Good news about load-shedding — Koeberg nuclear power station unit to come online soon
Eskom’s Koeberg power station could soon add 920MW to the grid as its Unit 2 generator’s start-up is now in progress, the power utility has told MyBroadband.
However, the unit would not be added to the grid by the end of June as planned, and it is unclear whether Eskom will be able to return the full 2,500MW it promised.
“The current Koeberg Unit 2 Outage has progressed safely, and the planned work has been completed, with the start-up of the unit now in progress,” the power utility told MyBroadband.
“The unit is currently expected to return to service by mid-July and will require about ten days to reach full power.”
“This work included a massive scope of maintenance work as well as a number of plant refurbishment modifications required for Koeberg’s life extension,” it added.
Eskom explained that it achieved a significant step during the planned outage — replacing Unit 2’s reactor pressure vessel cover.
It said replacing the cover was a prerequisite for Koeberg’s life extension.
“In addition, following the deferral of the Steam Generator Replacement project, a full suite of steam generator inspections were required to be performed to confirm the operability of the existing steam generators,” Eskom said.
The power utility explained that several factors increased the duration of the outage.
“The international nuclear experts for this work required a month to mobilise, and these inspections have impacted on the overall outage duration,” it said.
“During the plant commissioning and start-up phase, a number of defects emerged which had to be attended to and directly impacted the outage duration as each needs to be resolved before the plan can continue.”
Eskom explained that this is done to ensure that the unit runs safely and reliably when it goes back online.
It added that, as a result, the commissioning phase is taking longer than expected and remains susceptible to further defects during start-up.
During its State of the System update in May 2022, Eskom said it planned to bring three big generating units — two at Kusile and one at Koeberg, together representing 2,500MW — back to the grid by the end of June.
It took one of the Kusile units offline to modify and correct design defects, while the other required repairs to its flue gas desulphurisation system.
The power utility announced it was taking Koeberg’s Unit 2 generator offline in mid-January 2022, saying it would take five months for refuelling and scheduled maintenance.
Eskom expected to return Koeberg Unit 2 to service in mid-June after replacing its three heat exchangers.
However, Eskom had not completed the necessary containment building, so it postponed these modifications.
Koeberg is South Africa’s only nuclear power station and contributes significant amounts of electricity to the grid, with each of its two generators producing 921MW.
With the current power situation in South Africa, adding Koeberg’s Unit 2 to the grid could go a long way to help reduce power cuts in the country.
Eskom increased rotational power cuts to Stage 6 on Tuesday, 28 June 2022. The power utility was forced to increase the level of load-shedding due to a lack of generating capacity and ongoing protest action at its power stations.