South Africa’s Koya Capital has signed a partnership agreement with Stratek Global to assist in securing finance for construction of a high temperature modular reactor. The ZAR9bn ($480m) HTMR-100 is based on South Africa’s Pebble Bed Modular Reactor (PBMR).

South Africa began developing the PBMR in the 1990s, but it was put into care and maintenance in 2010. It 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 proposal for a direct cycle pebble bed reactor designed for South African conditions was formulated. 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 study of the project, and in 2000 South Africa approved the detailed feasibility phase. Internal research was strong, with the PBMR project generating more than 100 patents during the period 1999-2004. The PBMR was 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 as well as generating electricity.

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 4,000 MWe to the southern African grid. The PBMR Test Reactor was to be built at the Koeberg existing nuclear plant site north of Cape Town.

A large number of domestic and foreign subcontractors became involved in the project, which developed a massive supporting infrastructure, much of which is still in place but mothtballed. PBMR facilities included:

  • 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;
  • the 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.

HTMR-100 is designed to produce 100 MW of heat and 35 MW of electricity. The new partnership follows what Stephen Edkins, head of CleanTech at tech consultancy Koya Capital, told Biznews was a period of due diligence which has convinced them of the potential of the technology. They will now work to ensure Stratek Global's project is investor-ready, and to recommend the project to its investors, with a "strong commitment to break ground before the end of the year".

Koya Capital describes itself as “a learning transformation consultancy that works synergistically with Governments, Academia, Development, Financing & Technology Partners, Parents and Communities to develop skills for the 21st century world of work”. By focusing on learning modernisation, “we hope to grow and improve both the quality and relevance of Africa’s human capital to catalyse her economic emergence,” the website notes.

Edkins said the collaboration with Stratek Global transcends reactor construction. It is about establishing a benchmark in clean, dependable energy for Africa and the wider world…. There is a growing realisation that nuclear energy is the best way to address the substantial demand for clean base-load power in Africa and around the world."

Differences between the PBMR and the HTMR-100 include the gas outlet temperature being reduced from 940°C to 750°C, and, while the PBMR used a direct helium cycle through the reactor and into the turbines, the HTMR-100 instead takes the heat into a water heat exchanger or steam generator, which produces steam for conventional steam turbines or process heat. This means all the equipment downstream of the heat exchanger can be purchased off-the-shelf, reducing design time and costs.

The partners to the new agreement include Stephen Edkins and Warren La Fleur of Koya Capital and Dr Kelvin Kemm of Stratek Global, who previously worked on the PBMR project. The HTMR-100 is expected to break ground before the end of the year. Apart from the South African market, there’s been “a lot of interest” in the venture, not only from African countries, but from countries such as Australia, Canada, Indonesia, and the Middle East.

According to Stratek, “Our HTMR-100 was designed to look like the type of Power Pack that one would expect to find powering a South African gold mining complex in an arid, open expanse, reasonably far from a city or large town. However, it is easily possible for our architects to design any external facade which any customer may wish to have. So, a reactor complex could be designed to have an Arab appearance for some Middle Eastern country, or an East African appearance, or for that matter a European appearance to fit in with green fields and flowers. We have had inquiries from all three of those types of countries, so choosing an appropriate livery is no problem.”

The HTMR-100 is designed not to need a large body of water for reactor cooling. This simplifies siting for the reactor. The South African nuclear regulatory system is also well developed based on the PBMR experience and the operating NPP at Koeberg. “Internationally, South African technology developers are highly respected and so we have a high degree of confidence in their ability to deliver a successful product,” said Edkins.

Image (top): Cutaway of the HTMR-100 reactor (courtesy of Stratek Global)

Image (bottom): Dr Kelvin Kemm with a mock-up of the modular nuclear reactor (courtesy of Stratek Global)