Well, the premise looks interesting, but I have to agree with savinh0. I don’t even see how this would even work as a Feature script.

You marked it as being a thriller, so I assume it will be something more along the lines of “cabin in the woods” kind of feel. But, its a bunker. A bunker is made with the intent of keeping whatever is outside from getting in when closed. And it does the client no good to destroy the bunker to get in because then they can not use it. All in all, this idea is a bit flawed mate. I suggest revising.