The public is advised not to be alarmed at steam issuing from the Koeberg nuclear power station during the next few days, a spokesman said.

“Given the events in Japan, we want to assure the public that perfectly clean steam will issue from next to the reactor during the routine shut,” spokesman Tony Stott said.

He said that this was part of the cool down process of unit two, which began on Monday at 1.30am.

The unit would take two to three days to cool down enough for it to be opened for workers to begin the refuelling, maintenance and inspections.

Stott said that valves, pumps and high pressure components were among items scheduled for maintenance. One third of the fuel in the reactor would be replaced.

The shutdown would last about 55 days, and would recommence operations in the first or second week of May.

Once the unit had been reconnected to the power grid, it would take about four days to begin generating electricity. In about a week, the unit would be back up to full power.

At various stages of the power up, tests would be conducted to ensure all was working correctly.

Stott said unit two provided between 2 and 2.5 percent of SA’s energy capacity. — Sapa