The National Nuclear Regulator gave assurances last week that it was working to incorporate lessons learned from Japan's Fukushima nuclear incident.

A transatlantic row over a $250-million set of contracts for the replacement and upgrading of the Koeberg nuclear power station has been kept secret.

Despite objections from Greenpeace, the African National Congress considers nuclear power plants to satisfy rising energy demands.

Eskom confirmed on Friday that it had shut down unit one of the Koeberg power station to replace diaphragms on the valves in the main steam line.

Unit two of the Koeberg nuclear power station has commenced generating electricity, Eskom said on Thursday.

South Africa's sole nuclear power plant, already producing only partial output, was in a state of complete shutdown on Saturday.

Eskom confirmed on Tuesday that it initiated a controlled shutdown of unit two of Koeberg power station near Cape Town following a technical fault.

When a Koeberg reactor failed last year and the Western Cape was crippled by rolling power failures, the rest of the country sympathised every time power alerts flashed on our television screens.