The alliance said it's concerned about the impact of seismic activity at the Koeberg nuclear plant outside Cape Town.

Peter Becker of the Koeberg Alert Alliance said, "I've seen recently in the press, Eskom saying, "there is no risk at Koeberg", obviously that is simply a lie."

Becker said the risks and consequences of keeping Koeberg open need to be examined carefully.

The alliance has also raised concerns that no observers will be permitted at the Koeberg emergency readiness exercise this month.

eNCA