Koeberg Unit 2 back online, but what caused the ‘unplanned’ trip?

Eskom has announced that the newly refurbished Unit 2 at Koeberg nuclear power station was brought back online on Sunday evening following problems that contributed to the latest bout of Stage 3 load shedding at the weekend.

Koeberg Unit 2 went down last week due to a steam leak in its reheat system. This put the national grid under strain, resulting in rolling blackouts.

Delay

At the time, Eskom said the unit would be returned to service within 48 hours; however, after a brief return on 5 March, it has taken almost a week for the unit to be brought back online.

Eskom spokesperson Daphne Mokwena said the issue was resolved using the parastatal’s nuclear safety protocols “without compromising safety standards.”

“For more than four decades, Koeberg Nuclear Power Station has upheld an outstanding safety record, adhering to global best practices and stringent regulatory requirements.”

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Koeberg  

Koeberg is a key contributor to Eskom’s energy generation mix, stabilising the country’s electricity supply by providing reliable baseload power.

Meanwhile, Mokwena said Unit 1 is currently undergoing scheduled maintenance, including fuel refuelling and statutory tests, as part of the life extension process.

“These procedures are essential in ensuring the long-term reliability and safety of the unit.”

The station’s units 1 and 2 have undergone life extension exercises. In July last year, the National Nuclear Regulator (NNR) granted Eskom a licence to continue operating Koeberg Nuclear Power Station Unit 1 until 21 July 2044.

“As a result, Koeberg Unit 1 is expected to contribute over 930MW to the grid for another 20 years,” Mokwena said.

Unit 2

Given that Unit 2 is in a similar condition as Unit 1, the NNR was requested to extend its operations for another 20 years. Eskom awaits the regulator’s decision before its current licence expires on 9 November 2025.

“The recent Long-Term Operation (LTO) programme for Unit 2 included the replacement of three steam generators, extensive inspections, and refuelling activities, ensuring continued safe and efficient performance.”

While Unit 2 is back online and helps Eskom to keep load shedding suspended, Mokwena said Unit 1 is currently undergoing scheduled maintenance, including fuel refuelling and statutory tests as part of the life extension process.

“These procedures are essential in ensuring the long-term reliability and safety of the unit.”

Power station visits

Meanwhile, Electricity Minister Dr Kgosientsho Ramokgopa is expected to undertake site visits to Eskom’s Kendal and Lethabo Power Stations.

Eskom said this was in response to recent operational challenges and performance issues affecting these critical facilities.

“The visits aim to assess current performance levels, identify key constraints, and engage with power station management and staff to discuss strategies for improvement.”

While Eskom has warned that its planned maintenance outages will continue as it prepares for the upcoming winter season, Ramokgopa hopes that sabotage will not lead to load shedding during winter.

“Sabotage”

On Sunday, Ramokgopa said the problems at Eskom’s power stations were “non-technical related issues”.

“Clearly, we have become complacent. So it can’t be normal; it can’t be that we are reversing the gains that we have accumulated over time. I already know which candidate power stations are consistently dropping the ball.”

He suggested that recent load shedding could not just be attributed to the performance of units.

“There is something; there is a layer just below there. That’s why we need to ensure that we attend to these issues. One thing I will not do is manufacture excuses, so I will not mislead the country. We know what happened at Koeberg.

“We know what happened in Kusile, the two units that went out. We know what happened at Majuba. We know what happened at Camden. We’ll go and address that situation,” Ramokgopa said.

Eskom’s winter outlook is expected to be unveiled later this month.

ALSO READ: Load shedding remains suspended after Koeberg Unit 2 trips