Ed Huntress wrote:



Well, that *is* really a problem. All of the plutonium in the world
won't get them a bomb, but the gun trigger for Little Man could
probably have been made in a good basement shop. That's why it's a lot
scarier for them to have enriched uranium than plutonium. Any goof can
make a gun-trigger uranium bomb, if they have a plan that gives them
useable dimensions.
Anybody that has more than a gram of 239 Pu ALREADY has enriched uranium.
You need "weapons grade" enrichment, meaning about 90% 235U) to build a
breeder reactor to make 239 Pu. It has to be a fast neutron reactor
to transmute the 238 U at the edge of the core to 239 Pu, and that requires
a high proportion of 235 U for the chain reaction to continue. (I'm not a
reactor physicist, but that's my understanding.) So, if they have
kilograms of 239 Pu, they MUST have tons of pretty pure 235 U.

Jon