P!
I call BS on the claim nuclear grade graphite is a “controlled material”. Nuclear grade graphite is nothing more than high purity material, with low quantities of elements that can be transmuted by nuclear reactions. That same purity makes it suitable for use in the semiconductor materials industry: graphite susceptors used to hold crucibles that hold liquid silicon, graphite parts used in reactors that decompose gases to make silicon etc, etc.
C.W.
Ninety to 110 lbs. of highly enriched uranium (enriched to 90 percent U-235) is needed to make a simple gun-type nuclear weapon.