>"ya but if you screw it up you now have 10t of raw iron hitting St. Louis at 30 km/s"

Nothing lost /s

For real, a large concern with nuclear pulse for launching is introducing radioactive material into our atmosphere. I wish I could back this up with a source right now but I recall a study saying that using nukes to launch something to orbit would, on average, give 10 people terminal cancer due to the radiation released per launch.