- Eskom reports that after successfully completing the refuelling process, Unit 1 at Koeberg Nuclear Power Station has begun its start-up sequence and is currently undergoing hot commissioning — an essential stage in preparing the unit for full operation.
- Once back online, it will deliver 930MW to the national grid, bolstering the country’s electricity supply.
- In addition, Kusile Unit 6 which was introduced to the grid in March this year, is expected to be fully commissioned by the end of the month, adding another 800MW.
Unit 1 has been down since September last year after one of the isolation/block valves failed its three-monthly routine test. Eskom recently submitted a license change request application to the national nuclear regulator for the construction of a spent fuel cask storage area on the Koeberg nuclear power plant site. Concerns have been raised over the ageing containment buildings which have degraded over the last 40 years. Read more
Related news: Eskom assures that safety structural steps have not been skipped at Koeberg
Initially expected to return to service by July 2025, the unit is now scheduled to be back online next month. During scheduled detailed eddy current inspections in July — a non-destructive testing method used to detect cracks, corrosion, or wear in the metal tubes of steam generators — defects were identified on four tubes among several thousand tubes inspected, across two of the newly installed generators.
Related news: Koeberg Unit 1 shut down after isolation/block valves failure
Eskom immediately carried out an advanced automated process to address the four tube defects, supported by specialised international teams working alongside local experts. These critical repairs have now been successfully completed to uphold the highest safety and quality standards.
Related news: Eskom ordered to pay Framatome close to R1 billion in over Koeberg steam generator contract dispute
Importantly, the major maintenance activities, which included the legally required 10-year Integrated Leak Rate Test (ILRT), where the reactor building was pressurised over 72 hours and its leak rate and structural integrity were monitored — were successfully completed. The ILRT confirmed the robustness and leak-tightness of Unit 1’s containment structure, further reinforcing its safety in line with international standards.
Related news: Where did the R1 billion compensation claim paid by Eskom go?
Author: Bryan Groenendaal
1 Comment
Eskom should not pat themselves on the back for returning Unit 1 to service more 3.5 months late for a planned 5 month outage. This is the umpteenth time there has been an outtage overrun at Koeberg. Don’t believe that plugging 4 tubes on a steam generator delayed the outage by 3.5 months. It takes a day or two to do that.
Eskom’s CEO, head of generation and the power station manager were warned about matters that could and eventually did delay the just finished Unit 1 outage, yet nothing was done. The same thing happened during the ill-fated steam generator replacement project, with dire consequences for project duration and cost overruns.
The parliamentary committee on energy and electricity has proven itself equally ineffective at holding Eskom to account for these continuous outage slippages.