Big questions about Koeberg nuclear power station

Eskom experienced an unexpected shutdown of its Unit 1 generator at Koeberg Nuclear Power Station on 11 September 2024, raising concerns over safety at the power plant and prompting one environmental organisation to appeal the unit’s life extension.

Particularly concerning is that Eskom kept the shutdown quiet until the media exposed it. MyBroadband asked Eskom for further details surrounding the unexpected shutdown, but it hadn’t answered our questions by publication.

While Eskom said it followed protocol in shutting down the unit, energy expert Chris Yelland slammed the power utility and the NNR for a lack of transparency regarding the shutdown.

“Five days after Koeberg Unit 1 has been shut down due to a fault on Wednesday last week, at the same time that Koeberg Unit 2 was also offline, Eskom finally admits the shutdown after this was being exposed in the media and public domain,” said Yelland.

“Coming five days after Unit 1 went offline while Unit 2 is offline too, shows a complete lack of transparency and a level of contempt for the interests and concerns of the public by Eskom and the National Nuclear Regulator.”

He shared feedback from Eskom, which explained that the unit was shut down conservatively and safely after one of its block valves failed its three-monthly routine test.

“The unit was shut down in order to restore redundancy of the steam pressure relief system in line with the operating technical specifications,” the power utility said.

“The intervention has been completed, and the unit is in the process of being safely returned to service. All stakeholders who were required to notify were informed as per the stringent protocols.”

Following the breakdown, the South African Faith Communities Environment Institute (SAFCEI) has appealed to the Department of Energy to overturn the decision to extend the unit’s life until July 2044.

“SAFCEI contends that the extension of life decision is fatally flawed, citing the NNR’s failure to perform its oversight role properly with regard to significant safety risks, and Eskom’s egregious delays in performing maintenance that is critical to safety,” it said in a statement.

It says the International Atomic Energy Agency found signs of significant safety issues in Koeberg’s reactors, with SAFCEI executive director Francesca de Gasparis stating that both of the plant’s reactors have “well-documented structural issues.”

The environmental organisation said Eskom has been aware since 2015 that critical repairs to the concrete containment buildings are required.

It further alleged that, despite being described as being in an “advanced state” of disrepair, the only practical solution — installing impressed current cathodic protection — was not done before granting its life extension.

However, it noted that the National Nuclear Regulator’s (NNR’s) licence conditions state that this installation must happen by 2025.

“Given Eskom’s track record of delays, and for the protection of public safety, SAFCEI argues that the extension of life licence should be set aside and not considered again until these serious safety issues are addressed, including that the ICCP system is fully installed and functional,” SAFCEI said.

De Gasparis added that the lack of a functional monitoring system at Koeberg presents a severe concern for public safety.

“We demand that any major safety concerns identified by IAEA be fully completed before any further extension is considered,” she added.

According to a Mail and Guardian report, the Koeberg Alert Alliance is also concerned over safety at the power station, particularly considering Eskom’s silence over the recent breakdown.

It said the recent unexpected shutdown raises concerns about the sustainability of relying on ageing nuclear infrastructure.

It also questioned whether necessary upgrades and safety improvements for long-term operation were fully addressed prior to extending the unit’s licence.