Commissioning tests are under way at unit 3 of South Korea’s Shin Kori NPP, which achieved first criticality on 29 December.

Shin Kori 3 is the first Korean-designed Advanced Pressurised Reactor-1400 (APR-1400) to start up and becomes South Korea’s 25th operating power reactor. Construction began in October 2008 and an operating licence was issued by the Nuclear Safety and Security Commission on 30 October. Korea Hydro and Nuclear Power (KHNP) began loading 241 fuel assemblies into the reactor on 4 November.

During the tests output will be gradually increased to full capacity. Hot functional tests will also be carried out to ensure the reactor’s primary circuit is working correctly at normal operating temperatures and pressures. Further tests will check the unit’s performance in various abnormal operating conditions before unit begins commercial operation.

Unit 4 at Shin Kori – also an APR-1400 – is expected to start operating in early 2017. Unit 3 had originally been due to begin operating at the end of 2013, with unit 4 following in September 2014. However, the need to test safety-related control cabling and its subsequent replacement delayed their operation.

Two more of the 1,350MWe APR-1400s 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 both the Shin Kori and Shin Hanul sites.