Small Modular Reactors: A strategic opportunity for South Africa’s energy future

The global energy landscape is undergoing profound change. Among the most promising innovations is the small modular reactor (SMR), a nuclear technology being promoted as an alternative not only to large conventional nuclear plants but also to fossil fuel-based generation. For South Africa, SMRs represent both a technological advance and an economic opportunity.

The “small” in SMR refers to its generating capacity — typically between 50 and 300 megawatts electric (MWe) per unit. By comparison, a conventional large reactor such as Koeberg’s units generates around 970 MWe each. SMRs are often deployed in clusters such as four-pack, six-pack, ten-pack or more, depending on the electricity needs of a region.

The “modular” aspect means that these reactors can be manufactured on a factory floor, shipped to site, and added incrementally. A single module can be installed and commissioned, with more units added over time as demand and financing allow. This phased approach lowers upfront capital requirements and accelerates deployment.

The compact footprint of SMRs makes them suitable for sites where large plants would be impractical. Koeberg, for example, occupies a vast area due to its size and the “source term”, or the potential release of radioactivity in an accident. Larger plants require extensive emergency planning zones, creating buffers between the reactor and residential areas. SMRs, with their smaller source term, can be sited closer to demand centres because any potential release would be far smaller and more easily diluted.

This reduced land requirement also opens possibilities for locating SMRs near existing industrial hubs. They can be placed closer to the grid, reducing costly transmission infrastructure. In some cases, they could operate entirely off-grid, directly powering energy-intensive industries such as mines and smelters.

Consider South Africa’s mining sector. Large gold or platinum mining complexes in areas such as Rustenburg or Carletonville could be powered by dedicated SMRs, eliminating the need for long transmission lines. Similarly, smelters — which have suffered output cuts due to Eskom’s supply constraints — could secure reliable 24/7 power from on-site SMRs. This would cut carbon intensity and help meet ESG commitments. Excess electricity could be sold into the grid, providing both operational resilience and an additional revenue stream.

Factory fabrication is another major advantage. Traditional nuclear construction involves assembling vast quantities of components on site, often in challenging conditions. SMRs, by contrast, can be built under controlled conditions — creating opportunities to localise production and develop a domestic manufacturing value chain — subject to rigorous quality checks and regulatory inspections before shipping. This approach shortens construction timelines, reduces labour requirements on site, and minimises the risk of cost overruns.

Some SMRs, particularly high-temperature gas-cooled reactors such as the pebble bed design pioneered in South Africa, use fuel that is inherently safe. Each fuel particle is coated in layers of graphite and silicon carbide, creating a robust barrier to the release of radioactive material. Even in the event of an accident, the reactor is designed to shut itself down without operator intervention if temperatures exceed safe limits. This intrinsic safety significantly reduces the risk of major incidents.

SMRs are not theoretical concepts. Two are already operational: China’s high-temperature gas-cooled reactor (the HTR-PM), connected to the grid in 2021, and Russia’s floating nuclear power plant, the Akademik Lomonosov, which can be moored near coastal demand centres. In the United States, designs such as NuScale’s light water SMR and TerraPower’s advanced reactor (backed by Bill Gates) are progressing. Argentina is building its own version, and other countries are investing heavily in similar projects.

For South Africa, SMRs offer several strategic benefits. Their smaller capacity makes them more affordable to build in stages, easing the financing burden. A 300 MWe SMR produces less than a third of Koeberg’s output but could be replicated over time to meet growing demand. Deploying them at or near mines, smelters, industrial parks, or even large data centres could boost productivity, protect jobs, and attract investment.

The rise of artificial intelligence and cloud computing is driving demand for data centres. These are massive facilities that require uninterrupted, high-capacity electricity. Locating such centres in South Africa, powered by dedicated SMRs, could position the country as a continental hub for digital infrastructure.

However, for this potential to be realised, South Africa’s regulatory framework must adapt. The Independent Power Producer (IPP) programme has opened space for private investment in renewables, but nuclear is not currently included. Extending the IPP framework to allow privately owned nuclear plants, particularly SMRs, could unlock significant investment. Such a move would encourage participation from local and international companies that are wary of building large, centralised plants but are keen to deploy smaller, modular units.

SMRs could also replace ageing coal-fired stations, particularly in Mpumalanga. By siting new pebble bed modular reactors on or near existing coal plant locations, transmission infrastructure could be reused, reducing costs and speeding up integration into the grid.

The case for SMRs in South Africa is compelling. They offer flexibility in siting, whether on-grid or off-grid, and scalability, with capacity added as needed. Their advanced fuel designs and passive shutdown systems provide enhanced safety, while their ability to power energy-intensive industries and attract new sectors can stimulate economic growth. Furthermore, factory fabrication shortens construction timelines, making them a faster, more efficient option for expanding the country’s energy mix.

To seize this opportunity, South Africa must act decisively. That means establishing clear regulations for private nuclear generation, incentivising industrial users to adopt SMRs, and reviving domestic expertise in pebble bed reactor technology. The technology exists, international examples prove its viability, and the need for reliable, low-carbon power has never been greater.

Small modular reactors will not replace the entire energy system, but they could become a cornerstone of a diversified, resilient, and sustainable South African grid. The time to prepare for their deployment is now.

Professor Bismark Tyobeka, principal and vice-chancellor of the North-West University (NWU).

*** The views expressed here do not necessarily represent those of Independent Media or IOL.

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