[ggm]

Without casting the military as lying, if they declare they have <x> weapons in substantive state to be used, and place them in missiles, then the implication is they maintain a stockpile of pits capable of meeting that supply, constantly.

If we assume 1 pit per month ages out due to phase and corrosion, then they would presumably have a pipeline of 12 pits in refurbishment continuously.

Since the stockpile is still measured in the thousands, I would assume the stockpile of plutonium pits running through pantex facilities is at a similar scale.

(this also assumes there is no neutral gas non-corrosive, phase stable storage)