South Africa has two nuclear reactors which generate only 5% of its power. In 2008, Eskom power stations produced 230.0 billion kWh (TWh) of electricity, of which the Koeberg nuclear plant generated 12.7 TWh. Of its total installed net capacity of 40.5 GWe (44.2 GWe gross), coal-fired stations account for 34.3GWe and nuclear 1.8GWe. Early in 2008, demand in South Africa was uncomfortably close to this. According to Eskom, the country needs 40GWe of new generation by 2025, about half of which should be nuclear.
The Department of Energy has developed a 20 year plan called the Integrated Electricity Resource Plan (IRP) 2010-2030 which requires the development of new capacity (52GWe) by 2030.
South Africa’s generation mix by 2030 should include:
- 48% coal
- 13.4% nuclear
- 6.5% hydro
- 14.5% other renewable energy such as wind and solar
- 11% peaking open cycle gas turbine
In the May 2011 budget speech the energy minister reaffirmed that 22% of new generating capacity by 2030 would be nuclear and 14% coal-fired. The budget also provided ZAR586m (US$85 million) for the Nuclear Energy Corporation of South Africa (NECSA) "to continue with its central role as the anchor for nuclear energy research and development and innovation.
However, this doesn’t seem to have helped as the country continues to experience major financial constraints which slow generation development. As the country is heading for an energy crisis in the near future, more cost-effective solutions need to be found and fast.
Small nuclear reactors may be one solution.
Small reactors have been around for a while. These smaller, inexpensive reactors have powered navy vessels for many years. Companies around the world are starting to realize the potential of these mini-reactors and are coming up with designs suitable for civilian use in urban environments. A global race is under way to develop small reactor designs. According to Paul Genoa of the Nuclear Energy Institute, over 20 countries have expressed serious interest in buying small reactors. The International Atomic Energy Agency (IAEA) estimates that by 2030 over 90 small reactors will be in operation. It has been estimated that more than half of the countries that will build nuclear plants in coming years will opt for these smaller, simpler designs.
What are the advantages of the small nuclear reactor?
- Nuclear as a whole helps reduce carbon emissions-an issue that South Africa needs to address as the country has a very high emission level no thanks to its heavy reliance on coal for power
- Siting a large nuclear power plant can be difficult as it requires a larger emergency planning zone which could extend 10 miles. A small modular reactor may need only half a mile
- Small nuclear plants can be built at old coal plant sites which could simplify grid connections and other siting problems
- They are more cost effective and a more manageable investment. Power plants, based on small modular reactors and generating roughly between 200 to 300MW, can cost a few billion dollars. The typical cost of a traditionally sized nuclear reactor is several billion dollars (a recent plant in France cost over US$5bn). The initial cost of small reactors will be 10 to 100 times less than this
- Small reactors’ modularity as extra units can always be added to the plant. A modular facility is built within a few short years and will generate revenue almost immediately. A large reactor can take decades to build.Small reactors’ scalable nature allows utilities to cater the plant capacity to the demand of the area being served. This feature is also complimentary to the lower initial cost since a plant can expand capacity as it is needed, thus avoiding a high initial outlay
- The small scale of the reactors allows some passive safety features. For example, the NuScale reactor does not require any pumps for water circulation, instead relying on convection for heat transfer
- Small reactors are able to use existing power transmission lines without overloading them. This is key to South Africa as funds are low
- Coal plants can be easily converted to small nuclear plants, according to Philip Moor of the American Nuclear Society
- Small reactors are less vulnerable to terrorist attacks as they are protected by a heavy layer of concrete and buried
- Small scale nuclear power can be a cheaper option for small or rural areas that rely on a single, expensive power source, for example, diesel generators. These areas generally do not have the grid capacity to support a traditionally large nuclear plant
- The overall cost of energy to the consumer can be less due to the ability to tailor (and perhaps modify) the plant’s capacity according to the relevant demand
- Size and containment.Small reactors are designed to be constructed by the manufacturer and shipped to site. The reactor core is designed to be fully contained in a transportable package. This allows the use of much smaller power facilities (the small reactor cores are designed to be buried underground) without the need for enormous cooling stacks or containment buildings. In addition, the self-contained core package can be shipped back to the manufacturer for refueling or disposal.
There are many advantages but disadvantages must be considered before a decision is made:
- Although the up-front cost is lower than that of larger reactors, they may cost more per kW of capacity—and per kWh of power generated
- Even if small reactors can compete with conventional nuclear power, they still might not be able to compete with South Africa’s coal power plants which generate cheap power
- Licensing and building small plants may take too long to be profitable. The costs of solar, wind and biogas power continue to fall and investors may support this sector before looking in to nuclear
- Small reactors can be brought closer to urban centers which may bring about potential nuclear hazards closer to population centers
Small nuclear reactors could be an attractive solution to changing the balance of South Africa’s power portfolio away from fuels that emit high carbon emissions such as coal and oil. However, public acceptance and a lengthy regulatory process may prevent the smooth adoption of small reactors, especially as renewable energy sources (wind and solar) improve in technology and decline in cost.
The advantages clearly outweigh the disadvantages. The small nuclear reactor could well be a solution to South Africa’s poor power portfolio.