Eskom’s chief nuclear officer at Koeberg nuclear power plant, Keith Featherstone on Thursday, confirmed that Koeberg Unit 1 — which was meant to return to service 90 days ago but has since experienced several delays — will return to service by 3 November. 

The outage currently underway at Unit 1 began on 10 December 2022, and includes maintenance, refuelling, and the replacement of three steam generators as part of the life extension project for the power station. The outage was originally expected to last for about six months. In May, Eskom reported a 45-day delay in returning the unit to service. 

Speaking during a media engagement organised by Western Cape Premier Alan Winde on Thursday, Featherstone said the steam generator replacement at Unit 1 was complete, and he was confident that the unit will be operational by 3 November. However, he said teams at Koeberg are working around-the-clock to return the unit to service before then. 

If Unit 1 returns to service in November, it will be more than 10 months since it last provided power to the grid.

The delays at Unit 1, Featherstone said, can be associated with the “unrealistic belief” that the steam generators could be replaced within the original time frame. 

“In a nutshell, we were overly optimistic in terms of what we thought we could achieve, and in hindsight, if we could have done it differently we would have scheduled a [much] longer time for this intervention,” he said. 

Koeberg’s licence for long-term operation 

Last month, Electricity Minister Kgosientso Ramokgopa expressed concern about the delays in Koeberg’s refurbishment, which could lead to higher stages of rolling blackouts continuing into 2024. The delays in returning Unit 1 to service were a particular headache for Ramokgopa, who was concerned that this was leaving the national grid short of 920 MW of power — equivalent to nearly one stage of rolling blackouts. 

Dr Kgosientsho Ramokgopa, SA Minister in the Presidency responsible for Electricity on 19 May, 2023. (Photo: Gallo Images/Darren Stewart)

Read in Daily Maverick: Electricity Minister Ramokgopa ‘extremely upset’ over delays at Koeberg

The Minister also warned that the prolonged delay in bringing Unit 1 back online, presented the “real danger” of an overlap between the maintenance outages of Unit 1 and Unit 2. If both units were out at the same time, the national grid could lose about 1,840 MW of power, Daily Maverick reported.

However, in an interview with Business Day, following Thursday’s media engagement, Featherstone gave assurances that there would be no overlap between the maintenance outages of the two units. 

Eskom is in a race against time to meet the strict requirements needed for a 20-year life extension of the power plant before Koeberg’s operating licence expires on 21 July 2024 — after which, both Unit 1 and Unit 2 must either be refurbished and relicensed or shut down. 

Eskom has applied to the National Nuclear Regulator (NNR) to have two separate operating licences for Koeberg — one for Unit 1 where the licence would expire on 21 July 2024, and the other for Unit 2 where the licence would expire on 21 July 2025. While a decision by the NNR is still awaited, this may be possible because units 1 and 2 were commissioned and commenced operation a year apart, in 1984 and 1985, respectively. 

Read in Daily Maverick: Further delay in life extension of Koeberg nuclear reactor worsens power outlook

Featherstone said the application for the licence separation had been submitted to the regulator, which had requested additional information, which Eskom was in the process of collating. 

Koeberg’s Unit 2 was scheduled to go offline also for the replacement of its steam generators in September this year, but is now due to begin on 7 November, after the return of Unit 1, said Featherstone. 

“We have estimated that we will need longer than what we originally planned, based on the experience from Unit 1, and will be taking all the lessons that we have learnt from this outage into the Unit 2 outage, to make sure we can do it as speedily as possible,” he said. 

Additionally, Featherstone said that Unit 1 is expected to undergo a further 200-day shutdown beginning on 21 July next year, for a reactor containment building leak test. 

Speaking to Daily Maverick on Friday, electrical engineer and energy analyst Chris Yelland explained that, if it takes the same amount of time as it took to replace the steam generators on Unit 1, the Unit 2 outage is likely to last until September 2024. The planned 200-day outage of Unit 1 in July 2024, means that both units may be offline simultaneously for about four months – unless Koeberg’s operating licence can be extended, he said.

Eskom chief nuclear officer Keith Featherstone confirms the outage of Koeberg Unit 1 to replace 3 steam generators, started mid-Dec 2022, is now extended (with 90% probability) by further 2 weeks to 3 Nov 2023 – i.e. 10,5 month shutdown instead of the initially planned 5 months.

— Chris Yelland (@chrisyelland) August 10, 2023

“They are hoping they learnt some lessons on Unit 1 and that they may be able to finish [the steam generator replacement] on Unit 2 quicker. But they haven’t even finished Unit yet… We have now been told it will be by 3 November, but there could be unexpected problems”, he said. DM