I've been reloading since 1965, no accidents. But I remember reading, I think it was in the Rifleman or Handloader, a fellow was reloading and he stored his large volume of powder, and all the primers he owned close together, a primer ignited and touched off all the primers and all the powder. I used to store both fairly close together, but after reading that article I store my primers as far away from the powder as possible. A friend of mine stored all his 8 lb cans of powder on the shelf below about 15,000 primers. He read the same article, but it had no effect on him.