Gas Cooled Fast Reactor
Using gas as the main coolant has a long history in the UK as this was used for many years in Advanced Gas-cooled Reactors (AGR). However, instead of using carbon dioxide as the coolant as in the AGRs, the gas cooled fast reactor (GFR) uses helium, which can remove heat very effectively from the core.
The GFR uses a fast neutron spectrum, employing similar reactor technology to the Very High Temperature Reactor. The system’s high outlet temperature (850°C) makes it possible to deliver electricity, hydrogen, or process heat, which is invaluable for industrial processes.
The GFR’s fast spectrum makes it possible to use available fissile and fertile materials (including depleted uranium) more efficiently than thermal spectrum gas reactors. GFR is the only Gen IV design without an operating antecedent, and a prototype is not expected before 2025.
It is anticipated that GFR systems will minimize the production of long-lived radioactive waste and make it possible to utilize fissile and fertile materials two orders of magnitude more efficiently than thermal spectrum systems.