[Calpernia]

Emphasizing from post 92.


"• Tantalum metal sheets for making crucibles to cast atomic bomb cores. "

[jveritas]

The crucibles and other parts of this system that come into contact with molten uranium or uranium alloys are made of, or protected by, materials of suitable corrosion and heat resistance. Suitable materials include tantalum, yttria-coated graphite, graphite coated with other rare earth oxides or mixtures thereof.

A mixture thereof of Tantalum and Graphite is PROHIBITED. In this case we have Tantalum Coated Graphite, that is absolutely “Prohibited”.