Wolsong 1 resumes operation following licence extension

24 June 2015

Unit 1 of South Korea's Wolsong nuclear power plant restarted yesterday after having been offline since November 2012 when its operating licence expired. A new licence was issued in February.

Wolsong - 460 (KHNP)
The four-unit Wolsong plant (Image: KHNP)

Wolsong 1 - the country's second-oldest power reactor - 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 pressure tubes and calandria tubes. Candu reactors are designed to undergo refurbishment after about 25 years of operation, requiring a major outage but allowing reactor life to be extended by up to 30 years. For all Candu reactors, this involves complete retubing. The reactor came back into operation in July 2011 with its performance raised from 629 MWe to 657 MWe. However, Wolsong 1's operating licence expired around the end of 2012.

The NSSC began a process of stress tests, checks and discussions which culminated last October with a conclusion by the Korea Institute of Nuclear Safety that the unit is suitable for operation until November 2022 given certain engineering improvements over the long term.

On 27 February, the Nuclear Safety and Security Commission approved a seven-year licence extension for the refurbished and uprated Wolsong 1 pressurized heavy water reactor. At that time, plant owner Korea Hydro and Nuclear Power (KHNP) said that it anticipated restarting the unit in April.

The reactor has since undergone some 100 days of "comprehensive maintenance" and been subjected to inspections to ensure that it meets revised safety requirements following the 2011 accident at Japan's Fukushima Daiichi nuclear power plant.

KHNP announced yesterday that the unit had resumed operation after having been offline for a total of 946 days. The unit is expected to reach full capacity today.

KHNP signed an agreement on 8 June with local residents, including those in the nearby coastal city of Gyeongju, on the development of the region in accordance with the continued operation of Wolsong 1. Under that agreement, KHNP will provide KRW 1.3 billion ($1.2 million) for job creation, business growth and welfare of residents.

Researched and written
by World Nuclear News