[Wonder Warthog]

"What ever happened to the pebble bed design?"

It's still in an advanced research stage. Disassembly of earlier prototypes after long term usage showed unexpected safety issues with instability/damage to the "pebbles".

Absolutely necessary to "get a handle on"/eliminate before it can "go commercial".

[nomad]

I hope they put proper resources into it then,from what I`ve read it seems like a good concept.

An inherently safe reactor design,pretty cool concept, especially after Fukashima.