South African state-owned power utility Eskom is seeking to dispose of the state-owned company behind the development of the Pebble Bed Modular Reactor.

Eskom issued an Expression of Interest (EOI) tender for the “commercialisation of Pebble Bed Modular Reactor SOC Ltd (PBMR), design, development, manufacturing, and construction of [a] Small Modular Reactor and supply of TRISO coated particle fuel for various reactor designs”.

The EOI said Eskom, “is intended to publicly solicit and to determine an interest from the market in the future takeover of the [PBMR] technology."

It said that while various options were explored to commercialise PBMR in the past, Eskom now intends to dispose of the company, providing the market with unrestricted options to pursue.

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.

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.

A large number of domestic and foreign subcontractors became involved in the project, which developed a massive supporting infrastructure. Principal PBMR facilities included:

  • the 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;
  • 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.

The PBMR Test Reactor was to be built at the Koeberg existing nuclear plant site north of Cape Town.

Eskom now wants to move PBMR out of care and maintenance.

Interested companies can 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. They can also propose other possible transactions or relationships in their EOI submissions. The closing date for these submissions is 28 February.

PBMR project status

PBMR remains in a state of care and maintenance. All its intellectual property, including all its 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 PBMR project was placed in care and maintenance,  manufacturing was underway of 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.

"Given the products created and preserved, PBMR remains capable of re-starting within a relatively short period of time, or alternatively its technology being taken over by a third party in its configured state and utilised elsewhere," Eskom said.

Eskom renewed its interest in the PBMR in 2017.  Eskom’s former chief nuclear officer, David Nicholls, said then he thought there was “a window of opportunity still there” for the PBMR.

“In some way initiated by the former PBMR project in South Africa, many studies have looked into small nuclear reactors, and they conclude that power generation reactors of 150MW or so could be commercially viable… But no one has yet filled that window," said Nicholls.

Nicholls retired from Eskom in December 2018, a year earlier than planned. The company was facing serious financial difficulties resulting in staff cuts. Necsa also has been facing problems with the entire board resigning in January in the wake of a long-standing financial and operational crisis. However, the government has now appointed a new board headed by Nicholls, which may bode well for the PBMR revival.