South Korea starts construction of Shin Hanul 4 nuclear reactor

Freshly poured concrete at Shin Hanul 4 turned South Korea’s nuclear restart into something you can stand next to: the reactor building now has a physical foundation, and the project has crossed from permits and paperwork into steel-and-civil works. Korea Hydro & Nuclear Power poured the first concrete on May 29, 2026, formally starting construction on unit 4 at the Shin Hanul site on the east coast.

Shin Hanul 4 is one of two APR1400 pressurized water reactors planned at the site, each rated at 1,400 megawatts. Unit 3 already hit its own first-concrete milestone in May 2025, and KHNP says unit 3 is scheduled to finish in 2032, with unit 4 following in 2033. Together, the two units are expected to supply 46 percent of the annual electricity needs of the Gyeongbuk region, giving the project a scale that goes well beyond a single plant announcement.

The road to that pour has been long. KHNP signed an agreement with Ulchin County in November 2014, then applied for a construction licence in January 2016. Work was suspended in May 2017 after the Moon Jae-in administration moved toward a nuclear phaseout policy, but licensing kept moving in the background. The review resumed in July 2022 under the Yoon Suk Yeol administration, and South Korea’s June 2023 implementation-plan approval cleared 20 licensing and permitting procedures across 11 ministries. The Nuclear Safety and Security Commission issued the construction permit for Shin Hanul 3 and 4 on September 12, 2024, in what Yonhap described as the first construction permit for nuclear reactors in South Korea since 2016. The Korea Institute of Nuclear Safety also inspected the site and found no geological risks affecting safety.

The industrial backbone is just as important as the politics. In March 2023, KHNP and Doosan Enerbility signed a KRW2.9 trillion contract for the main equipment for both units, including the reactors, steam generators and turbine generators. The APR1400 design is already operating at Shin Hanul 1 and 2 and Saeul 1 and 2 in South Korea, and four more APR1400 units are in commercial operation at the Barakah Nuclear Power Plant in the United Arab Emirates. South Korea currently operates 26 nuclear reactors, and nuclear plants produced 180,494 GWh in 2023, equal to 30.7 percent of the country’s total power output.

For readers tracking the rebuild of Korea’s nuclear pipeline, Shin Hanul 4 is the milestone worth watching because it is concrete, not slogan. The next markers are already set: excavation, the main building foundation, the remaining civil sequence, and the commissioning path that has unit 4 aiming at 2033.