On 5/19/2016 5:42 PM, Thane Plambeck wrote:
From an email I just received that was signed by the governor of California and William J Perry
"A quantity of HEU the size of a basketball would be sufficient to make an improvised nuclear bomb that had the explosive power of the Hiroshima bomb and was small enough to fit into a delivery van. Such a bomb, delivered by van (or fishing boat) and detonated in one of our cities, could essentially destroy that city, causing hundreds of thousands of casualties, as well as major social, political, and economic disruptions."
My question: is this really true? I mean, supposing a small group of people accomplished getting that much HEU, is it really just a matter of "improvisation" to detonate it? I was under the perhaps mistaken impression that detonating it involved some serious engineering chops, especially if you dont want to kill or fatally irradiate yourself in the attempt.
What takes serious engineering is getting explosive yield. You have to take subcritical masses and slam them together very quickly into a supercritical mass, before the chain reaction can blow them apart. Otherwise you get a very low yield explosion and what is effectively a "dirty bomb". Engineering goes into designing neutron reflectors on the surface to increase the yield and in designing the chemical implosion system to assemble the critical mass. But it wouldn't be that hard to get a low yield explosion - and I think a dirty bomb might even be more effective as a terrorist weapon. Irradiating yourself isn't a big problem. Just be careful not to get a critical mass together. The hard part is getting enough highly enriched uranium. Brent