I am playing Civilization 6. I had attacked London with a thermonuclear bomb. It has been at least 100 turns. London is yet to heal itself. So will London heal at all?
PS: London has not been annexed by me, it's still under AI.
The city does not need to heal per se. After a nuclear attack or accident, tiles owned by the city or affected by the attack are contaminated with Nuclear Fallout. This effect does not decay normally, that is, I have never see it happen. Instead, you need to clear the damage by using a builder or similar unit with a charge such as a Military Engineer, Toa, or Roman Legion.
While affected by Nuclear Fallout, tiles cannot be worked but the city does function normally with its remaining tiles working as intended. While the city has likely lost a lot of population, if it can work enough food and production to repair districts and grow, it will prosper even without clearing the Nuclear Fallout.