I definitely agree it is difficult to kill a primer. I may have found a way…
Mouse pee. I had a tray of primed cases and we had one winter where we got assaulted by mice in the basement. They peed & pooped everywhere, including those primed cases and a number of them did not go bang.
I did not load those, but I did pop them just to see.
To the subject… I keep my primers in a cooler, like a beer cooler you would take to the beach. Closes well, keeps moisture (and MICE) out and it’s also not locked closed like an ammo can or a gun safe, so it won’t contain a blast like a bomb.