Eskom has taken unit 1 at nuclear power station Koeberg offline due to a leak, and has expedited planned routine maintenance, with the unit set to return to service in May 2021.
The power utility did not indicate if taking the offline would contribute to load shedding. Eskom assured there was no risk to the plant, personnel or the environment by the decision.
According to a statement issued by Eskom on Monday, there had been an increasing leak rate at one of three steam generators at Unit 1.
"Although the leak rate was well within the safety limits, a conservative decision was made to take Koeberg unit 1 offline for repairs," the statement read.
Eskom will also conduct routine maintenance on the unit as well as refueling - these were originally scheduled for the start of February.
"The steam generator is a tubular heat exchanger which mechanically dries the steam produced during the nuclear power generation process. Shutting down the plant takes several hours, and the process is still underway - once shut down, fuel will be unloaded from the reactor core to enable maintenance activities to be conducted, and the cause of the increased leak rate to be addressed," Eskom said.
Last year Eskom introduced Stage 4 load shedding after Unit 1 tripped. The fault related to a seawater pump which cools the reactors, Fin24 previously reported.
The power utility returned unit 2 of Koberg to service in October 2020, following routine maintenance and refuelling which took just over two months and required assistance of 32 international specialists. Eskom said on Monday that unit 2 is still operating safely and at full capacity.
Following an earthquake in November 2020, the power utility issued a statement assuring the public that the nuclear power station was still operating safely as the tremor was below the plant's design limits. No damage was found or reported after an inspection of the plant.