For those of you not familiar with TV Tropes: http://tvtropes.org/pmwiki/pmwiki.php/Main/MacGuffin
Basically, I need some information about radioactive material for a story I’m writing. The plot demands a couple of things for it: It and its shielding can’t weigh more than about 40 lb (it’s being carried on foot for a long distance, in a backpack), and it has to be able to do enough damage to be really worrying.
What about nuclear waste? Can you make a dirty bomb out of that? How can you transport it without frying yourself? I know enough Pu-239 to reach critical mass with all that lead shielding weighs upwards of a thousand pounds, so that won’t work. So how much scary can you fit into a backpack?
(And mods: if this is the wrong forum, sorry about that…)