Recent weeks have seen two unwanted outages at South Africa's Koeberg nuclear power plant. The effects on the fine balance of supply and demand would be unwelcome as owner Eskom struggles to maintain nuclear build plans.
|Koeberg (Image: Eskom)
Koeberg 1 was due for shutdown this afternoon for the replacement of some rubber diaphragms on main steam line valves. The shutdown is timed to come one week after Koeberg 2 came back online after itself suffering a very minor hydrogen leak in the non-nuclear turbine island.
In theory, minor repairs such as these should be carried out during refuelling outages scheduled about every 18 months. To make up for the loss of the 900 MWe reactor units, Eskom said it had - and would continue to - use the Ankerlig and Gourikwa gas-fired power plants in the Western Cape which can generate 750 MWe.
However, the disruption to nuclear power supply from Koeberg 2 coincided with sudden shutdowns at the Majuba and Duvha coal-fired plants, which between them generate 1254 MWe. Eskom appealed to its customers to conserve power, particularly by not using water heaters during peak hours.
The rapid expansion of the South African economy has combined with factors such as coal supply problems and the sheer distance between inland coalfields and the Western Cape to create conditions of great instability in the electrical grid. 'Load shedding' was common in months up to May this year and in January this even affected industrial operations key to the South African economy.
Eskom has plans a R343 billion ($44.7 billion) expansion program to build its way out of trouble, and the state has responded to its recent troubles by speeding up government loans and regulators have allowed two sharp rises in the price of electricity.
A R60 billion ($7.8 billion) loan from government will be delivered in over three years rather than five, while electricity regulator Nersa has allowed a 13.3% rise in the price of electricity - on top of a 14.2% rise late last year - to help address a 40% rise in primary energy costs. With diesel in use for reserve capacity, expenditure on the fuel shot to R1.9 billion ($240 million) in 2007 from just R23 million ($3 million) the year before. Ultimately, power costs are expected to double.
The price rise was a major factor in a one-day general strike on 6 August, although Eskom CEO Jacob Maroga said it "sets Eskom and the energy sector in general on the path to long-term financial sustainability."
A major plank of South Africa's future energy supply was meant to have been nuclear energy. Areva and Westinghouse both submitted bids on a project to build around a dozen new large reactors in January, and Eskom was expected to have selected a preferred bidder over a month ago. It is now hoped that an announcement could come in September to show the project is still on track, at a time when the stability and security of nuclear energy is most needed.