A fun model to have on your desk to remind you not to 'screw' up.

(If you do not get this reference a scientist was messing with a plutonium core with tungsten carbide bricks (which I did not add but I added the beryllium half sphere) when a screwdriver slipped [which was holding the top of the core up and keeping it from going super critical] causing it to go super critical and killing him after a few days because of of the intense radiation poisoning.

So yeah, don't screw up.