Koeberg, South Africa’s sole nuclear power plant, is a symbol of the country’s past nuclear prowess. Now, the country is looking to a new future powered by nuclear. However, a series of accidents at Koeberg this year has reignited worries over whether the operator and regulatory agency are fit for purpose as the country seeks to expand its fleet of nuclear reactors.
In July, 150 Koeberg workers were exposed to radiation and reportedly took iodine tablets, although South Africa’s National Nuclear Regulator (NNR) insisted that 245 workers only underwent precautionary measures. Eskom, a state-owned public utility that runs the plant, says that only a small amount of uranium dioxide was released, along with cobalt-58. James Larkin, past head of the International Nuclear Security Education Network, said the radiation these workers received was equivalent to a dental x-ray.
A week earlier, the NNR reported three other releases of radioactivity that occurred in June and July at Koeberg. As a result, a former nuclear insider and independent experts are growing uneasy about Eskom and NNR’s assurances that they can maintain high safety standards as South Africa aims to generate 5.2GW of nuclear energy via conventional nuclear power and a few small modular reactors by 2039.
Koeberg was commissioned in 1984 with twin 970MW pressurised water reactors with an original design life of 40 years. In 2019, the plant’s life was extended by another 20 years.
Dawid Serfontein, a nuclear engineer at South Africa’s North West University, says it is normal for equipment to degrade during nuclear plant life-cycle extensions. During steam generator repairs, the phenomenon of localised, restricted stress corrosion cracking in newly fitted components is a documented engineering risk in many life-extension projects worldwide, he notes. However, recurring ventilation failures that led to the release of radioactive material earlier this year indicate operational strain. ‘Truthful auditing is critical if the country wants to garner public trust in the nuclear buildout drive,’ he say.
‘There’s a whole culture of secrecy around nuclear power in this country,’ Peter Becker tells Chemistry World. Becker, a spokesperson for the Koeberg Alert Alliance watchdog, is a former member of the NNR. He was fired by South Africa’s energy minister in 2023 for expressing persistent concerns about the safety of the country’s only nuclear power plant before winning a court case for wrongful dismissal.
Becker says that South Africa has got a ‘very poor’ record of building large power stations and that there is a ‘problematic, cosy relationship’ between the regulator and Eskom. He adds that Eskom no longer has enough people with the technical depth of experience to operate Koeberg satisfactorily.
The board of the NNR is currently appointed by Gwede Mantashe, a very pro-nuclear energy minister, Becker adds. That directly contradicts the 1994/1996 International Atomic Energy Agency (IAEA) nuclear safety convention which explicitly mandates the independence of regulatory bodies, he says. And in a 2013 report, the IAEA found that while the country’s nuclear regulatory framework was robust, it flagged that the nuclear regulator had insufficient independence. ‘The NNR has never said no to Eskom,’ Becker says.
The failures that led to the release of radioactive material in June and July were a result of the fact that many skilled nuclear workers have left South Africa for the UAE’s Barakah Nuclear Energy plant, Becker says. ‘I know somebody who works [at Barakah] who used to work at Koeberg and he tells me approximately 150 people who used to work at Koeberg are now working there,’ he says.
The skills flight to foreign nuclear plants like Barakah is a concern, Serfontein agrees. Young nuclear engineers can be trained on the job and catch up on the technicalities, he says. However, replacing 25 years of plant-specific institutional memory is a high bar. ‘Yes, short-term safety metrics at Koeberg remain acceptable, however the loss of senior engineering skills creates ongoing, long-term risks for routine maintenance schedules,’ he says.
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