Last test for the upgraded Koeberg apparatus

Eskom announced that after installing new steam generators for the past year, Unit 1 at its Koeberg Nuclear Power Station will be going through its final test.

On Saturday, December 30, 2023, a full load rejection test will be conducted to "verify and demonstrate" the unity's capacity to supply its auxiliary load and resume steady state conditions in the event of an abrupt disconnection from the national grid.

The South African Grid Code (SAGC), according to Eskom, mandates that units be tested if any changes are made that might affect their ability to comply with the requirements of the SAGC.

“As part of the steam generator replacement project, significant changes were made on numerous plant components, including control systems,” Eskom said.

“Therefore, in line with SAGC, the response of the unit to a full load rejection incident needs to be tested and verified.”

Given that it had completed a number of successful commissioning tests prior to this final obstacle, Eskom expressed confidence that the test would be successful.

Eskom stated, "The Koeberg team is prepared to respond and will work towards safely returning the unit back to service as soon as possible, in the unlikely event that the test fails and results in a unit trip."

On November 18, 2023, the electricity provider synchronized Unit 1 with the grid once more. Since December 2022, it has been unavailable due to an extensive, protracted restoration and refueling project.

Eskom experienced several delays in its original plan to restart the unit by June 2023.

Unit 2 was taken offline for renovations on December 11, 2023, subsequent to Unit 1's return to the grid.

Eskom had learned from the errors and shortfalls associated with Unit 1, according to Energy Minister Kgosientsho Ramokgopa, who also requested that the project team adhere to the schedule for Unit 2's return.

Koeberg has been Eskom's most dependable power plant during its nearly 40 years of continuous operation, offering a peak capacity of roughly 1,940MW when both units are operating.

Even so, during the next few years, it is unlikely that the plant will run both Units 1 and 2 simultaneously, even if their renovations are successful.

After Unit 2's steam generator replacement is finished, each of the units will experience a 200-day outage, according to the National Nuclear Regulator.

The purpose of these outages is to test containment pressure and make sure the concrete structures that house the units are safe.

This is a significant roadblock in Eskom's efforts to prevent the power plant from operating past its authorized lifespan prior to the extension, as these extra outages will happen even if Koeberg's license is not decoupled.