The 40-year operating licence of Unit 1 of the plant outside Cape Town was due to expire this month, but in 2021 state-owned power utility Eskom applied for a 20-year extension to operations as part of efforts to end crippling power shortages.
Some environmental activists opposed the application during public consultations, citing safety concerns, which were also raised by the International Atomic Energy Agency (IAEA) during an inspection two years ago.
Issues flagged by the IAEA included corrosion and cracks to containment buildings housing the reactors, and dysfunctional monitoring systems. Eskom previously told Reuters it had addressed those issues.
South Africa's National Nuclear Regulator granted the extension of Koeberg Unit 1's licence subject to "safety improvements identified as part of the third periodic safety review," its Chief Executive Ditebogo Kgomo said.
The regulator is still assessing Eskom's application to extend the life of Koeberg Unit 2 by 20 years, but that unit's licence is valid until November 2025.
The regulator found that health, safety and environmental concerns raised during public consultations were adequately addressed by the licence conditions and Eskom's safety case, Kgomo said.
But community activists remain opposed to extending Koeberg's operations.
Peter Becker, a former civil society representative at the nuclear regulator, told Reuters the regulator's decision would probably be challenged in the courts.
Koeberg, currently the only operational nuclear power station on the African continent, was built under apartheid using French technology and connected to the grid in the 1980s. It has a capacity of around 1,900 megawatts, accounting for roughly 5% of the electricity generated by Eskom.
The IAEA plans to visit Koeberg again in September to discuss safety improvements.
The agency does not have the power to force nuclear power station operators to implement changes based on its recommendations, but in practice most regulators follow those suggestions, a spokesperson said.
