Japan’s Mitsubishi Heavy Industries (MHI) says it is keen to get involved in the development of the Pebble Bed Modular Reactor (PBMR) after signing a memorandum of understanding (MOU) with the South African firm developing the technology.

MHI and PBMR Pty are to study the possibility of collaborating on the design of a 200 MWt PBMR plant, and will also explore other possible areas of collaboration including the construction of the first reactor and marketing activities.

When the two companies have agreed on specific areas of co-operation, MHI will conduct part of the research and development activities for the 200 MWt plant design.

The 200 MWt plant consists of a 200 MWt PBMR and a steam generator that provides hot steam at 750°C. The plant uses silicon carbide-coated uranium particles encased in graphite for the fuel spheres and helium as the coolant, making it free from risk of reactor core meltdown.

The PBMR requires relatively low initial investment and is considered to be well suited to applications in areas lacking a fully developed power transmission grid. A number of potential customers, including South African chemical firm Sasol have been studying the introduction of the plant.

The 200 MWt reactor design is a scaled down version of PMBR’s original 400 MWt reactor design, the major components of which MHI did the basic design and research and development. The 200 MWt design delivers superheated steam through a steam generator and is aimed at the nuclear heat market as a viable alternative for carbon-burning, high-emission heat sources.

“We firmly believe that High Temperature Reactors will be one of the viable future reactors. We are therefore prepared to perform certain research and development work to assist in the success of this project,” said Akira Sawa, MHI’s Executive Vice-President and General Manager of Nuclear Energy Systems.

Sawa added that the future potential of the technology lies in the utilisation of higher output temperatures from the reactor system. “There are therefore important additional technological development opportunities that can be exploited. The possibility that PBMR may in future still want to pursue the direct cycle, gas-turbine design, should also not be ruled out.”

PBMR CEO Jaco Kriek welcomed the cooperation with MHI. He said the MOU could create interesting opportunities for the future commercialization of the technology, such as jointly developing and exploiting markets for pebble bed plants.

“Both companies believe that high temperature, gas-cooled reactors using pebble fuel offer the best potential for sustainable, clean, reliable and safe sources of energy globally,” said Kriek. He added that MHI’s participation in the project further demonstrates the potential for advanced reactor technologies with passive, inherently safe characteristics.

“The pebble bed technology will bring a new option to the energy market which offers flexible, smart grid solutions for electricity, customer-centric process heat and steam solutions for petrochemical industries, oil sands extraction and desalination. It will also pave the way to high-temperature hydrogen production.”