> most reactors in the US, which use carbon control rods (think giant thick rods of pencil lead that could catch fire) This is in no way an area of expertise f

> most reactors in the US, which use carbon control rods (think giant thick rods of pencil lead that could catch fire) This is in no way an area of expertise for me, so somebody please correct me if I am wrong, but I am under the impression that graphite moderated reactors are not, and never really have been, popular in the US; graphite moderated is more of a Russian thing. Most reactors in the US are water moderated (besides whatever the military is operating perhaps?). Also I don't think graphite or any other form of carbon has ever been used as control rods.