Not as cut-and-dried as all that. Seems that while inherently safe in a meltdown sense, these pebbles have other issues. https://en.wikipedia.org/wiki/Pebble-

Not as cut-and-dried as all that. Seems that while inherently safe in a meltdown sense, these pebbles have other issues. https://en.wikipedia.org/wiki/Pebble-bed_reactor#Criticisms_of_the_reactor_design https://en.wikipedia.org/wiki/Pebble-bed_reactor#Criticisms_... It does kind of make sense. If you're constantly moving these solid pebbles around, there will be issues with dust and the occasional broken pebble.