Eskom says it is investigating the cause of a turbine trip that resulted in unit 1 at Koeberg nuclear power station being taken offline in the early hours of Thursday morning.Koeberg, South Africa’s only nuclear power station, supplies about 5% of the country’s total electricity and plays a critical role in reducing load-shedding and stabilising the national grid.The turbine trip comes as workers at Koeberg were exposed to low doses of radiation during maintenance incidents in July. However, the electricity and energy department and Eskom said the exposure was within accepted industry safety standards. Three alerts of rising radioactivity levels were triggered at the Koeberg station in the Western Cape during routine surveillance, which were controlled in the station. High levels of exposure to radioactivity can cause health complications. SafetyLast year Eskom dismissed fears about Koeberg’s structural integrity and safety after concerns about the containment structure of the plant’s unit 2 generator. The country plans to expand its commercial nuclear capability with new stations. Koeberg’s unit 1 was last taken offline for major maintenance, which was completed in October 2025. “Since then, the unit has operated reliably, with generation temporarily reduced in August 2026 as a precautionary measure due to seawater intake challenges linked to a sardine influx near the station’s cooling water system,” Eskom said. Regarding the latest development, the utility said “nuclear safety was never compromised” and there was no risk to employees, the public, or the environment. “Koeberg’s protection and monitoring systems functioned as designed, ensuring the unit always remained safe. The removal of unit 1’s capacity from the grid poses no risk to the national electricity supply. Eskom has sufficient generation capacity available, and the grid remains stable and secure. “The cause of the turbine trip is under investigation. Eskom remains committed to transparency and will provide updates as new information becomes available.”With Sinesipho SchrieberBusiness Day