Power utility Eskom on Tuesday highlighted the success of the upgrade of the second reactor (known as Unit 2) of its two-reactor Koeberg nuclear power plant, located north of Cape Town. On Monday (March 9), Unit 2 had accumulated 365 days of uninterrupted operation, with an average energy availability factor (EAF) of 99.4%. In practice, this meant that Unit 2 reliably delivered some 946 MW of electricity to the national grid.

“This milestone follows major upgrades to Unit 2, which returned to the grid on 30 December 2024 and has operated continuously since 9 March 2025,” pointed out Eskom Group Executive for Generation Bheki Nxumalo. “It showcases the strength of South Africa’s nuclear skills base. The successful installation of the new steam generators highlights the skill and dedication of the Koeberg team, engineers, technicians, operators, and support staff, who have worked tirelessly to ensure the unit runs safely and efficiently.”

Unit 2’s record for continuous operation was 454 days. This was set on January 18, 2022. The current run would not reach that marker, because the reactor was programmed to be taken offline on April 26, for scheduled maintenance. By that point, it should have reached 412 days of continuous operation.

“Although this figure has not yet been reached, the unit’s present performance already reflects strong reliability and operational stability,” affirmed Eskom. “It also stands as proof of Eskom’s ongoing success in reducing unplanned outages and strengthening the dependability of its generation fleet.”

Koeberg provided locally-generated electricity for Cape Town and the wider Western Cape province. All the other Eskom power stations, which burned coal, were located far to the northeast, and the electricity they generated had to travel to the Western Cape along transmission lines that extending well over a thousand kilometres. Koeberg thus provided a more stable and reliable power supply for the province. It also helped stabilise the grid and reduced the need to run more expensive power stations.

“Nuclear power also produces electricity without greenhouse gas emissions, supporting a cleaner environment while keeping costs affordable,” highlighted the utility. “Unit 2’s nonstop run is a reminder of Koeberg’s vital role in supporting economic growth, protecting jobs, and ensuring energy security for South Africa.”