Small modular nuclear reactors could help solve load shedding

Dr Kelvin Kemm, the chairperson of Stratek Global. File photo

Dr Kelvin Kemm, the chairperson of Stratek Global. File photo

Published Feb 8, 2024


Small modular nuclear reactors could help solve South Africa’s load-shedding problem, but it required political leadership to implement, Dr Kelvin Kemm, the chairperson of Stratek Global, said at the Mining Indaba on Wednesday.

“South Africa has been ready for many years to expand its nuclear energy production as nuclear is carbon free and provides a reliable base load,” Kemm said.

He said South Africa was the first country in the world to start developing a commercial small modular reactor (SMR), which was called the Pebble Bed Modular Reactor (PBMR). This meant that South Africa became a world leader in SMR development, but the government pulled the plug on the Pebble Bed Modular Reactor in 2010, in part due to the 2009 global financial contraction.

Kemm and other like-minded scientists then started Stratek Global as an entirely private venture and they have now designed the HTMR-100, which can be deployed in remote areas as the HTMR does not does not need water cooling since it is cooled using helium gas. These reactors are affordable and can be owned by governments, provinces, municipalities and private companies, such as mining companies.

Kemm said Stratek Global was in advanced talks with more than one foreign funder with a view to raising R10 billion privately and foundation agreements had already been signed with more than one company.

The HTMR produces 100 megawatts of high temperature gas. The purchaser has the option of using the gas as is for processes such as water desalination, or for any industrial process which needs such heat. Alternatively, any buyer has the option of using an HTMR-100 to produce electricity. If this route is chosen then the 100MW of gas-heat will produce 35MW of electricity, via a conventional steam turbine and electrical generator.

Eskom calculates the unit cost of electricity produced by renewable independent power producers at about R2 000 per MWh, which is far less than the R7 000/MWh it costs to run diesel-fuelled open-cycle gas turbines, but far more than coal, which costs less than R500/MWh, or nuclear, which costs only R100/MWh.

In South Africa, a nuclear site for the construction of a prototype SMR nuclear reactor has been identified at the Pelindaba site of the South African Nuclear Energy Corporation (Necsa), near Pretoria.

A site in the Free State province has been offered as a site for setting up facilities for fabricating multiple reactor components and assemblies, for national and international deployment. This is the town of Kragbron, which is very close to the major industrial fabrication area of Vanderbijlpark, where many facilities provide heavy engineering, and thus not only expertise and experience for modern fabrication, but also industrial users for the electricity.

A big advantage of an HTMR-100 is that the reactor can be located anywhere as it does not require water. Furthermore, a single reactor can have its own electricity microgrid, so the problems with linking to a national transmission grid do not exist. That means that a remote mining community in Mali could have one or two reactors serving its own dedicated grid, which is only 10km or 20km wide.

Small nuclear reactors offer extensive flexibility, and they run continuously, independent of day or night, rain or sunshine, wind or no wind. They also do not need a system for delivering a continuous fuel supply; deliveries two or three times a year would be sufficient.

“The fourth-generation technology has been rigorously tested and is absolutely safe with a robust daily operation. You can take one of the pebbles that fuel the new reactors and drop it on the floor without any negative impact, yet if you do with a current nuclear fuel rod you would have a major problem. The reality is that electricity demand has doubled in the past 25 years and it is set to double again in the next 25 years, so we need the green energy that nuclear provides as the reliable base load,” Kemm said.