I am looking for the name of a 80's or early 90's movie or tv episode where a man lives in a bunker to protect himself from radiation and he thinks that his family is dead. His family is alive and living safely away from the radiation. The mother takes the children to the town where their father died and the town has a giant dome around it to seal all the radiation in. I cannot remember more, I was a child when I saw this. Anyone remember the name of this?