Koeberg 1 back online after milestone outage

20 November 2023

The pressurised water reactor was synchronised to the South African energy grid on 18 November after nearly a year offline for the replacement of the plant's three original steam generators, a prerequisite for the long-term operation of the plant.

Koeberg (Image: Eskom)

Completion of the longest outage in the plant's history is a "huge milestone" in its generational recovery plan and strategic objectives, Eskom said.

The steam generator replacement had originally been scheduled to take place in the first half of 2021, with similar work at Koeberg 2 to take place the following year. However, the schedule was put back due to concerns about the tight supply of electricity in South Africa. Koeberg 1's maintenance outage began on 10 December 2022 and had been expected to last about six months.

Koeberg 2 - which continued to operate for the duration of unit 1's outage - will begin an outage for similar work once unit 1 is stable and all the required commissioning tests are complete - but lessons learned from unit 1's outage will enable the duration of unit 2's outage to be reduced, Eskom said.

"This milestone is as a result of the hard work and determination of the Eskom employees, suppliers, and contractors who have had to endure a long and challenging outage in the Koeberg Power Station's history. I commend everyone involved on the project for ensuring that the unt was returned to service safely," said Eskom Group Executive for Generation Bheki Nxumalo.

Although Koeberg 1 has now been reconnected to the grid, South Africa's electricity system remains constrained: on 19 November, Eskom announced that loadshedding measures would continue with 16,264 MWe of its generating capacity in unplanned outages. Some 6,606 MWe of capacity was offline for planned maintenance.

Koeberg, with a combined capacity of 1,860 MWe, is the only operating nuclear power plant on the African content. Unit 1 entered commercial operation in 1984 and unit 2 in 1985, and the units are currently licensed to operate until 2024 and 2025, respectively. Eskom submitted its application to extend the operating life of the two-unit plant by additional 20 years beyond its initial 40-year operating life to South Africa's National Nuclear Regulator in May 2021. Public hearings in connection with the application are scheduled for February 2024.

Researched and written by World Nuclear News