The discovery of a previously-unknown geological fault zone – along with two earthquakes felt in Cape Town last week – has raised concerns over the safety of the Koeberg nuclear power station, the Sunday Times reported.
The newly-discovered Table Bay fault is closer to Koeberg than the epicentre of the earthquake in Tulbagh which killed 12 people in 1969.
The Council for Geoscience confirmed the discovery this week, but reassured there was no evidence to suggest the new fault is active or posed a seismic threat.
Council spokesperson David Khoza said this is not a newly-formed fault, but an ancient structure that has now been mapped.
“This fault has been present for at least the last 100 million, if not 500 million, years,” Khoza noted.
The epicentre of the earthquake measuring 6.2 on the Richter scale felt this past week was 1,600km south-east of Cape Town.
A subsequent tremor with a reading of 2.9 was measured in the Malmesbury area, with the Milnerton fault to blame.
The government has claimed Koeberg is designed to withstand earthquakes up to 7.5 on the Richter scale, however, thanks to giant built-in shock absorbers made of neoprene.
The worry over safety comes amidst this week’s arrival of the first of six new steam generators to be installed at the power station.
Koeberg has already completed 36 of the 40 years of its original design life, but Eskom plans to extend this by a further 20 years with the replacement generators.
The first three generators are to be installed at Unit 1 between February 2021 and June 2021, while the next three will be added at Unit 2 between January 2022 and May 2022.
More plans for nuclear
Despite the government’s pivot away from nuclear energy builds, Energy and Mineral Resources minister Gwede Mantashe has maintained that nuclear remains part of the country’s plans.
In May, the department said that it plans to expand nuclear capacity within the next five years.
Koeberg is currently South Africa’s only nuclear plant. A drive for additional facilities largely faded after the ruling party forced for president Jacob Zuma to step down in 2018.
Additional plants were widely considered unaffordable, and the nation’s economic slump has further dented the government’s ability to pay for them. Under Zuma, the government was pushing for a build of multiple nuclear plants in the country, which some analysts projected would cost the country over R1 trillion.
Speaking at the International Atomic Energy Agency (IAEA) general conference earlier this month, Mantashe said that South Africa has commenced consultations with suppliers of nuclear power reactors to provide costing and schedule information and possible ownership models, through a request for information for the 2,500MW programme issued in June 2020.