If the power station at Koeberg in the Western Cape were coal-fired and not nuclear, it would have needed to burn more than 105-million tonnes of the black stuff over the past two decades to equal the power it has produced from just 621 tonnes of uranium.
Since starting commercial operation in 1984, Koeberg has fed — up to the end of last year — more than 200-billion kilowatt hours (kWh) of electricity into South Africa’s national grid, says Minister of Minerals and Energy Phumzile Mlambo-Ngcuka.
In a written reply to a parliamentary question, tabled at Parliament on Thursday, she gives a comparative analysis between Koeberg and a coal-fired power station of similar output.
The figures show the environmental impact of having located a coal-fired power station near Cape Town would have been severe.
Waste produced by Koeberg up to the end of 2003 amounted to 1 004 tonnes of low-level radioactive waste, including the steel drums into which it is compacted; 1 067 tonnes of intermediate-level radioactive waste, including the concrete containers in which it is sealed; and 897 tonnes of spent fuel rods, many of which contain unused uranium suitable for recycling.
By comparison, an equivalent coal-fired power station would have created more than 28,5-million tonnes of ash; more than 1,7-million tonnes of sulphur dioxide and 805 820 tonnes of nitrous oxide, both noxious gases; and an unspecified tonnage of carbon dioxide, the greenhouse gas mainly responsible for global warming.
Although Mlambo-Ngcuka’s reply does not put a number on the tonnes of carbon dioxide a Koeberg-equivalent coal-fired plant would have pumped out over the past 20 years, Eskom figures show this would have been in the region of 196-million tonnes.
Eskom national spokesperson Fani Zulu said on Thursday this is six million tons more than the carbon dioxide put out by all Eskom’s coal-burning plants last year.
”A coal-burning power station producing the same amount of electricity as Koeberg would have pumped out 12,41-million tonnes of carbon dioxide during 2003,” he said.
Mlambo-Ngcuka’s reply appears to indicate there was also good financial justification for the decision to site a nuclear plant rather than a coal-burning plant in the Western Cape.
She says the annual cost of fuel for Koeberg ranges between 2,7c and 3,48c per kWh, while the average annual cost of coal to produce an equivalent quantity of electricity ranges between 1,83c and 3,14c per kWh.
However, transporting coal into the Western Cape from mines in Mpumalanga for a coal-fired station, at a rail tariff of 20c per tonne per kilometre, would cost more than R2-billion a year.
”An equivalent coal-fired power station to Koeberg requires about 1 000 tonnes of coal an hour when operating at full power.
”This equates to one train of about 17 wagons travelling into the Western Cape each hour,” she said.
Between 1996 and 2004, the annual cost of nuclear fuel for Koeberg had ranged between R319-million and R406-million.
Over the same period, ”the average annual cost of coal required to produce the equivalent quantity of electricity as that produced by Koeberg would have ranged between R215-million and R398-million”.
Mlambo-Ngcuka says all steel drums and concrete containers of low- and medium-level radioactive waste from Koeberg, stored at the Vaalputs Radioactive Waste Repository in the Northern Cape, ”contained a total of 39,500 Giga Becquerel (GBq) of radioactivity”.
”The spent fuel stored at Koeberg is estimated to contain 10-billion GBq of radioactivity.”
She says although nuclear power is environmentally clean, with no emissions of greenhouse and noxious gases, and no particulate matter, the ”spent fuel requires careful and expensive management for considerable periods of time”. — Sapa