The Gas-Cooled Fast Reactor (GFR) system features a fast-neutron-spectrum, helium-cooled reactor and closed fuel cycle.

The high outlet temperature of the helium coolant used in the GFR system makes it possible to deliver electricity, hydrogen, or process heat with high efficiency. The reference reactor is a 1200-MWe helium-cooled system operating with an outlet temperature of 850 degrees Celsius using a direct Brayton cycle gas turbine for high thermal efficiency.

Several fuel forms are candidates that hold the potential to operate at very high temperatures and to ensure an excellent retention of fission products: composite ceramic fuel, advanced fuel particles, or ceramic-clad elements of actinide compounds. Core configurations may be based on prismatic blocks, pin- or plate-based assemblies. The GFR reference has an integrated, on-site spent fuel treatment and refabrication plant.

The GFR uses a direct-cycle helium turbine for electricity generation, or can optionally use its process heat for thermochemical production of hydrogen. Through the combination of a fast spectrum and full recycle of actinides, the GFR minimizes the production of long-lived radioactive waste. The GFR's fast spectrum also makes it possible to use available fissile and fertile materials (including depleted uranium) considerably more efficiently than thermal spectrum gas reactors with once-through fuel cycles.

This diagram illustrates a schematic concept of the reactor system and does not represent the reference design.

Diagram source: http://www.ne.doe.gov/genIV/documents/gen_iv_roadmap.pdf

Advantages and challenges

It is anticipated that GFR systems will minimise the production of long-lived radioactive waste and make it possible to utilize fissile and fertile materials (including depleted uranium) two orders of magnitude more efficiently than thermal spectrum systems. The key challenges associated with this system concern the development of new fuels and materials capable of operating at temperatures of 850°C, the core design and helium turbine. The innovative GFR technologies and design features are intended to overcome the consequences of using a high-pressure gas with poor thermal characteristics to cool down a core with a low thermal inertia during depressurization events.

GIF progress in 2007

Negotiations to put in place GFR research projects in the integration, design and safety of GFR systems, the fast neutron fuel, core materials and fuel cycle processes specific to the GFR system, advanced during 2007 with the finalization of a System Research Plan. The aim is to have an experimental technology demonstration reactor (which will be used as an R&D tool) in place by 2020.

Recent GFR research papers

Garnier, J.C. et al (2005) GFR System: Progress of CEA pre-conceptual design studies, Paper 5305, 2005 International Congress on Advances in Nuclear Power Plants (ICAPP'05).

Mizuno, T., Okano, Y., Aida, T. (2005) Conceptual Core Design Studies of Helium Cooled Fast Reactor with Coated Particle Fuel, Paper 5197, 2005 International Congress on Advances in Nuclear Power Plants (ICAPP'05).

Rouault, J. et al (2003), Fuel Design, Management and Cycles for Generation IV GFRs, Topical Meeting on Advances in Nuclear Fuel Management III, Hilton Head Island, SC, USA, 5-8 October 2003.

Dostal, V., Hejzlar, P., Driscoll, M.J., Todreas, N.E. (2002) A Supercritical CO2 Gas Turbine Power Cycle for Next Generation Nuclear Reactors, 10th International Nuclear Conference on Engineering (ICONE 10), Arlington, Virginia, USA, 14-18 April 2002.

Melese-d'Hospital, G. and Simon, R.H. (General Atomic Company), Status of Gas-Cooled Fast Breeder Reactor Programs, Nuclear Engineering and Design 40 (1977) 5-12.

Related links

GFR System Arrangement signatories

DOE Nuclear Energy Research Initiative GFR Program Plan (pdf, 252 kb).

E-mail contact: gfr@gen-4.org

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