Home > Fusion Energy Directorate > For Establishment Fusion Fuel Cycle

Fusion Energy Directorate

For Establishment Fusion Fuel Cycle

Display printing page

-Tritium Processing Technology-

What is "Fusion Fuel Cycle"?

In a nuclcar fusion reactor, deuterium(D)and tritium (T) are the fuels, are the fuels(nuclear fusion reaction) in the vacuum vessel (VV:the core of the reactor). However, most fuel (>97%) does not react. Un-reacted fuel and helium produced by nuclear fusion reaction are exhausted from the vacuum vessel as the plasma exhaust gas. The plasma exhaust gas also contains some impurities such as methane (from wall material of VV), hydrogen (protium(H)) and water. So, the un-reacted fuel is recovered from the plasma exhaust gas and is reused. Furthermore, in the breeding blanket located on surroundings of plasma, tritium is produced by the reaction between lithium and neutron generated by the nuclear fusion reaction. This tritium is also recovered and used as fuel. These flow paths of the fuel arc called as "fusion fuel cycles".

photo of Fusion Fuel Cycle

The fuel cycle systems recover hydrogen isotopes from the plasma exhaust gas (FCU :Fuel Clean-Up system), separate the fuel from hydrogen isotope mixture (ISS:Isotope Separation System) and inject the fuel to the plasma. The fuel cycle systems also have a role of the recovery of tritium from the breeding blanket (BTR:Blanket Tritium Recovery system.

For realization of the nuclear fusion reactor, the smooth performance of the fusion fuel cycle systems is required. Thus the development of the tritium processing technology is necessary and indispensable.