South Korea’s Nuclear Safety and Security Commission (NSSC) on 23 June approved a plan to build two more nuclear reactors at the Shin Kori NPP, with construction to begin immediately following the approval. The decision allows the state-run Korea Hydro and Nuclear Power Co (KHNP) to add units 5 and 6 to the NPP in the southeastern coastal town of Gijang, Busan. It is almost five years since NSSC’s last such approval. It will bring the total number of South Korean nuclear power reactors to 30, including those currently under construction. The KHNP said it plans to start construction immediately aiming to finish the reactors by 2021 and 2022 respectively. Currently, 23 nuclear reactors are in operation, from which South Korea sources about 30% of its electricity supply.

The two APR-1400 pressurized water reactors (PWRs) have a design lifespan of 60 years and will cost around KRW8,600bn ($7.5bn), according to KHNP. The construction permit was applied for in September 2012 and in January 2014 the Ministry of Industry gave its approval. A consortium comprising South Korean construction companies Samsung C&T, Doosan and Hanhwa Construction was awarded a KRW1,1800bn contract in June 2015 to build the units. Construction of Shin Kori 5 is scheduled to begin this September, followed by construction of unit 6 a year later.

The Shin Kori site currently hosts two OPR-1000 reactors (units 1 and 2), which began operating in 2011 and 2012, respectively. Two APR1400 have already been built at the site (units 3 and 4). Shin Kori 3 had originally been due to begin operating at the end of 2013, with unit 4 following in September 2014. However, their operation was delayed by the need to test the cabling. Unit 3 achieved first criticality last December and was connected to the grid in January. Unit 4 is expected to start operating in early 2017.

Two more APR-1400 reactors are under construction as units 1 and 2 of the Shin Hanul site and are expected to enter service in April 2017 and February 2018, respectively. Two further APR-1400 units are planned for the site.

Meanwhile, KHNP has applied to NSSC for a change to its operating licence for the permanent shutdown of unit 1 at the Kori NPP. It will not seek a licence extension for Kori 1 – South Korea’s oldest operating reactor unit – and the unit will close in June 2017. The 576MWe PWR started operation in 1978 and was refurbished in 2007 and approved to run until 2017.