What is the badlands in the chrysalids?

The badlands is a place where the fringes people, when sterilised are sent to, to live apart from the people of Waknuk. In the time of the Old People, a nuclear bomb was dropped on what is now known as the Badlands, causing the land to become infertile. Nothing that is the norm of Waknuk can grow in the Badlands because this bomb was dropped.