The generators are housed alongside the reactor vessel, which heats water to 320°C while keeping it in a liquid state using a pressuriser.
Once the water enters the generators, it turns to steam which spins turbines capable of producing about 1,940 megawatts of electricity when both reactors are operating.
“Steam generator replacement is the most intensive and most expensive project a nuclear power station can undertake. Several stations internationally have done so successfully,” Eskom said on Wednesday.
The state-owned power utility said extending Koeberg’s lifespan was “the best investment into sustainable and less carbon-intensive electricity generation infrastructure Eskom can buy”.