APR1400

The APR1400 began in 1992 as the Korean Next-Generation Reactor and finished its basic design in 1999. It is a 3,983 MWt PWR with 241 16 × 16 fuel assemblies and a 60-year design life, and its primary circuit gives away its ancestry: two loops, each with one steam generator and two pumps, rather than the three or four loops with a single pump each of the Westinghouse layout. That architecture is Combustion Engineering's, licensed to Korea in the 1980s to build the OPR-1000. On top of it the APR1400 added an in-containment refueling water storage tank (IRWST), four safety trains and a seismic design for 0.3 g of ground acceleration.

That inheritance nearly blocked the export business. Westinghouse, which absorbed Combustion Engineering in 2000, sued KEPCO and KHNP in October 2022 arguing that the APR1400 embeds licensed intellectual property and that selling it abroad needed its consent; KHNP countersued, arguing that the US Atomic Energy Act gives that authority to the Attorney General and not to a company. The settlement of 17 January 2025 between Westinghouse, KEPCO and KHNP ended the litigation on confidential terms, and it is what unlocked the commercial talks that followed.

The first unit, Shin Kori 3, renamed Saeul 1, entered commercial operation on 20 December 2016, but the export came first: in December 2009 Korea won the Barakah contract in the United Arab Emirates, worth 20.4 billion dollars for four units. Barakah 1 entered commercial operation in April 2021 and Barakah 4 on 5 September 2024. As of 2026 eight APR1400s are operating, Saeul 1-2, Shin-Hanul 1-2 and Barakah 1-4, and four are under construction, Saeul 3-4 and Shin-Hanul 3-4.

The eight operating units share the same 3,983 MWt core and differ in electrical output: 1,429 MWe net at Shin-Hanul 1 against 1,337 at each Barakah unit, with gross figures between 1,417 and 1,491 MWe. The difference is not in the reactor but in the turbine island and the site conditions, because the same core yields less when the heat sink is the Persian Gulf. That is why any power figure has to say whether it is net or gross.

In the United States the APR1400 holds a credential no other foreign design has: the NRC certified it as a standard design in a rule effective on 19 September 2019, following the final safety evaluation report of September 2018 and the standard design approval of October that year. It is the first non-US design to earn that certification, and the reason it is named every time building Korean reactors on US soil comes up.