Eskom has announced a major milestone in the replacement of steam generators at Koeberg Power Station’s Unit 1. The first steam generator has been successfully removed from the containment building and placed in a newly built storage facility.
This achievement is significant for the Koeberg team. However, Eskom noted that the original date planned for returning Unit 1 to service can no longer be met due to delays in the project.
Eskom said, “It is a great relief to reach this point. The steam generator replacement project faced many setbacks during previous outages and unexpected challenges in the current outage.”
Each steam generator is very large. It measures 22 meters in height — about the size of a six-story building. The top half has a diameter of 4.5 meters, while the bottom half is 3.5 meters wide. Each unit weighs over 320 tons. To put this in perspective, a Boeing 747 weighs between 150 and 220 tons depending on its setup.
Eskom explained the next steps: “We need to remove the other two steam generators, which are ready to be lifted, and install three new ones.”
This work involves a complex process. It includes completing six critical welds that connect the steam generators to the primary system piping. New thermal insulation must also be installed on the steam generators and all the pipes that were worked on.
The team still has several tasks to finish before the unit can return to service. These include completing maintenance scheduled for the outage, commissioning all systems, refueling the reactor, and restarting the unit.
Due to delays, the original return-to-service date cannot be met. Eskom said they are working hard to reduce the delay but currently expect to be a few weeks behind schedule.
To manage this, the generation production plan is being adjusted to minimize the impact of the delay on the power system.
Unit 2 is still operating while Unit 1 remains offline. Eskom said Unit 2 will also have a long outage in the future to replace its three steam generators.
According to Eskom, replacing the steam generators is the last major step needed to safely extend Koeberg’s operating life by 20 years. This is part of the safety analysis submitted to the National Nuclear Regulator.
