From what I know about nuclear weapons:
Tritium reservoir needs to be filled.
High explosive section in the primary need to be checked for age and integrity.
Neutron generator tubes need to be serviced
Thermal batteries may need to be replaced
The plutonium pits may need cleaning or reprocessing
Software in the weapons triggering systems, permissive action links, etc., may need to be updated.
Codes may need to be updated.
If in a warhead, the Reentry Vehicle probably needs to be inspected
Propellant in the reentry vehicle and warhead buss probably need to be checked and filled and those systems verified for integrity and proper operation
Inertial guidance components in the buss and RVs probably need checking.
In some modern weapons the secondary is contained in the canned subassembly which may not be serviced as it's fairly inert.
of course the launch vehicle also needs to be maintained.
The meaning of the word nuclear weapon, is a weapon that has a nuclear warhead on it.
maintained.
This nuclear weapon is called an atomic bomb or a nuclear bomb
Nuclear weapon detonations
If by "bomb" you mean a conventional explosive weapon, then the nuclear weapon is more powerful.
nuclear chemicals such as plutonium
No. LLNL even tested several Uranium-Hydride bombs in the 1950s. Even though their computer models said the devices should explode, none gave a nuclear yield. One could use the waste from the reactor as a Radiological Weapon, but the reactor itself is not useful as a weapon.
NO
no
plutonium + weapon
the first nuclear weapon was issued in WW2 created by the americans in a chicargo squash court
you can't