What are the implications of the Chernobyl disaster?

Firstly, never build another RBMK design reactor, this has I think been accepted world wide, but in any case they were only built in the old Soviet block of countries.

Secondly, wherever possible shutdown such existing reactors permanently.

Thirdly, that even such disasters as this, which was just about the worst imaginable, have limited consequences, and that apart from those directly concerned on the site, and the need to evacuate surrounding population, there may be little long term effects. It does show however that it is a good idea to keep an exclusion zone of say 10 miles around nuclear plants, not allowing any sizeable settlements in that area.

Fourthly, that any procedures allowed on the station must be fully documented and thoroughly studied for safety, that the operating staff must understand them and their parts in the procedures, and the approved procedures MUST BE FOLLOWED even if senior managers intervene.