The plan to add additional nuclear energy generation to Eskom’s grid could see the introduction of small, modular nuclear reactors based on technology originally developed by South Africans, Netwerk24 reported.
Nersa recently announced its concurrence with energy minister Gwede Mantashe’s draft determination to procure 2,500MW of nuclear generation, with certain conditions.
This includes that the nuclear build programme must be at a pace and modular scale that the country can afford.
It also has to take into account technological developments in the nuclear space.
One possibility the government said will consider is Pebble Bed Modular Reactors (PBMRs) — helium-cooled, high-temperature reactors designed to provide small-scale power generation that can be deployed more quickly and safely than traditional nuclear reactors.
The modular reactor consists of a steel pressure vessel that holds enriched uranium dioxide fuel in graphite spheres (“pebbles”).
These pebbles generate heat that is converted into electricity through a turbine.
The earliest forms of the technology were developed by a South African team who worked for Eskom’s PBMR company.
The company once planned to build a new nuclear power station in Duynefontein, close to Koeberg, but after ten years, the project was shut down due to a lack of investment.
Two researchers who once worked on the project now have prominent roles in US nuclear and nuclear fuel company X-energy.
The company’s lead scientist is Eben Mulder, who previously served as chief scientific officer at Eskom’s PBMR company.
He was also the director of the North-West University Potchefstroom’s Post Graduate School for Nuclear Sciences and Engineering, and a Professor in the School of Mechanical and Nuclear Engineering.
X-energy’s lead reactor developer is Martin van Staden, who studied and graduated at the North-West University Potchefstroom campus and received his doctorate from the University of Johannesburg.
X-energy has developed the compact Xe-100 reactor, which delivers 80MW of electricity and is about the size of an elevator shaft in a four-storey building.
The US military has also signed a contract with the company in March to deliver its Xe-Mobile reactors.
These smaller, mobile versions will generate between 1MW and 5MW and are designed to be easily transportable on the road, rail, or military aircraft for rapid deployment scenarios.
They are expected to charge the military’s armoured vehicles, which will all be converted to electric power in the next 10 years.
The reactors are powered by the company’s own Triso-X nuclear fuel.
North-West University nuclear engineering professor Dawid Serfontein told Netwerk24 that the US and China were now leaders in technology developed in South Africa.
Serfontein said these reactors are sold as sealed units manufactured in a factory in the US. They can then be shipped to South Africa and deployed in specially designed buildings.
The big benefit is that their price is fixed and the safety licence approved upon ordering, eliminating the risk of delays and budget conflation, two of the biggest obstacles often punted by critics of nuclear energy.
Serfontein explained the government could order ten 50MW units and start installing them for a total capacity of 500MW.
If all goes well, it could multiply the order five-fold to 2,500MW. If it doesn’t, it can find another supplier.
According to Netwerk24, there are currently 23 companies worldwide building modular reactors, with three in operation in Russia.
China recently started loading South African-made nuclear fuel into the world’s first commercial PBMR station.
The US is also expected to licence the country’s first PMBR reactor soon.