Back then, it affected everyone in two ways, which were the things Greenpeace campaigned against: nuclear weapons, especially overland testing, and dumping waste at sea.
Chernobyl took out Welsh farming for years, and in a few places decades, because it spread a thin layer of bioaccumulative poison over the whole of Europe.
Neither of these have anything to do with running a well-regulated nuclear power program. Chernobyl happened because of the apathy and incompetence endemic to any Marxist-Leninist system, not because a modern democratic state is incapable of regulating the nuclear power industry.
Know what else spreads a thin layer of poison over the whole of the world? Coal power.