Wolsong 1 awaits decision

Monday, 16 February 2015

South Korea's Wolsong 1 power reactor continues to await permission to restart. The refurbished and uprated unit has laid dormant for two years while discussions continue on renewing its licence.

A series of meetings have discussed whether it is appropriate to issue a new operating licence to the Candu 6 pressurized heavy water reactor. It began generating power in 1983 but was taken out of operation in April 2009 for an extended maintenance outage that included replacement of all its calandria tubes. The reactor came back into operation in July 2011 with its performance raised from 629 MWe to 657 MWe.

The four Candu units at Wolsong (Image: Konicof)

However, Wolsong 1's operating licence expired around the end of 2012 and the Nuclear Safety and Security Commission (NSSC) must officially renew it before owner Korea Hydro and Nuclear Power (KHNP) can continue generating electricity. The commission began a process of stress tests, checks and discussions which culminated last October with a conclusion by the Korea Institute of Nuclear Safety (KINS) that the unit is suitable for operation until November 2022 given certain engineering improvements over the long term.

An NSSC meeting in January concluded that more opinions on seismic risk were required, and these were presented at a meeting last week, which again deferred the decision. The next meeting is planned for 26 February. 

Wolsong 1 is the first of four Candu units at the site, the rest of which continue operating normally. Across South Korea a further 19 units - all pressurized water reactors - combine to provide 28% of electricity. Another five reactors are under construction.

Researched and written
by World Nuclear News