Collaborative Research in Beyond PBMR Collaborative Research in Energy with South Africa Bill and Geoff’s new adventure Geoff Parks & Bill Nuttall University of Cambridge
Pebble Bed Modular Reactor Builds upon much early European work at Winfrith in the UK and Juelich in Germany 400 MWth / 165 MWe Helium cooled Graphite moderated 900 °C core Tout 9 MPa pressure Brayton power cycle On-line refueling Source: Westinghouse Electric Company
Pebble Bed Modular Reactor Vertical steel pressure vessel, 6 m in diameter, ~20 m high Lined with 100 cm thick layer of graphite bricks (reflector and passive heat transfer medium) Silicon carbide and pyrolitic carbon coated particles of 8% enriched UO2 encased in carbon form fuel ‘pebbles’ Fully loaded a core would contain 380k fuel pebbles and 150k pure graphite spheres (additional moderator) Source: www.pbmr.co.za
Pebble Bed Modular Reactor The reactor is continuously replenished from the top with fresh or recycled fuel pebbles, while fuel is removed from the bottom after each cycle Pebbles are measured to determine the amount of fissile material left in them and recirculated if feasible Each cycle lasts about three months Each pebble passes through the reactor about 10 times
Source: Technology Review
PBMR Brayton Cycle Source: www.pbmr.co.za
PBMR Safety Ceramic coated fuel particles provide primary radionuclide barrier No possible phase change in coolant Low power density and large thermal capacity Core heat removed passively by conduction and a natural circulation cavity cooling system Passive heat transfer and high fuel temperature capability preclude core melt
PBMR Status in South Africa In August 2008 PBMR (Pty) Ltd. announced the signing of a contract for the provision of engineering, procurement, project and construction management services for a planned demonstration reactor project at Koeberg near Cape Town The PBMR project also includes a pebble fuel plant to be constructed at Pelindaba near Pretoria The current schedule is to start construction in 2010 and for the demonstration plant to be completed by 2014
Our Proposal A two-year project to perform a technology assessment of possible beneficial variants of the basic PBMR concept Attributes to be considered will include: Economics Environmental issues Energy security Safety Public acceptance Nuclear proliferation Nuclear skills Industrial capacity Industrial supply chains
PBMR Variants Coolants beyond helium Direct process heat applications Steam generation (tar sands liquefaction) Steam methane reforming (hydrogen, ammonia) Water-splitting (bulk hydrogen, coal-to-liquids) Desalination Containment options Fuel options Alternative fuel forms Alternative fissile materials (reactor-grade Pu or U-233 bred from Th)
Planned Partners University of Cape Town Intergraph UK and South Africa PBMR (Pty) Ltd. The Cambridge Electricity Policy Research Group
Workplan 1 post-doc full time 3 UROP students Several visits to South Africa