I was reading an article on tornado shelters on website houselogic, and came a cross a statement that FEMA provides states with funds that can be used to reimburse people for up to 75% of the cost of installing a FEMA rated Tornado Shelter.
One would apply to the state, not directly to FEMA.

I found a 2012 article for Nebraska that correlates with this:
Maximum match would be up to 5250.00 (75% of 7000.00)

I have an email in to my state to see if this program is still supported in 2017.