Puerto Rico may not be the best location for a replacement
Given hurricanes, rain and earthquakes.
The desert southwest in the US would probably not be a bad spot - Meteor Crater would be ideal for a HUGE one if it weren't a tourist attraction. I imagine they could find somewhere else with a natural depression they could dig out a bit to fit. With little rain, no severe weather and no earthquakes there's plenty of federal land in Arizona or Utah that would work well for a new one.
I agree with the comments that China having built a bigger one could possibly help get some urgency to congress to overcome the usual political battles and fund it.
Biting the hand that feeds IT
