Eskom resynchronised Koeberg Power Station’s unit 2 generator to the grid at 07:00 on Saturday, 18 February 2023.

The unit tripped at around 22:00 on Friday, 17 February. The state-owned power utility said the unit would ramp up to full load over the course of the day.

“Around 22:00 on Friday evening, 17 February 2023, the turbine on Unit 2 of the Koeberg Nuclear Power Station tripped while replacing a failed electronic turbine protection module,” Eskom said.

“The reactor responded to the turbine trip by reducing power and it remained critical, as designed, with no nuclear safety consequences.”

The unit had been supplying power to the grid for an uninterrupted 145 days when this occurred.

Eskom said the generator returned to service and synchronised to the grid by Saturday morning.

The tripping of Koeberg’s unit 2 generator and breakdowns at several other power stations forced the power utility to implement stage 4 load-shedding on Friday, 17 February.

Eskom has confirmed that stage 4 load-shedding will remain until further notice.

Before upping rotational power cuts to stage 4, South Africa had been subjected to an alternating schedule of stage 3 and 4 power cuts during the week, lowering to stage 2 and 3 over the weekend for nearly two weeks.

Eskom explains Koeberg unit trip (mybroadband.co.za)