In a 20 May 2019 article at The Institute of Electrical and
Electronics Engineers (IEEE) Spectrum magazine web site,
Maria Gallucci interviews Vice Adm. Dave Kriete, who is the
Deputy Commander of U.S. Strategic Command, on why and
how the United States has designed and is building new nuclear
warheads, the first time it has done so since 1988.
The "pit", named after the hard core found in stone fruit, is the
plutonium sphere at the heart of a weapon.
A "top line requirement" articulated by Kriete in the article is for the
United States to get to a production rate of 80 pits per year by 2030.
Article here :-
https://spectrum.ieee.org/energywise...weapons-expert