A branch drain accepting waste products delivered to it vertically, by gravity, from one or more similar but usually smaller fixtures, and conducting them horizontally to the primary disposal drain.
But this preliminary document is the clearest indication of the Pentagon's thinking about the future of nuclear missiles. In short, the Pentagon plans to replace the Minuteman III ICBM with a new launch rocket, one that would launch from the same silos in Montana and South Dakota where the missiles sit now. However, a new missile does not mean a new warhead.
It's quite possible North Korea has all the parts and expertise to build a nuclear-tipped ICBM that can reach the United States. However, there is only one launching pad for a Taepodong-2, and it would require hours of preparation before the missile is ready. We also don't know how reliable the rocket would be.