From what I’ve read, the highly enriched uranium is in UF6 form. This I believe would be a gas in high-pressure cylinders.
The cylinders could be stored in mineshafts.
They might convert the UF6 to easily hidden uranium metal and a fluorine compound, but I don’t know uranium chemistry.
yes, one ‘international inspector’ report said it included gas cylinders
UF6 is a solid below 133 degrees.