[JanezStupar]

Off course they are mentioned - its the High-Temperature gas-reactor or "Next Generation Nuclear Plant". It is mentioned that a pebble bead and prismatic designs exist.

However - I am also missing LFTR - which BTW is also "unmeltable" and cannot go supercritical.

[Confusion]

I stand corrected; I missed the bit about the pebble-bed variety and thought they only mentioned the prismatic one.