Second Korean APR-1400 connected to grid

Shin Kori 4 achieved first criticality - a sustained chain reaction - on 11 April.

KHNP said today the 1340 MWe pressurised water reactor (PWR) was connected to the grid at 5:40pm on 22 April, marking the start of electricity supply from the unit.

The power level of Shin Kori 4 will now be gradually increased to full capacity during the commissioning process. After a successful full-power run, the unit will be ready to begin commercial operation. KHNP expects this around mid-August.

Construction of Shin Kori 3 and 4 was authorised in 2006, although the actual construction licence was not issued until April 2008. First concrete for Shin Kori 3 was poured in October 2008, with that for unit 4 following in August 2009. Unit 3 was originally scheduled to enter commercial operation at the end of 2013, with unit 4 due to start in September 2014. However, their operation was delayed by the need to test safety-related control cabling and its subsequent replacement.

Unit 3 eventually reached first criticality in December 2015, was connected to the grid in January 2016 and entered commercial operation in December that year.

KHNP completed cold hydrostatic testing and hot functional testing of Shin Kori 4 in November 2015 and April 2016, respectively. The company announced in August 2017 that it expected to load fuel into the unit in January 2018, with commercial operation beginning in September. However, it said fuel loading was delayed due to slight improvements in the unit's design resulting from commissioning work carried out so far. Additional seismic assessment work has also been carried out in response to the Gyeongju earthquake in September 2016 and the Pohang earthquake in November 2017. The loading of the first of 241 fuel assemblies into the core of Shin Kori 4 eventually began on 7 February this year.

The APR-1400 is a PWR designed by Korea Electric Power Company (Kepco) that KHNP said features improvements in operation, safety, maintenance and affordability based on accumulated experience as well as technological development. It supercedes the standardised 995 MWe OPR-1000 design, of which South Korea built 12.

Construction of two further APR-1400 reactors at Shin Kori - units 5 and 6 - began in April 2017 and September 2018 respectively. Unit 5 is scheduled to begin commercial operation in March 2022, with unit 6 following one year later. Two further APR-1400 units are under construction in South Korea as units 1 and 2 of the Shin Hanul site. A further four APR-1400s are under construction at Barakah in the United Arab Emirates, with the first of those units scheduled to begin operation in 2020.