No — that’s not accurate as stated. Deuterium is just heavy hydrogen, and graphite is carbon; they do not spontaneously undergo some big explosive chemical or nuclear reaction just by “meeting” each other, and studies on deuterium in graphite discuss implantation, diffusion, retention, and thermal release, not a dramatic blast reaction, as shown in this deuterium-in-graphite materials study. Graphite dust itself can be combustible under the right conditions, but that’s a dust explosion issue, not “deuterium + graphite = major explosion,” as noted in this graphite dust explosibility paper. There also doesn’t seem to be any meaningful InLeo discussion backing Adair’s claim here — the only nearby result was unrelated noise content, which tells you a lot.