[skorpeon87]

A single bomb core is a sub-critical mass; needing either neutron reflectors or another source of neutrons to start a chain reaction.

But if you pile a bunch of such cores up together like they were cannon balls, that inherent safety goes right out the window.

[ttyprintk]

In the context of this blog post, which explosive parts should we mothball and which ones are too dangerous to store intact, it’s unwise to store pre-boosted plutonium cores at all.

But, as a thought experiment, what is the difference between a pile of boosted-era plutonium cores; and a weird but moderated reactor? Specifically, does an arbitrarily-sized pile of weapons-grade plutonium marbles have the same inevitability of criticality you expect than if those are designed for use in boosted triggers?