MHI to collaborate on PBMR development

04 February 2010

Mitsubishi Heavy Industries (MHI) has signed an agreement with South African company PBMR Pty that will see the Japanese firm collaborating on the development and commercialisation of the Pebble Bed Modular Reactor (PBMR).

 PBMR impression (PBMR Pty.)
How a PBMR plant is envisaged (Image: PBMR Pty)

Under a newly signed Memorandum of Understanding (MoU), MHI will initially study areas for possible collaboration in the design of the 200 MWt plant being developed by PBMR Pty. Once areas for collaboration have been agreed, MHI will undertake some of the research and development activities, and in the longer term will look at possibilities for further collaboration, including plant construction and exploring market potential.


The PBMR draws on long proven German technology and has been under development in South Africa since the early 1990s. It is a high-temperature gas-cooled reactor (HTR) which uses fuel spheres of silicon carbide-coated uranium particles encased in graphite, with helium as the coolant. This gives the reactor a high degree of so-called passive safety, exploiting inherent safety characteristics depending on the physical properties of the system without the need for intervention. The ability to produce hot steam at 750°C means the PBMR can supply process heat as well as generating electricity, and its small size makes it particularly suited to applications in areas lacking a fully developed transmission grid.
In 2009, PBMR Pty decided to focus on a 200 MWt (80 MWe) design using a conventional Rankine cycle enabling it to produce steam and to generate electricity, rather than the previously planned 400 MWt (165 MWe) reactor using a full-scale Brayton cycle gas turbine. According to MHI executive vice-president and general manager of nuclear energy systems Akira Sawa, the possibility of going back to the original plan should not be dismissed. "The possibility that PBMR may in future still want to pursue the direct cycle, gas-turbine design, should not be ruled out," he said, noting the future potential uses stemming from the higher output temperatures achievable from such reactor systems.
PBMR CEO Jaco Kriek said the new MoU raised "interesting" opportunities for the future commercialisation of PBMR technology. "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," he said.
Various countries are involved in collaborations on the development of the PBMR. A major US-South Africa bilateral agreement signed in September 2009 covered collaboration in R&D on advanced reactor technologies and particularly focused on the PBMR and the US Next Generation Nuclear Plant project as an area for collaboration. Collaborations also exist with China, which is also developing a similar HTR project.
In September, Kriek confirmed that plans for a demonstration PBMR plant to be operating by 2018 were being delayed because of governmental funding constraints, and that his company was looking to attract funding from potential industrial users.
Researched and written

by World Nuclear News