South Korea’s first CANDU 6, Wolsong unit 1, is cleared to restart

By: Donald Jones, P.Eng., retired nuclear industry engineer, 2015 February

Wolsong unit 1, a CANDU 6 unit in South Korea operated by the Korea Hydro and Nuclear Power (KHNP) Company, was cleared for continued operation on 2015 February 27 by the Korean nuclear regulator (the Nuclear Safety and Security Commission – NSSC) after being out of service since 2012 November. Wolsong 1 was the first CANDU 6 unit in South Korea (reference 1) and went into commercial operation in 1983 April. The unit was taken out of service for refurbishment in 2009 April. At the end of 2008, the last full year of operation before the shutdown for refurbishment, the annual capacity factor was 93.2 percent and the lifetime capacity factor was 87.0 percent. The capacity factors are taken from the Power Reactor Information System (PRIS) database of the International Atomic Energy Agency (IAEA). Note that the Load Factor term used in the PRIS database has the same meaning as capacity factor. Capacity factors are based on the (net) Reference Unit Power and on the (net) Electricity Supplied, as defined in the PRIS database. For the 5 years prior to the refurbishment outage the average annual capacity factor was 89.4 percent.