South Africa: Eskom Dismisses Reports Of Radiation Leak At Koeberg Nuclear Plant

South Africa’s state-owned power utility, Eskom, has dismissed reports alleging a radiation leak during routine maintenance at Unit 2 of the Koeberg Nuclear Power Station, saying there was no release of radioactive material beyond the plant’s containment structures.

“At no stage was there any release of radioactive material beyond the containment structures, and there was no risk to surrounding communities or the environment,” Eskom said in a statement.

The utility added that no iodine tablets were administered to employees and that there was no impact on workers, the public or the environment.

According to Eskom, highly sensitive radiation monitoring equipment detected two brief, localised airborne radioactivity events inside a controlled work area within the Unit 2 containment building during scheduled steam generator inspections on July 2 and July 7, 2026.

It said the airborne radioactivity remained confined to the designated work area and was managed in accordance with established radiation protection procedures.

The utility said the incident had no impact on nuclear safety, plant operations, maintenance activities or the planned completion of the outage in November 2026. Unit 1 remains in full operation.

Eskom classified the incident as Level 0 (No Safety Significance) on the International Nuclear and Radiological Event Scale (INES), the lowest possible rating, and said it notified South Africa’s National Nuclear Regulator (NNR) in line with regulatory requirements.

The company said it remained committed to maintaining the highest standards of nuclear safety, regulatory compliance and operational transparency.

Eddy Current Testing

Eskom said Eddy Current Testing (ECT) is a non-destructive inspection technique used to assess the condition and wall thickness of steam generator tubes, helping detect early signs of wear that could affect plant performance or safety.

The inspections are carried out using robotic probes inserted into the steam generator tubes. During the inspections, a minute quantity of microscopic oxide particles, known in the nuclear industry as “crud”, became airborne within the enclosed work area.

The utility said such minor airborne particulate events are a well-understood phenomenon during steam generator inspections at pressurised water reactors and are effectively managed through established containment, ventilation and radiation monitoring systems.

Safety systems operated as designed

Eskom said the affected work area was protected by multiple safety measures, including physical containment barriers, High-Efficiency Particulate Air (HEPA)-filtered ventilation operating under negative pressure, continuous airborne radiation monitoring through Constant Air Monitors (CAMs), and comprehensive personnel protection programmes.

The monitoring equipment automatically detected the increase in airborne radioactivity, triggering standard safety procedures. Inspection work was temporarily halted while the area was secured, ventilation systems removed the airborne particles, and radiological assessments were completed before work resumed.

Eskom said the incident remained fully contained within the controlled work area, with no release of radioactive material into the environment.

The utility said the event demonstrated the effectiveness of Koeberg’s defence-in-depth safety systems, which detected and contained the airborne radioactivity as designed while allowing maintenance activities to continue safely.