Koeberg leads way for South African power plants

As South African utility Eskom anticipates months of load-shedding, the Koeberg nuclear power plant has been singled out to act as a blueprint for the development of operator capabilities vital to strengthen the country's vulnerable electricity supply system.

Coal accounts for 90% of South Africa's electricity generation mix, while nuclear and hydro power each provide 5%.

South Africa has very low electricity reserve margins, and in the company's latest briefing on the system's status, Eskom CEO Tshediso Matona described the system as vulnerable. Any extra load or faults in the system might therefore necessitate load-shedding - planned interruption of supply to certain areas in order to balance supply and demand and avoid a country-wide blackout.

The balance is very delicate. In its latest bi-weekly system status bulletin, published on 12 January, Eskom had 32,045 MWe of capacity available to meet the day's forecast peak demand of 30,106 MWe, with 3915 MWe in planned maintenance and 7374 MWe in unplanned outage. The company expects load-shedding to occur on most days until the end of April. Although large-scale use of diesel has so far gone some way to alleviating the country's energy problems, Matona said that a shortage of capacity for the next three years appeared to be unavoidable.

Over the past seven years, Matona said, Eskom's philosophy of "keeping the lights on at all costs" had largely enabled load-shedding to be avoided, but at the expense of proactive plant maintenance. With plant repairs being undertaken with the aim of keeping the given plant running, even if at reduced capacity, the company now faces a severe maintenance backlog. This in turn leads to increases in unplanned outages, further stretching the already delicately poised system.

"We have arrived at a point that does not allow us to ignore the health of our plants. Our reserve margin is so thin, that every incident creates a major systems issue and could also have safety implications for the plant," Matona said. To address this, the company is implementing a drive to address the maintenance culture at the plant level. A shortage of skills has also been identified as a contributing factor.

One plant where maintenance has not been neglected is Koeberg, and Matona singled out the nuclear power plant alongside the Matimba coal plant to provide the "blueprint" for the development of best practice and skills across Eskom's generating fleet.

Ultimately, new generating capacity will be the key to easing pressure on the system. The South African government's 2010 Integrated Resource Plan includes 10 GWe of nuclear capacity as well as a procurement process for renewable energy. Recent months have seen the South African government enter into negotiations with various reactor vendor countries as part of the pre-procurement phase of its nuclear new-build program.

Researched and written
by World Nuclear News