Had mine on shelf or in ammo can forever , never a problem. If you have an overly damp area put some dessicant bags in the ammo can. They will stay good 50 yrs or more
I store them in storage, my closet, and if I want to mass load for a weekend because I hate my right shoulder and left hand, the living room floor. Two weekends ago was that weeekend.
I keep them in the original boxes in a big rubbermaid container under my basement reloading bench. Some of my supply dates back more than 15 years. They all go bang.
I suspect they'll still all go bang long after we're gone. Primers are not made from eco-friendly / self-cleaning stuff.