Possible ‘80s movie!

My MIL posted this and i wanted to help her out in finding her movie!

“I need help finding a movie I watched as a kid. Probably 1981-82 on an ONtv pirate box.
The basics of it went like this.
The planet was destroyed. Humans went to live underground. A group of kids find a shaft to the surface. The earth has healed itself. That’s about all I can remember. Always wanted to watch it again”

“Solarbabies” 1986?