South Africa’s power utility Eskom said unit 1 at Koeberg NPP has been synchronised to the grid after almost a year, and the longest outage in the plant’s history. During the outage, the original three steam generators were replaced by three new steam generators. Unit 2 continued to generating electricity to the grid while the work took place and will continue to do so until the start of its next outage which will see its original three steam generators also replaced. The outage at unit 2 will start as soon as unit 1 is stable and all the required commissioning tests are complete, Eskom stated Although the unit 2 outage will be similar in terms of the scope, the lessons learnt from unit 1 will reduce the time needed with compromising nuclear safety.

The replacement of steam generators at Koeberg has been identified by Eskom as a prerequisite for extending the operating licence of the plant beyond its original design life of 40 years. Eskom has already submitted a licence application to the National Nuclear Regulator (NNR) for Koeberg’s operating life extension by additional 20 years, which is now being assessed.

This milestone is as a result of the hard work and determination of the Eskom employees, suppliers, and contractors who have had to endure a long and challenging outage in the Koeberg Power Station’s history,” said Eskom’s Group Executive for Generation, Bheki Nxumalo. “I commend everyone involved on the project for ensuring that the unt was returned to service safely.”

The two 930 MWe (net) pressurised water reactors at Koeberg, built by Framatome, began commercial operation in 1984 and 1985. They generate about 5% of the South Africa’s electricity. In 2014, Eskom signed a ZAR4.4bn ($240m) contract with Areva (now Orano) to design, manufacture and install the replacement steam generators. They were made in China under subcontract by Shanghai Electric Power Equipment Company.


Image: Koeberg nuclear power plant near Cape Town (courtsy of Eskom)