Early closure for Korea's oldest operating reactor

15 June 2018

Unit 1 of the Wolsong nuclear power plant will be retired prior to the expiration of its operating licence in 2022, Korea Hydro and Nuclear Power (KHNP) announced today as it also cancelled plans for four new reactors. The move is in line with the South Korean government's policy to phase out the use of nuclear energy.

Wolsong 1 - 460 (KHNP)
Wolsong unit 1 (Image: KHNP)

State-owned KHNP said its board had made the decision for the early closure of Wolsong 1 at a meeting today in Seoul. In a statement, the company said its decision was based on the "uncertain economic viability" of its continued operation and recent low operating performance. KHNP said it will "proceed with a follow-up process to acquire a licence under the Nuclear Safety Act to change [the unit's status] to permanent suspension of operation".

South Korean President Moon Jae-in was one of seven candidates in the May 2017 presidential election who signed an agreement in March for a "common policy" for phasing out the country's use of nuclear energy. At a ceremony last June to mark the permanent shutdown of Kori unit 1, he said plans for new power reactors will be cancelled and the operating periods of existing units will not be extended beyond their design life.

"According to the government's energy policy shift, we have reviewed the operational plans of the Wolsong reactors several times and concluded [that] keeping Wolsong unit 1 operating under strengthened safety regulations would not be economical," KHNP CEO Chung Jae-hoon was quoted as saying by the Korea Times.

Wolsong 1 - which became the country's oldest operating power reactor following the closure of Kori 1 - is a Candu 6 pressurised heavy water reactor that began generating electricity in 1983. It was taken out of operation in April 2009 for an extended maintenance outage that included replacement of all its pressure tubes and calandria tubes. The reactor - in Gyeongju, North Gyeongsang Province - came back into operation in July 2011 with its performance raised from 629 MWe to 657 MWe. However, Wolsong 1 was taken offline again when its operating licence expired around the end of 2012.

The refurbished and uprated reactor eventually restarted in June 2015 after being issued with a new operating licence, which expires in November 2022. The reactor has been offline since last month for a scheduled maintenance outage.

KHNP's board also today took the decision to cancel plans for four new reactors. Two units had been planned at Cheonji in Yeongdeok County, North Gyeongsang province. Two further units had been planned either at Cheonji or at Daejin in Samcheok, Gangwon province. The company said it will sell land it has already purchased for the Cheonji plant.

Jae-hoon told the Korea Times plans for the units had been "terminated in order to eradicate uncertainties in the KHNP's management and restore smooth relations with local residents".

"KHNP has decided to work closely with the government on matters related to the maintenance of legitimate and legal expenses incurred in accordance with the decision of the board of directors, and believes that there will be no problem of employment anxiety for employees due to the early closure of Wolsong 1," the company said.

South Korea has 24 power reactors in operation with a combined generating capacity of 22,505 MWe. Together they provide about one-third of the country's electricity. Two new reactors are currently under construction. The government has pledged to scrap new nuclear programs and not to extend the operation of existing facilities to decrease the number of reactors to 14 by 2038.

Researched and written
by World Nuclear News