CAPE TOWN – The return to service of Koeberg Unit 1, one of the two nuclear reactor units at South Africa’s only nuclear power station, has been delayed until the end of August 2025, following additional steam generator maintenance and technical evaluations. This extension marks a significant phase in Eskom’s long-term operation programme for the Koeberg Nuclear Power Station.
Koeberg Unit 1 was taken offline earlier this year for critical upgrades and life-extension work as part of the station’s broader long-term operation and maintenance schedule. The goal of the refurbishment is to extend the operational life of the nuclear power station by another 20 years—well beyond its original design lifespan.
Initially, Eskom had targeted July 2025 for the return of Koeberg Unit 1. However, following the identification of additional work needed on the unit’s steam generators, the schedule has been revised. Eskom now anticipates that the unit will only return to full service by the end of August.
In a statement released this week, Eskom confirmed that while the delay is unfortunate, it is necessary to uphold the utility’s stringent safety and quality protocols. The additional inspections and maintenance are aimed at ensuring the continued safe and reliable performance of the unit well into the future.
“While the updated timeline may cause concern, it is important to emphasize that this is part of our commitment to nuclear safety and long-term energy reliability,” said Eskom spokesperson Daphne Mokwena.
No Load Shedding Risk From Koeberg Unit 1 Delay
Despite the extension, Eskom assured the public that the delay in returning Koeberg Unit 1 to service would not lead to increased load shedding this winter. According to Mokwena, the winter outlook released on 5 May 2025 remains valid and unchanged.
“The revised return date for Koeberg Unit 1 will not increase the risk of load shedding. The outlook indicates that load shedding will not be required if unplanned outages remain below 13,000 MW,” she said.
This winter energy outlook takes into account the absence of Unit 1 and factors in projected energy demand across the country during the colder months. With power availability from other generation sources and improved grid management, Eskom remains confident in meeting the nation’s electricity needs.
Koeberg Unit 1 plays a critical role in South Africa’s energy mix. Together with Unit 2, the Koeberg station provides about 1,860 MW of baseload power, contributing significantly to the national grid with low-carbon electricity. Its location near Cape Town allows it to serve a key regional demand zone.
The current maintenance on Unit 1 is part of a multi-year strategy to extend the life of the Koeberg Nuclear Power Station by 20 years, a move that aligns with Eskom’s efforts to diversify energy sources and reduce reliance on coal-fired power stations.
South Africa’s energy roadmap, outlined in the Integrated Resource Plan (IRP), has included Koeberg’s long-term operation as a key component in securing stable, low-emission electricity supply in the years ahead.
The ongoing maintenance work includes replacement of three steam generators, pressure vessel inspections, structural upgrades, and comprehensive safety assessments. The steam generator replacement, in particular, is a complex and delicate task that involves high-precision engineering and adherence to international nuclear standards.
These upgrades are vital to ensuring Koeberg meets international nuclear safety protocols, as well as South Africa’s national regulatory requirements set by the National Nuclear Regulator (NNR).
“The safety of Koeberg and its ongoing operational reliability are non-negotiable,” Eskom emphasized. “We are working closely with the NNR and other oversight bodies to ensure that all work meets or exceeds the required safety benchmarks.”
Once Koeberg Unit 1 is fully returned to service, Eskom plans to initiate a similar long-term maintenance and upgrade process for Unit 2, which will also require several months of offline work. The two units are being refurbished sequentially to ensure that one unit remains operational at all times, maintaining a base level of nuclear generation during the upgrade period.
The completion of both units’ life-extension programmes will position Koeberg to operate safely and efficiently into the mid-2040s, offering South Africa an essential source of stable, low-emission power for decades to come.
As Eskom continues its efforts to modernize and stabilize the country’s electricity supply, the delay in returning Koeberg Unit 1 to service is a reminder of the complexities and importance of nuclear infrastructure maintenance. With safety and reliability at the forefront, South Africans can be reassured that long-term benefits are being prioritized over short-term disruptions.
source- EWN
