Eskom, the company behind the project is considering building Africa's biggest unit at Thyspunt, very near Jeffrey's Bay. Experts say waves and local economy will be affected.
Also, fishermen fear the water could become unsuitable for squid spawning.
The authorities are studying the environmental impacts of a nuclear power plant in Supertubes and there are other two areas being analyzed: Duynefontein (Koeberg) and Bantamsklip (between Danger and Quoin).
The area around Jeffrey's Bay has significant archaeological and palaeontological heritages which would be seriously threatened with the biggest nuclear power plant of Africa.