Bomb Grade Uranium Seized In Sting

CBS ^ | 1/25/2007 | AP

[MeanWestTexan]

Nah, it's chiefly an alpha emitter. Gammas, and x's are what fry the tadpoles.

[MeanWestTexan]

Isn't that with an implosion device?

I would bet your average terrorist will just slam two plugs of u-235 together in a tube.

[muffaletaman]

I agree - the 15kg figure is indeed the minimum for a well-designed highly engineered device.

But spontaneous critical mass can occur with lower concentrations and larger masses. In fact there is evidence in mineral deposits of naturally-occuring "reactors", where enough "high-grade" uranium ore was concentrated naturally into a small enough volume that a "reactor" process occurred spontaneously and naturally.

http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml