An estimated supply of 240, plus the only fully maintained cache of nuclear artillery still in active service.

shot grable may 25, 1953

It depends a little bit on who "they" are, but artillery-launched tactical nuclear warheads are not only plausible, they have been made. Both the U.S. and the Soviet Union developed small, kiloton-range nuclear weapons for battlefield use. These weapons took the form of artillery cannon rounds and unguided rockets.

Nuclear torpedos? Absolutely, both US and Soviets armed their attack subs with them. There were also nuclear depth charges, nuclear land mines, nuclear demolition charges, jeep carried recoilless rifles with nuclear warheads, nuclear artillery shells (from 16 inch naval shells down to standard 4 inch howitzer size), and probably many other things we can't even find out about.

not artillery