In a recent media briefing, South African Minister of Energy & Electricity Kgosientsho Ramokgopa affirmed that nuclear energy would be a crucial part of South Africa’s energy mix and that activity was under way to re-activate existing nuclear capacities. He was referring to small modular reactors (SMRs).
“What we have accepted is that SMRs are the future”, he said. “We know that we’ve got the capability and in fact, the genesis of the current generation of small modular reactors is the PBMR [pebble bed modular reactor]. We have sunk over … ZAR12bn ($662m) into that programme [and then] abandoned it for reasons that were explained at the time.”
He added: “We think that we need to exploit our skills, exploit the accumulated knowledge with regards to nuclear technology over a period of time and that’s the case we’re making to Cabinet.” The Department of Electricity & Energy (part of the Department of Mineral Resources and Energy – DMRE) is preparing a report to Cabinet to recommend lifting the PBMR from care and maintenance to allow South Africa to revive the development of its PBMR capability. Ramokgopa’s department is also currently putting the finishing touches to the Integrated Resource Plan 2024 (IRP 2024). The IRP is South Africa’s roadmap for electricity generation strategy.
South Africa began developing the PBMR in the 1990s, but in 2010, the South African government ceased funding for the project due to a lack of viable customers or investors, leading to significant staff reductions and ultimately halting development efforts. PBMR was put into care and maintenance and was reincorporated into Eskom in 2012.
The pebble bed reactor design was developed in Germany and was used there in the 1970s and 1980s. South Africa became involved in 1988 when Johan Slabber – then with the Atomic Energy Commission (later Necsa) – met with the German pebble bed reactor scientists. The PBMR design was for a small-scale high-temperature reactor using graphite-coated spherical uranium oxycarbide tristructural isotropic (TRISO) fuel, with helium as the coolant, able to supply process heat for industry as well as generating electricity.
Slabber later joined the South African systems engineering company IST and introduced the concept to IST’s Dieter Matzner and to Eskom’s David Nicholls. The three founded PBMR (Pty) Ltd in 1993. In 1995, the South African government lent support to the project, and in 2000 approved the detailed feasibility phase. The PBMR project generated more than 100 patents during the period 1999-2004.
State power utility Eskom committed to purchase a demonstration reactor and to operate it. The Nuclear Energy Corporation of South Africa (Necsa) drew up plans to acquire 24 PBMR reactors over the next 20 years to contribute 4000MWe to the southern African grid. The PBMR Test Reactor was to be built at the Koeberg NPP site north of Cape Town. A large number of domestic and foreign subcontractors became involved in the project, which developed a massive supporting infrastructure. Principal PBMR facilities included:
- Headquarters in Centurion;
- The Pebble Bed Micro Model at the Potchefstroom Campus of North-West University to test gas turbine principles;
- A High Pressure Test Unit and High-Temperature Test Unit, which were part of the Heat Transfer Test Facility at the Potchefstroom Campus;
- A Helium Test Facility at Pelindaba; a high temperature, high pressure rig designed to test key systems before going to site; and
- A prototype fuel fabrication plant, including kernel production, coated particle production, fuel sphere production, and quality control.
In 2020, Eskom said it wanted to move PBMR out of care and maintenance and said interested companies could propose taking an equity stake in PBMR, investing in the PBMR reactor technology or the pebble fuel technology, buying PBMR technology or products developed by PBMR. However, this was not achieved.
Although the PBMR currently still remains in a state of care and maintenance, all its intellectual property, including designs, specifications, and reactor engineering calculations has been preserved. The company retains ownership of nearly 300 patents. PBMR’s large Helium Test Facility is still operational, and the Fuel Development Laboratory is still fully equipped. PBMR’s management system, which is ISO 9001 and ASME NQA-1 compliant, has also been preserved.
When the project was placed in care and maintenance, manufacturing was underway of the reactor pressure vessel, the core barrel assembly and reactor graphite internals for a demonstration 400MWt/165MWe plant. A smaller 200MWe model – an indirect cycle design – of the PBMR was also in the concept design phase.
When Eskom’s chief nuclear officer, David Nicholls, retired in December 2018, both Eskom and Necsa were facing serious financial and organisational problems. Plans to transfer the PBMR from Eskom to Necsa have not yet been realised. In a report tabled before Parliament’s portfolio committee on electricity and energy in September, it was noted that Necsa acknowledged that the transfer of the PBMR from Eskom to Necsa “has not been finalised yet” but that Necsa was “looking forward to resuscitating the technology and taking it forward”.
The report said: “Necsa stated that one of their key strategies is positioning itself for energy generation with small modular reactors and the PBMR is one of those. However, according to Necsa, the country has lost some ground with this technology, and it would thus make more sense to identify a partner, to take this technology further – but this partner must not be prescriptive in what the country wants to do.”
At the end of November, DMRE’s Deputy Director General for Nuclear, Zizamele Mbambo, speaking at a Stand Up4Nuclear event, confirmed that the government remained committed to the use of nuclear energy and was planning to revive the PBMR programme and embark on new builds.
