2. Basic technology

The high-temperature reactor is characterized by :

• a highly divided ceramic nuclear fuel whose cladding, composed of several layers, is able to maintain its tightness up to very high temperatures (1,600°C);

• a graphite moderator providing good mechanical stability and thermal inertia as well as good neutron qualities;

• a gaseous cooling fluid, helium, which is single-phase in all operating conditions and chemically inert.

The combination of these three components leads to the following benefits:

• safety properties linked to the HTR concept and special environmental qualities;

• the ability to supply high-temperature heat, opening up new possibilities for the application...