Korea's Kori 3 and 4 set for restarts in 2027

The 1,025 MWe Westinghouse pressurised water reactors at the plant, near Busan, were given operating licences in 1984 and 1985, respectively, with their 40-year design lives expiring in September 2024 and August 2025, respectively. The units are currently not in operation.

Korea Hydro & Nuclear Power (KHNP) says it plans to restart the units during the first half of 2027. The extensions approved by the commission allow unit 3 to operate until September 2034 and unit 4 to operate to August 2035.

KHNP President Kim Hoe-cheon said: "Continued operation will contribute to the national economy by responding to the increasing power demand of advanced industries such as semiconductors and AI and supporting a stable power supply, while also playing a crucial role in carbon neutrality. We will do our utmost to ensure the safe restart of Kori units 3 and 4 by prioritising safety and carrying out follow-up procedures, such as facility improvements and regular inspections."

KHNP applied for a licence amendment for the operating period of the two reactors in November 2023. The Korea Institute of Nuclear Safety, a regulatory agency of the Nuclear Safety and Security Commission, conducted a four-year safety review, with other studies including a radiation environmental impact assessment.

The commission said that although the two units have the same design, "their operating and maintenance histories differ, so the actual condition of structures, systems, and equipment, as well as ageing deterioration and life assessment, were evaluated and reviewed separately".

Chairman of the commission, Choi Won-ho, said they would "thoroughly inspect the site to ensure that Kori units 3 and 4 are operated safely” and verify that agreed “facility improvements are implemented in compliance with safety standards".

Background

Kori Nuclear Power Plant is a four unit facility. Unit 1 was permanently shut down in June 2017, after 40 years of operation. It became the first South Korean reactor to enter decommissioning. KHNP submitted its application to dismantle the unit to the NSSC in May 2021. The regulator approved the decommissioning of Kori 1 in June last year.

In April, KHNP restarted unit 2 at the plant, which had been offline since its original 40-year operating permit expired in April 2023.

South Korea has 26 operable reactors which generate about one-third of the country's electricity.