South Korea had 24 operating reactors with 23,231 MW of capacity at four sites in November 2019, according to the World Nuclear Association (WNA), with a further 5,600 MW under construction.

The country produces a higher proportion of electricity from nuclear than anywhere else in North Asia, with its reactors generating 23.7% of output in 2018. The percentage increased to 28% from January to July 2019, according to the Korea Energy Statistical Information System (Kesis), as reactors closed in 2018 for maintenance and safety checks resumed operation.

The 25% year-on-year jump in nuclear output to 91.4 TWh in January-July 2019, combined with an increase in renewable output and fall in overall electricity supply…