REALLY Heavy metal work

Really?

How much room for shielding is there in an itty bitty (relatively speaking) bomb? How good is this hypothetical terrorist, or "rogue nation" going to be at building the shielding?

Enough to reduce the values below that in space? which while not a "high radiation environment" still seems to require radiation hardened electronics, especially for longer term use or reliability.

Or do you think that being in close proximity to fissile material that hasn't (yet) gone critical isn't "high radiation", just because it hasn't gone critical?

jk

For Pete sake... They don't have to build a Bomb (capitol "Bomb") at all.

All they need is a conventional explosive and enough 239PU to render an area uninhabitable for years. Dirty bombs are the perfect terror weapons. And they can be set off with a Bic lighter!