FROM BUSINESS DAY

Jocelyn Newmarch
15 May 2007 11:59

Currently, South Africa’s only nuclear plant, Koeberg, supplies about 1 800MW of the country’s power, mainly to the Western Cape. More than 40 000MW of new generating capacity is required over the next 20 years, says Eskom spokesperson Tony Stott, and this could come from a variety of sources. Currently, renewable sources such as wind and solar power are more suitable for peak electricity generation, to complement base load stations.

Worldwide, governments are shifting to investment in nuclear power and forcing coal-fired power stations to include external costs. Argentina aims to shift nuclear contribution to electricity generation from 6% to 27% and is exporting a reactor to Australia. Germany was slated by the European environment commissioner for its plan to build 26 coal-fired power stations, to make use of its large brown-coal reserves. The European Union is aiming to include the external costs, such as damage to the environment, of coal power in electricity generation, and some estimates see the price of electricity from this source doubling as a result.

The capital costs of nuclear power are higher than that for coal power, says Stott. But if costs are compared for the full life cycle, and carbon taxes are imposed on future coal stations, then nuclear power is more competitive. If these taxes don’t materialise, coal power is likely to be more competitive.

The average efficiency of the United Kingdom’s power stations in 2004 was just 38,5%. The best coal-powered stations have an efficiency of 40%, meaning that 60% of the coal’s energy is wasted, according to George Monbiot’s latest book, Heat. In South Africa, there is further energy wastage as power is transmitted over long distances, such as from Mpumalanga to the Western Cape.

Rob Adam, chief executive of the Nuclear Energy Corporation of South Africa, says that nuclear power is the only workable solution for far-flung provinces such as the Western and Eastern Cape. Nuclear stations can be located where the consumer is, rather than where the mine is. (Screw the people who have to live next to the mines, hey Mr Adams?) Coal-powered fuel stations are concentrated in Mpumalanga, but power is lost when transmitting over distance. In the absence of coal deposits, Adam favours nuclear stations, such as Koeberg, for these provinces.

“By a process of elimination, one gets to nuclear. Wind and solar have a role to play; we put research into them, but one can’t guarantee their reliability. One won’t bet on them for industrial base load,” he says.

Nuclear power would reduce our carbon footprint, but opinion is divided on its suitability, given waste storage and safety concerns. Environmentalists resent the growing cost of the pebble-bed modular reactor (PBMR), which has already spent more than R2-billion and is projected to cost another R11,3-billion. This is before a single unit of power has yet been produced. Critics say that the focus on the PBMR as an alternative energy source has drawn investment away from wind and solar power.

According to Stott, Eskom is investigating the feasibility of both the PBMR technology and conventional nuclear power stations, including more advanced versions of Koeberg-type power stations. Nuclear power produces virtually no greenhouse gases, he says.

“Over its full life cycle — from mining of the uranium, iron ore and other minerals, manufacture of the components and construction of the power station through to decommissioning of the station and the management and disposal of waste — nuclear power emits less than 11g of carbon equivalent per kWh. This is the same order of magnitude as wind and solar power, including construction and component manufacturing, and two orders of magnitude below (that is, one-hundredth of) the average for coal, oil and natural gas,” he says.

Stott says it is likely that both coal-fired power and nuclear will be used to meet future base load demand. Nuclear power, he adds, has the potential to make a substantial contribution to sustainable development and a significant contribution to reducing South Africa’s greenhouse-gas emissions.

But because there is a longer lead time for nuclear power stations, Eskom’s first new base load station will be the coal-powered Medupi plant. Stott says future base load stations could be either coal-fired or nuclear, depending on lead times, economics and government approval.

One overlooked advantage of Koeberg is that it uses sea water to cool its condensers, which is returned to the sea after use. According to Eskom, a coal-fired power station of the same size would use more than 160-billion litres of fresh water, and the water would be consumed entirely, compared with Koeberg’s 7,5 tonnes of uranium over 21 years. Any nuclear station located in Gauteng would have to use fresh water, perhaps from the Vaal River, but this could potentially be reused for agriculture. Given that water is increasingly scarce in South Africa, this is a substantial advantage.

But environmentalists are sceptical of nuclear power. Earthlife Africa quotes a Friends of the Earth International claim that compared with renewable energy, nuclear power releases between three and four times more carbon dioxide per unit of energy produced, taking account of the whole fuel cycle. “If nuclear energy generation is to expand, demand for uranium will increase and lower and lower grades of this ore will be used,” the organisation says.

Generating nuclear power also uses fossil fuels, and uranium is a finite resource. Earthlife Africa says that most uranium resources will be depleted in 60 years if global nuclear energy production is maintained. The remaining uranium will either be expensive to mine or unsuitable for electricity generation.