Eskom Reaffirms Koeberg Nuclear Safety Integrity Amid Public Concerns

Eskom has moved to reassure South Africans that the Koeberg Nuclear Power Station in Cape Town remains structurally sound, secure, and compliant with international safety requirements. This follows recent commentary suggesting that the utility was “flying blind” at Koeberg—a claim Eskom has rejected as inaccurate and misleading.

Safety Systems and Monitoring Fully Functional

In a statement issued on Wednesday, Eskom emphasised that all safety-critical systems at Koeberg are operational and under continuous monitoring. The utility said these systems are regularly upgraded to align with evolving global nuclear safety standards.

“Assertions that safety tests have been skipped or that Eskom is operating ‘blind’ undermine the rigorous engineering and regulatory processes that govern nuclear operations,” the utility stressed.

Structural Assessments of Containment Buildings

The containment buildings, which are the massive concrete domes designed to prevent any release of radiation in the unlikely event of an accident, have been subjected to rigorous structural testing. These included:

• Concrete core sampling

• Mechanical testing

• Independent verification by reputable institutions

Results confirm that the concrete material remains sound, stable, and within safety margins. Eskom added that the data collected through these assessments supports the long-term operational safety of the plant.

Integrated Leak Rate Test (ILRT) Results

The Integrated Leak Rate Test (ILRT), considered a cornerstone of nuclear safety, was recently completed on Unit 1 during Outage 127 in 2025. This test pressurises the containment building to simulate accident conditions and verifies its ability to remain leak-tight.

The results confirmed that Koeberg’s containment structures are fit for continued safe operation for at least another 20 years. The ILRT for Unit 2 is scheduled for Outage 227, in line with the mandatory 10-year testing cycle.

Eskom highlighted that the 10-year ILRT interval is consistent with global practices:

• In France, most nuclear plants use the same schedule.

• In the United States, the Nuclear Regulatory Commission allows extensions of the interval to 15 years, based on plant performance.

The utility stressed that there is no technical justification to reduce the testing cycle to every five years, as some critics have suggested.

Upgraded Monitoring Technologies

Eskom has made substantial investments in modern monitoring systems to strengthen safety oversight. During the 2023 and 2024 maintenance cycles, the utility fully refurbished and restored its containment monitoring equipment.

In 2025, Eskom introduced new technologies, including:

• Vibrating Wire Strain Gauges (VWSGs)

• Optical fibre sensors

These upgrades improve precision, redundancy, and reliability in detecting changes in structural behaviour, enabling early detection and preventative maintenance.

Looking ahead, Eskom confirmed that further modifications are planned in the medium to long term to enhance containment monitoring in line with global best practices.

Oversight and Regulation

Koeberg operates under the close watch of the National Nuclear Regulator (NNR) and remains compliant with international nuclear conventions. Eskom reiterated its “safety-first mindset”, emphasising that safety processes are transparent, accountable, and subject to stringent oversight.

“Eskom will continue to invest in its safety systems, infrastructure, and personnel to ensure Koeberg remains a reliable, secure, and compliant source of energy for South Africa,” the utility said.

Commitment to Public Assurance

Koeberg is Africa’s only nuclear power station and a critical contributor to South Africa’s energy grid. Eskom reassured the public that both Unit 1 and Unit 2 containment buildings are structurally sound and fully capable of performing their design functions.

With ongoing upgrades, rigorous testing, and international oversight, Eskom maintains that Koeberg is among the most closely monitored nuclear facilities on the continent.