The Nuclear Regulatory Commission (NRC) has certified the Advanced Power Reactor 1400 (APR1400), a third-generation design developed by deployed by South Korean state-owned companies Korea Electric Power Corp. (KEPCO) and Korea Hydro and Nuclear Power (KHNP).

The U.S. nuclear regulatory body on May 1 said it will issue a direct final rule certifying the reactor type as “fully acceptable for U.S. use” for 15 years. “Absent adverse comments, the rule will become effective 30 days following publication in the Federal Register,” the NRC said.

The South Korean companies submitted a design certification application for the APR1400 in December 2014, and the NRC on Sept. 28, 2018 issued a final safety evaluation report and a standard design approval.

The APR1400 will be the NRC’s sixth certified reactor design. Others include the Advanced Boiling Water Reactor, System 80+, AP600, AP1000, and the Economic Simplified Boiling Water Reactor. NRC staff is currently reviewing applications to certify two other designs: the U.S. Advanced Pressurized Water Reactor and the NuScale small modular reactor.

The APR1400 is a two-loop, evolutionary design, pressurized water reactor (PWR), which evolved from the OPR1000 Korean Standard Nuclear Power Plant design and Combustion Engineering’s (now Westinghouse) System 80+ design. It was developed for use in South Korea.

According to KHNP, the evolution from the OPR1000 took just 10 years and 234.6 billion won ($193 million) to develop. The advanced design incorporates a number of modifications and improvements to meet the utility’s needs for “enhanced safety and economic goals and to address the new licensing issues such as mitigation of severe accidents.”

KHNP also noted that the APR1400 has been developed to meet 43 basic design requirements, such as 4,000 MW-rated thermal power, a 60-year lifetime, and lower probabilities of core damage and accidental radiation release than the country’s OPR1000 plants.

Only one APR1400 is officially operational, though several are under construction. The world’s first APR1400 came online in January 2016 at Shin Kori 3 in South Korea, eight years after construction kicked off. That project was originally scheduled to be operational at the end of 2013, but it suffered years of delays posed by delivery delays and a crippling documentation scandal that required cabling replacements.

Shin Kori 4, where construction began in August 2009, was scheduled to be online in September 2014, but isn’t yet commercially operational. The project was originally planned to be completed in November 2017, but in January 2019 that date was pushed to August 2019. KHNP on April 25 announced that the reactor had achieved first criticality on April 11.

Construction of other APR1400 reactors at Shin Kori, Units 5 and 6, began in April 2017 and September 2018. According to the World Nuclear Association, Unit 5 is scheduled to begin commercial operation in March 2022, with Unit 6 following one year later.

Construction at two more APR1400s began in July 2012 at Shin Hanul (Units 1 and 2), but they have also been plagued by delays. They were scheduled to come online between April 2018 and February 2019, but have been delayed to October 2019. KHNP in May 2017 announced it suspended design work for two other APR1400 units at Shin Hanul until South Korea’s government made a firm decision on the direction of its nuclear power policy.

Meanwhile, the first of four APR1400 reactors under construction at the Barakah plant in the United Arab Emirates (UAE) was completed this March, but commercial start-up has been delayed to between the end of 2019 and early 2020, Nawah Energy Company, the operator of the Barakah Nuclear Energy Plant, said in May 2018. On March 29, the UAE’s Federal Authority for Nuclear Regulation (FANR) said it was in the final stages of the process to review the plant’s license application documents submitted by plant owner ENEC in 2015. However, FANR Director General Christer Viktorsson said the entity is “not yet ready to issue the operating license.”

—Sonal Patel is a POWER associate editor (@Sonalcpatel, @POWERmagazine).