For claustrophobia, you may just sit outside the shelter until you feel you must enter.  If you are monitoring the weather play by play, you may never have to close the door!  Many times a storm shelter shoppers has sat snugly inside this shelter when they inform me that they have claustrophobia!  This tells me that the small "claustro-friendly" design elements are doing their job, including the fan, bright lights, ventilation, peep hole, colors and patterns.