Good news about Koeberg nuclear power station

Eskom says the critical maintenance on Koeberg’s Unit 2 nuclear reactor is almost complete and the unit should return to service later this month.

The power utility was forced to delay its return to December 2024 due to welding challenges during the maintenance of the nuclear generation unit.

“Koeberg Unit 2 is still on track to be returned to service later this month. The reactor has been reloaded and the required start-up and commissioning activities are in progress,” said Eskom.

According to Eskom CEO Dan Marokane, it is critical that Koeberg Unit 2 and two other large coal-fired generators are brought online by the end of the 2024/25 financial year.

During an Electricity Portfolio Committee progress report on Wednesday, 4 December 2024, Marokane said that only then, will Eskom be prepared to declare the end of load-shedding.

For reference, Eskom’s financial year runs from 1 April to 31 March, meaning these units must return to service before 31 March 2025. This will also allow Eskom to declare the end of load-shedding confidently.

“As far as putting the whole issue of load-shedding behind us, there’s the issue of retaining Medupi Unit 4, Koeberg Unit 2 that had gone through for steam generator refurbishment, and also Kusile Unit 6,” said Marokane.

“These are units that we have to bring in before the end of the financial year.”

In October 2024, Eskom confirmed to energy expert Chris Yelland that Koeberg Unit 2’s return to service had been delayed to December 2024. It had been taken offline to replace its steam generators in December 2023.

Eskom attributed the delay to welding challenges that arose during the maintenance of the nuclear generation unit.

Yelland added that Eskom is reluctant to declare the end of load-shedding until Koeberg Unit 2 and Medupi Unit 4 have been successfully repaired.

Shortly before, Electricity and Energy Minister Kgosientsho Ramokgopa alluded to delays in returning Koeberg Unit 2 to service after Eskom noted in July 2024 that it would soon begin contributing to the grid.

“At Koeberg, we have not been able to meet our own targets. I’m talking about that target of the return of unit 2,” said Ramokgopa.

Critical life-extension upgrades

The 980MW Koeberg Unit 2 reactor was taken offline on 11 December 2023 to have its steam generator replaced. The unit one generator had the same work done between December 2022 and November 2023.

Replacing each unit’s steam generators is critical for extending Koeberg Power Station’s operating licence, which expired for Unit 1 in July 2024.

“The replacement of steam generators is a huge milestone in the life of Koeberg as it was identified by Eskom as a prerequisite for the extension of the operating licence for Koeberg beyond its original design life of 40 years,” said Eskom.

“Eskom has already submitted a licence application to the National Nuclear Regulator (NNR) for Koeberg’s operating life extension by an additional 20 years, which is being assessed by the NNR.”

Despite major delays in the work on Koeberg Unit 1, Eskom was granted a 20-year life extension in July 2024, allowing it to operate until July 2044.

It joined approximately 120 reactors worldwide that have safely continued operations beyond their original 40-year lifespan.

“Together with our business partners, we are proud of the achievement that ensures that Africa’s first and only nuclear power plant can now continue to operate safely into the future,” said Eskom Group Executive for Generation, Bheki Nxumalo.”

Eskom Chief Nuclear Officer Keith Featherstone said the Koeberg team had identified and implemented safety improvements derived from French and US nuclear experiences, reducing operation risks to levels only usually achieved by modern plants.

Koeberg Unit 2 was first synchronised to the grid in November 1985, more than a year after Unit 1. Its nuclear licence expires in November 2025.