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Repair of the rotor and stator at Koeberg Nuclear Power Station

In February 2006, South African President Thabo Mbeki contacted French President Jacques Chirac to request his assistance in obtaining a replacement rotor for the Koeberg nuclear power station’s damaged unit one. French utility Électricité de France (EdF) agreed to swop a rotor to fix the damaged reactor (the stator is being repaired locally). The rotor will be returned once the original rotor - damaged along with other components by a loose bolt left in a generator after routine maintenance - has been repaired.

The rotor cannot be installed until the stator has been repaired.

The Drakensberg, a South African naval supply ship, was diverted from a mission escorting the first of South Africa's new submarines from Germany to Simon's Town, to pick up the 20m part at Antwerp - in an operation the navy dubbed "Operation Khanyisa" (Zulu for "bringing light").

SAS Drakensberg with Table Mountain in the background SAS Drakensberg with Table Mountain in the background

The 200-ton second-hand rotor was transported by theSAS Drakensberg and arrived at Cape Town harbour on on Wednesday, 5th April 2006. As the vessel berthed it carried a hand-painted banner tied to one side that said: "Going the extra mile to light up your lives" a welcome message for residents of the Western Cape, who have had to live with regular power cuts since Koeberg's unit one went down in December last year.

Light up your Lives

Cape Town mayor Helen Zille said the city was "delighted" to receive the rotor. "It has been a small miracle. In January this didn't seem possible," said Zille.

The rotor is too big and heavy to be moved into the vessel's cavernous cargo hold. The 200-ton rotor was carried to South Africa from France inside a large, coffin-shaped container held down by shackles welded to the vessel's helicopter flight deck.

Cutting the rotor loose from the deck of the SAS Drakensberg Rotor welded to the deck

Eskom used a couple of large cranes operating in tandem (one of which was sent from Gauteng to Cape Town by road) to lift the rotor from the helicopter pad on the ship .

Mobile cranes at CApe Town harbour

A twelve-axle flatbed trailer transported the gigantic rotor to the Koeberg power station, where permanently installed cranes would manoeuvre it inside.

The flatbed truck used to transport the rotor to Koeberg Flatbed truck used to transport the rotor to Koeberg
Transporting the rotor along the West Coast road

The flatbed truck transported the rotor along the West Coast road from Cape Town to Koeberg. The route was Marine drive to Boundary Rd to Koeberg Rd to Blouberg Rd to R27 (the bridge and causeway over the vlei were not deemed sturdy enough to support the weight of the truck and rotor). The truck drove at a top speed of 15km/h, and arrived at Koeberg on Friday (9th April 2006) mid afternoon and was offloaded from the truck upon arrival.

The flatbed truck loaded and on its way to Koeberg with the rotor The flatbed truck with the rotor loaded
Timescale

The first deadline of Monday 15th May, for reconnecting unit 1 to the national grid, was missed because of technical problems with the unit's generator. Eskom returned unit 1 of the Koeberg nuclear power station to service and reconnected it to the national grid on Wednesday, 17th May 2006; at this point the unit 2 reactor was operating at about 60%. A two month refuelling and maintenance outage of unit 2 begins in the week starting 29th May 2006. If all goes as planned both units will be running by the end of July 2006.

Cost of new rotor

The damaged generator cost R150 million to repair, which includes the cost of the replacement rotor and shipping it to South Africaaboard the SA Navy supply ship SAS Drakensberg, Public Enterprises Minister Alec Erwin said in reply to a parliamentary question.

What happened to the original damaged rotor?

The original rotor, damaged by a loose bolt left in a generator during maintenance was repaired by engineers in Johannesburg. When the repairs are finished, it will be sent to France as part of the swap. It took 12 days to move the damaged rotor from Koeberg to Johannesburg.

References

R150m Koeberg repair