon reaching the end of its design life, and unit 4 halted operations on August 6, 2025.

Continued operation allows a nuclear reactor to operate for another 10 years beyond its design life if it is judged capable of operating safely. The approval authorizes Kori unit 3 to operate through September 2034 and unit 4 through August 2035.

The actual restart is expected to take at least three months. The operator, Korea Hydro & Nuclear Power, will carry out repairs, including equipment replacement, to ensure safety, followed by on-site inspections by the commission before power generation resumes.

The proposal was first presented on the 15th, but no decision was made because supplementary materials and further review were needed. At the second meeting, it was approved as proposed after six hours of deliberation, with five votes in favor and two against, securing a majority of the commission's nine members.

The Nuclear Safety and Security Commission will meet on the 27th for its second review of continued-operation permits for Kori units 3 and 4 in Gijang, Busan. Unit 3 stopped operating when its design life ended on September 28, 2024, and unit 4 did so on August 6 last year.

The commission approved the reactors' accident management plans on the 15th after three rounds of discussions. The documents cover equipment, response strategies and training for design-basis accidents, multiple failures, external disasters beyond the design basis and severe accidents. The continued-operation proposal was first introduced that same day, but its late placement on the agenda left each commissioner time for only one round of questions.

Approval of accident management plans and continued-operation permits are separate agenda items. Nuclear industry observers cautiously anticipate possible approval at this meeting, judging that overlapping issues such as severe-accident response have already been substantially addressed.

If continued operation is approved, unit 3 could operate until September 2034 and unit 4 until August 2035. Current rules count shutdown time toward the permitted operating period, so allowing for several months of restart preparations would leave actual operating periods of about seven years and eight years, respectively.

Environmental groups criticize the review as inadequate, saying it has failed to ensure safety.

Nuclear safety commission to hold second review of Kori 3 and 4 operating extensions

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