Cracking Koeberg no cause for alarm, says Eskom

Eskom and the country’s nuclear regulator say cracks, caused by sea-air corrosion, in the concrete of buildings housing Koeberg’s reactors are no cause for concern.

The sea air has corroded the concrete housing Koeberg’s reactors, but Eskom and the country’s nuclear regulator say it’s no cause for alarm.

According to the anti-nuclear activist organisation, Koeberg Alert Alliance (KAA), one of the concrete containment domes was found at one stage to have cracked around the entire 110 meter circumference. Both domes housing Koeberg’s two reactors were founded to have suffered corrosive damage.

KAA said a Koeberg insider had alerted them to the structural problems at the plant. Peter Becker, of KAA, said that last August they had made two requests for information from Eskom under the Promotion of Access to Information Act (PAIA) legislation.

“The first was a request for the latest report on chloride damage to the concrete reactor containment domes, and the second was related to damage to the stainless steel used in the structures of the plant. Not only was Eskom very slow to respond but what was eventually provided was heavily redacted, with about half the contents blacked out. Eskom are aware that to challenge these redactions in court requires a budget of hundreds of thousands of rand, which most civil society organisations cannot afford,” he said.

Mr Becker said that the containment buildings were the last line of defence against harmful radiation being released into the environment should there be a breach in the reactors.

Melkbosstrand resident Sarah McKay fears Eskom is not putting the safety of surrounding residents first.

“It’s very worrying hearing that the infrastructure has physical damage to it. What happens during another earthquake or another natural disaster? The residents that live in Melkbos, and even surrounding neighbourhoods, should be very concerned about what is happening there,” she said.

Melkbosstrand Ratepayers’ Association chairwoman Smokie la Grange said she was aware of Mr Becker’s concerns.

“From my personal perspective, I live very close to the power station, and I intend to stay here. I have a great deal of respect for the engineers and all members of staff who work there. Bear in mind that modifications to the plant and safety regulations are monitored by national and international agencies,” she said.

In a statement, Eskom said it was aware of the risk posed by corrosion at the plant and ongoing tests were done on buildings housing the reactors.

“The tests have proven the structures to be capable of withstanding the most severe accident. The tests are done quarterly and annual measurements to identify any abnormal movement or physical degradation, such as cracks, spalling, efflorescence and by performing the integrated leak rate tests (ILRT). The results of the ILRTs have shown conclusively that the design functions of the containment buildings are met. The test results of the ILRT were also compared with international plants of similar design and it was found to be in-line with industry norms,” Eskom said.

Repairs were done to the concrete where corrosion had caused small cracks, Eskom added.

“A long-term solution to prevent rebar and tendon corrosion due to chloride ingress is the implementation of an induced cathodic protection system. This is being implemented as previously recommended by a team of international civil engineering experts,” said Eskom.

According to the National Nuclear Regulator (NNR), the structural integrity of the containment structures at Koeberg currently complies with the relevant safety tests required by the NNR.

NNR CEO Dr Bismark Tyobeka said that as the authority body responsible for overseeing nuclear safety regulation in South Africa, the NNR was committed to enforcing nuclear safety rules and requirements in support of protecting people, property and the environment from nuclear damage.

“The Koeberg nuclear power station is continuously monitored to ensure that the operation of the plant complies with nuclear-safety requirements at all stages of operation. With the information at our disposal, we can confirm that despite the concrete cracking and delamination observed on the outer surface, the containment structures remain currently effective for protecting the environment from radiation during accident conditions,” said Dr Tyobeka.

Members of the public were encouraged to report any nuclear safety concerns to the NNR. Visit, email or call 082 535 5365 to do so.