"In 1989, Korea began construction on their first domestically developed OPR-1000 design... Twelve reactors of this standard design began construction between 1989 and 2008, and their costs declined in a stable manner... representing a 13% cost decline (1% annualized)." (Lovering 2016)
The problem is, even after reaping this cost decline, totaling 50%, nuclear power is still noncompetitive in South Korea. They were built for energy independence after oil shock, not for cheap electricity.
Same source as you (Lovering 2016), the Koreans built several 1 GW plants for an overnight cost of 2 Billion USD per plant or less in many cases. A seriously impressive feat. The graph seems to show a far greater cost decline than 13%.
The Koreans just recently ousted an administration that was overtly hostile to nuclear energy and had declared a phase out. Now they are planning on increasing the share of nuclear electricity to 35%. https://www.world-nuclear-news.org/Articles/South-Korea-incr...
The problem is, even after reaping this cost decline, totaling 50%, nuclear power is still noncompetitive in South Korea. They were built for energy independence after oil shock, not for cheap electricity.