That's exactly right, which is why you don't replace your crumple zones and roll cages (primary and secondary containment) with tin foil. That way, even if your

That's exactly right, which is why you don't replace your crumple zones and roll cages (primary and secondary containment) with tin foil. That way, even if your brake lines are cut, you still have something protecting you. Modern reactors are designed so that they will be passively safe. Even if the safety systems get shut down and the reactor core turns into a radioactive puddle of metal, it shouldn't be able to lose containment.