Koeberg Power Station near Melkbos as seen from the air. Picture: Sam Clark/African News Agency
Cape Town - Eskom has refuted claims by activists that sea air corrosion at the Koeberg containment building endangers the public and has said “the building is capable of withstanding the most severe accident”.
According to Koeberg Alert Alliance (KAA) spokesperson Peter Bekker, a recently released Eskom document revealed that 40 years of exposure to sea air at the Koeberg Nuclear Power Station had damaged the concrete of the containment buildings.
Bekker said: “At one stage the concrete containment dome was found to have cracked around the entire 110m circumference.
“The containment buildings are the outer shells of the reactor buildings, built as pressure vessels to withstand the pressure if the reactors inside them ever malfunction and therefore prevent harmful radiation being leaked into the environment.
“Where the chloride salts have entered, they have caused corrosion of the reinforcing steel bars, resulting in spalling and delamination of the concrete – it is even more alarming than we thought,” said Bekker.
The KAA has made two requests under the Promotion of Access to Information Act (PAIA) legislation but claims Eskom is stalling.
Bekker said: “Despite PAIA stipulating that a response must be as soon as reasonably possible, but in any event within 30 days, which can be unilaterally extended to 60 days, Eskom did not respond for 143 days.”
“Unfortunately this has been the pattern with PAIA requests made to Eskom. Not only was Eskom very slow to respond but what was eventually provided was heavily redacted, with about half the contents blacked out.”
Eskom released a statement on Friday in which it said it was fully cognisant of the risk of corrosion of civil structures at the Koeberg Nuclear Power Station, which is a result of the station being located in a corrosive environment.
The statement said: “Ongoing testing on the Koeberg containment buildings, which house the reactor and associated nuclear components, have proven the structures to be capable of withstanding the most severe accident. This containment programme has been managed closely since construction.
“The tests comprise quarterly and annual measurements to identify any abnormal movement such as expansions, settling, etc, visual inspections to identify physical degradation such as cracks, spalling, efflorescence and by performing the integrated leak rate tests (ILRT) on a 10-yearly basis,” said Eskom.
“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. The ILRT represents the worst case accident scenario and proves the containment buildings to be capable of withstanding the most severe accident.”
It 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. Eskom remains confident that the issue is fully under control.”
Cape Argus