Name of the Project
Koeberg nuclear power plant steam-generator replacement (SGR) project.

Location
Western Cape, South Africa.

Project Owner/s
State-owned power utility Eskom.

Project Description
The current steam generators in Unit 1 and Unit 2 at the Koeberg nuclear power plant (NPP) have been in operation since 1984 and 1985 respectively. The aim of the project is to extend the design life of the NPP by 20 years to 2045.

The project involves the replacement of all six steam generators for units 1 and 2.

The SGR project involves the design, manufacture and installation of three steam generators in each of the Koeberg power plant's two operating units, as well as safety analyses and studies to comprehensively demonstrate the plant's design integrity, with no adverse impact on public and worker safety and health or the environment, including the enhancement of nuclear safety.

The new generators will incorporate modern design features for easy maintenance and inspections and improve heat-transfer efficiency, leading to an overall efficiency improvement of Koeberg.

The installation of the generators will be conducted during the scheduled refuelling, inspections and maintenance outages of the two units at Koeberg power station. Eskom is on track and progressing according to plan for installation during the next unit 1 and 2 outages.

The other major components of the life-extension plan include:

• a refuelling water storage tank replacement project, completed in 2019.
• the Unit 2 reactor pressure vessel head replacement.
• the replacement of feed-train components on the conventional power plant, which is conducted during maintenance outages.
• the ongoing Koeberg safety aspects of long-term operation assessment. The assessment is designed to provide the equipment-ageing management confirmation to enable the Koeberg plant to operate beyond its original life span of 40 years to at least 60 years.

Capital Expenditure
The cost of the project is estimated at R25-billion.

Planned Start/End Date
Not stated.

Latest Developments
Eskom has announced a delay to the return of Koeberg Unit 1 from another extended maintenance outage, but insists that the risk of loadshedding this winter has not increased as a result.

The unit was shut early in the year for the second phase of its long-term operation maintenance programme, which was a requirement of the unit’s 20-year life extension granted by the National Nuclear Regulator (NNR) last year.

The outage was meant to last 150 days, and the unit was initially scheduled to return to service in July.

However, on July 15 Eskom announced that Unit 1 was now scheduled to be back online only by the end of August, following inspections that revealed tube defects.

The utility also announced the conclusion of other maintenance activities, including the legally required ten-year Integrated Leak Rate Test (ILRT), where the reactor building was pressurised over 72 hours and its leak rate and structural integrity monitored.

“The ILRT confirmed the robustness and leak-tightness of Unit 1’s containment structure, further reinforcing its safety in line with international standards,” the utility said.

Meanwhile, Eskom has insisted that the delayed return of Unit 1 does not increase the risk of loadshedding, which has waned materially since 2023 when power cuts were an almost daily or twice daily occurrence.

In March, Eskom resorted to Stage 3 loadshedding after Koeberg Unit 2 unexpectedly tripped, having been synchronised to the grid again on December 31. This, following the unit’s own extended and delayed outage, which was also undertaken in a bid to secure a licence to operate for another 20 years.

The NNR has not yet pronounced on the long-term operation of Unit 2, but is expected to do so in the coming months.

Eskom has reported that Unit 2 remains fully operational, generating up to 946 MW, with a year-to-date energy availability factor of 99.38% as of the end of June 2025.

Key Contracts, Suppliers, and Consultants
Framatome (main SGR contractor); General Electric (modifications to the balance of plant or secondary turbine system); and Jacobs Engineering (balance of plant hardware changes).

Contact Details for Project Information
Eskom media desk, email mediadesk@eskom.co.za.