Cape Town - In what Eskom has described as a major milestone towards the completion of the steam generator replacements at Koeberg Power Station’s Unit 1, the first steam generator has been removed from the containment building and placed in the storage building erected to house it.
While Eskom on Tuesday said this was a significant accomplishment for the Koeberg team, the original return to service date for the unit was no longer achievable following delays.
“It is a great relief to have reached this milestone as the steam generator replacement project has experienced numerous false starts in previous outages and some unexpected challenges during the execution in the current outage to get to this point in the project,” Eskom said.
Each steam generator is 22m tall, equal to a 6 story building, with a diameter of 4.5m at the top half and 3.5m at the bottom half and they each weigh over 320 Tons. To compare, a Boeing 747 only weighs between 150 and 220 tons depending on its configuration.
“From here on all that is needed, is to take out the other two that are ready for lifting and install the three new steam generators.”
‘This however involves a complex sequence of activities including performing the six critical welds that joins the steam generators to the primary system piping and installing new thermal insulation over the whole steam generator surface and all the pipes that were worked on.
“We still need to complete the maintenance activities scheduled for the outage, commission all the systems, refuel the reactor, and return the unit to service.
Due to the delays that have already been experienced, the original return to service date for the unit is no longer achievable. Although every effort is being made to reduce the impact, we are currently running a few weeks late.
The Generation production plan is being optimised to minimise as far as possible the impact of the projected delay on the system.”
Unit 2, which continues to operate while Unit 1 is in this extended outage, will undergo a similar long outage to replace its three steam generators, Eskom said.
“In accordance with the safety analysis that was performed and submitted to the National Nuclear Regulator in support of the application to extend the plant life by 20 years, the steam generators are the last large component replacements that are needed to ensure Koeberg can operate safely for the requested additional period of operation,” Eskom said.
Cape Times